Where Should Space Exploration Go From Here? 1159
Since Congress has been steadily cutting back on support for NASA, Nick suggests this idea: "I'm sure there are many taxpayers out there like me that would love to see NASA's budget doubled. The problem is there isn't enough support to get congress to increase the budget by that amount, and I really don't want people to pay that don't care to. I propose an opt-in, one-time contribution box added to tax returns. I would require that my money be used only to advance the space program with either a shuttle replacement, an extra crew compartment for the space station, or a launch vehicle for a manned trip to Mars. Would you support a bill that would allow taxpayers to voluntarily contribute money to NASA? Are you ready to put your coin where your Dreams are?"
Easy Question (Score:3, Funny)
Sleazy answer (Score:4, Informative)
Perhaps they should have priced it in terms of Shuttle missions. The shuttle has launched over 100 times, at a typical cost of about $500M per launch equals roughly $50G, so their elevator would be priced at 80 shuttle missions or under 4/5 of the money spent so far running the Shuttles.
Speaking of which: in terms of fatalities per passenger mile, they're much safer than jetliners, orders of magnitude better than your car. OTOH, you car doesn't cost billions of dollars to replace if you write it off. OT3H, I'd be really happy if I got that many miles out of any car, ever. (-:
MONEY gets in the way (Score:5, Insightful)
The Budget Sucks (Score:4, Informative)
NASA's budget for 2003 - now $15.5 billion after the Columbia tragedy
Military budget for 2003 - $396 billion
Now of course I think the military needs a massive amount of money, but they spend it like water, and on things that we do not need.
Here's an example of new weapons we are buying that are included in the 2003 budget -
the Army's RAH-66 Comanche helicopter (Boeing and the Sikorsky Aircraft Division of United Technologies, $941 million); the Air Force's F-22 Raptor (Lockheed Martin, Boeing, and the Pratt and Whitney Division of United Technologies, $5.2 billion); the Navy's F-18E/F fighter plane (Boeing, General Electric, and Northrop Grumman, $3.3 billion); Joint Strike Fighter/F-35 (Lockheed Martin and Northrop Grumman, $3.5 billion); the V-22 Osprey (Boeing Vertol and the Bell Helicopter Division of Textron, $2 billion) the DDG-51 destroyer (Bath Iron Works and the Ingalls Shipbuilding Division of Northrop Grumman, $2.7 billion); the Virginia class attack submarine (Electric Boat Division of General Dynamics and the Newport News Shipbuilding division of Northrop Grumman, $2.5 billion); the Trident II Submarine-Launched Ballistic Missile (Lockheed Martin Missiles and Space, $626 million); and the Crusader artillery system (Carlyle Group/United Defense, $475 million).
Total - $21.2 billion
These are known as "cold-war relic" programs. In fact, many of these systems were mentioned as candidates for major reductions or cancellation during the Bush campaign and during the early months of Secretary of Defense Donald Rumsfeld's defense review. In addition they have been criticized in the past by Bush advisors or independent advocates of military reform as being too heavy (the Crusader), redundant (the three new fighter plane programs), or otherwise out of step with our current situation.
If our space shuttles could bomb Iraq we would be getting new ones all the time.
Re:The Budget Sucks (Score:4, Insightful)
I'm familiar with all these programs, and unfortunately for those opposed to military spending, a good argument can be made for all of them. Military spending suffered massively in the last 10 years under the Bush and Clinton administrations, and the result has been a lot of insufficiently maintained and obsolete equipment. About the only program that you mention that probably should be abandoned is the F/A-18E/F purchase (and possibly the Trident II if you're convinced that we've found "peace in our time" and no longer need a nuclear triad) and maybe Crusader.
These are known as "cold-war relic" programs
No, they're not. They're necessary purchases if the US is going to have an effective military. The DDG-51 and Virginia programs are vital for the Navy (we've already gone from Reagan's "600 ship Navy" to barely 100 combatants). The Air Force needs the F-22 in order to replace planes that are probably older than most of the people reading this (1970s technology).
We could probably lose the Crusader (in fact, we probably already have in the FY2003 budget) and the F/A-18, but the rest of these programs are sufficiently vital that cancelling them would just result in having the money spend elsewhere on similar programs (for example, cancelling the F/A-18E/F would just mean a purchase of its follow-on aircraft unless you expect carriers to go to sea without any aircraft). There are lots of places where the budget could be cut (for example, Bush's proposal for an extra $25 billion for AIDS assistance to Africa would more than double the budget of NASA), but there really isn't that much pork left in the military budget.
Re:The Budget Sucks (Score:4, Insightful)
there really isn't that much pork left in the military budget.
I'd like to argue with that. Not in terms of cutting military development programs, but in terms of efficiency. A good friend of mine works for a large defense firm (baesystems), and by all reports they LOVE the US military. Why?
It seems that when they score a big contract from most countries, they have set delivery dates and tightly controlled budgets, as one would expect in a contract a modern, state-funded institution. Get value for money for the tax payers and try not to let things run over. It's just common sense. Under this system companies start to lose money if they go over time or over budget.
The U.S. military works differently. Defense firms love contracts from the US military because they just keep on paying and don't seem to care much about deadlines. The reasoning behind this seems to be "We want the best, we don't care if it costs the earth and takes until the end of time", which is all very grand and powerful sounding but ends up wasting money and time, all at the taxpayers expense.
Surely money could be saved by tightening controls on defense contracts and could then be diverted to other ventures such as space?
Re:The Budget Sucks (Score:3, Insightful)
Unfortunately for Bush, he was mostly wrong. Yes, some of the systems could be cancelled, but they would just have to be replaced with something else because there is a necessary role for each of these programs.
Now I want the USA to have the best weapons in the world. I also want us to have the best space program. I think we can do both.
I agree. Unfortunately, over the last 10 years both the military and the NASA budget have both been cut; the place spending is out of control is on social spending, and that is a situation that doesn't seem to be changing under Bush (although, to his credit, at least he's increased military spending enough so that some vital programs are going to finally be funded).
Do we "need" all of the weapons I mentioned in my post? Do we need all of them now? Probably not
That's the problem with modern warfare; and NASA is suffering from the same mentality. National defense is a "come as you are" environment; if you don't "need" them now and thus don't spend money on them, you won't have them when you do need them. The same is true with NASA. We didn't "need" an improved orbiter in the 1990s, so Clinton cut the space budget back and killed off all the many, many promising programs that could have provided alternatives (Delta Clipper, etc) now that we do need them. The result of such policies is the tragedy we've just witnessed.
Clearly, we need to spend more money on space development (although perhaps, not necessarily NASA, who hasn't shown a willingness to embrace the state of the art technology as it did in its infancy). But we can't do it by cutting the military budget, because there simply isn't enough money there to cut. However, there ARE a lot of places in the social spending sector where money could be spent without such a risk. Bush's $25 billion for Africa/AIDS is one such place. Medicare/Medicaid is another. Considering that the long-term payoff for space (new pharmaceuticals, geriatric research, etc) development is more likely to solve these issues than direct funding would be in any case, it is simply more logical to spend money from these sources than to risk national security.
Re:The Budget Sucks (Score:4, Insightful)
Re:The Budget Sucks (Score:5, Insightful)
The upshot of all this spending is a few thousand jobs for engineers, programmers, and others in the tech field.
Just think of the millions of job openings for these same people if space were to become an industry rather than a curiosity.
If you want something to achieve commercial success, don't let the churches or the government dictate how to do it. Give it to some greedy, money-grubbing parasitic corporation (like MS, or IBM) and they'll find a way to bring it to us (and then jack up the prices).
For the record, I'm *not* suggesting we entrust future shuttle missions to Microsoft. Keep in mind, I want this to *succeed* with a *minimal loss of life*.
Re:MONEY gets in the way (Score:5, Insightful)
Exactly! We need to have cheaper spaceflight and cheaper vehicles. (I guess they go hand in hand, of course)
Manned spaceflight these days is not cost effective for the scientific knowledge gained. The shuttle costs 500 million dollars per flight, including upkeep, the shitloads of people at Cape Canaveral, etc. Considering that Mars probes have been launched for 250 million, it ain't such a good deal.
Low earth orbit is not a worthwhile place to bother sending people to anymore. We've done most useful experiments that justify the huge cost of launching somebody into space (ie, longterm effects of weightlessness on the human body) Now we're just finding excuses to keep people in the ISS or put launch people up in the space shuttle. The Columbia's main experiments with last week's mission included ant biology in space, and I believe biology of 2 other animals. Who the fuck cares?
Manned spaceflight is worthwhile. However, before we should resume manned spaceflight, we should get a practical way of launching people into space! IE, a way that doesn't cost $5000 per pound of payload. NASA should cancel the shuttle program, and parlay the money into development of a cheaper launch method, such as the cancelled X-33, a SCRAMJET-assisted launch vehicle, a low cost "big dumb booster," or a ribbon-style space elevator.
Also, we should discontinue manned spaceflights to LEO. We should focus on human habitation on Luna and Mars. Once we got a cheap launch method (~$500/lb or less, achievable with any of those methods listed above) we could build a relatively low cost moon base. Moon habitations could be simply constucted with an inflatable fiberglass stucture, which would be inflated and allowed to cure. After curing, several feet of rocks would be piled on top, shielding the inhabitants from radiation and extremes in temperature. An excellent inexpensive, low weight method of lunar construction. Anyway, if water ice is available on the moon, the ice could be used for growing crops, drinking water, and, perhaps most importantly, it could be electrolyzed into rocket fuel.
For the long, long term, I can envision Luna as kind of a shallow gravity well springboard to Mars and the rest of the solar system. Trips from Luna to Mars (although not necessarily from Earth to Luna) would be very inexpensive due to the plentiful electrolyzed rocket fuel and Luna's shallow gravity well. Mars could eventually become even more viable than luna. It has the advantage of a thin CO2 atmosphere, which could actually harbor special genetically engineered plants in the equatorial areas. In addition, water is widely available, both frozen in the ground and in the ice caps.
I'm not quite sure other places in the solar system will ever harbor more than a few scientists and researchers. To get people to move en masse, there would have to be some kind of economic opportunity in space. I can't see how it would ever be economically feasible to leave a planet with a breathable atmosphere, food, good climate, etc, to a planet which would kill an exposed human instananeosly.
There was a cheaper way (Score:5, Insightful)
Before the Space Shuttle you could launch payload cheaper using NASA's rockets:
Link [washingtonmonthly.com] For $23 million, for instance, you can buy the services of a Delta, a rocket that will toss 2,750 pounds of whatever you have into the 22,000-mile geosynchronous orbit used by communications satellites. For $33 million, you can get the more powerful Atlas-Centaur, which could kick a small payload out of earth orbit altogether. If you plunk down $50 million or more, you could probably arrange to get a Titan III, the rocket the Air Force uses to launch military satellites. A Titan III, the Clydesdale of space horses, will heave 29,000 pounds into due-east, low orbit.
That was in 1980. The Space Shuttle was a Very Bad idea. It should be buried.
Re:There was a cheaper way (Score:5, Insightful)
There is a world of difference between a man-rated launch vehicle and an unmanned one. Between the increased design redundancy of the vehicle itself, and the additional personnel and ground systems required for crew safety, the cost difference between a $50M unmanned launch and a $400M shuttle launch dwindles rapidly. There is merit to the argument that man-rated, expendable boosters could launch a manned vehicle more economically than the shuttle. However, it is misleading to compare the shuttle's launch costs to those of current, unmanned rockets.
The cost efficiency of the Russian space program is impressive, indeed. The last I heard, their entire annual budget was on the order of $300M or so. NASA could emulate that, if it could find a suitable workforce of scientists, engineers, and technicians willing to work for months at a time without pay.
AFAIK, the manned spaceflight accomplishments of the ESA are related to the International Space Station. They do not currently have their own operational, man-rated launch vehicle.
FWIW, NASA's original concept for the shuttle was much more sensible. The eventual design was a compromise necessitated by budget restrictions and significantly increased payload requirements levied by the DOD.
Let NASA make the decision (Score:5, Insightful)
Re:Let NASA make the decision (Score:3, Insightful)
Re:Let NASA make the decision (Score:5, Informative)
Re:Let NASA make the decision (Score:5, Insightful)
Unfortunately, the decisions of what it's going to do in the future are not made by its experts, it is made by the politicians, which (at least indirectly) are influenced by our democracy.
Why? It all comes down to funding, which comes from the government.
For example, why do you think the shuttle is the way it is (part reusable, part disposable)? Politics. The fully reusable one was too expensive. This article [washingtonmonthly.com] outlines the compromises that were made, and is an overall interesting read.
A quote from the article, "But you're in luck--the launch goes fine. Once you get into space, you check to see if any tiles are damaged. If enough are, you have a choice between Plan A and Plan B. Plan A is hope they can get a rescue shuttle up in time. Plan B is burn up coming back. "
Note that this article was written in 1980.
Re:Let NASA make the decision (Score:3, Insightful)
More specifically, Congress should instruct NASA to expose all its science programs to the normal process of peer review used to make funding decisions in the sciences. Congress should then abide by those decisions. This would have the effect of eliminating the manned space program, which has a ridiculously low ratio of scientific results to funding. Unmanned probes are the real workhorses of space science and planetary exploration.
That's just science, of course. NASA shouldn't even be involved in commercial stuff, which can be handled more efficiently by private enterprise than by a government agency.
Re:Let NASA make the decision (Score:3, Informative)
And so it should. Listen. If some commerical launch goes wrong, do you honestly believe that any business will have the money to clean it all up? I mean if it hits a population center we're talking about some crazy cash. The government would have to bail them out, no question.
The whole notion of a corporation is 'limited liability'. The idea was concieved to encourage exploration of the New World when the loss of a ship could completely bankrupt the financial backers. That's what the 'Ltd.' stands for. Limited liability means if something goes real bad then "Super Space, Ltd." pull a Chapter 11 and the people in the crater are SOL.
Re:Let NASA make the decision (Score:5, Insightful)
So much money wasted on such a stupid, bureacratic-minded, committee-designed contraption. Well, now is the time to use all the badass technology the last 2 decades have brought us, and end the misguided shuttle program.
Re:Let NASA make the decision (Score:3, Interesting)
"When Columbia's tiles started popping off in a stiff breeze, it occurred to engineers that ice chunks from the (external) tank would crash into the tiles during the sonic chaos of launch: Goodbye, Columbia. "
Freakin' prophetic.
Re:Let NASA make the decision (Score:5, Insightful)
Do I think it sucks? You bet. Do I think the answer is to throw more money at NASA? No. I think NASA should be acting as a technology incubator. The X-plane program is really good, and getting much better since the aircraft no longer need to be man-rated to explore the flight envelope. I would like to see a private venture use NASA technology to build a rapidly serviceable, man-rated heavy launch vehicle, whether or not it is SSTO. (Me, I think that SSTO rocketry is not yet viable. I would prefer something like a reusable staged system, or else a cheap disposable booster pushing a reusable people capsule and/or a disposable payload section).
Shuttle's "one size fits all" approach is not ideal.
And yes, that is my professional opinion.
Re:Let NASA make the decision (Score:3, Insightful)
How about a rapidly serviceable, man-rated _light_ launch vehicle? Its arguably a mistake to have combined the freight transport needs in the inappropriately named Shuttle with the passenger "shuttle" vehicle. So NASA would be better off having a separate human passenger vehicle solely for transporting humans, perhaps something that gets launched from an airborne platform, like the old X-nn concepts. Then NASA avoids the expense and demand of making a 140 ton vehicle man safe (a goal that apparently has not been met). What would we do with the current shuttle craft? Modify them to fly as un-personed freight transports.
Re:Let NASA make the decision (Score:3, Interesting)
No building stuff in orbit. Just two big damn rockets and five people spend half a year on Mars. Now THAT, my friends, is space exploration.
Re:Let NASA make the decision (Score:5, Insightful)
Then, in the 80s, it became about military projects and defense initiatives. Putting up surveylance stations and communications arrays. They still have exploration, but they are essentially at the bidding of the military for a lot of things.
NASA right now lacks a goal. The last (successful) big project they had was the unmanned Pathfinder mission. It was a great success for them, but was followed by two failures (Mars Global Surveyor and it's sister lander). The Galleleo showed that they could get over major technical hurdles (damage to main array and then an extra-long mission life), but these are not pushing how far man can go into space.
What NASA needs is a dream to get going, something that won't be cut down by beuracracy and red-tape. A non-military initiative that can get both the world and the government behind it. There is not really a bigger government PR entity in our country (the Military only has PR for recruitment), and that is something that NASA hasn't been using effectivly lately.
I think if the project was risky, but captured that same spirit as the Apollo and Early Space Shuttle missions, the people would step up to get it done, despite those risks.
Re:Let NASA make the decision (Score:3, Interesting)
Space exploration has languished without a raison d'etre for decades now. What better motivation could there be than eliminating the largest source of pollution on Earth, providing for the energy needs of the entire planet in the process?
Re:Let NASA make the decision (Score:3, Insightful)
Disposable missions have been economically sound, and the space shuttle had proven that point well. One of the most interesting points of the pathfinder mission was the landing method that was chosen (take this thing and let gravity do the work. Kinda playing bouncy ball with a planet and our little rover).
Any mission involving people will be a huge mission. Our way of life puts the value of human life higher than that of machines, so that is what complicates matters greatly. Unmanned missions are wonderful for scientific advancement and testing, but they have never held the interest of the public as long as the manned missions.
Let NASA sit tight (Score:5, Interesting)
Neither science nor democracy nor human safety will benefit from giving NASA free reign. We who pay the bills have to decide what the goals our and then work with the engineers to realize them. NASA has focused on self-promotion for too long, though it does a good job of it; its contractors do the work. I am astonished to hear insinuations that NASA budget cuts were behind Challenger, because they didn't have enough money to do it safely. Well, if true, they shouldn't have done it at all.
Frankly, I think watching too much Star Trek and Star Wars is what perpetuates the manned space program. There is very little real science that can only be accomplished with manned flight, except perhaps research to support manned flight, and the circularity of that argument is obvious. The ISS practically exists to justify the shuttle program. We are squandering the opportunity to accomplish more in space and on the ground by funding an extravagantly expensive program based on the assumptions of 70's technology. The capabilities of robotics and automation, and our understanding of science, has advanced far since then.
If decionmaking were placed in the hands of scientists (not NASA) instead of voters, if anything manned spaceflight would suffer the most. Many scientists have been furious for decades at the Shuttle for siphoning money off from useful research, especially interplanetary probes like the ones that brought us so much, Pioneer and Voyager and Mariner and Viking and so on.
The shuttle is not financially justified, especially given its incredibly poor return, when they are many other projects in health, research, and education threatened with cuts because the U.S. faces a record budget deficit. It is hard to shrug off NASA's budget as "only" $14 billion (plus billions in cost overruns) when programs like Head Start that cost "only" $2 billion are criticized as too expensive. Certainly there are a lot of roads that could be built, too; a billion buys a lot unless it's unnecessary space travel.
Absolutely, manned space travel is neat stuff, and I love it. As a kid I paid rapt attention to the shuttle's development, toured a mock-up at Rockwell, and trekked out to the desert to see Columbia land after its very first mission. I am shocked to see it destroyed in 2003, possibly for some the same reasons of mismanagement as Challenger (if it proves relevant, similar but nonlethal tile damage had occurred before, just as known O-ring malfunctions predated Challenger). But we can not let this tragedy spur us into the totally illogical course of wasting even more money on a program that will inevitably lead to more deaths for no reason better than "space is neat stuff."
Is our goal manned space flight for its own sake? *That* is the kind of bad decision democracy can make.
Re:Let NASA sit tight (Score:5, Insightful)
People should go to space to explore.
Both are important to us as a species.
No, don't (Score:3, Insightful)
A whole bunch of private companies have wanted to make space access cheap and sensible, with definite corporate goals in mind, but NASA has blocked every single one. I imagine cost to orbit could be a tenth what it is now, and safer to boot, if NASA had not stomped on them.
The best thing for NASA is to get it out of the space transportation business altogether. Auction off the shuttle and space station, if no one wants them, abandon them. Let private industry have a shot at it.
Lead, follow, or get out of the way. NASA won't do the first, they need to be made to do the second or third. Satellites, Mars exploration, nice political and scientific goals. Space stations and space transportation, get gone.
Re:Let NASA make the decision (Score:4, Insightful)
It's amazing how many people I would have considered economic conservatives think it's a great idea to spend billions and billions of tax dollars on manned spaceflight because it's "cool." I'm happy with the government spending huge amounts of money on actualy research, but the space station and shuttle involve very little research. This is readily observable from the naked PR stunts like sending up the first Israeli/Saudi/schoolteacher/senior-citizen astronaut. (Of course the moon was a naked PR stunt too. . . I'm very conflicted about that. How do you reconcile the greatest scientific and technical acheivement in human history with the 30 barren years that followed?)
Some people argue that we need to continue manned spaceflight because the technology will improve to make it easier. Um, no. The technology can improve plenty without risking lives and wasting money; nuclear propulsion sounds like a great idea, but can be tested with robots. Once we can reliably send a probe to Mars quickly, let it roll around and do research, and have it return safely, with relatively little expense, then we can send people.
The asteroid belt. (Score:3, Interesting)
Re:The asteroid belt. (Score:4, Insightful)
But who would do this? Only private enterprise would be this dedicated (and cost oriented.) And, if you don't give private enterprise a reason to go up there (exotic fuels, tax incentives, profit), they won't go. Giving government this goal would result in the most costly pork-barrel projects known to man (ie, the ISS and the space shuttle.)
Declare space off limits to taxation. In 10 years, every major multinational corporation will have a presence there, and we'll all benefit from the infrastructure necessary to loft people into orbit and maintain livable conditions there.
Where? Forward. (Score:3, Interesting)
The only reason space isn't the top priority of all of the governments of the world today is because we humans as a majority don't really seem to care what happens to our great great great great (and so on) grandchildren. We only care about the here and now. The folks and NASA and the folks in other space programs across the world may be the only ones who care about the future of humanity.
We (the United States) need to stop wasting our money on our already most-powerful military for the purpose of revenge against the middle east and start backing NASA more. Start researching new ways to travel in space, and make a colony in Alpha Century a priority. If we really are the evolved species we claim to be, we'll start caring less about squabbles on this blue marble and more about exploring the universe in which we live.
But again, that's just my 2 cents (and a paper clip)
Re:Are you sure? (Score:3, Insightful)
America's social experiment wouldn't have worked if it were not geographically separated from the monarchies of Europe. While I would be the last person to argue that America's system is perfect, I do believe that it's a damn sight better than even a constitutional monarchy.
There's nothing to say that the citizens of another world wouldn't go ahead and charter a new social contract. That, more than anything, is what makes me want to travel to the stars.
Next gen vehicles (Score:5, Insightful)
Jet fighters and Missle Defense (Score:4, Insightful)
Before you poo-poo Defense Spending remember that you have an Internet because of a certain DARPA project started in the late 60's. The Moon Walk was cool and all but how did it change your daily life? I would argue that the Internet has had a much greater impact on mankind than the moon walk.
Brian Ellenberger
Re:Jet fighters and Missle Defense (Score:5, Funny)
Re:Jet fighters and Missle Defense (Score:4, Informative)
Soles designed for moon boots are used in tennis shoes.. sports bras, portable coolers that run on your cigarette lighter, scratch and fog resistant coatings for your glasses, teflon, composite golf clubs, quartz timing technology, compact hi-yeild batteries.. these are ALL the result of NASA research for things necessary for space flight.
Digital Imaging Breast Biopsy system, and Laser Angioplasty.. also both spinoffs...
Im not saying the experimental military stuff is useless.. but damn dude.. NASA has invented or necessitated the invention of a hell of a lot of stuff we all take for granted these days!
Maeryk
http://www.thespaceplace.com/nasa/spinoffs.html
Re: (Score:3, Interesting)
Re:Jet fighters and Missle Defense (Score:5, Insightful)
Walking on the new world was cool, but how did it change your daily life?
[1] Or "European who led to a massive wave of immigration" or some other explanation.
Vehicles are a secondary consideration (Score:5, Interesting)
I doubt it would take any incredible breakthroughs in materials science to make it work... you could just use normal superconductor technology and conventional rocket/jet vehicle tech.
I know this is an old idea, so why haven't I seen more about it? Anyone have ideas what the weaknesses in this method are that it should be ignored for so long?
Re:Vehicles are a secondary consideration (Score:5, Informative)
Re:Next gen vehicles (Score:5, Informative)
Last semester my classmates and I wrote a draft for the AIAA design paper competition for a reusable, air breathing single stage to orbit "rocket" plane.
Bottom line? Unless we get a lot better fuels, or radically lighter structures, it's not going to work. That's even assuming that you can keep the scramjet lit. (which would get you a PhD, if not a Nobel prize)
X-30 is not the way. Venture Star [nasa.gov] was much closer. A shuttle-oid with Boeing's fly-back boosters might be a really good short term solution.
Re:Next gen vehicles (Score:4, Interesting)
Your proposal to use "regular propulsion" to get to a max altitude has some merit, but not the way you think it does. A big, fast airplane powered by low-bypass turbofans or turbo-ramjets might be a good platform to launch a light rocket ship from, but it would take a lot of engineering to figure out if that would be more cost effective than using a small spaceplane (powered by rockets exclusively: Air breathing single stage rocketry is, I believe, not viable) coupled with a large semi-reusable heavy launch system.
And what the heck do you need flight control and power for on reentry? Just pick your de-orbit point to land wherever you want. The last thing you need when coming down from space is more speed, so an engine is totally useless. The ideal spacecraft gets into orbit with only enough fuel to maneuver and de-orbit. Any excess fuel is a colossal waste because of the equations that govern orbital insertion.
Re:Next gen vehicles (Score:5, Informative)
A scramjet is a Supersonic Combusting Ramjet. Let's back up a step. A ramjet is an engine that uses shock waves, instead of fan-shaped compressors, to compress the air to mix with your jet fuel. If you don't grok why you need to compress air, go thou and Google search for a description of turbojets or any other internal combustion engine. This is going to be a long enough post as it is. : )
As the ramjet passes air through the shock wave system in its inlet, the air a) heats up and b) slows down. The speed of sound increases with temperature, and the speed of the gas goes down (from the Mach 3 to Mach 6 where ramjets can typically be operated). At some point, the air is actually subsonic. At that point, fuel is introduced and ignited. Hot air go out back of motor, airplane go forward.
Scramjet is basically the same idea, except without the slowing the air down to subsonic part. The entire combustion process happens in a supersonic airflow. While the physics of "low speed" combustion are pretty well understood, doing the same thing in a high speed flow is seriously non-trivial. In the paper we wrote, we adopted a technology called a "hyper-mixing injector" to dump fuel into the stream, and we actually let the high temperature air ignite the fuel all by itself. Keeping that fire going is, well, hard. Stick a Zippo out your sunroof. You get the idea.
Scramjets are way tricky. If you don't manage the airflow very precisely by varying the geometry of the intake section and not maneuvering the aircraft EVER, you might get a condition called an "unstart". Basically, all the nice shock waves you've been using to compress your gas glom together into a big strong shock wave perpendicular to the gas flow directon in your inlet, and basically at that point the temperature and pressure in your combustion chamber go from really really improbably high (which is good, and you've designed for that) to freakin' nutty crazy blow-up-spaceship now high, and you start collecting pieces of the thing across three states.
See recent Columbia accident for a much less violent example of what would happen. It would be far worse.
Scramjets are scary. Yeah, they might work, but they're REALLY finicky, and I don't believe our flight control systems are sufficiently advanced to fly them reliably and safely.
And forget about having a guy driving the plane. If you pitch the nose a few degrees off the trajectory, or roll the airplane at all, the shock system will change formation, and very likely you won't even know what hit you. No way to do it without computer control end-to-end.
You might have observed that the low speed for a ramjet is Mach 3. In order to have the shock waves in the inlet, you already have to be going really fast. You might be interested to know that the SR-71 used a partial ramjet cycle at its Mach 3 cruise condition. It also had a turbojet engine core to accelerate it to ramjet operating speeds.
Nuclear powered plasma would work great in an atmosphere...if you don't mind dumping a very highly radioactive plume all over Florida.
Actually, even though the specific impulse of the nuclear rockets is really good (specific impulse is a good measure of the fuel efficiency of a rocket. It tells you the number of pounds of thrust you get per pound of fuel) the peak thrust values are not very high. In other words, it'll be a good interplanetary drive, but really not ideal for launch systems (bad environmental issues aside).
Re:Next gen vehicles (Score:5, Informative)
SR-71? Mach 3. Teeny payload. However, the design we worked out used upgraded J-58 engine cores from the SR-71 to get up to scramjet operating speeds. And yes, having to fly for a long time while you accelerate is a big problem. You're burning just incredible amounts of fuel the whole time, and burning fuel to accelerate the fuel you need to burn to accelerate fuel that you need to burn to accelerate. Ad nauseam.
The other problem with air breathing rocketry is wave drag. In order to get the same thrust as a rocket, an airbreathing space craft's cross-sectional area has to be about 1.5 to 4 times as large as the rocket is to ingest enough air. Since wave drag (the primary drag force at high speeds) is very strongly dependant on cross sectional area, you swiftly get to a point of diminishing returns. Let's make up some numbers.
Rocket A thrusts at 100lbs, and weighs 10 lbs, and has (say) 10lbs of drag acting on it. That gives it an excess thrust of 80lbs to do the force=mass*acceleration thing.
Scramjet B thrusts at 100lbs, flys mostly horizontally so its weight isn't a factor (it's a lifting body), but has (say) 80lbs of drag on the airframe. So it only has a quarter of the thrust available to accelerate as our rocket, meaning it will take much longer to get to orbital insertion velocity.
In a nutshell, that is the problem with air breathing rocketry.
Re:Next gen vehicles (Score:4, Insightful)
A scramjet is a ramjet that works above about Mach 5 (it's a ramjet with Supersonic Combustion; hence, the name). You use it _instead_ of a rocket for as much of your early launch as you can, because three quarters of the weight of rocket fuel is oxidizer. If you can get oxygen from the atmosphere instead, your specific impulse goes up by a very large amount (so you need less fuel per unit craft weight).
As Moofie pointed out, though, nobody's been able to build one that works (yet).
Friction is a problem, but it's a manageable one. If you can survive dropping back down into the atmosphere at orbital speeds, you can survive friction on the way out. It just slows you down (i.e. above a certain speed, drag will equal scramjet thrust, and further air-breathing boosting doesn't help you).
To recap, the benefit of doing any of this is to use air as the oxidizer instead of carrying oxygen with you. Altitude isn't the issue (from orbital height you'll still fall like a rock if you aren't moving very, very fast *sideways*).
what about a nuclear powered plasma system? it works in space (theoreticly) would it not work in the atmosphear?
All electric propulsion drives studied to date (ion, and many plasma variants) have thrust far, far too low to use for launch. They're designed to work at moderate power and very low thrust for a very long time. Specific impulse is great (lots of delta-v for a small amount of mass), but thrust isn't (thousandths of a gravity).
Other nuclear drives have been investigated for launch, but they have problems, and are very messy. NERVA style drives - where you feed gas through a reactor core to heat it instead of forming hot gas by burning fuel - work, but because of temperature limits specific impulse is at best about twice that of chemical fuels. You also have to lug a lot of very heavy shielding and other reactor material, so the effectiveness for launch starts looking questionable. You're *also* spraying radioactive crud out behind you, because the flowing gas is hot enough to etch the reactor away over time.
In space, NERVA drives are a bit more practical, but you're better off using the nuclear plant to power an electric drive (better specific impulse).
The other ground-to-orbit scheme proposed for launch was to detonate fission bombs beneath the craft and let the shock wave drag you along, but a) minimum craft size is _large_, and b) this is messy enough to not have a prayer of being used.
In short, nuclear drives won't be useful for ground-to-orbit in the forseeable future. Wait a century, and we'll have a space elevator. Until then, chemical will be good enough (and very good if we get scramjets working).
private sector (Score:4, Insightful)
easy.... (Score:4, Interesting)
getting to mars with the new propultion technology is the lynchpin that will put emence presure on governments to allow for the exploitation of space and the flurry of missions to discover new things in the solar system.
Being Single Sucks (Score:5, Informative)
Economies of scale are what are lacking in our space program, and why the Shuttle fleet is a failure. We should have kept building Shuttles, and retiring the old ones. An optimal life span of 10 to 15 missions might have been found, and who cares if you only get 10 missions, as long as the replacement price of a Shuttle falls below 500 Million, instead of the 3 billion we're talking about today. Why don't you keep riding your 1958 Impala forever? You don't because at some point it becomes cheaper to replace it with a newer (safer) car than to keep repairing or upgrading it. You also keep building Shuttles, so you don't forget how to build Shuttles (and why it will now cost 3 billion plus to field a replacement). When you have a working replacement, then you retire the old girl. We got into the same fix retiring our expendable vehicles before the Shuttle was up and running and lost Sky-Lab as a result.
I could get behind SSTO (single stage to orbit), if it had a power assist from some huge catapult method (there are several to choose from). Here you would be investing in an infrastructure that could bring all launch costs down for manned and unmanned craft.
While we are at it, lets fling cargo up on cheap vehicles, and then over-engineer piloted craft whose only purpose is it to get bodies up in space for a rendezvous with the cargo you just flung up. The Shuttle should never have been built without simultaneous building a cargo only expendable derivative, using the same solid boosters and external tank (economies of scale again).
While we're at it, we should never have started building the ISS knowing how old and creaky the Shuttle fleet was becoming, and how expensive per pound the lift to orbit currently is. That money should have been spent on bold new booster initiatives and infrastructure projects that really could bring launch costs down by a factor or 10 or even 100 times. Then the ISS becomes a breeze to build, and Mars is only a step away.
Simplify.... (Score:5, Interesting)
--
Bless the crews of the Columbia and Challenger. From your sacrifices will come greatness.
Money to NASA (Score:3, Interesting)
Why not do this with NASA, as well? Especially since my state has a NASA research center. I'd be happy to spend an extra $10 for my license plate to show that I support our NASA research.
More info at http://www.oplates.com/
A modest proposal or two (Score:5, Funny)
- Build a cheaper single-stage-to-orbit vehicle.
- ...
- Profit!
Proposal B:- Develop a self-replicating nanoscale device [slashdot.org] that eats air.
- Let its progeny digest the entire atmosphere and excrete it as solids.
- Ta-daaaaa, we're in space!
Of course, further study may be advisable.Article in Time Magazine (Score:5, Informative)
Although some of his arguments are not convincing or even insulting ("Did Israeli astronaut Ilan Ramon really have to be there to push a couple of buttons..."), the article makes several important points. Here's one of them:
Re:Article in Time Magazine (Score:4, Insightful)
How many people have died trying to get into space? 14 from the challenger and columbia, shoot from the hip says no more than double that have died?
That is only the start of it. Many many more brave men and women are going to die trying to turn us humans into a spacefaring race. This is hostile, hostile environment and we aren't supposed to be going there if evolution has anything to say about it. Playing a game of tortise and retreating into our shell "for a decade" every time there's a problem is defeatist, not going to make space a fluffy paradise where children run free, and will in the long run increase the costs of space exploration because we get so wrapped up in our politicaly correct bureaucracy that nothing revolutionary ever happens.
Every man and woman who's died in space did it with the full knowledge this was one of the most dangerous jobs they could have picked. I see no reason to insult their sacrifice by scurrying under rocks, pretending like it's only a matter of time before a 100% safe route into space evolves.
You don't quite get it (Score:3, Insightful)
Your arguments are even less convincing. I'm sure you could come up with equally dramatic descriptions of the environment in which early airplanes operated, and they killed people, too. Airliners are a bit safer than they were in 1910. The early sailing craft were dangerous.
The technology has improved quite a bit since the 1970s. Perhaps we do know enough now to build a shuttle craft with safety comparable to that of an airliner.
We've been putting people into space since the 1960s. Surely something has been learned since then about getting to orbit and back safely.
Every man and woman who's died in space did it with the full knowledge this was one of the most dangerous jobs they could have picked. I see no reason to insult their sacrifice by scurrying under rocks, pretending like it's only a matter of time before a 100% safe route into space evolves.
Don't insult the ability of our engineers and scientists, either. 100% safety is impossible. You can get killed on a trip to the mailbox. Humans have paid for the right to explore every new domain we have taken with their lives, and there are a few of those people buried or lying around within a few miles (kilometers) of every reader of this post. However, as a result of those sacrifices, most of us can walk safely to the mailbox without a gun and without watching our backs.
When do we get out of the human sacrifice stage with respect to the kind of trip that should have become routine with the second generation shuttle and something you buy tickets from your travel agent for the third generation available Real Soon Now? We've been putting people into orbit for 40 years. I think it's time to find out whether or not we can do it right now.
It's time to honor our pioneers and move on to the future. It's time to get out of the status quo. You know as well as I do that if we keep flying a shuttle that's been kept running longer than the average city runs a public transit bus that more and more of these vehicles are going to fall out of the sky. Will the public support NASA if one of these deathtraps hits a public building full of people?
It's time to either start putting real money into the manned space program or shut it down. It's wrong to ask people to give their lives to solve problems that should be solved with money and engineering skill no matter how dedicated or brave they are. If America doesn't have the will to do this right, we don't deserve to keep our technological leadership and we won't be allowed to.
Your argument in favor of the status quo is pointless at best.
Re:Article in Time Magazine (Score:5, Interesting)
Eaterbrook's article is right on. The shuttle has killed the space program. I heard Walter Cronkite being interviewed right after the burn up. He spoke about the exploration of space. Made me sad. That was what NASA was about in the 60's when he was covering launches. Now it's a waste of time joyride that accomplishes nothing and everyone knows it. I hate to admit it because I'm a space nut. I want to see man in the stars. I want to see the human race out there. Right now all I see is us marking time.
There are cheaper and more efficent ways that are available. Hell, there were better ways when the Mercury capsules were being shot around the world.
Check out the x-13 project.
NASA and Congress like the income generated from shuttle launches. That carries more weight than any dream of space.
Re:Article in Time Magazine (Score:4, Informative)
See the 23 year old critique at:
http://www.washingtonmonthly.com/features/2001/8 004.easterbrook-fulltext.html
NASA now exists to support aerospace contractors. Jerry Pournelle [jerrypournelle.com], noted SF authour, proposes a simple system of rewards to encourage private ventures into space. Unfortuantely, the pork-barrel politics of NASA funding mean that the US will be tied to an incompetent bureaucracy for at least another generation...
Re:Why aren't his arguments convincing? (Score:5, Insightful)
Exceptions:
Buran was a 3/4 scale duplicate of Shuttle, not the same size. It also never carried a crew...its one mission was unmanned. Read more here. [astronautix.com]
A crew escape section (a jettisonable cockpit, for instance) is a good idea for launch related problems. Howevet, on reentry, it would be absolutely impossible to get the capsule a) protected from the reentry heat and b) away from the Mach 20 reentering shuttle. It would also be absurdly heavy as a retrofit. I do believe that it should be considered for next-generation reusable spacecraft.
The reason that the Challenger problems were left up to the "old boy" network is the same reason the same engineers that crashed Mars Pathfinder builts its successors: There just aren't a hell of a lot of people who know how to do this stuff. It's horrifically complicated, and the stakes are impossibly high. You don't just let a recent graduate (like I will be soon! Yay!) design a new Shuttle. Or even a system on the shuttle. You use experienced, seasoned engineers, checking and cross-checking each other. And you still have fatal mistakes.
He's also wrong about his (rhetorical) contention that throttling up Challenger's engines was fatal. The solid rocket boosters were already burning (fatally), and they are not throttled. As soon as those things were lit (that is, before it left the ground), the fix was in. That ship was going to die.
I do disagree with a lot of his conclusions. This fellow doesn't seem to be committed to manned space exploration. His discussions about going to the Moon (which is a dead end: Been there, done that) are red herring arguments.
My personal feelings on the future of the space program are very ambiguous. I use that word in the sense that I have very strong, opposing opinions on the topic.
I believe passionately in
However, I think NASA is doing a very bad job of stewarding our resources. They're given a budget (although I certainly wouldn't call it lavish), with the understanding that that budget will be returned to the communities around major NASA installations, and the contractors that supply them. Good engineering or no, that is the only way you can get any sort of large-scale project done in this country: Spread the wealth to as many congresscritters' pork barrels as possible. I don't like it either, but I don't know how to change it.
So, I want people in space. But I don't think that going over and over to LEO accomplishes anything. If I thought it would be possible to say "OK, we're not going to fly any people for five years, but then by God we'll start flight testing our Mars hardware!" I'd be a happy guy. However, I believe that if we don't keep in the habit (if you will) of putting people in space, we will lose the political will to do it. I think that would be Bad, because we (America and its partners) would cede to somebody else (China?) primacy in solar exploration. I think that's a Baad Idea.
Mars! (Score:3, Interesting)
I would like to find out more about Mars.
We don't need manned missions either, just some good robots.
I'd like to see a couple sample return missions. One of the most intriguing ideas recently is the suggestion that there may have been life on Mars at one point.
Finding out if there was (or wasn't) life on Mars could tell us a lot about how likely there is life on other planets. Let's get some probes on there, and roam around a bit, dig up some stuff, and bring it back!
Until launch costs get much cheaper (and that's a whole 'nother rant), let's just do some good, meaningful science. We have the technology. NASA's existing budget (if we weren't building the ISS) is good for a dozen missions per year to the rest of the solar system, plus another spiffy space telescope.
Now's the chance to take the money from something that isn't nearly as useful (the shuttle and ISS) and put it into answering some questions about life, the universe, and everything.
Let's do it!
Simple way to move 10x faster (Score:4, Interesting)
First, take half of NASA's budget, and make it totally devoted to unmanned missions exclusively. NASA suddenly gets 10x more research done for half the money.
Second, take the other half (billions of dollars, BTW) and make a series of prizes to be won by any group willing to take the risks. Prizes could include:
$200M prize for first profitable 100 megawatt power plant space.
$200M prize for first profitable factory that produces at least $1M in sales. $100M bonus if its a product that currently produces a lot of toxic waste.
$500M prize for agriculture pod that produces 1000 tons of food per year. $250M bonus if it's a forest pod that produces wood.
The key is that SPACE HAS TO PAY FOR ITSELF. Right now the risks are too high and expensive to get started.
Note by the way that this is the ideal way to sell space to people. "Think about all the bad, bad stuff that we can put in orbit instead of polluting the earth. Cheap power. Cheap products. Great for the economy.
Too bad this entirely logical, rational, practical and most importantly, extremely likely to succeed scenerio will never happen. NASA will never give up the control.
Re:Simple way to move 10x faster (Score:3, Insightful)
Real quick. it costs $10,000/lb to put something in orbit. You weight 100 pounds? It's going to cost $1,000,000. $200 mil? Puh-lease. The shuttle costs darn near close to 450$ mil to launch. NOTHING IS PROFITABLE AT 10,000$/lb shipping COSTS!
No, it costs NASA -- a bloated, unbelievably inefficient organization that has absolutely no vision to radically reduce costs -- that much to launch payloads.
The advantage of having a huge prize is that allows EVERYONE no matter how crackpot the idea to try a lot of different things. NASA will never, ever get us cheap access to space, much less profitable access to space. It simply is not in their mission.
With all due respect, quoting NASA or any government figures as somehow carved on stone tablets is a sign of the problem, not any solutions.
Re:Simple way to move 10x faster (Score:4, Insightful)
The disadvantage of having every crackpot trying out his own favorite launch vehicle is that sooner or later, someone is going to drop his launch vehicle on a school or a neighborhood...
There has to be some kind of space agency to regulate and review the crackpots, so that the inherently dangerous ideas are at least moderated. The space agency would also need to manage launch facilities for the better ideas, so that in case of failure there's a large body of water to drop the fireball into...
It shouldn't necessarily be NASA, though.
Moon and mars, but not too fast (Score:3, Insightful)
As for Mars, our (I speak as a human being) succes rate at going there isn't very good yet. Almost one spaceship out of two that tries to enter Mars orbit is lost. We need a "welcome" infrastructure: communication and meteo satellites around Mars so that the following probes (and crews!) can safely reach destination.
We also need something strong to cruise rapidly (I don't believe yet in 3-years-plus missions). Prometheus (nuclear propulsion) would facilitate the trip a lot...
Choose with your taxes (Score:3, Insightful)
A lot of people signed in the campaign, but the government, of course, did not change anything.
Now imagine if something like this could be done in the USofA, which spends on weapons as much as the 10 next most-spending countries put together!
(All this data is taken out of UN reports, which I'm now too lazy to find...)
With just one year of the DoD budget, famine could be erradicated forever in this planet, and you'd have enough spare change to build another shuttle and send a mission to Mars!
Of course now the important thing is bombing Iraq because the stupid dictator there tried to kill someone's daddy *and* has huge amounts if oil...
First we need space mining (Score:3, Interesting)
Step 2. Build an ore processing space station so we can mine the asteriods. This will provide most of the raw materials needed for everything else, such as
Step 3. Large scale self-sufficient space station. This might not be a single station. There might be one station devoted to living quarters, recreation, etc. and another for manufacturing and science.
It would probably be decades before this system reaches the break even point, and a few more decades before it pays for itself (financially). But that gives you...
Step 4. Profit! (sorry, I couldn't help myself).
That's my amateur class analysis. Feel free to blow huge holes into it.
We all enjoy and desire space travel (Score:4, Informative)
Only a space elevator makes sense. (Score:5, Insightful)
While it's nice to think that we'll be pulling some cowboy bebop style shit and just pulling back the throttle on our Swordfish II and going orbital, we need at least an order of magnitude more efficient power generation, power storage, or drive technology, or some combination thereof. The bottom line is that it takes a huge load of energy to build an orbital craft, and it takes quite a bit to launch it. Piggyback designs have thus far not proved to be a solution though there is hope there, I will admit; Still, I don't think it's worth making craft capable of launching from a planet until materials technology improves considerably.
A space elevator would make it downright inexpensive to put things in orbit. If you reserve space, when it becomes cost-effective you can run a superconducting strip down its length (That's a long-ass strip of superconductor! But eventually it will become worth it) and plant nuclear power generation at the other end of the tether where you can simply eject the core if it fissions out of control. (Mount it on a rocket; If the pile goes bad, fire it at the sun.) You could also just put a gigantic solar array there; It should be affordable if it is cheap to put into orbit and has obvious advantages in terms of required maintenance.
In any case, the first step towards building a space elevator is building the massive structure which will have to sit at the other end. If we are going to accomplish this, we need to be working on ways to mine asteroids, smelt ore, form steel, and build structures in space. In other words, we need to be thinking about supporting mining engineers, steel workers, steel fabricators, and so on. It just doesn't make sense for us to be mucking around in space too much (more on this in a second) when it costs us so much, and it costs so much because of the fuel required to lift a given mass. Reduce the amount of mass you lift, this reduces the amount of fuel you have to spend, and the whole thing gets cheaper. Build a space elevator, and you don't even have to use fuel any more; The direct cost and the long-term environmental cost (Putting that much energy into a system always has some effect, and some of the stuff we're putting into the atmosphere is nasty) of a space elevator is essentially nothing when you consider how much traffic you will have if you make it cheaper, and how much less energy must be expended.
Here comes the later: It still makes sense for us to be sending out probes, and testing new technologies for space. But it doesn't make sense to spend a lot of money on that. We should be spending our money on technologies which will bring us the space elevator.
Ameliorating risks. (Score:3, Insightful)
A space tether would be a huge structure. Yes, it would be thin. It would nevertheless be very tall. As a result, it would be easy to hit. A cruise missile, ICBM, or an airplane that struck the tether would break it. An explosive device, including either a conventional explosive or a nuclear device, would break it. If the tether were stationed at sea, a submarine could clip the tether, or shoot a torpedo at it.
Clipping the bottom of the tether, or firing a missile at it, would do next to nothing. The single-ended tether (with counterweight) is 40,000 km long; the double-ended one is twice that. Low earth orbit - which is the maximum practical range for things like ICBMs, unless they're built specifically to be anti-geostationary missiles - is in the 200-300km regime. Lose the bottom of the tether? Just send down a replacement segment from the hub, and you're back in business.
There would be no way to defend the tether from terrorists. You would have to create a large no-fly zone and a no-sail zone around the perimeter. This would create a humongous, circular no-commerce zone that would harm the global economy.
Not really. What is the maximum distance a hostile craft could travel from detection to interception? That's the radius of your no-fly zone. This is tens of kilometres at most if you're dealing with civilian craft. Antimissile interception range is left as an exercise for people with more military background than I have. Either way, impact on trade is next to nil. Commercial flights fly *thousands* of kilometres - why would a 10-km detour have any effect at all?
Natural events are also dangerous. A lightning strike could break it. An earthquake or volcanic activity could result in enough stress on the tether to break it. A tornado, with winds in excess of 400 mph, could damage the tether.
Extreme weather only exists in the lowest 10km or so of the atmosphere. 99.97% of your tether is above this level. If you see the storm coming, pull up the bottom 20km or so until it passes. If you get blindsided, send down another small segment as a replacement.
I'd worry more about space junk, myself. More of the tether could fall.
If a tether ever became damaged or underperformed its design specs, there would be no way to repair it. Should we ever decide to remove the tether, there would be no way to take it down without it causing a catastrophe on the ground.
How do you figure this? You can just spool the darn thing back up to the counterweight/hub in geostationary orbit! That's where its center of mass is.
As for repair - how do you think the cable would be built in the first place? You aren't going to lift a full-thickness cable on chemical rockets - you'll lift a very thin leader cable, and send crawlers up it with extra strands/ribbons to thicken it with.
To repair a damaged (but still holding) cable, send down a patch, connect above and below the damaged section, and remove the damaged section. Or, if multistranded, remove the damaged strands and send down replacement strands. You've overspecced the cable strength, so the undamaged strands will hold. Any given strand breaking isn't a big deal with a multistranded design.
Even if you're foolish enough to build a difficult-to-repair elevator, there's nothing to stop you from lifting materials for a new one up ahead of time. Keep a backup elevator - spooled up - in geostationary orbit for use as a replacement if anything happens to one of the elevators currently in service. Only the first elevator will be expensive to build - cost of lifting matter goes down drastically once that one's done.
In summary, I find your claim that an elevator would be fragile or impossible to repair puzzling.
Any breakage of the tether would result in catastrophe. First, there would be damage to the ground. Anything that big (about as long as the circumference of the Earth) is not going to totally burn up in the atmosphere.
Firstly, since it'll wrap around like twine as it orbits (speeding up tangentially as it falls to conserve angular momentum), it could easily burn up - it's impacting over a very large area.
Secondly, there's a strong upper limit on the amount of damage it can do - that limit being the gravitational potential energy of the cable. Potential energy per unit mass for something most of the way outside the gravity well is on the order of 10 times its equivalent weight in TNT or other high explosive. Declare a maximum acceptable explosive yield for the whole cable coming down, and that gives you the maximum weight of the cable. Simple enough.
Any real disaster would be far _less_ severe, as a) it's unlikely the whole cable would come down; most logical point of breakage is within easy reach of the surface, and b) even if the whole cable from geosynch onwards came down, it would impact over a large and mostly-uninhabited area (if you've placed your cable with any sense at all). Only the fraction that hits populated areas matters.
Our economic security and probably our military security and national security would come to depend on this tether.
The big problem is that once the tether is destroyed, you're probably looking at years before a replacement tether could be erected.
If the tether's that important to the economy, you'd a) have more than one in service at any given time, and b) have replacements stashed in geosynch, ready to unspool. If space travel is that widespread, then you also have the manufacturing facilities off-planet to produce a new one. Build it, send it to geosynch from wherever else it's built, and spool it down.
In summary, all of the risks you've pointed out have easy workarounds.
Lastly, there's a very compelling argument for a tether being much better in the long run than a space plane. An *ideal* space plane would have a specific impulse of perhaps three times that of chemical rockets. Lifting cargo is still expensive with such a beast - on the order of thousands of dollars per kilo even under ideal conditions (and likely much more, given the industry's track record with other launch vehicles). Lifting cargo with a space elevator is orders of magnitude cheaper, if you have high volume. The theoretical limit (cost of the gravitational potential energy paid in electricity) is absurdly low (on the order of $1/kg). The practical limit is determined by how fast you can haul cargo up the cable (no more than, say, an amount equal to the cable's weight can be in transit at any given time, and it has 40,000 km to travel before being unloaded). Haul fast enough, and you can make the cost per unit weight as low as you please. All of your hauled weight is cargo, because your fuel can either be burned on the ground with electricity sent up the cable, or (more likely) produced at the counterweight by solar or nuclear generation, and sent down.
The long-term rationale for building a tether is clear.
game on! (Score:4, Interesting)
Giddy up - I'm all for it. Maybe we can get a tax exempt charity status for NASA donations. Maybe one already exists, I dunno. If it was on my 1040 though I'd like that -- more people would see it at least. It'd put it on the forefront of my mind come Tax time.
Personally, I have two uses for the federal government. My military and my space exploration. Beyond that, they're pushing into things that I think my state should handle. I'll spare y'all that ramble though.
I like the idea of space exploration. I sure wasn't around in 1969 when man landed on the moon, but I still get a little lump in my throat when I see things about that era. It makes me proud, not only to be an American but just to be a human being. Hell, I'm filled with awe when I read little tidbits about the early Russian space program, and I was raised in the '80's when the Russians were "bad bad peopole."
I think it's about time we set a real goal for space exploration again, although I'm certainly no expert on this subject. It just seems like it's time to me. We need somebody to step up like JFK did and say "We're going to point X by date Y, and there's no stopping us."
What will we do when we get to Mars, or a station on the moon? I don't know. We'll get something out of the deal though as a society as a whole though I think. Necessity is the mother of all inventions, right?
As it sits, over 50% of my money goes away in taxes right now -- I'd much rather it go to things that I really had an interest in is all.
Up is easy; down is harder (Score:5, Interesting)
It was at this point that I started thinking. Ever read Starship Troopers? In that book, Heinlein advanced the idea of mobile infantry troopers being dropped from orbit to ground in their own individual little re-entry pods. I started thinking about this.
Picture an astronaut in his spacesuit. He's enclosed in an egg-shaped structure made of aluminum and ablative materials, just barely big enough to hold him. Maybe the structure has a small solid-fuel booster attached that's sufficient to execute a de-orbit burn. With nothing more than the mass of the astronaut and the shell to push around, you wouldn't need much energy to execute such a manuver in low Earth orbit. After the burn, the spent booster falls away (to burn up harmlessly in the atmosphere) and the shell, with astronaut inside, descends through the upper atmosphere, shedding heat through ablation. (In other words, the heat shield boils away on the way down.) At a reasonable altitude, say 100,000 feet or so, the shell opens via explosive bolts and the astronaut free-falls, Kittinger-style. At a suitable altitude, the parachute opens automatically and the astronaut touches down safely.
The advantages of such an orbit-to-Earth system seem kinda obvious to me. We know all about ablative heat shields, having used them for the Mercury, Gemini, and Apollo programs as well as every ICBM ever built. A small, symmetrical re-entry structure would be relatively immune to the kind of atmospheric forces that may have destroyed Columbia. Finally, not to seem morbid, in the event of a failure, only one life would be lost instead of the lives of an entire crew.
I don't know. It's just an idea.
Re:Up is easy; down is harder (Score:3, Funny)
Then, the astronaut would rely on a built-in heat shield to survive the fiery plunge through Earth's atmosphere and wait for a parachute to automatically deploy for a safe landing.
You can check out this out-there but admittedly cool idea at Space.com [space.com]. I'm still waiting for it to be used in a major motion picture...
Re:Up is easy; down is harder (Score:3, Interesting)
Can't find a link, but this was seriously considered. Might not be a bad emergency way to get out of space...but I don't want to be the first. : )
Cutbacks?! FALSE! (Score:3, Informative)
Ahem, I point you to the most recent story on my website [franceisoc...ermany.org] you will find this link with a pretty graph [nationalreview.com]
So, enough with the "cuts" talk, the budget has risen $900 million in the past 2 years and is slotted for another $470 million. If you want to debate whether this is "enough" then fine, but it had been in decline for a while before Bush RAISED it two years i a row and proposed raising it again BEFORE the Columbia re-entry.
It should go on. Period. (Score:5, Insightful)
Beyond that, the overall economic contribution that the space program contributes is not just in scientific advancement. People often overlook the fact that while NASA takes billions of dollars in tax revenue, they also provide thousands of jobs. Not just to astronaughts like the heroes (yes, heroes) we lost with the columbia, but people from console operators, to sysadmins, to ground keepers.
Nothing in the history of the US has been a symbol to peaceful cooperation like the space program has. At the height of the cold war, we were able to work with our biggest enemy on a joint Apollo-Soyuez (sp?) mission. It represents triumph and advancement against odds, from the story of Apollo 11 and 13, to the tragedies of Apollo 1 and Challenger. It's given kids something to dream about, and actually tells us more about the universe we live in.
The answer is not where it should go, but rather how it should go on. Personally, I would like to see some privatization in the Space Industry, because that would greatly lower the costs of development and space travel. We also need more exploration missions like the Galleleo and Pathfinder projects, which brought a great deal of positive public spotlight to NASA.
The Pathfinder mission showed that NASA could get something done using economic constraints. However, there is a legitimate need for money just to get some of the basic maintinence done (such as the housing facilities for our remaining shuttles). We need to press farther out than the distance that our shuttles and the space station hit.
As a personal recommendation, I'd like to suggest a little reading that I found years ago. The Case for Mars by Dr. Robert Zubrin is an excellent book that shows both the feasibility, need, and purpose on manned exploration beyond our local little planet. It shows, realistically, how we could get the project done without an outlandish budget. While the project talked about at the end is no longer around, the MarsDirect project still exists. http://www.nw.net/mars/ Give it a look.
Remember, NASA is not just about Space Shuttles, but also about exploration and education. Things like those great space picture backgrounds would not be possible without them.
Space Elevator (Score:3, Funny)
Manned Spaceflight is important. (Score:5, Insightful)
Re:Manned Spaceflight is important. (Score:5, Insightful)
They have the ability to, in a pinch, come up with solutions to problems that no machine technically can. When they had to build a CO2 scrubber from spare parts on Apollo 13, do you think a robot with the same computational power available in those days could have done the same? Of course not.
Additionally, humans seeing an anomalous phenomena would be immediately intrigued by it (such as nebulae, et al), and would set to studying it about as quickly, possibly even discovering something otherwise completely unknown. A robot would see known gasses, shrug because it's known, and ignore it, going on its way (forget about human intervention, when you're talking outside the solar system. By the time we find out it found something, it's long flown by).
And one other critical factor: Humans have a survival instinct. Robots do not. Humans, when threatened, can respond almost immediately. Robots cannot.
Manned Space Exploration: (Score:3, Interesting)
The "flying box-car" we have now.. either in current config, or structurally refigured to a more current design.. (this design was finalized in the seventies, remember). The Shuttle is a great idea.. but its _old_.
ram-driver/mass-lifter.. bung a ruddy great magnetic impulse tube up the side of Kilimonjaro or something, and use that to hurl crap into space. use small gadabouts to retrieve said stuff to the station/s. All we need then is a relatively small (read: 3 crew, small) craft to get people up there to service, position, etc.
Re-useable self launching vehicle.. Delta Clipper style. Though Buzz Aldrin seems to think it is a step backwards, the videos of the tests at White Sands are quite impressive. (Even if it _did_ fall over and blow up on the second test). Extremely "Flash Gordon" and evoked mental images of the "bounce rockets" that Heinlein usually had laying about.
I personally think a shuttle-type craft is the way to go. its not a bad idea, its just an old idea that could do with some updating.
As far as funding goes, let NASA patent its inventions, for a change, and let them charge for spaceflight. Citizens in space? No problem.. sign that fat juicy check and you can ride shotgun, Mr Billionaire! Just sign this D/D waiver.. have a nice trip!
Its time to stop treating NASA as the bastard stepchild of the US.GOV and begin viewing it as the scientific testbed it is. NASA's only vehicle, at the moment, is the Shuttle. All the other rockets (Titan, ESA stuff, etc) are owned by other countries or by the Armed Forces.
Unfortunately, NASA is the first one to get their budget slashed whenever belts get tightened, and five minutes after vehicle blows up people who control said budgets promise to "spend whatever it takes" for safety. Then they slash the budget some more. How else do you explain a 20+ year old spacecraft still flying routine missions?
(And no, ejection seats wouldnt have helped.. even if the pressure suits could have kept them alive at 40 miles up, I think the mach-18 or so speeds would have presented an issue the instant the canopy popped).
I love NASA, I love spaceflight.. im tired of it being viewed as a joke until something (experimental and dangerous) goes wrong, and then CNN is glowering at me, accusing me of not even knowing the orbiter was coming home today, or who was on it. (The press is 2/3 of the problem, I suspect. The minute a launch gets scrubbed, they get pissed, and 10 minutes after an accident, they are demanding accountability and raking up stories about "fired" directors (who actually just ended their tenure, according to o'keefe).
Maeryk
porn (Score:3, Funny)
That, and it really *is* silly that we send up so much oxygen and water with a lot of missions. Remote control is the future.
Where do you want to go today... (Score:4, Insightful)
if (!deadAstronauts)
nasaMoney += moreMoney;
else
nasaMoney = 0;
But, looking at the situation, it's about as logical as having Congress make air travel illegal after 9-11.
But no, instead Congress desides to throw gobs of money at national security to prevent terrorism, and yet they think that it's wise to pull funding from a program which does a much better job of uniting the word together.
What Congress should do is pay NASA $20 million dollars (I think their current budget is about that much) to paste a big warning sticker on the entrance door of each shuttle saying "You fly at your own risk." That way, they state their beliefs, the world has a chance to unite people from around the globe once again, and NASA gets extra funding. Problem solved.
the timeline of flight (Score:5, Insightful)
"It took man 66 years to go from Kitty Hawk to the moon, and in the 34 years since were have gone absolutely nowhere."
That was a pretty good summation of the problem with the Shuttle. It is a proof of concept, but hasn't expanded man's horizons.
I say that the tribute to Columbia's astronauts should be a man stepping on Mars.
Another idea (Score:5, Insightful)
First, one of the stated goals for the space program is to develop new technology. But when are you more likely to use the latest and greatest bleeding edge experimental engine? On a manned spacecraft where loss is catastophic to the whole program, or a relatively cheap robot? Fact is, the pathfinder mission used some of the fastest processors and lots of new off the shelf technology. They had some bugs with it, which is why it can't be used with a manned mission. Sometimes this approach (known to the press as "better faster cheaper") fails, but the point is its SO much cheaper than a single manned mission a failure is not really that big an issue. For the price of one year of shuttle launches we could send dozens of probes to mars (as said before).
Be honest here. While its said that manned exploration is a precursor to manned colonization, the hard fact is that it takes too much energy to put people in orbit. For a very long, long time it will be easier to use advancing technology to support more people on this earth than move them to space. Besides that, humans aren't adapted to live in space. The basic plan has always been to go to the final frontier...then build a huge enclosed, sheltered colony that the human colonists huddle in 99% of the time. Its like going to the Grand Canyon or Yellowstone then huddling in your Winnebago all week.
A far more realistic plan is to create a life that can live there. I imagine "big clanking replicators" : a huge factory with fairly familar machinery, all of it automated and only requiring human supervision to perform repairs. Mining machines, robotic rock haulers, nuclear power plants, smelters, presses, lathes, ect...most of the robotic tech similar to what you would find in a general motors plant. This facility would be built on the moon, remotely operated by people on earth. It would be capable of constructing the parts to build another facility (and so on). While expensive, it would be a fraction of the cost of human missions, and after enough replications be able to produce useful products.
Unmanned boosters blow up 4% of the time, and its nothing but a finanical nuisance. I've just described a plan that would develop far more advanced, bleeding edge tech than anything that could be used in a manned mission. The technology developed (better industrial automation, better artificial intelligence, better remote telepresense) would be immediatly useful on earth. A manned trip to mars would involve mostly old, proven technology, with a few exotic exceptions necessary for the mission. (such as a nuclear propulsion system, something NOT usable on earth)
I understand why noone will listen to me : there's an incredible glamour about blasting off our heroes into orbit, sending a man out in space to get the job done. Hell, I want to go too. But the truth is, without all the overhead associated with minimizing the risks to said heroes a lot more could be accomplished with the same money. In addition, the new tech and perhaps even real products from space would eventually provide a real return on investment, enriching us on the ground.
Space travel isn't feasible (Score:3, Insightful)
It's just barely possible to overcome this limitation. But the costs are enormous. Desperate efforts to reduce weight are needed to make it work at all. The result is spacecraft that are both incredibly expensive and fragile.
That's where it's been for thirty years. And it's not getting any better. In fact, it's getting worse. The Saturn V had the best cost per unit weight to orbit ever. The Shuttle costs far more, and this latest disaster runs up the cost per unit weight even more. All of NASA's attempts to design replacements for the Shuttle have been flops. (There have been three major attempts.)
Heavy-payload spaceflight is an ego trip for superpowers, not a useful technology. Commercial small boosters have been built and launched successfully, but that's the limit of commercial interest. Single stage to orbit remains a fantasy. (Roton looked promising, but a bit of weight growth made the thing; it was that marginal.) The spaceplane idea goes back to the USAF's Dyna-Soar in the 1960s, but still hasn't worked.
We either have to go to nuclear propulsion or give it up. Those are the options.
Re:Space travel isn't feasible (Score:3, Informative)
The costs to minimize this danger, and the liability if it fails, would make the space shuttle seem cheap.
However, there is in fact a third option you have not mentioned. A laser beamed from the ground would superheat an inert propellant block on the spaceship. Pulsed in the right timing, and it would generated a planar shockwave. No thrust nozzles or anything needed. Merely a heavy cube of propellant and the spacecraft bolted on top, as well as some sort of stabilization system. Much safer, nothing to explode, astronaut escape vehicles possible, and a far far better propellant/payload ratio (the laser would heat the propellant up at least 10 times hotter than a conventional rocket can reach). For the initial liftoff phase a short linear accelerator might be used to give the spacecraft its initial kick (and providing a safety delta V if the laser on the ground fails)
This is something that would make space travel feasible in mass. Since the main power system, and most of the complexity , is on the ground (plenty of room to have backups then) the maintainence and operation costs would be far lower. Its estimated that unmanned payloads might reach orbit for perhaps $60 a pound (just the electricity to run the laser).
Epic Thinking (Score:3, Insightful)
The grand plan after Apollo was going to Mars. This needed a couple of key things:
1) Reusable vehicle to ferry cargo and personnel to
2) Space Station that could be used to house personnel and behind a vehicle to go to
3) Mars
After Apollo (during the end actually) funding was cut back and each of the steps listed had to stand on its own.
So instead of building a reusable vehicle to ferry personnel and some cargo to orbit we got the Shuttle. So it was beefed up to spend 2 weeks in orbit, self contained, and big enough to carry ridiculous amounts of cargo and satellites.
We then got a re-re-re-redesigned space station with a primary mission for science instead of a place to build an interplanetary vehicle.
The Mars mission you ask? Well that's just a pipe dream since each of the parts necessary to get there were meant to stand on their own instead of working together for the big payoff.
Space station (Score:3, Interesting)
The first short-term priority should be a cheap efficient way to launch materials into space. If it costs a small fraction what it does now to get material into space, the space station will get built much faster and using far less expensive materials and designs. Humans can still ride the space shuttles or some similar thing, but materials can survive a much more violent (and one-way) trip to space. Perhaps the shell of the launch vehicles could double as space station modules.
Once the space station can support a fairly large crew, how about adding an assembly facility, so that long-range space craft can be sent into orbit in pieces, then launched from the space station. Additions to the station will also become easier to complete.
The basis of all exploration beyond Earth orbits seems to me to lie in a functional space station. Without it, space will continue to be wildly expensive and insanely dangerous.
Then, explore, baby!!! With the problem of re-entry gone for long range space vehicles, long range missions should be much cheaper and safer. So let's start by exploring the moon a bit more, some asteroids (and see if money can be made mining those suckers), and then Mars.
Long-term goal? Space station in Mars orbit and at least a minimal surface base.
Comment removed (Score:4, Interesting)
More horsepower gets you into trouble FASTER (Score:3, Interesting)
Consider how seemingly simple modifications can have unforseen implications. The External Fuel Tank USE to be painted white, until a handful of years ago when some beancounter discovered ~200K of savings simply by allowing the foam covering to remain unprotected by a millimeter thick paint spray. We never had this problem before, but now the last 10's of shuttle missions suffered from Foam Erosion.
Risk mitigation requires any and ALL changes to intricate systems be compiled and monitored over time. The Engineers at Kennedy where OBVIOUSLY concerned about the external fuel tank, and should have spent more time correcting the malfunction.
Replacing the on-board computers with Intel 64-bit Microprocessors? Running 2.5GHz? This is just tinkering with complex systems without fully understanding that more horsepower just gets you into trouble FASTER. The interconnections between processors, how the processors collect data, how reliable the data rate is at 2.5GHz and expecially HOW FAST YOU CAN CHOKE YOUR TELEMETRY Stream back to NASA central are just 4 ways to run into catastrophe.
Makes me madder than a One-Legged Man in a butt-kicking contest.
The SSX and DC-X (Score:5, Interesting)
The X-series (discounting the dumb X-33/34, and I use dumb lightly) were a smashing formula for success, and they were the blueprint for the process of getting man on the moon. Pournelle says we need a similar project to focus on building a space ship. Haven't you always wanted a space ship? :)
Armadillo Aerospace (Score:5, Interesting)
As long as our space efforts are funded by the government, they will always be politicized. People on Slashdot always say "we should give NASA more money," or "we should let NASA be more independent," but you just can't alter the fundamentally political way in which they're run. It's one of the bugs in democracy. Actually, it's present in other political systems as well ("In Soviet Russia, politicians assasinate YOU!"), but that's not important, because I don't think anyone here thinks we should give up democracy for the sake of greater efficiency in NASA. But look at the government programs that surround you every day. Look at the bitter controversies over what age sex education ought to be taught in the public schools (if at all, and should the subject of condoms be raised?). Look at the way the post office raises the price of stamps a penny every year, instead of a nickel every 5. So long as the entire county has to live under only one government, governmental programs are always going to be inefficent, as they must satisfy at least 50% of the population, and a few rich interest groups. The essence of democracy is what they say about a good compromise: "everyone's a little bit upset."
NASA probably was useful in its day. They did get the ball rolling after all. But today, with corporations sending up satellites as part of routine business, expecting a govenrment program to do all of America's space exploration is just not a good idea. We need sustainable space efforts, we need people who have an interest in bringing the cost of getting into space down, and who can take risks without having to think about what it'll mean next November.
Well, this has been a bit of a rant, but that's alright.
Solutions for NASA? (Score:3, Interesting)
That said, it is difficult for me to imagine what goes through the minds of people trying to stop NASA at every mishap. Do they really believe that we'll magically fix all the problems we have here on Earth before the population density grows so high that real-estate in Antarctica starts looking attractive to management? I believe our future lies in space, spreading out from the Earth is the only way to ensure the long-term survival of the species, and Mars is the second step in that goal.
For those of you with less lofty ideas, might I remind you of the HUGE number of technological advances that came out of the well-funded space program of the 1960's? Anyone here use plastic? How about microwave ovens? Miniaturized computers (aka laptops)? Batteries to run them? All of these are available to us now, because they were developed for use in the space program, and then refined by the military.
Imagine what kinds of new technology we'd see if Congress would toss the same $2 billion dollars at NASA that they're tossing to AIDS resarch. Isn't our long-term survival and quality-of-life worth just as much as our short-term survival? Probably not. Most politicians can't see beyond the next election, so having things like an actual Goal for the nation is a concept that died with the Soviet Union.
I think if the public knew (or remembered) all the good that CAN come from a well-funded space program, they'd be screaming at Congress to fund them, knowing that in 5 years they'd get it all back in lower-priced consumer goods.
It's entirely possible that... (Score:4, Interesting)
However, that having been said, making expensive incremental advances is the best we can do until then -- so we must keep plodding along.
But what I want to know is WHY haven't important advances like the linear aerospike engine developed for the X-33 been put to use? I thought NASA's job was to push technology forward, not to bury it. For those unaware of what a linear aerospike engine [boeing.com] is, here's one small tidbit that helps explain its value: conventional rocket engines lose effectiveness as the ambient air pressure changes and must use expensive and complex nozzle geometry changes to minimize this. The linear aerospike maintains a near-constant efficiency from surface to orbit.
Before the X-33 program was folded amidst cries of bug-ridden technology and cost overruns (ostensibly due to a single fuel tank failure during testing -- remember the early problems with shuttle tiles? the Apollo 100% oxygen atmosphere that resulted in 3 deaths before everything was redesigned to become more flame-retardant? The X-33 fuel tank problems were a stalking horse designed to let the military take it over.), the linear aerospike performed flawlessly. And where is it now? Check the url above to see in what part of Boeing it resides.
And with the inherent weaknesses of the decades-old shuttle fresh in your mind, check out this link [216.239.53.100] (originally from www.milnet.com, but now only available via the google cache) for the advantages the X-33 presented over the shuttle. The VentureStar might not have made as good a truck as the shuttle, but unmanned cargo rockets (like those the Russians do so well) are better vehicles to boost freight into orbit.
Perhaps when we have a Chinese space station passing over the US every ninety minutes the government will figure out that NASA has a role other than a place to take funding from to backfill budgets that cannot be supported on their own merits.
Eventually, when large scale robotic manufacturing and practical nanotechnology drive the cost of making things through the floor (assuming it doesn't bury us in grey goo), we'll be able to grow space elevators and put hotels and shopping centers in orbit (not to mention nanotech development facilities, zero-G hospitals and organ farms). Until that time, access to space will continue to be controlled/blocked by that servant of the people, the gummint.
My $0.02 (Score:4, Interesting)
Also, a "from orbit" escape system wouldn't be a bad idea. Set up a "mini" space station that orbits in the same general area as the new shuttle system. Said mini station would merely be a truss (similar to what they've been putting on the ISS), with two Apollo-style capsules attached, a solar panel system to keep the capsule systems warm and the batteries charged, and a small set of OMS thrusters to automatically maintain the station's orbit. This way, if an orbiter is ever damaged on the way up again, and it's uncertain whether or not it will survive re-entry, it can dock with this, the crew can return to Earth in capsules, and a later servicing flight can come up to repair the orbiter and replace the capsules.
I'm not sure we can cease shuttle flights altogether, and I also think it's important to remember that Columbia was the oldest in the fleet and on the verge of being retired. I think we have to keep flying Atlantis, Discovery, and Endeavour for the time being. Along those same lines, I'm also an advocate of "Big Can" [space-frontier.org] construction projects in orbit. It's a clever hack.
I also think it would be dangerously stupid to build just a reusable launch system again. The Space Shuttle Main Engines (SSMEs) are extraordinarily powerful and extremely reliable, and we're in need of a good heavy-lift booster system...especially if we're going to do what NASA needs to do in the near future -- the Moon and Mars. A system similar to what Robert Zubrin proposed in A Case for Mars would be great: basically, a space shuttle launch stack without the space shuttle, and the primary tank fueling four SSMEs. I believe this would allow you to throw ~200 tons into LEO, but I don't have the book in front of me.
Once a new reusable launch system and heavy-launch system are in place, I'd give the last three shuttles a final flight into orbit, with return capsules for the crews. Once in orbit, they ought to be stripped down and overhauled for use as orbital "tugboats"...
And lastly, start going somewhere again...first the Moon, then Mars and the asteroids...then...who knows?
Robots, drones, remote control vehicles, etc. (Score:3, Insightful)
Besides, the goal is not to explore space. That is a side effect of the real goal, which is to _colonize_ space.
Re:Don't blame the doorknob (Score:3, Insightful)
Manned and unmanned space exploration should go hand in hand. Without unmanned missions, space is hella dangerous. Without manned missions, we're just wanking.
Need both to advance the species.
Re:A better way to explore the cosmos (Score:3, Insightful)
Make it cheap, and they will come (Score:5, Insightful)
And the sad part is, there are hundreds of designs that could and would reduce the cost to orbit from its exorbitant $10,000/lb to less than $100/lb. But you know what? All of the aerospace contractors have lobbied for years for these advances to be underfunded, never considered, or just plain cancelled.
I agree with the Cliff, I'm pinning all of my space dreams and hopes on the advent of mass-produced carbon nanotubes. Once they become available, the entire economics of space will change radically. Finally, it will make economic sense for even the most conservative corporations to invest in space industrialization.
Planet P Blog [planetp.cc] - Liberty with Technology.
Re:Make it cheap, and they will come (Score:5, Interesting)
Think cheap dumb boosters - the kind of vehicle the shuttle should have been before it was hijacked into being a commuter service. Keep in mind, we don't need to throw away the STS infrastructure (crusty as it may be.) Just replace the orbiter with a larger unmanned payload module, keep the external fuel tank and boosters. Then, build dozens of payload modules, external fuel tanks (screw the insulation - which is needed to keep ice from forming on the fuel tank, make the payload module disposable), and boosters, in order to get economies of scale. Since there's nobody on board, we don't have to worry about having 99.999999% reliability, nor do we have to waste money on life support.
Just so you know, this payload version of the shuttle already exists on paper, as one of the alternate configurations of the shuttle combo - known as the Shuttle C [orbit6.com].
If you're curious about other never-built shuttle designs, visit http://www.abo.fi/~mlindroo/SpaceLVs/Slides/sld02
Or, we can buy Russian rockets wholesale, if we don't want to invest in our domestic rocket industry. Just don't put pilots in cargo vehicles - there's no point! If you want to send up pilots, put them in spacecraft specifically designed to deliver people... survivable spacecraft.
Re:The obvious answer (Score:3, Interesting)