Japan Tests Reusable Rocket 135
HobbySpacer writes: "Japan's ISAS (Institute for Space and Aeronautical Science) is testing a sub-orbital rocketship called the Reusable Rocket Vehicle Test (RVT). A video of a recent test flight is available. (Alternate source.)
According to Space News, the vertical-takeoff-vertical-landing vehicle
was built on an annual budget of $400k and assisted by volunteers from the Japan Rocket Society. The highest flight so far is 25m but the priority is technology development and low-cost operations, i.e. learning to run a rocket vehicle like a jet. Gradually, the flight envelope will be expanded and later more powerful engines and lighter components will be tested." Low budgets, encouraging volunteer participants -- now that's the way to run a space program!
"Like the DC-X project, the approach is a throwback to the successful X projects of the 1950s when great progress was made by progressing in small steps with small dedicated teams and modest budgets. (As with the X-15, at least 2 or 3 vehicles should be built because if you don't lose at least one during testing, you aren't pushing hard enough.) Perhaps the U.S. will return to this approach, as well, since the mega, 10 bleeding edge technologies at once, all or nothing approach of the X-33 failed miserably."
Wow 25 meters for $400,000! (Score:3)
better than other projects (Score:3)
Here we go again... (Score:4)
On making space cheaper. (Score:5)
This is why I was interested to read an article at the somewhat notorious discussion site adequacy.org [adequacy.org] detailing how to make space travel and exploration less elitist and more widespread.
This article [adequacy.org] shows and provides backing for widening the franchise of people we send to space. Meanwhile, this one [adequacy.org] shows the possible threats we the human race may face from embarking on our seeming destiny among the stars (NB: Both these articles are controversial in nature)
My own opinion is that space needs a public-private partnership in order to best take advantage of the best the state and the private sector has to offer. All nations realise this to some extent just now, but the Japanese and Europeans much more so than the americans. We need to do similar here in the USA.
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Re:The benefits of not having a military (Score:3)
Actually, Japan is among the top 5 military spenders world wide. And has an extremely modern Air Force and Navy.
The Japanese fly Mitsubishi/Boeing built F-4s and F-15s. And they are working on a new advanced F-16 class fighter, as well as buying 767 based AWACS aircraft from Boeing/Ratheyon.
The Japanese Navy has a number of Aegis class DDGs, similar in all respects to the US DDGs of the Burke class. The Japanese Army uses a very nice tank called the Type 74.
Japan is a strong ally of the US in Asia and is vital to US warfighting plans for Korea or other hotspots around the South China Sea.
Re:From one of those articles: (Score:1)
You lost your virginity when you were three and a half years old?
Re:The benefits of not having Democrats (Score:1)
Funny, this is basically the same project that Bush Sr (and Dan Quayle) funded, then Clinton strangled, transferred to NASA, which crashed it and replaced it with the X-33 monstrosity. Thanks to the Clinton-era mergers, the corporation which thought DC-X was possible doesn't even exist anymore.
The main question is, what's next? Are we going to let NASA run our entire space program, or are we going to finally let DoD and DAPRA do reusable launch research again? You may not know this, but for about the past eight years, DoD research into reusable launch vehicles was forbidden. Maybe they were scared they'd come up with something that worked.
YES! (Score:1)
Anti NASA sentiment (Score:1)
Your snide Anti-NASA insinuations are an affront, and baseless, too. Why the insinuation that NASA hasn't done anything worthwhile or impressive since the X-Projects? I think they've done some impressive things, like acheiving orbit, for one. Also, this project is not comperable with the X-Projects. Those were learning aids; this is supposed to become a useful launch vehicle. Further, the X-Projects were nowhere near cheap.
And second, why laud the Japanese for having a low cost vehicle. For one thing yet, it doesn't work, second, it's only acheived 25m (unless the units are a typo on your part.) Also, what is it's carrying capacity? Thing looks like it would have trouble carrying 10 kgs to orbit, much less a payload of useful size.
Japan doesn't have a space program worth a damn because the government wont spend the money. Frankly, private space launches aren't there. We can push for NASA to get us there, which is preferable, since we won't have patents on scram-jets, re-entry sheilds, etc. The point is, NASA is it when it comes to space, for now. (Of course, there are other agencies, like the europeans, who need NASA to exist, but they're far from independant.)
By the way, re-read you last sentence. I'm not talking about your content, just the grammer. It's painful.
From one of those articles: (Score:1)
can see that the issue of sex in space will become important, and that it is unreasonable and even
cruel to send men on long, protracted missions without romantic company"
Erm, I'm not gay, but I went for 3 1/2 years without sex. By the above reasoning, shoul out medical services provide sex for sale? This is not a troll, it is a serious question, so I'm not posting anonymously.
OK, I take it back : ) (Score:1)
If he says it's the same, who am I to argue?
Plus, I'm way interested in this 2nd generation vehicle he mentions!
Jon Acheson
Not really... (Score:2)
Plus, his budget is at least an order of magnitude less than the Japanese budget.
Who says Americans can't do small and cheap? Go John Carmack!
Jon Acheson
Gliding isn't free. (Score:2)
This is not to say that a glider approach could never work, just that every design has tradeoffs.
Jon Acheson
Re:Volunteers (Score:1)
If they supplied a room and board, I'd be up for it. There's already government housing in the area at Patrick Air Force Base... I don't know how occupied they are, but perhaps the gov't can make an allocation for volunteers. From the road, they look like reasonable houses/duplexes... and they're accross the road from the Ocean (and that's always cool). I'm sure you could fit a small gaggle of geeks into one of these (we've all had roommates before, right?)
Given some food and perhaps a small clothing/entertainment allowance (money that could easily be obtained through private sponsorship and public fundraising), I'd be up for it.
Maybe I'm asking too much.. i dunno
Re:Volunteers (Not) wanted for Federal Government (Score:1)
A guy donates a few hectares of land to the city with an agreement that a non profit group will turn it into a park with soccer and fastpitch fields. Volunteers for the non profit will clear the land, plant grass, install sprinklers, put up washrooms and storage buildings, erect stands, etc., etc. over the course of a few years. All with donated materials.
Only problem is that the local city workers union goes balistic (on topic :) saying that the volunteers are taking union jobs away resulting in lost wages ~C$750,000, yada yada yada. Non profit responds with "that's stupid we just want to improve the local community at no cost to the tax payers."
Long story short: The Union was succesful in stopping the project. The land owner took back the land and it now sits as a vacant weed infested eyesore. And the nearest park is couple kilometres away. But hey that's OK because no union member lost any wages this way :( I'm not bitter, can you tell?
Re:Just use a parachute! (Score:2)
Long term there's no substitute for aerodynamic assist. Putting a winged vehicle at 50,000 ft using aero engines takes a fraction of consummable liquid (fuel/propellant/oxidant) compared to a conventional rocket. Future space vehicles will without doubt carry either multiple or multi-modal engines to take advantage of each engine type's optimal performance environment. Considering that a conventional rocket consumes a substantial percentage of its fuel just to get out of the atmosphere, it only makes sense to take that first step with jet engines.
Re:Volunteers (Score:2)
Not me. I'd be more likely to volunteer with an organization that would work towards making it possible for lots more people to go. That's pretty obviously not on NASAs priority list.
Re:Volunteers (Score:2)
It would depend on their design and on their testing program. Call me crazy, but for some bizarre reason I'm much more interested in what the results would be than in whether or not they passed out pieces of colored paper to the participants.
Re:On making space cheaper. (Score:2)
Do it well enough, and you can hit escape velocity without rockets at all. For further info, see The Moon is a Harsh Mistress, R. A. Heinlein.
Sounds like an updated DC-X / Delta Clipper. . . (Score:4)
Some Links to DC-X:
The really sad thing is, we'd likely almost be at the operational SSTO stage now, if we hadn't killed DC-X. . ..
Re:"If you don't lose one..." (Score:2)
Other notes:
1) I wasn't responding to Timothy [monkey.org], rather HobbySpacer [hobbyspace.com], the article's submitter. At least, that's how the quotes lead me to read it.
2) I don't think that this person presumed that this statement was only meant for unmanned flights; the link included in this comment was for the X-15, which did have a fatal disintigration, as memorialized in the link he gave [fiddlersgreen.net].
3) I didn't mean to suggest that I thought this vehicle was manned. I was responding to his comment about the X-15.
Sorry if I ruffled any feathers; I guess I wasn't sufficiently clear.
"If you don't lose one..." (Score:5)
In fact, on the X-15 page [fiddlersgreen.net] you link to, you give a prime example of why they might object:
I'd have to say that, of course more than one prototype should be built, but it's rather insensitive to snidely say that "if you don't lose one during testing, you're not pushing hard enough".
Fuel? (Score:1)
Re:Uh-oh (Score:2)
reliable repeatable and on demand (Score:2)
Re:Donate your garage! (Score:2)
AVATAR (Score:1)
There is not much info in that news item but another website [geocities.com] has a little more information.
What is unique in this is it collects oxygen while in suborbital cruise, converts it to liquid oxygen and uses it to reach orbit. This process has already been testing at the ground level.
They expect to use it for launching LEO satellites and defence surveillance purposes.
Re:On making space cheaper. (Score:1)
Re:One thing I don't get (Score:1)
""Low budgets, encouraging volunteer participants -- now that's the way to run a space program!"
I would defenatly agree, but why do we have so much ranting here about NASA's low budget?"
Well, you won't hear that from me
I don't think the government should be in the space business at all, except insamuch as it is necessary for national defense.
Darnit.
timothy
Re:No, that's Not the way to do it (Score:1)
Some people [rotaryrocket.com] have solutions that give you VTVL without needing to balance on the point of a needle. Unfortunately, they seem to be out of money.
Kinda sad, really.
The abbreviated Laws of Thermodynamics:
1)You can't win.
2)You can't break even.
Re:The benefits of not having a military (Score:1)
-jeff
NASA: The Big 1 (Score:2)
The Big 3 US auto manufacturers took over 15 years to effectively respond to the Japanese, but they had to start losing money. NASA is in a lot worse shape than the Big 3 US auto manufacturers were in the early 1970s because NASA is more:
Now, what are the chances NASA is going to act to reform itself based on the Japanese embarrassment alone? I think they need to be embarrassed a whole lot more before they'll wake up and smell the coffee like the Big 3 US automakers did in the 1980s.
false logic? (Score:1)
I think there is actually a benefit in not having a military... nobody comes to take over the project because of "National Security" reasons.
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Brute force (Score:1)
NASA got an unlimited budget to meet the goal of landing a man in the moon and they did it using plain and simple brute force (huge and inefficient rockets). The problem is, they got used to have unlimited resources is the only way they work.
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Uh-oh (Score:1)
only 25 meters for 400 grand?!!!? (Score:3)
In Other News (Score:3)
Damn... too much anime...
Re:They're using Hydrogen. That's not a good thing (Score:1)
Tastes great, less filling... (Score:1)
Re:"If you don't lose one..." (Score:1)
I would respectfully disagree. You don't sign-up to be a test pilot for experimental aircraft if you want a safe and secure job. Obviously the designers do everything they can to make it safe, but every test pilot knows their next flight could be their last. Crazy, maybe, but if you want safe, you sign-up as a designer, not the pilot.
NEWSFLASH: Japan tests reusable rockets (Score:1)
who's economy is raw-materials based? - answer (Score:2)
Origins of NDP for Japan:
* agriculture - 1.9%
* industry, of which: - 38%
manufacturing - 24.7%
* services - 60.1%
Origins of NDP for United States:
* agriculture: - 1.7%
* industry, of which: - 22.9%
manufacturing - 17.4%
* services - 75.4
Hmm.. so who's economy is raw-materials based? I understand what you're getting at, but you'd have a much more convincing case if reality jived with your notion.
Benefits of not having a military - false logic (Score:3)
Further, your notion that the US approach of science and technology as a "side-effect" is no longer true. Here's an excerpt from an article on Japan's technology policy, which can be found here [ucla.edu]:
"Traditionally, the public sector in most countries has been an important source of funding for basic scientific research.(6) As recently as 1995, the Japanese government contributed 22 percent of the nation's U.S. $140 billion in total R&D expenditures, while the U.S. government chipped in 35 percent of that country's U.S. $179 billion in R&D expenditures.(7) At first glance, it would appear that government support for basic research is alive and well."
"However, if we examine the numbers more carefully, we find that funding for "pure science" is indeed drying up. If one considers purchasing power parity, Japan's total R&D expenditures for 1995 are cut nearly in half, to U.S. $78 billion.(8) Even if we assume that the bulk of public money goes to fund basic scientific research, this means that only U.S. $17 billion is available for this purpose each year."
"By comparison, using the same assumption, the U.S. government is providing roughly U.S. $63 billion on behalf of basic science. The important element here, however, is the decline in military outlays on behalf of scientific research resulting from the end of the Cold War. Not only have overall budgets been cut, but there has been a fundamental change in philosophy regarding the most efficient way to obtain leading-edge technology."
"Given the limited applicability of products typically funded by the U.S. government, whether for military or aerospace applications, it is often hard to justify massive government investment in the basic research underlying such products. It is far more economical to rely on the private sector for such research, and simply tailor the resulting technology to military needs or purchase the end products outright. Consequently, there has been a shift from a "spin off" to a spin on" policy. Rather than the government financing basic scientific research through Pentagon programs such as the Defense Advanced Research Projects Agency (DARPA), which gave birth to the Internet, and then "spinning off" the resulting technologies for private sector commercialization, it is increasingly turning to the private sector for "dual use" technologies that it can "spin on" into military applications."
As for seeds of destruction, how is it that after supporting Japan's defense needs for over 50 years, the United States hasn't been eclipsed by Japan economically?
Remember the 1980s, when suddenly every American businessman was reading books about Japanese business practices? Well, the Americans learned a lot, and managed to make painful changes that turned the American economy around.
Unfortunately, Japan is having a tougher time making the infrastructure changes it really needs. Japan's banking industry is a mess, and the Keiretsu system has shown weakness throughout the 1990s.
Finally, your contention that a Japanese military would become "unbeatable within 25 years" is pure conjecture, and the thought that the Japanese could have a working missile defense system within 10 years is fantasy. There are many primarily political reasons this is true, as this National Bureau of Asian Research paper [nbr.org] indicates.
If you want to talk about Asian superpowers, think China, my friend.
One thing I don't get (Score:2)
I would defenatly agree, but why do we have so much ranting here about NASA's low budget?
"One World, one Web, one Program" - Microsoft promotional ad
Re:Just use a parachute! (Score:3)
With a 400 Isp engine, one percent of the vehicle landing mass can kill 40m/s of velocity. That is over 80 mph, which an efficient VTVL vehicle could expect to have as its terminal velocity.
A parachute masses more than 1% of its load.
There are lots of other factors that can push the decision either way, but it is certainly within the realm of feasible engineering decision.
John Carmack
Re:carmack (Score:5)
www.armadilloaerospace.com
Their current vehicle is a good deal larger than ours, has an aeroshell, and significantly, uses liquid hydrogen / liquid oxygen, a much more potent and difficult propellant than the hydrogen peroxide we use.
On the other hand, my project has been a lot faster and cheaper. I have spent about $50k and we have been working on it for nine months, versus their $400k and four years.
Our first up scale vehicle is going to be ready in a few months. It won't go very high or fast, but we can carry a person on it...
Next year, at the very least, we will have a supersonic manned rocket ship.
John Carmack
Re:carmack (Score:3)
Has anyone noticed? (Score:1)
Interestingly enough, the X33 is now dead. I'd be willing to bet that Microsoft had something to do with its demise. That would have been a helluvan advertisement for Linux!
official X-33 site with no penguin-like images [nasa.gov].
Re:The benefits of not having a military (Score:1)
F-bacher
Re:Just use a parachute! (Score:1)
F-bacher
Re:No, that's Not the way to do it (Score:1)
F-bacher
Conservationism BAD (Score:3)
F-bacher
Learn what? (Score:1)
Yeah, so? As I recall, we won WWII. Keeping weapons totally up to date is very expensive. Keeping weapons semi up to date, and then replacing everything in the event of a real war makes a lot more sense.
The only "intuitive" interface is the nipple. After that, it's all learned.
Re:Learn what? (Score:1)
Actually, Israel won WWII. They were the only ones who came out with more than what they started with.
Re:Anti NASA sentiment (Score:1)
Flaming grammar be dangerous, especially if you spell it grammer.
Let's be kind here...
The DC-X program died becaues NASA wouldn't fund it to the tune of, what, ten mil? The SSTO vehicle worked (tho a tech inadvertently failed to lock a landing strut and it went boom) and was working well. Tho I love NASA and its accomplishments dearly, they do not like competition, firstly; secondly they are winged aircraft afficianados; thirdly, if the cheap SSTO concept worked, they would have had a lot of 'splainin to do about the tens of billions the superplanes require for research.
I love the supertech, but, like the wet navy, you make incremental moves towards new vehicles. The slow and cheap, use-what-works method the Japanese are using will get them to orbit sooner or later, and when they do, it'll be a efficient workhorse (which blows up occasionally). Think a Honda Civic vs. a formula racer. The thing about cheap is, you can make more ships if they crash or explode, or just wear out. NASA has no safety margin with 2 billion dollar craft. They must not fail; to fail would be the end.
NASA once upon a time floated dreams about Mars and lunar cities, and was brutally disillusioned about the public's desire for such things. So they have to be safe, flying 31 year old designs into orbit, building a station which does little. I grew up on space, i dreamed it. Gerry O'Neil was my god. But space is locked up by an agency that, tho it wants to fly, can only plod if it wants to live.
Small. Cheap. Composite. Cheap fuels. Fast turnaround on land/launch cycles. Vertical take off, vertical landing. These will open space for commerce, maybe even open up the moon and the solar system for us all, eventually. NASA's programs cannot.
I mourn the Roton and the DC-X/Delta Clipper. I am damned happy someone, somewhere is carrying on making the sky our new home. I don't want new drugs made in microgravity, or more intensive astronomy. I WANT TO GO MYSELF, and this project brings it a little closer to reality. NASA will never give us that.
Re:Actually, it is the way to do it (Score:1)
dam (Score:1)
Peace,
Amit
ICQ 77863057
Re:On making space cheaper. (Score:2)
You'd need an incredibly streamlined design, that only takes up a fraction of the opening, since you'd otherwise encounter the problem that builders of underwater train tunnels encounter - pushing a huge column of air ahead of you. You'd want the coil that provides an opposing force to detach as soon as you leave the surface, and your chemical rockets to fire once you get high enough into the atmosphere. Sure, this would only get you a few miles benefit, but that's a few miles you don't have to be thrusting during. All sorts of complications could occur - massive heat generation during liftoff, problems with sonic effects, etc... Some of the problems could be alleviated by artificially lowering the pressure by running a strong air current across the opening... but... I don't know, it was just an idea
Naturally, such an idea would work far better on thinner atmosphere/lower gravity planets than earth (on some, you could do away with chemical rockets alltogether, except for what's needed during spaceflight), buuuut...
I don't know. Flame away
-= rei =-
Re:The benefits of not having a military (Score:1)
why are the major japanese corporate powers courting Americans for CEO positions?
Why is the role of "salary man" fading away?
Since the Japanese missle defence system would only need to protect an area the size of california, its no wonder it would take 10 years.
If the Japanese where allowed to build a military, how long do you think china would stay away?
The benefits of not having a military (Score:1)
The real irony is the way the United States imposed this condition on the Japanese after World War II. While the US may have enjoyed several decades of military and industrial masochistic dominance, the seeds of her destruction were already planted.
The US knows this, of course. That's why several of the hardline "America-First" groups are suggesting its time to let Japan build its own military. The more realistic amongst us know that a Japanese military would almost certainly do more with less and become unbeatable within 25 years. Indeed, experts project Japan could have a working missle defense system within 10 years -- a concept that makes the US Bushies decidedly uneasy.
Japan is the superpower of the future. The US is on its way to being a has-been.
Re:Canada set to take over the world! (Score:1)
It's not flamebait, just simple economics.
In case you haven't noticed, the post started at 2 and has been modded down to 1.
Anonymous moderation has brought more harm to Slashdot than anonymous posting ever did. Gotta stick with that groupthink, folks.
Re:Actually, it is the way to do it (Score:1)
Shuttle pilots have to practice final approaches again and again and again using a specially modified jet, because they cannot afford to get it wrong.
Powered descent is what is required. Perhaps at some time someone will combine the two so that your space vehicle lands like an aircraft, but under power, not a one-shot glider. And on regular airfields. But that's not likely. I just hope the Japanese manage to avoid the leg problem which hit the DC-X - and perhapse use a lower centre of gravity.
Hacker: A criminal who breaks into computer systems
Re:Volunteers (Score:1)
Are [nasa.gov] you [nasa.gov] sure [nasa.gov] there [nasa.gov] isn't [nasa.gov] more [nasa.gov] to [stsci.edu] show [nasa.gov]?
Re:carmack (Score:3)
Re:They're using Hydrogen. That's not a good thing (Score:2)
It is possible to make kerosine from biomass if we really wanted to.
The fraction of CO2 produced by rocketry is totally irrelevant next to the huge amounts used to drive cars or generate electricity. It's going to be maybe one hundred years before we reach the point where launch vehicles are significant; and the technology will probably shift to beamed solar energy or something by then anyway.
Finally, Hydrogen is more expensive because it takes more energy to produce. Practically speaking, unless you use nuclear power (or perhaps even
Re:They're using Hydrogen. That's not a good thing (Score:2)
They're using Hydrogen. That's not a good thing (Score:4)
Secondly, liquid hydrogen (LH) is a deep cryogenic fluid- the insulation values needed to keep it are very high, and this adds mass, plus it has lots of nasty habits like condensing oxygen from the air- LOX reacts with loads of things explosively.
If you do the simulations for an entire rocket, the performance of LH/LOX is entirely comparable to kerosine/LOX fuels- kerosine is much denser, lighter engines etc; but kerosine doesn't give as much kick per unit of fuel. So your rocket ends up heavier (more kgs of fuel), but the 'dry weight' is less. But this heavier rocket burns weight off much more quickly and hence goes as far as the LH/LOX.
Another advantage? Kerosine is a lot cheaper than hydrogen, even allowing for needing more of it. Kerosine can be carried in trucks.
Another? The kerosine/LOX rocket is much smaller (easier to build and transport).
Cars? (Score:1)
I thought that the German's made the best cars?
Re:Volunteers (Score:1)
Think about how many people would volunteer, and then think of the odds that you are the one chosen.
"Lottery is taxes on those with bad math skills" (I know that's probably misquoted, but you get the jist).
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Volunteers (Not) wanted for Federal Government (Score:1)
How many people here would jump at the chance to work for NASA for free if it meant the possibility that they may, themselves, go into space?
I don't know about future of the space program or all the rules associated with working for NASA, but I was told that you are not allowed to work for the (US)Federal Government for free, i.e. volunteer your time. Of course you could argue that you are being "paid" with a trip into space. But for some reason all contracters and employees must be paid.
Re:"If you don't lose one..." (Score:1)
That's why you use unmanned prototypes for the questionable stuff. Not an option in the 50's and 60's, but quite do-able now.
Re:Volunteers (Score:1)
Perhaps we'll give "kiddie" rides to finance it as well.
This sort of project is a natural for an open group effort, sort of junkyard wars gone "loony"
Hydrogen Oxygen rockets are well understood, as are flight control systems, vacuum canisters and all the other components that go into making this sort thing.
I think it is time that private people and or corporations realized the long term benefits of the utilization of space and got off their colletive duffuses and starting doing something real.
Of course, I could take my own advice . . . nah, I'm happiest sitting here in the dark.
Is it for consumers? (Score:1)
Re:Just use a parachute! (Score:2)
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Low budgets, volunteer participants (Score:3)
Low budgets, encouraging volunteer participants -- now that's the way to run a space program!
An extreme version of this philosophy is central to the Portland State Aerospace Society [pdx.edu], Portland State University's group operating under the auspices of the IEEE [ieee.org] Aerospace and Electronic Systems Society (AESS) [gatech.edu]. Check out in particular our ongoing work on our Inertial Navigation System [pdx.edu], which currently costs out at around $500. All of our work is open source, and is specifically targeted at usability by other amateur rocketry groups.
Re:The benefits of not having a military (Score:3)
Well, actually quite a bit of our technology has been developed for the military. For example, look at how air travel came to be. It started off as some people tinkering around on their own time (like the Wright brothers), and was eventually adopted by the military and the technology advanced very rapidly. Fighter planes and bombers were designed for the military and because of WWII our planes started using jet propulsion (this had been worked on before the war, but development was really pushed along during WWII). That is the same technology that was used to design the commercial aircraft currently available.
Also, look at the history of rockets. While the Chinese did invent fireworks many thousands of years ago, most modern rocketry comes from inventions like the German V2 rocket (invented by Von Braun if my memory serves me correctly). While those rockets were mostly used for things like bombarding England, they were the same design used later for space exploration and I'm sure are pretty similar to the Japanese rocket mentioned above.
That's just my opinion... now let the flaming begin...
Re:Volunteers (Score:2)
There have only been something on the order of 350 people in space. That's all we have to show for 50+ years of serious space research. If it meant all who wanted to go to space could book a flight on the Japanese rocket then it's worth the volunteering.
Volunteers (Score:4)
I know I would.
Poll (Score:3)
Re:News Flash... (Score:1)
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Re:The benefits of not having a military (Score:1)
Re:News Flash... (Score:1)
Re:News Flash... (Score:1)
Geez, some people...
Re:Railguns (Score:1)
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Re:Fuel? (Score:1)
Me, I'm all for the idea. If they get it work, good on them! If not, well, they won't be the first. Right now, though, it's way too early in the game to say.
Re:The benefits of not having a military (Score:1)
Re:The benefits of not having a military (Score:1)
Re:Fuel? (Score:1)
Fuel efficiency for rocket motors is measured by a quantity called Specific Impulse, or Isp. This is roughly described as the length of time you will get one pound of thrust for, if burning one pound of fuel. Typical values for professional engines are 250-330 seconds, for hydrogen/oxygen engines 400-450 seconds. Model rockets are 80-180 seconds depending on the fuel.
You only need a little bit more thrust than weight to take off and hover. Space launch rockets typically launch with thrust of 1.2 to 1.3 times their weight. For low altitude demonstrators, if you have half your takeoff weight in fuel (low for a space launcher, typical for a cheap demo) then you should be able to hover for 3-5 minutes or do low altitude flights and then land with not much less endurance.
Re:Actually, it is the way to do it (Score:1)
Very simple answer:
Why are you carrying wings all the way to orbit and back which are only useful on landing? Wings are heavy, and expensive to engineer, build, and protect from re-entry heat.
Professionals argue back and forth about the relative advantages of powered versus aero-glide landing all the time. It's very clear that at best, it's very close between the two options. Extra fuel requires just slighly larger tanks and restartable rocket motors, which isn't all that hard. The numbers can work out either way.
For more info, and to re-start the perpetual flamewar, Usenet's sci.space.policy [sci.space.policy] is a good place to look (or sci.space.tech, but I moderate it, and hesitate to push outside conversations into the moderated group...).
Re:Actually, it is the way to do it (Score:1)
You're going riiight past it. *launch* weights don't matter a bit for landing. What you're trying to land is the empty weight (plus any returned-to-the-earth payload).
The tradeoff is wings (empty weight) versus fuel (and slightly larger tanks) to land with. You need fuel for say... slowing from 50 meters per second (free fall speed of your empty rocket) to 0 and hover for a bit, from an altitude of 500 meters or so for engine ignition. That works out to about 20 seconds of thrust, at an average of something like 1.25 Gs, or 250 meters per second of velocity change. About 6-10% of the landed mass in fuel, perhaps.
If you don't think wings weigh 6-10% of the landed mass of an aircraft or glider or glide-landing spacecraft, you need to research more. They're typically 9-15% of the weight, including the control surfaces and such.
Re:dam (Score:2)
I'm just wondering how long before one of these reusable rockets begins to look like this. [warnerbros.com]
-- .sig are belong to us!
All your
Canada set to take over the world! (Score:2)
What? Military spending and research have more often than not HELPED the progress of science and technology? Hogwash. Look at Poland c1939. They rode horses, while their citizens took weekly trips to the moon!
Amazing how such unoriginal anti-American flamebait consistently gets modded UP. And I'm a Canuck, to boot.
Actually, it is the way to do it (Score:2)
All space vehicles do the vast majority of their braking from orbit using air drag, so the remaining issue is subsonic braking and landing. You can do this with wings, you can do this with parachutes (mostly) or you can do it with rockets. Since a re-usable rocket will have to have the engines along for the landing anyway, it is just a question of whether the fuel weighs more than the necessary wings or parachutes.
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It's not "free", that's the problem (Score:2)
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Points the previous responder missed (Score:2)
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Forget rail guns in mine shafts (Score:3)
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Very impressive even if its just 25m (Score:2)
Don't worry, we can do it in software. (Score:2)
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News Flash... (Score:3)
That's the way to run anything. The employees are happy, because they aren't doing it for money (hence the volunteering) but for the job itself and the goal in mind, and the results are astounding.
We do this now with Open Source. Many organizations are on route to this style. Globalization will stifle us to death otherwise.
Screw 3...
Donate your garage! (Score:3)