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Space Science Technology

SpaceX Reveals Plans For Full Launch System Re-usability 227

Posted by Soulskill
from the waste-not-want-not dept.
FleaPlus writes "During a talk at the National Press Club, SpaceX's Elon Musk revealed the company's plans for making their Falcon 9 rocket fully reusable. A rendering depicts the first stage, upper stage, and Dragon capsule all separately returning to the Earth's surface and making a controlled, rocket-powered landing. During the next few years SpaceX will be testing VTVL (Vertical Takeoff, Vertical Landing) maneuvers and re-usability with their Falcon 9-based 'Grasshopper' testbed, with up to 70 test launches per year. Musk stated that if reuse is successful, it would result in a 100x reduction in their already-low launch costs, a key step toward Musk's long-term aim of lowering the price of a ticket to Mars to $500K."
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SpaceX Reveals Plans For Full Launch System Re-usability

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  • by Doc Ruby (173196) on Friday September 30, 2011 @07:55AM (#37565792) Homepage Journal

    I am glad Americans invested in the Space Shuttle programme that gave, among so many other benefits, the basic R&D into reusable space vehicles and launch systems for them, to SpaceX, the rest of the growing private space industry, and to the world in general.

    I look forward to SpaceX and its competitors paying the taxes that will repay that investment, even as they make good profits without having had to take the risks or pay the costs of those decades of R&D on their own.

    • by khallow (566160)
      Yes, this demonstrates the vast value of government. Throw a few hundred billion in, get a billion dollar rocket out.
      • I suggest that you never use a weather report for the rest of your life, asshole. Where do you think weather satellites come from, Santy Claus? Any moron knows that without the Feds there would be no weather satellites. I guess you're not even at the level of the average moron.

        Of course without the benefit of global weather forecasts international shipping by air and sea would be a lot more expensive, so you should also give up anything made outside North American.

        And no GPS for you either. So that means

        • I think someone needs a time out.
        • So that means no automated tellers, because they all use GPS time signals for synchronizing transactions.

          ATMs do not use GPS. They get their time signal when they connect to the network to do the transaction. If they used GPS then they would have to be outside so they could get line of sight to the GPS constellation. Now, some ATMs do have GPS units built into them, but those are for tracking the unit when somebody walks off with the whole machine.

      • by sjbe (173966)

        Yes, this demonstrates the vast value of government. Throw a few hundred billion in, get a billion dollar rocket out.

        I hope you were joking because the ROI on research dollars invested in NASA to the US economy is somewhere between 3X and 14X [nationaljournal.com] depending on which study you look at. There are over 1650 [wikipedia.org] spin off technologies. NASA may run an inefficient manned space program but they are a genuine research powerhouse that MORE than pays for itself once you consider it's net effect on the economy. Just because the benefit isn't a direct one doesn't mean it isn't a benefit.

    • by PinchDuck (199974)

      For starters, taxes paid aren't allocated to whatever wishing well you think they should go into. Federal taxes go into the general fund, so it's not like NASA's going to be getting a check from SpaceX. Secondly, it's not like SpaceX isn't doing a ton of R&D and taking a lot of risks. Thirdly, I hope that SpaceX has a talented accounting team that allows them to maximize their return on investment, including taking all applicable tax deductions. If you don't like companies taking tax deductions, blame t

      • by Lifyre (960576)

        I think you were missing his point when it came to the taxes. NASA's funding comes from the general fund just like most federal agencies. His point was that the investment into NASA for the space shuttle is or will generate a real return in the form of taxes on SpaceX to the general fund that will repay the original investment. If and when that return will equal or exceed the value of the original investment remains to be seen.

    • by Andy Dodd (701) <atd7&cornell,edu> on Friday September 30, 2011 @09:55AM (#37567156) Homepage

      You clearly don't know much about the Space Shuttle.

      In terms of reusability, it was an utter and complete failure.

      Yes it was "reusable", but it turned out more expensive to launch than one-shot non-reusable systems because its reusability approach was completely hosed. For example, half the tiles needed to be replaced after each launch.

      That's why the Space Shuttle has been decommissioned in favor of nonreusable systems.

      SpaceX's reuasbility research will use nothing from the shuttle except possibly lessons learned on what NOT to do.

      • by mrchaotica (681592) * on Friday September 30, 2011 @10:50AM (#37567966)

        That's why the Space Shuttle has been decommissioned in favor of nonreusable systems.

        I believe you're mistaken: the Space Shuttle has been decommissioned in favor of NOTHING AT ALL.

      • SpaceX's reuasbility research will use nothing from the shuttle except possibly lessons learned on what NOT to do.

        Regardless of the success or failure of the shuttle, that work helped pave the way for the current situation. NASA pioneered a huge amount of research, both successful and less so. You can't take any credit away from them just because the shuttle was less than spectacular. NASA's contributions to knowledge and technology in general over the years have been staggering. Some of that knowledge is relevant, even if it's not a direct copy-and-paste situation for SpaceX.

    • Yes, surely corporate CEOs and even private citizens can do the minimal amount of thinking required to see that much of the modern communications infrastructure we take for granted wouldn't have been possible without a functional space program. I am certain that the innovation and materials science that allowed us to get in to space will not be overlooked by anyone, nor will people make the mistake of conflating the sunk costs of basic research with some sort of profit/loss business model that doesn't apply

    • Falcon 9 does not use any of the Shuttle technology. At least as far as we know. They developed there own engine the Merlin, they are not using the tiles or the solid boosters. So how do you figure this.

      Why are you so bothered that the government is not doing this and a private company is are you that myopic in your politics that only the government can do for you? That's really just quite sad.

      If the government was doing this it would not be cost effective. It would be years over due and over budget and cos

    • by Nyeerrmm (940927)

      Thats how its supposed to work. Governments should be doing the things private industry and individuals can't -- in this case development of technologies that have the potential to benefit society as a whole that are expensive enough and uncertain enough to never make a valid business plan or hobby project.

      Then, those developments should be fed back to the citizens (and the companies they form), so that when its possible for the private entities to take advantage of it, they can. I work for NASA, and pers

    • by FleaPlus (6935)

      Actually, I'd argue that SpaceX has benefitted much more from NASA's efforts in unmanned exploration and low-cost space technology than it has from the much higher-funded Space Shuttle program. For example, SpaceX has used and improved on technology like the PICA heat shield material (now the PICA-X used on Dragon) and the principles from the Fastrac [wikipedia.org] experimental low-cost engine were used in the first version of SpaceX's Merlin engine. I can't think of a single thing from the Shuttle program that has benefi

  • Bizarrely, it's starting to feel like the old Flash Gordon / old cartoon style "rocket ships" are actually the future! I'm not sure I'll ever be able to see them as "retro" and less futuristic-looking than the shuttle, no matter how much more advanced and practical they actually are.

    • by khallow (566160)

      I'm not sure I'll ever be able to see them as "retro" and less futuristic-looking than the shuttle, no matter how much more advanced and practical they actually are.

      Doesn't matter. There's a good reason we don't use fancy Italian sports cars to haul our garbage. Function trumps style.

  • Commercially, without massive amounts of money spent on lobbying, and showing you can do it by generating significant results rather than shiny piles of paper that do not fly.

    I note in the speech - at around 33 minutes - one telling quote.
    (Paraphrasing, as it was yesterday I watched it) "We have 1% of the lobbying power of Boeing and Lockmart. If the decision depends on lobbying power, we're screwed'.

    This was about the decision to extend the sole-source monopoly for airforce rockets.
    And he notes also that t

  • by OzPeter (195038) on Friday September 30, 2011 @08:01AM (#37565838)

    That was a line from the backing song. Interesting choice.
     
    On a different topic. It takes X amount of rocket fuel to move a payload to orbit. It takes Y amount of rocket fuel to soft land the components back to Earth. So can anyone give ball park figures for X and Y that would make sense in the context of delivering people to the ISS? It seems to me that scaling up X to include Y in the payload is a losing game.

    • by Talderas (1212466)

      As long as the extra cost from the extra fuel needed plus the cost of the fuel for soft landing the rocket is less than the cost of building a new rocket it's a winning game.

    • by trout007 (975317)

      Good question. I don't have an answer but here is something to consider.

      On the way up you have to fight air resistance for quite a while.On the way down it works for you. On the way up you aim the pointy end into the wind and on the way down you point the long side into the wind. Then you only need enough fuel to go from terminal velocity to stop.

    • It's not just the fuel you need to soft land, but all of the other added components (heat shield, landing legs, incremental fuel tank size) to make up a "recovery system" that you need to consider. The fuel is the cheapest part of the formula. Against that incremental recovery system cost you have the savings of recovering the expensive parts of the rocket such as the engines. Since fuel tanks are relatively cheap compared to engines, on a per kg basis, it's worth spending a bit more on larger tanks to g

    • Barring aerodynamic effects, it takes as much effort to lift a mass to orbit as to lower it from orbit. (You can consider a launch/landing as a special orbit that intersects the planet's surface.) However, there are certain things to take note of:
      • Booster rockets are almost never empty when they are jettisoned. They will all have extra fuel on board. (You want to make sure the boosters run at least the minimum length of time it takes to get the rocket up.)
      • Boosters will already have small ullage or kick
      • Hey Slashdot! What happened to my bullets? You indented the list, but the bullets are missing.
    • by wvmarle (1070040)

      No matter what, getting stuff up there is expensive. So I'm surprised they want to bring fuel for a rocket-assisted soft landing, as that's a lot of extra weight to carry, and it directly decreases the payload (and in effect pushes up the cost per kg of payload).

      Personally I'd rather go for a shuttle-type rocket plane that can glide back to earth. Or, that failing, parachutes. Of course recovery is harder as you can't guide them so well but it's surely cheaper than a soft landing using rockets when you hav

    • by khallow (566160)

      So can anyone give ball park figures for X and Y that would make sense in the context of delivering people to the ISS?

      As I recall, putting stuff into LEO (but perhaps a bit lower than the ISS) was around $30 per kg for kerosene/LOX and $100 per kg for liquid hydrogen and LOX. The rest of the cost is other stuff like the launch vehicle, ground staff, etc.

  • No, I am truly in awe of this idea, if they pull off even a third of it they will roflstomp the national programs. As someone else commented, the music was an interesting choice, it really confers they are high confident of their design and eventuality of success. Frankly, stuff like this is what it will take to inspire the next generation about space because it is so fantastic looking.

    • by bondsbw (888959)

      if they pull off even a third of it they will roflstomp the national programs

      Not so sure that getting a third of the way into space will do anything to those national programs.

    • by Sperbels (1008585)
      Don't be silly. NASA could build this. There are no revolutionary concepts here, they go back to a time before we even launched a single rocket into space. But the question is, is it safe and practical? Frankly, I don't see how it could be. High performance rocket engines are not inherently reusable things. And the more fuel you leave on the rocket for controlled re-entry and a powered landing, means a lot less cargo you can take into orbit. SpaceX is wasting their time pursuing this.
      • by 0123456 (636235)

        Don't be silly. NASA could build this.

        Given how many development programs they've cancelled since the shuttle, that's debatable.

        High performance rocket engines are not inherently reusable things.

        That's why reliability is more important than performance if you want a reusable engine.

        And the more fuel you leave on the rocket for controlled re-entry and a powered landing, means a lot less cargo you can take into orbit. SpaceX is wasting their time pursuing this.

        If halving the payload means you can reuse the stages ten times, then you can launch up to five times as much for the same amount of money. You seem to have fallen into the 'efficiency is everything' mindset which plagued NASA when designing the shuttle and is why it ended up costing so much.

  • by JoshuaZ (1134087) on Friday September 30, 2011 @08:07AM (#37565894) Homepage

    This requires separate landing systems for each stage of the rocket. This is a lot more added mass. And the worst thing to add to a rocket is more mass. Simple reusable systems like parachutes (as were used by the shuttle's solid rocket boosters) are one thing, but full-out rocket powered landing will weigh a lot more, will require a lot of additional fuel, and will add all sorts of technical requirements.

    At this point, it doesn't seem that chemical rockets will become that more efficient barring major breakthroughs, like much lighter alloys, or totally new chemical reactions for the fuel. Neither of these seem very likely right now, and the second seems to be much less likely. The first also won't do that much. At this point, I have to be wondering if we should be spending a lot more resources on researching non-rocket methods of going to space. It seems like we may have a bad example of technological lockin since we've put so much work into chemical rockets.

    But there are a lot of other methods out there and we should be looking at them. Nuclear rockets are an obvious example, and they can be built without having any serious radioactivity (you use a conventional fission reactor to heat steam). The basic reactor can be suprisingly light- in the 1950s the US and the USSR both experimented with nuclear powered aircraft http://en.wikipedia.org/wiki/Nuclear_aircraft [wikipedia.org] and reactor technology has improved a lot since then. Another possibility is a space gun. http://en.wikipedia.org/wiki/Space_gun [wikipedia.org]. They have been successfully used to do suborbital lobs. They are completely reusable. And since they don't require sending most of their own fuel into space they avoid the common problem of needing more fuel to lift fuel (which is why rockets get bigger fast compared to the size of payload). There are more exotic ideas also like launch loops, space elevators, and space fountains but they seem to be much further from practicality at this point. In the case of space elevators, the main technical problem is making enough high quality nanotubes in a supporting resin, and research into that is ongoing because high quality carbon nanotubes will be useful a large number of different much more mundane technologies.

    • by EdZ (755139)
      Forget nuclear aircraft, the [url=http://en.wikipedia.org/wiki/NERVA?useskin=monobook]NERVA[/url] engine was pretty well tested (at least one destructive test too).
      • Forget nuclear aircraft, the [url=http://en.wikipedia.org/wiki/NERVA?useskin=monobook]NERVA[/url] engine was pretty well tested (at least one destructive test too).

        Forget nuclear aircraft, the NERVA [wikipedia.org] engine was pretty well tested (at least one destructive test too).

        FTFY

    • by bondsbw (888959)

      Space guns are impractical for launching humans to full orbital velocity due to high G-forces and atmospheric drag. However, combined with rockets, a hybrid system could do the trick and reduce onboard fuel. That is essentially the launch system used in aircraft carriers, but on a massive scale.

      And I like the idea from the AC, although you still have the fundamental problem of high atmospheric drag at low altitudes. Perhaps we should add a ramp built a few miles upward... :)

    • by tgd (2822)

      If you can cut your payload in half, and in return cut your costs to launch that payload in half, you break even on your launches.

      If you cut your payload in half to have recoverable rockets, but you cut the cost of the launch by 90%, you can launch five times as much to orbit for the same price.

    • Take a look at the big island of Hawaii. On the west side you have a nearly constant slope formed by lava flows. You can build a "space gun" there with a barrel d = 20 km long. Assume you want to limit it to a = 3 g's (30 m/s^2) so humans can ride. The muzzle velocity is then sqrt ( 2 * a * d ) = 1100 m/s (Mach 3.6). This is in the range of what rocket first stage boosters do. The rest of the trip uses normal rocket stages.

      Now assume what you are launching masses 100 tons (100,000 kg) and has a diamet

      • by andycal (127447)
        Rail gun instead of cannon
        Start way out at sea
        • by Gravatron (716477)
          i'm having final fantasy VIII flashbacks now. the Ragnarok launched via an electric driven rail and a ginormous ramp prior to it's rockets igniting. Normal spacecraft launched via a giant canon.
    • by FleaPlus (6935)

      This requires separate landing systems for each stage of the rocket. This is a lot more added mass. And the worst thing to add to a rocket is more mass. ... At this point, it doesn't seem that chemical rockets will become that more efficient barring major breakthroughs, like much lighter alloys, or totally new chemical reactions for the fuel. Neither of these seem very likely right now, and the second seems to be much less likely.

      Actually, the Merlin engines SpaceX has been using have been getting more effi

    • by david.given (6740)

      This requires separate landing systems for each stage of the rocket. This is a lot more added mass. And the worst thing to add to a rocket is more mass. Simple reusable systems like parachutes (as were used by the shuttle's solid rocket boosters) are one thing, but full-out rocket powered landing will weigh a lot more, will require a lot of additional fuel, and will add all sorts of technical requirements.

      Does it?

      Don't forget, those Merlin engines are restartable (something NASA never went in for much). So the first two stages land on the engines they took off with. And now they're empty, so they're very light. The second stage needs an heat shield, but other than that the only extra mass you need are the landing gear, avionics and attitude control, and the fuel. And even some of the fuel comes for free too, as there's a hefty safety margin in both stages, which you can eat into when landing.

      So yeah, you

    • Fuel is ~$200,000 per launch, the rocket is ~$51,000,000. Even if they failed to recover the launcher 50% of the time... Even if they had to launch twice for every non-recoverable launcher they're still outclassing the non-reusable launcher on cost by two orders of magnitude. SpaceX would be brain dead to not try.
  • Slightly worrying (Score:2, Insightful)

    by EdZ (755139)
    Something else tucked away in there:

    Musk also confirmed that the currently scheduled November or December flight of SpaceX’s Dragon capsule to the space station will likely be delayed due to the failure of a Soyuz rocket carrying a Progress re-supply ship to the ISS on August 24, 2011.
    “It actually will likely result in a delay to our launch to the ISS,” Musk said, “and NASA rightly wants to have the appropriate level of astronauts with the right training when we arrive, so it looks like January for the launch to space station, and that is contingent upon the Russians meeting the schedule they’ve currently stating."

    It sounds reasonable, but it also sounds like someone doesn't want SpaceX to have the enormous PR gain of launching a mission to the ISS when everyone else's pants are down.

    • It sounds reasonable, but it also sounds like someone doesn't want SpaceX to have the enormous PR gain of launching a mission to the ISS when everyone else's pants are down.

      For the tests, SpaceX needs two astronauts onboard the ISS who are qualified to operate the DEXTRE/Canadarm2 robotic arm. One is on board, and the other was set to launch on a Soyuz around this time. However, the accident has shifted the launch schedules, so the second astronaut won't make it up in time for SpaceX to make their qualification flight this year.

      But maybe you're right. Maybe they blew up a Progress re-supply ship and endangered the lives of not only the ISS crew, but all the ground crew at

      • by EdZ (755139)

        But maybe you're right. Maybe they blew up a Progress re-supply ship and endangered the lives of not only the ISS crew, but all the ground crew at the launch site (not to mention the millions of dollars that a supply schedule slip brings about), just to make SpaceX look bad.

        I'm not sure how you possibly got that idea from my post.
        My point was that at the scheduled launch time for COTS2, with Progress being unavailable, SpaceX would have the only resupply vehicle available (the next ESA ATV isn't scheduled for another 6 months). Like with the 'wheel of cheese' on COTS1, I wouldn't have put it past SpaceX to add a large quantity of unofficial resupply material as 'test mass'.

  • by tekrat (242117) on Friday September 30, 2011 @08:26AM (#37566112) Homepage Journal

    I peripherally worked on the DC-X program which was a single stage to orbit concept vehicle that would have eventually lead to a larger rocket that was considered as a shuttle replacement.

    The problem with the DCX was that it had to reserve fuel for the landing. The whole idea was to take off from something no bigger than a heli-pad (no gantry, and just a few people manning launch control) fly, and land back on the heli-pad.

    Worked great until you got to the landing part: Two big issues were during landing, thrust would bounce off the tarmac, and end up setting the rocket on fire, the other problem was the landing gear. On one test flight, one leg failed to deploy, the rocket landed, then tipped over and exploded... which essentially killed the project.

    The DCX was conceived during Reagen's "Star Wars" project, and built and flown during the Clinton era.

    Unless there's been some breakthrough for the Falcon, I believe Musk is going to run into exactly the same issues.

    Personally, I believe Rutan is on a better track, following the X-15 and scaling up. That's the only method for full re-useability.

    • by Arlet (29997)

      Unless there's been some breakthrough for the Falcon, I believe Musk is going to run into exactly the same issues.

      You mean that on one test flight, one leg will fail to deploy, the rocket will land, tip over and explode, and Musk will cancel the project ?

    • by joh (27088)

      The DC-X failure happened because they were on a shoestring budget, couldn't afford neither redundancy in the pneumatic lines for leg deployment nor someone checking twice (someone forgot to connect a line before launch)...

      What do you think would have happened to the Space Shuttle if they had treated the hardware the same way? *Everything* operated like DC-X would fail. There is no room for amateurs in spaceflight, period.

      • by 0123456 (636235)

        What do you think would have happened to the Space Shuttle if they had treated the hardware the same way?

        It would have exploded and killed the crew one flight in sixty?

    • Don't forget DCX was also trying out composite fuel tanks, aerospike engines and new body lift profile and I'm sure lots of other things that I can't remember off the top of my head.
      I get the impression it was typical modern NASA, everyone put their latest pet project/ "cool idea" onto the one thing that has funding and then it doesn't work because it's too many new things at once. The whole thing goes up in flames and we're left with the shuttle.
      If they just did normal engineering and what they used to do

      • by tekrat (242117)

        No, you're thinking of the X-33 VentureStar.

        The project I'm talking about was the DC-X Delta Clipper. It looked like a flying salt shaker, took off and landed vertically (i.e. on its tail).

        The engines were not aerospike, but gimbaled like the shuttle engines, so they could individually pivot to maintain balance as well as provide a form of thrust vectoring (the vehicle could hover for example, and then slide sideways to a different landing area, while maintaining an upright flight profile).

      • No, you're mixing up the DC/X with the X33.

        The DC/X was an inexpensive test vehicle, using off-the-shelf technology. The X33 was a hugely expensive boondoggle that perfectly demonstrates what's wrong with NASA.

  • /-- So if could reuse it would lead to 100 times reduction in cost.

    If they can (launch + re-assemble + launch) * 100 at no additional cost for repairs they need to let the engineers of the world know wtf they are making this rocket out of. I don't know of any substance or design that allows for that much use. These guys probably have private shark tanks with full laser gear so I'm not going to completely discount them. Regardless, the numbers sound way fishy.

    • by pavon (30274)

      Yeah, even ignoring wear on the rocket, these number would mean that their integration, test, fuel, launch ops and profit only account for less than 1% of the cost of a current launch. There is no way that is correct. Either someone took that number out of context or they are on crack (I'm guessing the former).

    • by Thagg (9904)

      I was with Musk right up until he said 100x cheaper.

      If he had said 2x cheaper, that would have been a revolution, 10x cheaper is substantially beyond believability, but 100x cheaper just means that he's lying, and doesn't care that you know it.

      Landing the first stage makes some sense -- it's the biggest part, and it's not going all that fast at burnout, and it's not all that far from the launch pad at that point, either. It's light and has a lot of drag, and should slow down quickly.

      The second stage though

    • by x6060 (672364)
      Um, I think they are saying that rocket fuel is cheap (which it is), but the rockets themselves are not.
      • by sgt scrub (869860)

        The sentence I quoted is saying they do not have the expense of replacing, repairing, or maintaining the rockets in 100 launches.

    • As I understood the speech - at this point he took off onto what was achievable in the far future.
      It's reasonable to assume that with a mature technology - you can get an order of magnitude or two on launch cycles, with a similar mass fraction.
      Can the current hardware do 100 launches - even with service - vanishingly unlikely.

  • by magamiako1 (1026318) on Friday September 30, 2011 @09:23AM (#37566804)
    SpaceX has yet to put a person into space, let alone to the ISS, let alone returning safely, let alone a person on the moon.

    All of this talk about how "SUPER CHEAP AND AWESOME IT CAN BE WHILE BEING PRIVATIZED" means NOTHING until they show that they can do it safely and repeatedly with a human being.
    • by joh (27088)

      It already IS "super cheap and awesome", really. SpaceX is the first private company to have flown a craft to orbit and return it again. And after Russia, the US and China as nations/states the fourth at all. OK, fifth if you count the subscale demonstrator ESA flew decades ago. And all of this on a budget that wouldn't be enough for NASA or ESA to even build a launchpad, not to speak of a launcher and a capsule (and two launchpads as SpaceX built).

      I'm not saying that SpaceX is able to do miracles, but it a

      • Putting a satellite into space is cheaper than putting a human into space. I mean, if you want to go there, nearly anyone could throw a "capsule" up into orbit provided they have enough money--but is that capsule capable of supporting a human being?

        And you can't even compare a capsule to the shuttle--a freaking giant flying space-bound airplane that lets you *land it* and return safely.
        • by jnaujok (804613)
          The Dragon capsule they sent up and recovered is built man-rated. Had you been in the capsule they launched (and had they turned on an oxygen supply) you would have had, in the words of Elon Musk, "a really sweet ride."
  • I don't know about you, but I live fairly near the cape- and the last thing I want is half a rocket returning to Florida with... well, anything... not working.

    It's rather easy to miss your mark when re-entering. It's even easier to miss your mark when you can't maneuver freely after heating. Things get worse yet still if the booster has a guidance failure or gimpy motor.

    Don't get me wrong, I like the idea of a reusable rocket and I'm excited they are willing to try something so very, very ambitious. But I a

  • Reusable Falcons (Score:5, Interesting)

    by mbone (558574) on Friday September 30, 2011 @10:50AM (#37567962)

    I was there for the talk, and had a little chat with Mr. Musk beforehand. The first thing to note is that he said that the video (which should go on their web page soon) is incomplete and may be vague about certain things, for proprietary reasons. What follows is my reverse engineering.

    This is what the Grasshopper [slashdot.org] described previously in Slashdot is all about. Mr. Musk didn't use the word Grasshopper at all, so it must have been some sort of code word, but the tests in Texas will clearly be for Falcon reuse engineering.

    Now, it makes no sense to return the first stage to the landing pad (as he said). The first stage is on a ballistic trajectory which (for a launch from Cape Canaveral) would have it impact somewhere far out at sea. It makes no sense at all to have the first stage reverse course and fly back to the Cape, as that would take as much delta-V as the original launch. It would make a lot more sense to land that stage in Ascension Island, Africa or Nova Scotia (depending on the inclination of the orbit). The first stage could then brought back by ship or plane.

    The second stage actually goes into orbit, and the plan is to deorbit it one rev later. The trouble with that is the Earth rotates and the Earth will have rotated by ~ 20 degrees of longitude. That (again for a launch from the Cape) puts it over Texas, and it could conveniently land at McGregor, Texas, where SpaceX is doing their Grasshopper tests. So, although they haven't said so, I bet that McGregor will be the second stage landing area, and probably the Dragon landing area as well.

  • by wisebabo (638845) on Friday September 30, 2011 @10:57AM (#37568098) Journal

    Look, the first stage doesn't just go up, it goes (presumably) eastwards to take advantage of the earth's rotation. So, if they launch from Florida the nearest land is, Africa. That means a foreign country and transport back by sea, not good for cost savings. If they launch from say California then you have all the hazards of a launch over land (isn't Vandenberg used primarily for westward ICBM testing and polar launches for this reason?).

    Also, the second stage, even though it looks like it might go all the way to orbit doesn't appear to have much cross-range capability (no aerodynamic surfaces). So its choice of landing sites might be severely restricted. Finally, just to nitpick, the system isn't "completely" reusable, the service module looks like it is abandoned in orbit.

    By the way, I think Elon Musk should henceforth be given the mantle of "Rocketman"! NOTHING (other than the heat shields) is used to slow down the stages AND CAPSULE other than ROCKETS; not parachutes or lifting bodies or airbags! He's got a LOT of faith that they will function in absolutely split second critical situations. WOW.

    Still I say, go for it! If he can make the rockets work, maybe they can launch from that spaceport in New Mexico. (Maybe he'll have to give the FAA a destruct switch on a MANNED spacecraft in order to launch over populated areas). Has engineering gone so far as to really make these things that reliable?

In the sciences, we are now uniquely priviledged to sit side by side with the giants on whose shoulders we stand. -- Gerald Holton

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