Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
NASA Space Science

More New Details on NASA's CEV Launcher Studies 361

Posted by timothy from the space-bureaucrats-will-find-a-way dept.
TheEqualizer writes "Continuing on the NYT story on NASA's current CEV launcher plans, spaceref has an even more extensive look with detailed assessments of the available options. By all accounts, it looks like NASA is picking up where it left off with Apollo but also combining it with established Shuttle technology -- the capsule concept of the 1960s atop the shuttle boosters of the 1970s being the winning combination under the current budgetary limitations. However, is this coupling of old technology and designs really the best we can do?"
This discussion has been archived. No new comments can be posted.

More New Details on NASA's CEV Launcher Studies More

More New Details on NASA's CEV Launcher Studies

Comments Filter:
  • So what if it's old tech?

    It works.
    It stays within budget.

    What's the problem?

    Cooper
    --
    I don't need a pass to pass this pass!
    - Groo The Wanderer -

    • Just like we have replaced 4 wheel cars with 5 wheel ones. You know, 4 wheels is so old so its gotta be bad, right?

      The evidence seems to be pointing strongly in the direction that a traditional multi-stage rocket is the cheapest and safest way to space with current technology. At some point in the future when we have better materials and much better propulsion some kind of single stage spaceplane might make sense.

      • Re:If it ain't broke... (Score:4, Insightful)

        by gunnk ( 463227 ) <gunnk@mail . f p g . u n c . edu> on Wednesday August 03, 2005 @08:29AM (#13229893) Homepage
        To me, that's the problem.

        The shuttle should have been a step towards true spaceplanes. It wasn't efficient, but it explored our prospects for fully reusable launch vehicles.

        The next step was to be real spaceplanes. After that we could begin talking about things like commercial spaceliners, orbiting manufacturing facilities and all the other sci-fi dreams of my childhood.

        Instead, we're finding that we can't (or won't: $$$) build on what we learned with the shuttle to create spaceplanes, so we're going back to rockets.

        We went from sails to steam-driven paddleboats (which worked poorly) to propeller-driven steamships (which worked really well). The shuttle program is equivalent to saying "These paddleboats just have no future. Let's go back to sails."

        • Re:If it ain't broke... (Score:3, Informative)

          by joib ( 70841 )

          The shuttle program is equivalent to saying "These paddleboats just have no future. Let's go back to sails."

          I'd rather say that the space shuttle is like a paddleboat before the steam engine was invented. Perhaps it's a good idea, perhaps not, but without a steam engine to turn those paddles there's not much point in it. Sailing usually beats muscle power (rowing or turning the paddles by hand).

          The hard things in space flight at our current technology level is getting to orbit and reentry. Putting wings on
          • Looking back over the past 30 years, you can make the case that the single largest problem in the STS program, was building it in a side-mount configuration. There were a whole slew of things done that, in hindsight, were stupid, delta planform vs. lifting body, etc. The shuttle design was predicated on the assumption that it was going to become a 100% reusable system once launches were underway, and they could stop throwing away the ET.

            But it taught us a whole lot about how *NOT* to build a reusable spa
            • I remember in high school a younger neighbor of mine got a GI Joe space shuttle. It was a lifting body with a rocket powered and MANNED booster stage. It was not a jet, but it was a liquid fueled space craft on it's own (well, it looked like it was). Anyway, I always thought why did they not build something like that instead of the current design? Anyway, I think the plane format has merit as soon as we figure out how to make more compact and efficient rocket engines. Launching a current Shuttle from t

              • Re:If it ain't broke... (Score:3, Informative)

                by joib ( 70841 )

                I remember in high school a younger neighbor of mine got a GI Joe space shuttle. It was a lifting body with a rocket powered and MANNED booster stage. It was not a jet, but it was a liquid fueled space craft on it's own (well, it looked like it was). Anyway, I always thought why did they not build something like that instead of the current design?

                I think I have seen some drawings of some booster stage with flyback capability. With todays electronics, there's no need to have it manned though. But anyway, the

        • Re:If it ain't broke... (Score:4, Insightful)

          by mwood ( 25379 ) on Wednesday August 03, 2005 @09:04AM (#13230129)
          I think here we're seeing the tension between development and production.

          The shuttle has been a decent way to learn about the problems faced by reusable vehicles of a particular type. I'm glad that we did it, and that we have it. Yes, the next step, from a development standpoint, is to take what we learned and figure out how to do it more and better.

          But meanwhile we have actual business in space and we need a way to get there and back again. We don't need it twenty years from now; we need it today. What we have today is (a) shuttles with a number of known problems (see above), and (b) big honkin' rockets with three decades of experience in interplanetary travel. Which can we have ready to go by next month? A design that's just been grounded again after two years of fixing, or a design that Just Works? Remember that it's for today, not next decade; we have plenty of time to work up something better for the twenty-teens and beyond.

          We need *both* programs to keep the pipeline full today *and* tomorrow. Declaring a single winner sacrifices either today or tomorrow. I'm greedy: I want both.

        • Space.... planes? (Score:3, Insightful)

          by DragonHawk ( 21256 )
          "The shuttle should have been a step towards true spaceplanes."

          Why?

          What's the big deal about spaceplanes, anyway? Why are we so in love with them? Is it just because the idea of a VTOL rocket seems dated, like some bad 1950s sci-fi flick?

          An airplane is practical because as long as you're moving forward (going someplace) anyway, you might as well generate lift with all that air you're flying through. It's the simplest, easiest, cheapest way to the solve the problem.

          On the STS, I believe the wings don't do
    • People will be bitching they are still using wheels on the shuttle, and fire for the thrust...

      These ancient technologies are outdated, and should be replaced as soon as possible with something else.

      To confirm you're not a script,
      please type the word in this image: construe
    • It is broke.

      The manned portion consists of an SRB. You know, the big candle thing that keeps blowing up either in-air or on the ground? And now that it goes higher I'm not sure they plan on gettng them back.

      The unmanned portion consists of two SRB's (ditto x 2) along with the ET, which was designed for off-axis thrust. In fact it is the off-axis thrust that doomed the wire-round SRB the Air Force worked on, because it was too stiff and couldn't flex enough when the SME's lit up. Now to this we put 100 tonne
  • Hopefully, the fact that we just discovered an ice lake in Mars [esa.int] should provide NASA its much needed funding. On a slightly different note, why can't NASA work with private contractors to outsource their delivery vehicle research? I can understand their concerns of technology getting leaked, but don't the defense departments do it all the time? This can only benefit space research, right?
    • why can't NASA work with private contractors to outsource their delivery vehicle research?

      According to an MSNBC article [msn.com], the Japan Aerospace Exploration Agency (JAXA) is now exploring the possibility of developing a manned spacecraft. The article has an artist's rendering. The picture is slick and looks like something out of "Star Trek: Enterprise".

      NASA should open up the competitive bidding process to Japanese companies. If American companies cannot design a safe reusable spacecraft, then perhap

  • Budget (Score:2)

    by Ripp ( 17047 )
    Unfortunately, it probably is the best they can feasably come up with given the budget pinch they're under. There is already a huge infrastructure in place for testing and launch of L/SRB vehicles. To totally re-design everything from scratch would cost just way too much. Unfortunately.

    On top of that if we are planning on re-visiting the moon before the Chinese get there, and going to Mars, then continuing the rocket program seems logical.

    Let the privateers handle the space freight trucking industry IMO.
    • And don't forget the number of employees currently producing shuttle parts. That the new approach keeps everyone in their current jobs makes a number of politicians very happy.

      I agree that redesigning everything from scratch is painful and expensive. I also suspect that the decision wasn't completely technical.
    • >> ...continuing the rocket program seems logical.

      What other program did you have in mind?
      • I was thinking of the re-usable launch vehicle concept they'd been toying around with, along with stuff like what Rutan (sp?) has been doing... As opposed to the standard 'controlled explosion' they're doing now :)
        • The reusable vehicle concept they've been "toying" with is the Shuttle. You may have noticed it has issues. The only advantage of reuse is cost savings. Shuttle has demonstrated that those cost savings are not there. As for Rutan, his techniques, edpecially his reentry technique, only work for a vehicle coming back at the very slow speed of 3000 mph. It won't work from orbit. (His Spaceship One is incapable of reaching orbit, but, if it had, it would have burned to a cinder on reentry.) If Rutan sends a v
          • The only reason the current shuttle isn't cost-efficient is because it was built too big [wikipedia.org]. When NASA was having trouble gaining support for a shuttle program, they asked the Air Force to move all their launch payloads to the new shuttle (ending the need for single-use rockets for such loads). The Air Force agreed, but only if the payload were doubled, and the shuttle were given more atmospheric maneuvering capabilities for more landing options. Both of which vastly increased the bulk of the shuttle and cause
    • My stance is complete overhauls are often worth it. I'm not sure that a shuttle should fly again. There are cheaper and safer ways to get people in space and back.

      Now I'm no expert on physics, or space stuff in general, but I'd like to think I have a good dose of common sense, so I'd like some serious replies. Given that we have a space station, why don't we have a reusable launch vehicle designed to bring up just people (with as much life support as possible). Aside from that, no payload. Th
  • We (meaning the US government/Russia/ESA), still want to use humans in LEO, and we want to keep the ISS in operation for the foreseeable future. The Space Shuttle has been a reasonably effective way to do that, but has shown it's age and the limitations of the "reusable space plane" approach. If it costs the same or more money to launch the Shuttle than it does to send "traditional" rockets into LEO, why not use traditional rockets instead?

    Not only that, but this plan seems to recycle the best parts of th
  • The solid rocket boosters used for the shuttle today is reliable, reasonable safe (as safe as anything can be in space I guess) and not at least very cheap for the power they deliver. A capsule, in the mould of Apollo or Soyuz, is cheap(ish), can be made reusable (I would assume - allthought it might be cheaper to make them recyclable) and has a proven track record. A rescue rocket mounted on top of a capsule is simple and has a proven trackrecord (IFAIK, one russian capsule was saved by it). I think it'
    • ""

      Where the heck do you get that from? EVERY shuttle accident was caused by a problem from those boosters. From 'O' Rings to insulation. They were not shuttle poblems, but booster problems.

      "Take the best we got today and make it better, as opposed to inventing the Wheel Mk. II."

      When you start with crap, we should build on it because it's the best we have? We should through the whole program out the window and stop blowing billions per launch 9well 1 billion per launch anyways) on a piece of cra
      • "Where the heck do you get that from? EVERY shuttle accident was caused by a problem from those boosters. From 'O' Rings to insulation. They were not shuttle poblems, but booster problems."

        No it wasn't. The foam came off the tank, not the SRB.

        Equally, had the astronauts been in a capsule on top of the SRB when Challenger's SRB started to leak, they'd have hit the 'Abort' button and come floating down by parachute. The only reasons Challenger was destroyed were because the SRBs were on the _side_ of the fuel

      • Where the heck do you get that from? EVERY shuttle accident was caused by a problem from those boosters. From 'O' Rings to insulation. They were not shuttle poblems, but booster problems.

        Challenger [wikipedia.org] blew up because someone at NASA decided to ignore the fact that the guys who had designed the solid fuel boosters told them not to launch in the cold weather - and the boosters was redesigned afterwards to allow for even better margins. Operating any sort of equipment outside the design envelope is asking fo

      • I know the other two people who replied to your entry have said pretty much what I wanted to say, but I'll add this one bit: the SRB's have been redesigned (thanks in part to the recommendations of one Dr. Richard Feynman) and they do have a solid track record (nearly 100 launches with no glitches).
  • ... space planes? Take off and land just like an airplane. Whatever happened to that idea?
    • You have a real problem about how to get it up to the speed required for orbit and then back down to a speed which can land. Planes deal with a significantly reduced set of velocities and acceleration and deceleration requirements.
      • I agree that a space plane faces a problem of operating in two very different environments, but there are ways...

        A two-part launch system is a good candidate for a practical, reusable "space plane" system. Scaled Composites' White Knight/SpaceShip One concept is a good example of this; use a plane for the first 30,000 feet and 300 MPH, and a rocket for the out-of-atmosphere leg, leaving the plane in the air where it belongs.

        (Recall that the Shuttle uses most of its fuel load, representing a significant frac
        • Rutan and friends have set up a new company called t/space that's working on a spaceship that would be capable of reaching LEO. It basically looks like a traditional cylindrical rocket with a capsule for 4 guys that is launched from an aircraft. See here [transformspace.com].

          One neat thing is that they are using a small parachute to turn the rocket vertical after the plane drops it and just before the rocket engine fires. That way they can get rid of wings, saving weight.
    • ... And whatever happened to air-breathing rockets [wikipedia.org]?

      Although what NASA needs now is some tried-and-tested, reliable and simple launcher rather than some extremely difficult blue-sky research, of course.

    • Re:What about... (Score:5, Insightful)

      by XNormal ( 8617 ) on Wednesday August 03, 2005 @09:24AM (#13230263) Homepage
      .. space planes? Take off and land just like an airplane. Whatever happened to that idea?

      The unforgiving results of the rocket equation [wikipedia.org] when applied to the orbital velocity (as determined by the Earth's mass and radius) and the chemical energy available per lb of propellant. They all combine to make the task just barely possible. You get the impression that that some god wanted us to be able to get to space - but that it should be a serious challenge.

      When your spacecraft must be made almost entirely of propellant it wants to be as close as possible to a sphere: lots of internal volume for propellant, minimum weight of the enclosing envelope. Airplanes really don't want to be anything like a sphere. They like un-spherelike protrusions known as wings. These weigh a lot, especially when you need to cover that much surface area with a heavy thermal protection system.

      Landing with wings or lifting bodies can make sense in some circumstances but taking off with wings is ridiculous. The weight of the spacecraft at launch is much higher. If you size your wings for take-off weight you will pay the penalty of those big wings all the way to orbit and back (if it can even make it to orbit).

      Just because the idea is intuitively appealing doesn't mean that it makes sense from an engineering point of view.

      Weight happens.
  • To do that, we need to go nuclear [nuclearspace.com]. No, not Orion - there are several designs that don't vent radioactive exhaust and you can even use them to get rid of nuclear waste.
  • The story demonstrates a lot of ignorance about technology. By looking at a few images, the writer leaps to the bogus conclusion that NASA is planning a remix of 1960's and 1970's engineering. All this only because the CEV will have a conical shape and sit at the top of the launch vehicle.

    This is more than a bit like criticizing F-117 Stealth aircraft as a mix of 1920's and 1940's tech: Look at any picture of planes in the '20's and you'll see wings and the jet engine was flying in the '40's. So, since
    • They ARE looking at upgrading the design for the J2S engines from the Saturn 4/5 in one of the designs, so I would say it IS a remix of technology from the past.

      They did'nt say if they would strip a J2 engine from somewhere or completely re-create it. I'd imagine they would take one from an existing Saturn V since re-tooling to create a J2 engine would probably be expensive.
      • No, they are going to go back to the schematics and make some changes and re-tool it. The certification scheme wouldn't allow for just taking a J2 off the shelf. And there aren't enough just lying around anyways to support the space program.

        -everphilski-
        • Makes sense....although currently Rocketdyne (now owned by Pratt/Whitney I think) does'nt currently make the J2 (has'nt for 30 years) so I'd imagine it's no small order to modifiy and re-tool for it.
  • Notice that the story is about a guy with a partisan interest in the outcome- he's a Thiokol engineer and they make the solid-fuel boosters for the current shuttle. These boosters are the heart of the proposal, and my only question is, do we want solid fuel rockets as the primary lifter for human crews? Don't they present special challenges and risks because they can't be shut down in case of problems? Just asking, IANA astronautical engineer.

    Apart from that, this seems like a good blending of proven tech f
    • These boosters are the heart of the proposal, and my only question is, do we want solid fuel rockets as the primary lifter for human crews? Don't they present special challenges and risks because they can't be shut down in case of problems?

      Yeah but strapped to the sides of the stack, they can just be jettisoned if they start to misbehave. It's not like the crew & payload would survive a major liquid-fueled engine malfunction on launch anyway.

      So just lose them and abort. Your ensuing news photo looks l

  • Old and New Tech is the BEST Idea (Score:3, Insightful)

    by ausoleil ( 322752 ) on Wednesday August 03, 2005 @07:57AM (#13229707) Homepage
    The original poster posits: "However, is this coupling of old technology and designs really the best we can do?"

    Apparently, s/he misunderstands how aerospace technology works: you stay with things that work and improve upon those things that have been problems in the past.

    For example: When Wehrner Von Braun and his team set out to design the Saturn V, Boeig was tasked with building the most difficult part, the first stage, or S1-C.

    Did they use new technology? In some cases, yes. For the rocket engines, no. The F-1 engines were actually initially designed by the Air Force in the mid 1950's. Boeing instead took the basic design of the F-1, improved it with better construction techniques, better materials and of course, new tubo-pumps, but nonetheless, the basic design of the F-1 stayed what it was.

    Later, the S1-C flew flawlessly on every launch but one: on Apollo 6, there was a problem with "pogo-ing," which is a severe reverberation along the axis of the rocket. At that point, they re-studied the issue and re-engineered the ignitors of the engines, and the S1-C was the most impressive weight-lifter in human history from there on.

    That's a for example. In the Shuttle design, there is a lot of work on rocket design and implementation that would be crazy to throw away, not to mention extremely expensive to engineer. These are man-rated vehicles, and there, NASA is exceptionally conservative -- they will stay with they know works and create replacements for that they know does not.

    This in not building a new computer CPU, or engineering a new product that a failure is tolerable. I would be very surprised and actually disappointed in NASA and their contractors if they were to toss out the baby with the bathwater, and am personally relieved that they are not.

  • "However, is this coupling of old technology and designs really the best we can do?"

    I don't know if it's the best we can do, but there is something to be said for using older technology that works well and then adding new technology to it. I have had some good success using this weird operating system built on very old Unix technology and coupled with the newest version of Firefox and KDE.

    Sometimes old things work very well and it pays to go back to them. As an example, back in the eighties stereo manufactu
  • There's an awful lot of 'old tech' out there. And it runs great. Or at least well enough. Think of all the copper running phone lines right now. Sure, it's been married to new technology like fiber optics and VoIP, but you can just as easily plug in an old rotary phone and start clicking away.

    Puting the vehicle on top of the launch stack makes a great deal of sense. As does carrying the vehicle aboard a parent ship and then launching (SpaceShipOne, the X-15, etc).

  • But it may be the best we SHOULD do under the circumstances. Sounds like a good idea to me to recombine known quantities, rather than trying to reinvent the wheel. Revolutions are good, when they work, but a gradual evolutionary path generally ensures that you have something working all the time. Small changes to an existing design are MUCH easier to test.

  • The best we can do (Score:3, Interesting)

    by jmichaelg ( 148257 ) on Wednesday August 03, 2005 @08:23AM (#13229865) Journal
    The best we can do, energy wise, is nuclear propulsion. Back in the late 50's, we designed a nuclear bomb propelled ship. Initial enthusiasm for using it to get off the Earth waned when Freeman Dyson realized each launch would kill 10 people. At the time, we were firing off atmospheric nuclear bombs all the time with no perceptible ill effects so Dyson's realization wasn't obvious. For some, those 10 lives were offset by the knowledge that any large scale activity kills people.

    To alleviate the problem, the Orion team proposed a hybrid solution - use Saturn-class chemical rockets to launch an Orion booster. They figured they could build an Orion-class ship that weighed around 150 tons, well within Saturn's ability to loft 400 tons.

    NASA's current proposal takes us back to being able to re-consider Orion. What killed the idea was NASA's aversion to risk. There wasn't any appetite for developing a rocket engine that could only be fully tested in space.

    The idea of using nukes for Earth launch never completed died. Ted Taylor, one of the Orion team members, figured he could design a nuclear bomb that didn't emit any radiation at all. Ironically, the neutron bomb was an outgrowth of his work.

  • I am not a rocket scientist... but I imagine that, yes, perhaps it is the best we can do.

    That is to say, given some caveats. Reading about the aborted space plane, it seems that we're having trouble developing materials that can really take the heat of re-entry. Ablating blast shields, while not re-usable, work really, *really* well.

    Furthermore, the shuttle was just too complex. The ability to make machinery that complex that performs reliably is perhaps many years ahead of us, and we're ( I think rightfull

    • Also consider the DC X ( or whatever it was called, Delta Clipper? ) which had such problems with cracks in the carbon fuel tanks and such. This stuff is *complicated*.

      That was the Lockheed X-33 Venture Star. Where they were trying to build non spherical composite fuel tanks, and couldn't get the process right.

      The DC-X was a subscale, sub orbital technical demonstration vehicle, which flew several times to show that vertical take-off vertical landing rocket powered vehicles were possible. At some point a

  • I guess I have "government waste" and big NASA dollars on the mind--When I first read the summary blurb, I thought the link said, "an even more EXPENSIVE look..."
  • The current shuttle-derived CEV/SDHLV design is the most pragmatic design possible, for now. The only way to get Shuttle retired is by throwing a bone to the contractors (USA, Lockmart and Boeing) and to NASA's workers - the choice is either use Shuttle-derived hardware or never have another "Big Aero" manned launch system. The political pressure to maintain all those jobs in Houston, KSC, Utah and southern Cali would mean a clean-sheet CEV is dead-on-arrival. The Single-Stick plus capsule is a good answer,
  • I like the idea of using an SRB-derived crew-transfer vehicle. It could sit on station almost indefinitely and be launched quickly in the event of an emergency, no need to refuel or keep large cryotanks topped up.

    While it would keep costs down, I don't think that hanging the payload or crew alongside the external fuel tank is the safest design. Keep the crew as far away from the fuel as possible. Also, an error with the crew recovery rocket attached to the capsule could send them into the fireball, which i

  • We need to follow NASA's own description of it... return to flight, and develop an aircraft hybrid to lift things up to the top of the atmosphere, then boost into space from there.

    With good old fashioned flight, there is a hell of a lot less stress on components, and the option to fly back home is a lot less dangerous. The flying option also means we get away from the world of one-use rocket components, and into the far safer world of aviation.

    We need to dump the solid rocket booster strap-on. It's expen

  • One question I have always had...I recall a NASA study which stated that the External Tank could be boosted to orbit rather than burnt on re-entry (I know, it didn't always burn). The point was that for no extra missions, an essentially airtight aircraft aluminum shell could have been placed into orbit with each mission - as a bonus, containing some leftover LOx and H2 for use there.

    One of the biggest problems with using the tanks once they arrived was that they were, in fact, covered with insulating foam,

  • If only (Score:3, Funny)

    by WormholeFiend ( 674934 ) on Wednesday August 03, 2005 @10:14AM (#13230628)
    they would declassify their UFO-captured technology, we could be zipping around the solar system by now for pretty cheap!

Slashdot Top Deals

Some people manage by the book, even though they don't know who wrote the book or even what book.

Close