Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
NASA Space Politics

NASA, Congress Reach Accord On Commercial Crew Program 137

MarkWhittington writes "NASA and Congress have reached a deal on how to proceed with the commercial crew program that provides government subsidies to pay for the development of private spacecraft. NASA will select two competitors from the current four — SpaceX, Boeing, Blue Origin and Sierra Nevada. A third competitor will be picked for partial funding as a fallback in case both of the main competing companies run into difficulties developing a spacecraft on time and on budget."
This discussion has been archived. No new comments can be posted.

NASA, Congress Reach Accord On Commercial Crew Program

Comments Filter:
  • Re:SpaceX (Score:5, Informative)

    by camperdave ( 969942 ) on Wednesday June 06, 2012 @01:12AM (#40229233) Journal
    From what I understand, a few demos of their launch abort systems, and they should be shiney. The crewed Dragon and the cargo Dragon are the same pressure hull, and share the same liftoff and on orbit flight characteristics. So every cargo flight will be a test flight for the crewed vehicle.
  • by Jane Q. Public ( 1010737 ) on Wednesday June 06, 2012 @01:16AM (#40229257)
    The original Orion concept -- and it get serious attention, even today -- was for an enormous, massive parabolic dome with a spacecraft on top of it. The spacecraft injects small nuclear bombs into the dome, and they explode at the focus. It's pretty much guaranteed that thing will MOVE! And yes, it is quite feasible and technically possible.

    I don't think anybody is seriously considering building one of those right now, but the name stuck, and Orion has now been known to generations as "the nuclear bomb powered spacecraft".

    Kind of a negative name to pick for your newfangled, modern, but chemical-powered machine.
  • Re:3 out of 4 (Score:4, Informative)

    by mark99 ( 459508 ) on Wednesday June 06, 2012 @03:37AM (#40229793) Journal

    What is your logic here? You think it costs signifcantly less to turn Dream Chaser around than a Dragon Capsule? It looks an awful lot like a Space Shuttle to me for that.
    The two who seem to be doing a lot for bringing the price down would be Blue Origin (who are banking on a seemingly unlikely SSTO), and SpaceX with their Resuable Powered Decent stages (which also seem pretty far away at this point). It takes a 130 million Atlas V to put a Dream Chaser into orbit last time I looked, where as the Dragon only needs a 60 million dollar Falcon 9. Although Dream Chaser *could* probably fit on a Falcon 9 and in either case you are looking at additional costs on top of the basic launcher.

  • by Rei ( 128717 ) on Wednesday June 06, 2012 @08:31AM (#40230931) Homepage

    New Sheperd in all regards hits me as pure naivete. For example, using HTP as an oxidizer. I'm well familiar with the logic here. "Oh, sure, it's got less ISP than LOX, but it's SIMPLER! And ISP isn't everything! We'll go simple and cheap, and get a simple, cheap craft!"

    And that logic is wrong.

    First off, the lesser issue: ISP may not be everything, but it's huge. The scaling factor for having bad ISP is pretty massive, and your other costs will add up quickly as your craft balloons, everything from your transport costs to your launch liability. People who just discount it like that do a big disservice to themselves.

    But the bigger issue: HTP is *not* simpler than LOX. It's a giant pain in the arse. It's explosive, which requires that you have sterile, defect-free tanks and systems with very specific materials requirements and purity constantly maintained. Its explosivity can be greatly reduced by the presence of stabilizers, but therein lies the other problem: the more stable you make it, the less reactive it becomes, and if you're using any sort of catalyst pack (which themselves are full of problems), you tend to clog it. Peroxide vapors from even stabilized HTP are explosive. Stored HTP can become less stable over time, and leaks can be catastrophic (as many people, perhaps most famously in recent years the crew of the Kursk, have learned). Heat can set it off. It's difficult and dangerous to concentrate in terms of oxidizer production. It's illegal to ship in tanker trucks due to its hazardous nature. Etc.

    People think about household H2O2 solutions and just picture a more powerful version of that. That is not what HTP is like. The Germans and later the US went with HTP a lot early in their rocketry programs. The fact that its usage became greatly curtailed over time should speak volumes.

    Basically, HTP is just reinventing a bad wheel. There's one little explored fuel combination that I'd like to see more focus on, personally: LOX/Propane. Propane is of course widely available, cheap, and easy to transport. It's higher ISP than RP1 (LOX/RP1 being a common propellant combination), but the downside when you first look at it in a table is it's much lower density. BUT, at the same temperature as your LOX - aka, they can share a common bulkhead without insulative separation, reducing system mass -- it's actually quite dense. LOX/Propane is also easier to vaporize and ignite.

  • by NoNonAlphaCharsHere ( 2201864 ) on Wednesday June 06, 2012 @10:38AM (#40232225)
    Map legend for non-rocket scientists:
    HTP == High Test Peroxide [], a high percentage Hydrogen Peroxide (H2O2) solution.
    ISP == Isp == Specific Impulse [], basically MPG for rockets.
    LOX == LOx == Liquid Oxygen [], not smoked salmon.
    RP1 == RP-1 == Rocket Propellant 1 [], a highly refined kerosene used as a rocket fuel.
  • Re:3 out of 4 (Score:4, Informative)

    by Rei ( 128717 ) on Wednesday June 06, 2012 @10:49AM (#40232359) Homepage

    I don't think it's that clear cut. As I mentioned before, the problems were overambition and budget cuts during the development process that made everything worse.

    The overambition is actually quite understandable. Think of what we had gone from, at the start of the 1960s to the Apollo moon landings. This incredible pace of accomplishment was driving people's sci-fi dreams of the future wild, even people in high places. The notion was that, clearly, we're about to become a spacefaring race in a major way, we need a vehicle to haul people and tons of cargo with a rapid launch rate turnaround; that's where the inception of the concept came from. Of course, that was not to happen, and not only due to the fault of the shuttle program.

    If the overambition itself wouldn't have doomed the goal of affordable reusable spaceflight, the budget cuts in development (brought about in no small part due to the Vietnam War) certainly did. The sacrifices made in development to accommodate them pretty much ensured that it would not be a reliable, affordable system. Turning to the air force for funding meant adding crossrange capability and even greater cargo capability. Disastrous. The lower level of funding meant less system reuse and higher maintenance on the systems that were to be reused. For example, the early shuttle designs called for a titanium frame which could run hot, instead of the current (cheaper) aluminum frame which can't. Letting the frame get hotter means you can use a simpler, and thus easier to maintain, TPS. Not to mention safer; the Columbia disaster couldn't have happened and there wouldn't be nearly as much metal fatigue concerns.

    Again, hindsight is always 20-20, but it's easy to see how the problems came about from overambition and then huge budget cuts in development. And I don't think calling it a jobs program, at least initially, is totally fair. Unlike Ares, which is "let's use as much shuttle hardware as we can to keep the plants open and keep developing it even when there's no longer a niche for it", the Shuttle wasn't heavily based on Saturn hardware. Now, what I think clearly became a jobs program and takes no hindsight to see is that when the Shuttle program went down the tubes, and it clearly had failed at its nominal goal of affordable reusable spaceflight, of not only keeping it running but keeping it as the workhorse of the US spaceflight fleet.

How long does it take a DEC field service engineer to change a lightbulb? It depends on how many bad ones he brought with him.