DIRECT Post-Shuttle Plan Pitched To Obama Team 189
FleaPlus writes "Popular Mechanics reports that a 'renegade' group including NASA engineers has met with President-Elect Obama's space transition team to present information on the DIRECT architecture for launching NASA missions after the Space Shuttle is retired. According to the group, DIRECT's Jupiter launch system will be safer, less expensive, better-performing, and be ready sooner than the Ares launch system NASA is currently developing, while still providing jobs for much of the existing shuttle workforce. Meanwhile, it's expected that current NASA head and adamant Ares supporter Michael Griffin will be replaced by a new NASA administrator."
Re:Oh yeah that sounds great (Score:5, Interesting)
And yeah, Griffin does come off as a real jerk, esp. when discussing the Shuttle accidents.
Re:Renegade Space Vehicle designers (Score:4, Interesting)
They are 'renegade' engineers, and they are 'bucking' their bosses. I'm not sure what part of the factually-correct description you have a problem with.
And knowing the kinds of engineers who work at Marshall Space Flight Center, I wouldn't be surprised if some of them did ride Harleys.
Re:First chance to see if Obama is a retard or not (Score:3, Interesting)
How many Ares class rockets have been build and tested to date? I wasn't aware they actually build any yet.
=Smidge=
Re:First chance to see if Obama is a retard or not (Score:5, Interesting)
While not a NASA engineer, I am a rocket engineer, and I've worked indirectly with NASA. I've also been following Ares and the DIRECT plan in some detail. I believe I'm qualified to say that the DIRECT plan looks better now than Ares did at a similar point in its development. Even including sunk costs on Ares, it seems quite likely to me that DIRECT is cheaper, quicker, more reliable, and more capable. Ares is already overweight and behind schedule; I would rather bet that it will become more so rather than less so before development is done. DIRECT is not immune to the same effects, but it is a much wiser plan in that it has *much* more margin to work with at a comparable stage in development. Its engineers understand that rockets always get heavier as they get closer to completion, never lighter.
Oddly enough, the only way to compare the two projects is to actually look at the details. The fact that one is further along in development than the other does not automatically make it better, any more than it automatically makes it worse. It may take a little bit of effort to make a reasonable apples-to-apples comparison between the two programs, but it is by no means impossible. AFAICT, comparisons of that sort appear to either be products of bureaucratic inertia ("we've already decided on Ares, therefore it must be right") or they conclude that DIRECT appears to be faster, cheaper, safer, and more capable.
Re:Well, if we're going to try to use old stuff... (Score:1, Interesting)
ICBMs don't have enough oomph to do what's required here. They were built to shove comparatively light warheads halfway across the world, not boost large manned capsules to Earth orbit and beyond.
Furthermore, as their origin is such, their acceleration profiles aren't exactly comfortable for humans. Ask veterans of Gemini that rode on Titan-you might as well be a warhead-ICBMs
Re:Oh yeah that sounds great (Score:3, Interesting)
I'm no expert, but on a general reading, it sounds like Aries was designed by people trying to meet the specs on paper and this was designed by people who know the astronauts and know what they're doing and want to protect the people and do their job -- not just meet the specs and make a profit.
But I have to admit, calling any spacecraft a Jupiter makes me uneasy. I'd risk a ride in the first one and anything from the third on, but there's no way I'd trust any vehicle referenced at all as the Jupiter II.
Re:Differently-abled? (Score:1, Interesting)
Do a little reading about the Spirit of St. Louis - Lindbergh chose a single engine plane for the same reasons.
If you have a vehicle that can travel on one engine, two is a spare.
If you have a vehicle that NEEDS two engines to fly, and has two, then there's twice the risk of engine failure.
Re:Oh yeah that sounds great (Score:5, Interesting)
Ares I is an abortion, and Ares V is being made without specific applications in mind. With the specs changing so often, I doubt either will ever fly.
Why, oh why, did NASA drop funding for SLI which was supposed to develop new generation staged combustion engines? Developing new engines is the first step in developing any new space transportation system. If we had RS-84 [astronautix.com], or something like it, it would change the game. We need to develop technologies for reliable and cheap access to orbit dammit, not gigantic White Elephants made of old tech, that is fitter for launching nuclear warheads than people.
Then there is the fact that they dropped landing, like the Russians have done for yonks, in favour of dropping into the ocean. What a retrograde step! If they couldn't make the stupid air bags light enough, they just needed to add retrorockets like the Russians. That capsule is too damn big anyway. They should shrink it into something that can fit an EELV.
Re:First chance to see if Obama is a retard or not (Score:3, Interesting)
The thing is, Ares never looked all that good -- even on paper. The idea that an extended SRB is anything other than a new large solid is a fantasy; it was obvious to everyone with technical knowledge on the matter from the beginning that any nontrivial changes to the SRBs lost most of the advantages of keeping Shuttle hardware involved.
Amen.
To clarify for the non rocket engineers, in a solid rocket, the whole thing is your combustion chamber. The casing has to be designed to a certain operating pressure, and the shape of the hole through the center of the fuel also has to be shaped to maintain a certain thrust profile (thrust is going to depend on the surface area burning, and burn rate depends in part on the chamber pressure). Just adding another segment and a half onto the top of a Shuttle SRB isn't going to do it, no matter how attractive that might look to paper designers or model makers -- you need to redesign the whole stack to take the changes into account. At that point it's no longer Shuttle hardware.
Changes to the main fuel tank are less problematic, but still not wonderful.
From the pure rocket standpoint, agreed. But making the fuel tank wider means that all-new assembly tooling has to be made, the transport barge has to be modified (if not a new one built), and the platforms in the VAB have to be modified to accommodate. All added cost.
Using only a single (extended, and therefore new) SRB as the first stage of Ares I obviously had problems -- the performance characteristics meant it was being used in a highly suboptimal manner in that application.
Serious problems. Using a single solid engine as your main stage? That might be OK for ICBMs (where storage in a ready-to-launch configuration overrides some reliability issues). Not very steerable and no control over the throttle at all once the fuel is lit. On top of that the Ares I is a hammerhead design - the upper stage is wider than the SRB. Yes, that works for ELVs that have liquid first stages with gimballed engines, where you can react more quickly to odd aerodynamic loads (wind sheer, etc). The fact is that that configuration -- hammerhead on a single solid booster -- has (to my knowledge) never been used in 50 years of spaceflight. To me Ares I looks like an accident waiting to happen. I'm just waiting for them to decide to fix that by putting tail fins on the thing ;-)
For the record, I think there is a lot less wrong with Ares V than there is with Ares I.
Agreed.
None of these are how I think the rocket *should* be designed, given ample time and budget -- but replacing the Shuttle is a project that doesn't have ample time. If NASA is to get anything flying soon, it will have to be a suboptimal design that has significant Shuttle heritage. Of such projects that I've seen proposed, DIRECT is the best compromise between doing the job well and something that could actually be built in time.
Also agreed.