Tuesday, May 06, 2008
[With apologies to Arthur C. Clarke, who isn't here anymore to defend his work---seriously]
According to Michael Griffin, the "future" begins in 2010. It won't be pretty.
Back in the dark days after the Columbia tragedy, a lot of us were hanging around the alt.sci.space.* newsgroups. In the midst of all the rather silly suggestions for "fixing" the Shuttle---things like pulling a giant sock over the External Tank, or painting it with something or other---was this peculiar suggestion that we just go back to building somewhat upgraded Apollo hardware. It was a sort of nostalgia for the last time that a manned spaceflight program seemed to more or less work and accomplish a meaningful goal. I thought the notion had faded away over the months with all the giant socks, and conspiracy theories, and other malarkey. It wasn't the only case in which people later wondered if NASA had been taking notes....
Whether that is the case or not, we now have the whole Ares-Orion-Constellation thing going on. In the long recent lineage of manned spaceflight vaporware---X33, X34, International Spaceplane, and probably a few I've forgotten about---NASA's marketing concepts seem to be going stale, to have begun to lack even the SSTO kind of imaginative spark. I have begun to wonder if they're even trying anymore.
But enough about me. It has been difficult to find anyone actually independent of the NASA community who has anything positive to say about this "program". They certainly aren't coming from the GAO:
The GAO is being very polite, but it amounts to saying that the "Shuttle Successor" is vaporware. All the classic symptoms are in the report. Problems listed include:
---NASA has started to sign contracts for billions of USD without finalizing the requirements. Some people may have been surprised.
---The major components of the Successor system are "interdependent".[without final requirements, a change in weight requires changes in performance, and pretty soon you start bringing the writers back to have another go at the next round of manned spaceflight "imagineering". ]
---There are "knowledge gaps" in all of the major components---I would have just said they didn't know what they were doing, but I'm unprofessional that way.
---Most troubling of all, NASA has no facilities available which are adequate to test the spacecraft or its major components. They are supposedly going to fly an Ares/Orion on a suborbital test flight next year, apparently to see if it flies apart or anything.
For some outside analysis of the GAO findings:
Then there are the less-polite comments, from outside the government:
Naked Emperor? - Transterrestrial Musings [I haven't looked in on Simberg's weblog in over a year, for some reason.]
From this and some other sources, we can find the criticisms of the Shuttle successor program which would make most sensible people need a prolonged nap, or maybe a mild sedative....
It is apparent that Michael Griffin originally sold the Ares/Orion/Constellation to Congress as a way to re-use existing Shuttle components in a new way to do human space exploration to the Moon, Mars, and some other places like the ISS, maybe. The 2004 report on the Exploration Systems Architecture Study, or ESAS (http://www.nasaspaceflight.com/content/?cid=4164), in response to President Bush's exploration "Vision" requirement, refers to an SDLV (Shuttle Derived Launch Vehicle). But that wouldn't have been enough feature creep or requirements meddling for the NASA management:
---Are they going to use the existing Shuttle 4-segment solid propellant boosters? Um...no. The Ares and Constellation will require a redesigned 5-segment booster with an extended carbon-composite skirt extension. They have no real working plan to produce the new booster, and no adequate way to test it and its acoustic, vibration, and flight properties. [the 5-segment design will suffer major design problems due to vibration on ascent.]
---Are they going to use the liquid-fueled Shuttle Main Engines? Ah...no. They have decided to resurrect the J-2 second-stage engine from Apollo so they can make the single-use second stage cheaper...if anyone actually believes that.
---Well, are they going to use the Apollo J-2 engine in the Ares second stage? Well...no. They are going to fiddle with it and come up with a virtually all-new design called the J-2X---which---they have no adequate means to produce, and---no really good way to test.
A number of these sources describe various problems NASA would have if it ever tried to make actual man-carrying spacecraft to do actually useful things out of the current successor concepts:
--- The current engineering numbers show that the proposed booster design will impose even more severe vibration on the spacecraft structure and crew than the old 4-segment boosters. [one of the comments to the above Simberg rant quotes unnamed astronauts as likening the current SRB ascent vibration to "..a long running train wreck..". Another comment quotes an unnamed structural engineer as likening the proposed Ares/Orion craft to "a piece of spaghetti (1st stage) pushing a balloon (second stage) with a lead weight on top (Orion)"]
NASA professes to be "unfazed" by the GAO's report on the new booster design's vibration problems:
Then we get to see what they propose to do about the vibration:
Ares I Thrust Oscillation mitigation options head into trade study - NASA SpaceFlight.com
These include sets of liquid-fuel reaction motors arrayed around the aft booster skirt and pointed upward, to actively counter vibration moments---and/or various contraptions made of rails and springs to sort of passively damp out the vibrations from various places in the structure. Why should they be worried?
---As mentioned earlier, nobody knows how to make a one-piece heat shield using the Apollo-era technology anymore. One proposed "solution" has been to adapt the tiles from the Shuttle's TPS, which have worked so well in the past.
---Not surprisingly, the weight of the Orion capsule continues to creep up. Simultaneously, projections for the performance of the Ares booster are creeping down. Proposed vibration solutions all add significant weight, also causing a downward trend in available payload. One of the first casualties of the weight problem has been the landing bag system required to land the proposed capsule on land. They would have to go back to ocean recovery.
How did manned spaceflight get into such a dead-end mess? Simberg has another prolonged, and probably at least partly correct, rant on the subject:
But NASA's "fundamental problem" is that its most important "payload" is some marketing. Its Administrator frets publicly about the projected five-year gap in American manned missions between the retirement of Shuttles in 2010 and the supposed debut of Ares/Orion, and wheedles to Congress that NASA needs more money to extend the Shuttle's service or otherwise shorten the "gap" to four years.
Both gap lengths are, or course, fiction, like "completion" of ISS, the Ares/Orion/Constellation, trips to the Moon and Mars, and the "Vision" in general. The Shuttles will retire---either peacefully or through another catastrophe. Soyuz will fly until the stress of its new role as sole provider causes its own catastrophe or the crumbling Russian Federal space program finally collapses like the government that created it. China and maybe a few others will piddle around for a while until the futility causes them to lose interest, and then we'll be left with a few forlorn reconnaissance robots around or on some planets, while our attention is diverted by other problems. Eventually, nobody will have time to care.
NASA long ago vigorously suppressed or fired anyone with the "vision" to dream of or implement a future for space exploration, and likely replaced them with a few lawyers and some marketing professionals, both of which are far more urgently needed in the standard government model for success.
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