Tuesday, 22 April 2008

Ares or Taurus?

The Great White Elephant Whale Hope of the US space program is the Ares 1, pictured on the right. (Picture courtesy of Mark Wade's excellent Encyclopedia Astronautica).

As you can see, this comprises a solid-fuel shuttle booster (with an additional segment added, just enough to invalidate most of the test data we have on it), and a new upper stage, based on the J2-S engine that was partially developed many years ago for the follow-on Apollo missions that never happened. Again from Mark Wade :
The J-2S engine and components were developed between 1965 and 1972 and the effort was based on experimental engines tested between 1964 and 1968 (the J-2X engine series).
The J-2S, while not a qualified in-production engine, was not a paper engine. It was an engine with significant flight heritage in the J-2 Saturn program engine, and it had significant ground test experience. It was not put into production only because a follow-on order for Saturn launch vehicles never materialized. Because of the excellent flight history of its heritage system, and because of its "almost ready for flight" status, the J-2S was considered by NASA for a number of applications after its development.
It was estimated by ATK Thiokol in 2005 that restarting the J-2S program, including engine fabrication, design and reliability verification, certification, and production, would require four years. Although no J-2S tooling was known to exist, modern soft tooling could be developed quickly and less expensively than the original hard tooling. There was an existing manufacturing and supplier network in place to support a J-2S restart.

In the event, NASA was unable to resist 'improving' the J-2S, and by early 2007 the engine for the second stage of the Ares 1 Crew Launch Vehicle was the redesignated and substantially different J-2X.
Just enough change to invalidate all the existing test data once again...

OK, but at least the new testing schedule is timely, with a launch scheduled for this time next year.

Well, it was scheduled for this time next year. There's been a few delays. And the booster won't have all 5 segments live, only 4 and a dummy. And will use a different grain size in the propellant. And the upper stage will be a dummy as well.

Now I'm all for stepwise refinement, but one thing you do not do in stepwise refinement is change the bits you're testing after they've been tested successfully. You test one bit, get it working, freeze it, then test the next bit. You don't get "do-overs", unless you're just trying to prove principles. This program was supposed to use "proven technology", not "loosely based on proven technology somewhat but not really".

So why are they doing this? A Cynic would say that they're launching something, anything, in the hope that it will put pressure on a newly installed Democrat president not to can the whole thing, and effectively abandon the US manned space program.

Good luck on that.

From Space Politics :
These fiscal pressures will force the next president—regardless of whoever is elected in November—to make some hard decisions in the years to come about discretionary spending. It is unrealistic to expect that NASA will somehow be immune to pressures to cut spending. A budget cut in the next Administration that is equivalent to last decade’s cut would result in reduction of NASA’s budget of over $3 billion per year. If that happens, it will be difficult, if not impossible, for the current exploration architecture to continue in anything resembling its current form and schedule. It will be significantly delayed, radically altered, or even cancelled.
NASA's budget is currently $18 billion. That's rather less than the projected cost of hosting the Olympics in 2012, and less than Athens spent in 2004.

That's less than 2c per day per US citizen.


RadarGrrl said...

Does it run under DOS?

Anonymous said...

That's less than 2c per day per US citizen.

I predict we'll hear "We need to solve our problems on Earth rather than throwing that money into space." As if our next administration is more likely to be solving problems instead of creating them.

Anonymous said...

A well planned and executed development program was the DC-X SSTO (single stage to orbit)

http://www.astronautix.com/lvs/dcx.htm and others.

It's a classic: build, test, fix, test, ...

I was irked when it was defunded.

Nicole Joy

Steve said...

Didn't I read somewhere that some are worried about the solid rocket stage vibrating the whole thing apart?