QUOTE (nprev @ Oct 19 2007, 06:20 PM)
Brings up an interesting point, Gordan: Wonder how many unmanned test flights of Ares V are planned? IIRC, the Saturn V had five (Apollos 2 through 6). If a similar campaign is designed for Ares, then maybe we could do an interplanetary mission for the last test, assuming all the bugs are worked out...
There were several different missions proposed to make use of the amazing capability provided by the Saturn V -- Mars landers, outer planet flybys and orbiters, Venus orbiters... a plethora of missions that could all benefit from the incredible lifting capability of the massive Saturn.
They all ended up shelved. Mostly because a Saturn V was immense in every respect, including its cost. It became glaringly obvious that no one was willing to spend the kind of money it would cost to buy a Saturn V to launch their unmanned probe.
They became incredibly reliable vehicles, but they were never cheap.
QUOTE (nprev @ Oct 19 2007, 06:20 PM)
EDIT: There were only two tests of the Saturn V: Apollos 4 & 6. What's amazing in my perspective from the current era is that 6 had
many serious problems...so they figured them out, fixed them, and launched Apollo 8 less than eight months later...
We need to figure out how to do things like that again.
In some ways, we need to figure out how not to *ever* have to do things like that again. But first, let me say a couple of things:
The guys at Marshall, German and not, overdesigned the vehicle such that there was enough margin to absorb potentially fatal events and keep going. Not just keep the crew alive, but keep going.
Apollo 6 seemed to have a lot of unrelated problems when it flew, that's true. But they actually boiled down to only two basic problems with the first two stages of the rocket (with one simple wiring error compounding the problem), an easily-solved problem with the in-flight ignitor system for the S-IVB, and an easily identified and fixed problem with the materials used in the SLA adapter between the S-IVB and the CSM.
The Germans built those vehicles (especially the early ones) to telemeter so much information about themselves that the problems were rather easily diagnosed and fixes readily identified. So, while the problems seemed to be nearly insurmountable, the direct way in which the problems could be diagnosed led to a lot of confidence in the performance of the next rocket.
But...
The Apollo-Saturn development philosophy of "All-Up" testing was an *extremely* risky approach. It relied on the design and, moreso, the engineering philosophy upon which the Saturn was based being *so* well done that you just had to have confidence based on the engineering. Period. It's true that independent testing of the stages incrementally would have taken too much time (and incidentally cost more money) -- but in Mueller's original concept, he was willing to man a Saturn V after only a single successful test flight.
Saturn V had a magnificent flight record, mostly due to the margin built into all of its systems by those methodical Germans. But even after the deadline had been met and the time pressure was off, we nearly lost a crew when a malfunctioning engine came within about one second of vibrating itself out of the thrust assembly and tearing into the tankage above.
The problem with a huge and expensive launcher like a Saturn V or an Ares V is that they will always be too expensive to test a little bit at a time, and so will have to be over-engineered. Problem is, aerospace engineering these days seems to be all about doing as much as you can within your power/mass envelope, to cut your margins as slim as you possibly can and still get away with it. So I have doubts that the Ares V will be as immensely successful as its predecessor.
But I have no doubts that the all-up concept, carried over from Apollo to the Shuttle, will continue to prevail and that NASA, in its arrogance, will likely plan to man the Ares I and place Orion equipment for actual manned flights on the Ares V -- both after one successful test flight.
-the other Doug