posted 07-24-2011 01:54 AM               

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Originally posted by Robert Pearlman:
While I think we should have man-rated Delta and Atlas years ago, so we weren't in this position today ...

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Wasn't the Atlas man-rated for Mercury?

posted 07-24-2011 02:01 AM               

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Originally posted by Sy Liebergot:
When it was moved to i=51.6 degrees, we became stuck in LEO.

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Was this because the Russians were unable to launch into a 28 degree inclination and was one of the prices paid for their involvement in the ISS?

posted 07-24-2011 06:34 AM               

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Originally posted by moorouge:
Wasn't the Atlas man-rated for Mercury?

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The first sixteen American space crews, from Al Shepard through Gemini 12's Lovell and Aldrin, all went aloft atop ballistic missiles that were never designed to carry human cargo, and looking back it's still rather amazing that we got away with it. At what point were the Redstone, Atlas, and Titan II boosters ever "man-rated?" After the guys splashed down?

Even the Saturn V, conceived from the start to boost manned craft, not only carried crew on just its third all-up flight (after a second that was far from flawless), it carried them all the way to the Moon. Was the Saturn V "man-rated" in December 1968?

Okay, that was a different time, with higher stakes, and we don't do that stuff anymore anyway. Given that, did John Young and Bob Crippen strap themselves into a "man-rated" system on April 12, 1981? We put their lives on five engines that had never been tested in flight, and we weren't even trying to beat the Russians anywhere. This was a system that then experienced two catastrophic failures in 135 launches. Practical factors aside, our astronauts would have been statistically safer riding non-"man-rated" Delta II's or Atlas V's.

Another recent thread on this board discussed the legacy of George Mueller. When Mueller essentially mandated all-up testing of the Saturn V, he did so in recognition of a central truth that holds today, notwithstanding any deadlines or Moon races: We can never fly enough hardware to reach any meaningful, quantifiable "magic number" at which we can say, "OK, you can put the astronauts on it now." This is true whether you're Boeing, Lockheed-Martin, USAlliance, SpaceX, or whoever.

posted 07-24-2011 07:08 AM               

Item that are reviewed include: Functional Hazard Assessments, Preliminary System Safety Assessments, Failure Rate Prediction Techniques, Failure Mode and Effects Analysis, Fault Tree Analysis, and Common Mode Analysis. Principles apply to all types commercial aircraft certification and may also be adapted for any system safety activity.

There are probability numbers that are developed based on the criticality of the system and what the failure of that system would mean to the vehicle i.e. Hazardous, Critical, Catastrophic, and others. Therefore when a vehicle is designed without being a manned vehicle different (lesser) requirements must be met. That does not mean the vehicle can not meet those requirements it usually means at the time of design it was not analyzed for those requirements. To get "man-rated" it may be a task of a re-analysis of some systems, adding some redundancy to others and beefing up some structure then the vehicle is considered "man-rated"

In aviation we then go test the aircraft. And like all test programs there are risks and people can die. This happened to us this year in the loss of our G650 test vehicle with four of our friends on board (tough week for me as it was just days after I had to bury my Dad). The vehicle was "man-rated" and everyone thought that all was good. But something happened and we had to back up and review what it was that we did. A painful process but we are moving on.

Nothing will bring back a loss of a crew, but all of the families said, yes everyone, that we must press on and certify the G650 so that the loss of the crew would not have died in vain, for nothing. As humans we do our best but sometimes we fail. The real failure is in giving up, the triumph is in learning and moving forward.

posted 07-24-2011 08:36 AM               

quote:

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Originally posted by moorouge:
Wasn't the Atlas man-rated for Mercury?

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posted 07-28-2011 02:47 AM               

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Originally posted by GACspaceguy:
As I understand it "man-rated" was the term for the designed in safety margins, reliability requirements as well as system redundancy and not an operational term.

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The biggest difference with a lot of the current generation launchers designed for satellite launches to GEO is they head upwards on a higher lofted trajectory early in the flight because they are targetting an orbit higher than LEO (a GEO transfer orbit). They've never flown a flight profile to LEO and this can result in a few differences in how the vehicle performs. At least a ballistic missile is targeting a lower sub-orbital arc already in its design. So with a ballistic missile, the problem was adding power to the mix to get a spacecraft into orbit.

A more lofted trajectory could be used for a manned craft, but it can result in black out areas in the flight profile where if an abort is called and the capsule has to come back at an extreme ballistic angle, the resulting gee forces could kill the crew and/or cause the craft to burn up from the extreme heat and aerodynamic loads.

posted 07-28-2011 07:44 AM               

quote:

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Originally posted by moorouge:
Was this because the Russians were unable to launch into a 28 degree inclination and was one of the prices paid for their involvement in the ISS?

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posted 07-28-2011 08:58 AM               

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Originally posted by Sy Liebergot:
I believe, yes. ESA, as well.

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posted 07-28-2011 11:46 AM               

I've alluded to this in another thread, but in my opinion it's a serious mistake to blame the lack of whatever one may consider a satisfactory objective in the space program on the current administration, or on any administration for that matter. As has been pointed out innumerable times on this board, administrations come and go on a fairly regular basis, and their objectives for the space program usually go with them.

I had an epiphany recently that I think many of those on this board may have already had. There can be no longterm sustainable goal in the space program under the current model. It doesn't matter who is president because no stated longterm goal can be expected to survive his or her term in office.

Yes, we got to the Moon over the course of three administrations, but the goal of the Moon race wasn't really to land a man on the Moon, the goal was to win a high profile battle against the former Soviet Union in the Cold War. Despite all the soaring rhetoric about our future in space and JFK's legacy, it is a historical fact that the US only set the goal of going to the Moon in reaction to the challenge put forth by the USSR.

The various presidents, Congress, and the people of the US have little real interest in establishing or paying for any arbitrary goal that might be set in the exploration of space, but they will go to any lengths and expend virtually any amount of money to beat an enemy in battle.