Quote from: QuantumG on 01/02/2015 11:02 pmQuote from: Hog on 01/02/2015 01:58 pmThe incentive to move onto a new system was strong enough that STS was slated for cancellation a year later.(there's always 1% who need it explained...)How's the new system goin'? Much safer than the old - so it looks like the CAIB recommendations worked well! (And not sure if you're part of the 1%, but I hope you understood )
Quote from: Hog on 01/02/2015 01:58 pmThe incentive to move onto a new system was strong enough that STS was slated for cancellation a year later.(there's always 1% who need it explained...)How's the new system goin'?
The incentive to move onto a new system was strong enough that STS was slated for cancellation a year later.
Everything to be launched in the next few years, whether SLS-Orion, Dragon2, Soyuz, or CST-100 will be safer by far than SLS was....
Quote from: llanitedave on 01/03/2015 04:39 amEverything to be launched in the next few years, whether SLS-Orion, Dragon2, Soyuz, or CST-100 will be safer by far than SLS was....I don't see it in such black and white terms. STS after 2000 was much safer than the initial flights. A Launch Escape System doesn't magically fix all problems. A failure where the crew was saved by a LES would still be a catastrophe and ground all launches for a long time, even without loss of life.We tend to over-weight incidents we've experienced, and under-weight those we didn't -- regardless of how dangerous they were. E.g, Apollo 13 came very close to losing the entire stack due to severe pogo during stage 2. It was by sheer luck the center engine prematurely shut down and damped the vibration, likely from the 68 g oscillating force as it bent the I-beam thrust structure three inches.Had it not shut down, the S-II 2nd stage could have broken up, and it's unclear if the crew would have survived. By that point in the ascent, the escape tower had already been jettisoned, and abort mode 2 was the only option. The CSM could only accelerate at about 0.3 g, so an exploding or tumbling stack could easily damage the CSM before it got safely away.Likewise the Saturn V was extremely vulnerable to an early engine failure. If any single F-1 engine failed within the first approx. 15 sec, the entire stack would fall backward onto the pad. By contrast the shuttle (after year 2000) could tolerate multiple SSME failures right off the pad.All planned LES systems cover a small fraction of the flight envelope. They introduce weight, complexity and risk. Some Apollo astronauts breathed a sigh of relief once the LES tower was jettisoned. When the Gemini VI Titan II shut down after indicating it had launched, Wally Schirra didn't eject. This was partially because he was afraid of the ejection system.All crewed space vehicles have a multitude of "criticality 1" items which simply must work. Whether an SRB, a parachute pyro, or the rocket-powered guillotine that cut the LM ascent stage free, there is no backup. The system is permeated with these. Picking out a couple of past obvious failures where solutions have already been applied doesn't mean the overall safety picture is greatly changed going forward.
Quote from: QuantumG on 01/02/2015 11:02 pmQuote from: Hog on 01/02/2015 01:58 pmThe incentive to move onto a new system was strong enough that STS was slated for cancellation a year later.(there's always 1% who need it explained...)How's the new system goin'?I understood your question, in all the flippancy it encompasses.
Quote from: Hog on 01/04/2015 08:01 pmQuote from: QuantumG on 01/02/2015 11:02 pmQuote from: Hog on 01/02/2015 01:58 pmThe incentive to move onto a new system was strong enough that STS was slated for cancellation a year later.(there's always 1% who need it explained...)How's the new system goin'?I understood your question, in all the flippancy it encompasses.In retrospect, perhaps you'd agree there was unintended consequences?
" By contrast the shuttle (after year 2000) could tolerate multiple SSME failures right off the pad. "What is the source for a statement like that ?
Quote from: dks13827 on 01/05/2015 12:07 am" By contrast the shuttle (after year 2000) could tolerate multiple SSME failures right off the pad. "What is the source for a statement like that ?The previously-posted contingency abort charts showing the "three out blue" case was potentially survivable. This was further covered in astronaut Charles Precourt's presentation at the 1999 Shuttle Development Conference, plus discussions with shuttle ascent procedures specialists.As the chart shows, this is not a clear-cut situation but updates to ET/orbiter structure, guidance, control and software were done to enable this possibility. By contrast the Saturn V required 100% reliability on all five engines for the initial ascent, else it would be like Vanguard on a stupendous scale.
Stupid question?Were there 2 reports on Columbia and Challenger? Thinking like an internal NASA & a public?
I still say that we could have flown the shuttle at a reduced rate while its replacement was being put together. From what I can tell, the shuttle could have ferried up way more supplies and so forth in 1 launch than several Space X flights. Understand I'm not down on SpaceX either. I just think retiring the Shuttle before its replacement was ready was crazy to do for a host of reasons. Maybe its because I am still enamoured with the Shuttle. It was the most complex machine we have ever built and in some cases, it never got the due it should have gotten...
1. I still say that we could have flown the shuttle at a reduced rate while its replacement was being put together. From what I can tell, the shuttle could have ferried up way more supplies and so forth in 1 launch than several Space X flights.2. Understand I'm not down on SpaceX either. I just think retiring the Shuttle before its replacement was ready was crazy to do for a host of reasons.3. Maybe its because I am still enamoured with the Shuttle. It was the most complex machine we have ever built and in some cases, it never got the due it should have gotten... MikeEndeavor