Jim Oberg has the most extensive public report yet on last months Soyuz mishap, over at IEEE Spectrum.
It’s a fascinating read, but it has to give us pause in relying on Soyuz when the Shuttle is retired.
6 thoughts on “A Robust Design?”
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maybe im misunderstanding the word “robust”, but isnt the fact that all astronauts are back on earth alive in spite of the technical problems outlined, a testament to the robustness of the system ?
isnt the fact that all astronauts are back on earth alive in spite of the technical problems outlined, a testament to the robustness of the system ?
I’d say so. It sounds to me like the Russian engineers applied failure mode analysis to reduce the danger during reentry when things go wrong. Bad stuff happens sometimes and it’s good to be prepared for it.
It sounds to me like the Russian engineers applied failure mode analysis to reduce the danger during reentry when things go wrong. Bad stuff happens sometimes and it’s good to be prepared for it.
There’s no evidence the Russian engineers actually did that. If you read the read the article, you’ll see that it’s just Oberg’s speculation.
More importantly, you and Kert are reasoning from a single data point. The overall record of capsules remains poor. Professional bullriding is safe by comparison.
Single data point ? It was pointed out that the thing has had problems before, which i personally believe because i have first hand knowledge with russian manufacturing standards and approaches. ( Anecdotal evidence : listen to the interviews with Yi Soyeon on Youtube on her experiences in Star City )
Soyuz, all things considered, has been a pretty dependable workhorse, good enough that chinese decided to start their own manned program with knocking it off. Imitation, flattery and so.
Single data point ? It was pointed out that the thing has had problems before,
Yes, and it’s killed cosmonauts before, and crippled cosmonauts, too. You and Larry are looking only at selected data.
The overall record shows that capsules are no better than the Space Shuttle, when it comes to safety, and orders of magnitude worse than genuine reusable vehicles.
Soyuz, all things considered, has been a pretty dependable workhorse,
That statement merely shows how low your standards and expectations are when it comes to spaceflight.
Most vehicles are designed for 99.999% reliability. ELVs and capsules don’t even have 99% reliability. Calling that safe, dependable, reliable, etc. doesn’t make it so.
good enough that chinese decided to start their own manned program with knocking it off. Imitation, flattery and so.
So, if Laurel hits his thumb with a hammer, then Hardy does the same thing, that proves that hitting one’s thumb with a hammer is a good thing? And you will want to hit your thumb with a hammer, too?
Besides, the Chinese are not just building Soyuz knockoffs. They’re also developing a military spaceplane. If we’re going to copy something the Chinese are doing, why not copy something that actually has some utility?
Maybe a better analogy is that the U.S. Air Force sends lines of people, from EM ranks through officers, to sweep runways and taxiways for junk that could be injested into jet engines, while the Soviet and now Russian Federation air force has airbases that are junk piles, but they build fighters with inlet doors to take in air from the top of the wing so they don’t have to worry about injesting a screw on the runway.
Imagine Columbia on reentry, where when the computer detected that it couldn’t counteract an increasing yaw angle with thrusters, and if such a thing were even possible, put the thing into a flat-spin, belly-first reentry, the crew having to bail out into a Lousiana bayou to be rescued by duck hunters, who called it in to 911 with their cell phones.
The Shuttle design has absolutely no margins, while the Soyuz, apparently, has generous margins.
On the other hand, I cannot recall the Shuttle having a failure along the lines of the recent Soyuz. The Challenger and the Columbia disasters are comparable to say, an escalation of ASAT testing results in tons of debris in orbit, and unless a spacecraft had a proper “meteor shield”, one our of 100 or perhaps one out of 50 would be lost to a space junk pellet, only the weight margins are such that fitting a workable meteor shield is prohibitive.
After the Apollo 13 tank explosion, I don’t think NASA has had a major failure attributable to quality control, although the Apollo CM/LM spacecraft apparently had margins enough to bring the crew home after a heroic effort. A similar failure happened on the Shuttle with Columbia, but the response was denial instead of a heroic rescue because even though there was talk about a rescue Shuttle, any such plan was probably unworkable.
It is great that the crew of Soyuz is safe, and having a craft like that with generous margins is better in some ways than the Shuttle with no margins, which depends entirely in tight quality control. But having a quality control level where you can’t count on the explosive bolts to separate the service module on reentry, leading one to fall back on those robust design margins, doesn’t seem like a good approach either.