Culture names and Maydays (split from SpaceX)

[Guest]

You seem to think we're talking "send the Soyuz twice as often as we do now" levels. I'm talking about "major airport level traffic at a space station". Sure, in nominal flight, computer will be controlling everything (like it does for airplanes), unless manual docking proves to be much more time and fuel efficient (which it may). That doesn't mean you can ditch any and all crew. Even if all your "captain" does is make announcements and fill paperwork on nominal flight, you still want a captain that will be able to do everything the computer normally does. Just in case. FIY, even the otherwise very automated Soyuz involve pushing a few buttons during the flight, and the crew is able to take control if they need to. This has saved at least one Intercosmos mission.

BTW, Neil Armstrong had a problem during landing and, guess what, he landed the LEM pretty much by stick. Starship is bigger and has better computers, but that doesn't mean training people to land it in an emergency is a bad idea. This is an unlikely scenario, but nonetheless one that you want to plan for. Computers fail. So do humans. Failure of both at the same time is very unlikely, not that such incidents don't account for a few hundred deaths in air crashes. An unlikely event becomes much less so once you multiply the probability by 1000 flights per year. Or more. Leaving peoples' lives hanging 100% on a computer is very irresponsible and, quite frankly, stupid. The only reason spaceflight looks like it does now is that there is no traffic to speak of and a single destination to go to.

Edited May 24, 2019 by Guest

[Bill Phil]

10 minutes ago, Dragon01 said:

You seem to think we're talking "send the Soyuz twice as often as we do now" levels. I'm talking about "major airport level traffic at a space station". Sure, in nominal flight, computer will be controlling everything (like it does for airplanes), unless manual docking proves to be much more time and fuel efficient (which it may). That doesn't mean you can ditch any and all crew. Even if all your "captain" does is make announcements and fill paperwork on nominal flight, you still want a captain that will be able to do everything the computer normally does. Just in case. FIY, even the otherwise very automated Soyuz involve pushing a few buttons during the flight, and the crew is able to take control if they need to. This has saved at least one Intercosmos mission.

BTW, Neil Armstrong had a problem during landing and, guess what, he landed the LEM pretty much by stick. Starship is bigger and has better computers, but that doesn't mean training people to land it in an emergency is a bad idea. This is an unlikely scenario, but nonetheless one that you want to plan for. Computers fail. So do humans. Failure of both at the same time is very unlikely, not that such incidents don't account for a few hundred deaths in air crashes. An unlikely event becomes much less so once you multiply the probability by 1000 flights per year. Or more. Leaving peoples' lives hanging 100% on a computer is very irresponsible and, quite frankly, stupid. The only reason spaceflight looks like it does now is that there is no traffic to speak of and a single destination to go to.

This is why they have multiple redundant computer systems. On the LM this was not possible (not to the same extent at least, even then they could’ve aborted the landing and returned to the CM using a backup afaik) but on Shuttle there were 5 computers, if I recall. Computers have only gotten better since then, so there’s no reason to not have redundant computers.

Computers can fail. 5 computers probably won’t fail, and if one does it can be cut off from the system. A larger number of computers can be used to reduce the impact of failures even further.

Though manual flight would be the last resort, even then.

Edited May 24, 2019 by Bill Phil

[Flibble]

I think computers are better than you give them credit for. Could a human do a SpaceX style hover slam and land a booster?

[Guest]

Yes. Done that multiple times in KSP (well, not this exact configuration, but the same general idea).  You just need a suicide burn timer (any stopwatch will suffice, if you pre-calculate the time required), good reflexes and a steady hand. That said, you don't want a manned vehicle to land like this. If you're able to hover, then it's a lot easier. 

The real problem is probably not so much computers themselves as the devices that feed data to them. A computer can be wrong without an actual failure on its part. A human pilot can notice that the airspeed indicator is giving ridiculous readings, for instance, while a computer will not, as long as all pitot tubes are giving consistent readings. If your pitots ice up then you're flying manual even if you have ten autopilots (airline pilots routinely train for that eventuality). Or you may have a software bug, which is a good reason for a Shuttle-style scheme, where one computer was completely different from the others. Generally, a complete shutdown of all electronics is not survivable in a modern plane, much less a spacecraft, but there are several scenarios short of that when computer can do something stupid that can be counteracted by the crew.

Edited May 24, 2019 by Guest

[mikegarrison]

1 hour ago, Dragon01 said:

The real problem is probably not so much computers themselves as the devices that feed data to them. A computer can be wrong without an actual failure on its part. A human pilot can notice that the airspeed indicator is giving ridiculous readings, for instance, while a computer will not, as long as all pitot tubes are giving consistent readings. If your pitots ice up then you're flying manual even if you have ten autopilots (airline pilots routinely train for that eventuality). Or you may have a software bug, which is a good reason for a Shuttle-style scheme, where one computer was completely different from the others. Generally, a complete shutdown of all electronics is not survivable in a modern plane, much less a spacecraft, but there are several scenarios short of that when computer can do something stupid that can be counteracted by the crew.

Yeah, lots of aviation cases where bad sensors screwed up the flight computers. In most cases the pilots could have saved the airplane, if they responded correctly. Sometimes they didn't respond correctly, though.

A space example of this was that 2013 Proton launch that failed because the accelerometers had been installed upside down.

The software itself can also have hidden bugs, like the 1996 Ariane 5 crash where they converted a value from 64-bit floating point to 16-bit signed integer. When the floating point value exceeded 32767, the conversion failed. They had been using that same software for years on the Ariane 4, and that particular floating point value had never before exceeded 32767. (The really sad part was that the particular subroutine that caused the error wasn't even being used by Ariane 5. It was just included because it was easier to reuse the Ariane 4 software package than to write a new one for Ariane 5.)

Edited May 25, 2019 by mikegarrison

[kerbiloid]

16 hours ago, Dragon01 said:

f you have pax (as in, actual pax, not a bunch of scientists with basic flight training), you need some sort of crew

Ok, a bartender with waitresses, and a cop.

16 hours ago, Dragon01 said:

Computers aren't nearly as good as most people here seem to think.

Iirc, an absolute majority of aviation accidents of previous years was caused by a human decision.
So, if instead of 2+8 accidents there will be 2+0, it's anyway better.

13 hours ago, Dragon01 said:

unless manual docking proves to be much more time and fuel efficient (which it may)

The manual docking should be an incident requiring immediate landing.

13 hours ago, Dragon01 said:

Neil Armstrong had a problem during landing and, guess what, he landed the LEM pretty much by stick.

If an airplane pilot sees that the place he is trying to land on, is covered with rocks, he should abort landing and continue flight.
Of course, Armstrong is a tough man, and so on, but instead of this heroism he should just abort landing and return to orbit. A computer would do that, keeping both crewmen safe.
Though, in this case he would not be the first man on the Moon. So, it's just a personal desire, which should be punished, but "winners don't make excuses".

Edited May 25, 2019 by kerbiloid

[tater]

The name of the craft will have no important impact on communications efficiency. Nominally, doesn't matter, and in some special case, they'll abbreviate. It's not a concern. We're asked to assume an airline-like future (which is fine), but then somehow we have an Apollo 13 style emergency, or an Apollo 11 1202 alarm situation which requires comms to resolve. An airline pilots with a problem on the flight deck communicate primarily with each other to resolve the problem, comms to the outside world are more letting them know a problem exists. Digital comms will be tagged with the craft ID, anyway, they won't be using tube radios.

[kerbiloid]

A proper ship name is very important.
 

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