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SpaceX Plan To Fuel Rockets With People Aboard Raises Alarm Bells (fortune.com)
Several space industry experts that advise NASA have told the US space agency there are safety risks in a proposal by Elon Musk's SpaceX to fuel its rockets while astronauts are on board. From a report on Fortune: "This is a hazardous operation," Space Station Advisory Committee Chairman Thomas Stafford, a former NASA astronaut and retired Air Force general, said during a conference call on Monday. Stafford said the group's concerns were heightened after an explosion of an unmanned SpaceX rocket while it was being fueled on Sept. 1. The causes of that explosion are still under investigation. Members of the eight-member group, which includes veterans of NASA's Gemini, Apollo and space shuttle programs noted that all previous rockets that have flown people into space were fueled before astronauts got to the launch pad. "It was unanimous ... Everybody there, and particularly the people who had experience over the years, said nobody is ever near the pad when they fuel a booster," Stafford said, referring to an earlier briefing the group had about SpaceX's proposed fueling procedure.
"Additional, unnecessary risk" would have been better wording, but the article was pretty scant on details. Some explanation as to why SpaceX feels it's necessary to go against 60 years of risk management recommendations would have been nice.
"Tell me doctor, with all of your defenses, are there any provisions for an attack by killer bees?"
The Soviets lost a lot of their key technicians by having them hang around the rocket during fueling and tests.
Table-ized A.I.
...to refuel the Spaceship?
If that's already the case, why not send up an empty Spaceship, refuel it robotically with Tankers, *then* send up the passengers?
It's only one extra trip out of an already envisioned ~3-5 trips that his keynote talked about anyway.
The only other way than to fuel the rocket with the crew on board would be to fuel it first and then let the crew board it. The latter would mean that the astronauts as well as pad crews would be near or on a fueled rocket with no way to escape if something goes wrong during boarding the capsule.
If the astronauts board the capsule on top of the empty rocket and the rocket is fueled only when they're safe and strapped in there, there is no point at which they couldn't fire the escape system and get away when something goes wrong. Look at the fueling accident they had: The payload sat up there for several seconds after the rocket was already falling down in flaming pieces. The Dragon 2 LES is within less than 1/10 second at full thrust, pulling the capsule away.
So yes, fueling the rocket with people aboard is dangerous but boarding an already fueled rocket would be even more dangerous.
Has any escape system ever deployed in practice?
Well... kind of. The Little Joe was set to test the Saturn V launch escape system by commanding it to set off at a certain point in the flight. However, a gyro on the Little Joe was attached the wrong way about, causing the rocket to go out of control during ascent and break apart in a completely unintentional and unplanned manner. This broke the continuity wires, which triggered the LES to fire in a real and unplanned breakup scenario, which worked perfectly.
...to refuel the Spaceship? If that's already the case, why not send up an empty Spaceship, refuel it robotically with Tankers, *then* send up the passengers? It's only one extra trip out of an already envisioned ~3-5 trips that his keynote talked about anyway.
This isn't about the interplanetary rocket on the drawing board, but about how SpaceX fuels all their rockets. They now use super-cooled fuel for maximum thrust, basically once fueled it either has to take off or be de-fueled again quite soon, it can't wait for long. So either the astronauts have to either be on board, arrive from a bunker real quick and get themselves strapped in or SpaceX will have to modify their launch method. And the latter is really unlikely in general for cargo/satellite launches, so it'd be a manned-only setting and less tested.
They'd still have the launch abort system that could hopefully get them out of harm's way just like a mid-launch problem, but sure in an ideal world it's best not to be around things that can go boom. But principally a construction site would be much safer without construction workers too, the only way to be really sure humans aren't hurt is to not send humans at all. It's a question of acceptable and necessary risk, but sometimes we do give up safety for progress. Lots of people have hurt themselves badly with chain saws, few have done the same with a hand saw. Still not going back for safety's sake.
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