06 May 2018

I'm With NASA on This

NASA has said that it is profoundly uncomfortable with man rating the SpaceX booster, because one of its core technologies, super-cooled propellants, would require that fuel be loaded when the astronauts are already in the capsule.

I agree.  Cooling LOX and kerosine well below their boiling point prior to loading does increase the total mass of fuel in the tank, but, because of thermal issues, this requires very fast loading immediately before launch, and as such is a menace:
When Elon Musk and his team at SpaceX were looking to make their Falcon 9 rocket even more powerful, they came up with a creative idea — keep the propellant at super-cold temperatures to shrink its size, allowing them to pack more of it into the tanks.

But the approach comes with a major risk, according to some safety experts. At those extreme temperatures, the propellant would need to be loaded just before takeoff — while astronauts are aboard. An accident, or a spark, during this maneuver, known as “load-and-go,” could set off an explosion.

The proposal has raised alarms for members of Congress and NASA safety advisers as the agency and SpaceX prepare to launch humans into orbit as early as this year. One watchdog group labeled load-and-go a “potential safety risk.” A NASA advisory group warned in a letter that the method was “contrary to booster safety criteria that has been in place for over 50 years.”

Concerns at NASA over the astronauts’ safety hit a high point when, in September 2016, a SpaceX Falcon 9 rocket blew up while it was being fueled ahead of an engine test. No one was hurt, but the payload, a multimillion-dollar satellite, was lost. The question on many people’s minds at NASA instantly became: What if astronauts were on board?

The fueling issue is emerging as a point of tension between the safety-obsessed space agency and the maverick company run by Musk, a tech entrepreneur who is well known for his flair for the dramatic and for pushing boundaries of rocket science.

he concerns from some at NASA are shared by others. John Mulholland, who oversees Boeing’s contract to fly astronauts to the International Space Station and once worked on the space shuttle, said load-and-go fueling was rejected by NASA in the past because “we never could get comfortable with the safety risks that you would take with that approach. When you’re loading densified propellants, it is not an inherently stable situation.
(emphasis mine)

Think about Autopilot.

Also notice the next bit:
SpaceX supporters say tradition and old ways of thinking can be the enemy of innovation and thwart efforts to open the frontier of space.

Greg Autry, a business professor at the University of Southern California, said the load-and-go procedures were a heated issue when he served on Trump’s NASA transition team.
Note that Musk, and the rest of the "eBay Mafia", made their fortunes by exploiting an area of regulatory forbearance, which allowed them to operate without the (expensive) consumer protections that banks were required.

And note that Greg Autry, is a f%$#ing Business Professor talking about literal rocket science.

Launching unmanned payloads is not as much of an issue, because if Musk attempts to launch something unreliable, the insurance industry will price it into their premiums.

This is not possible with a life on the line.

I would note that even with the NASA safety standard of 1 in every 270 flights with a death, it means that you have a 50% chance of death after 186 flights, and this is what the dotcom and the business types find to be an insufficiently risk-taking culture.

Seriously, this is not ordering shoes online.

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