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Skylon

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14 hours ago, sevenperforce said:

It probably means they tested it to three atmospheres of internal pressure.

The stress on a pressure vessel (or, in this case, a pressure suit) is a function of differential pressure, not absolute pressure. In other words, if the inside has one atmosphere of pressure and the outside has zero atmospheres of pressure, that's one atmosphere of differential pressure. If the inside has two atmospheres of pressure and the outside has one atmosphere of pressure, that's still just one atmosphere of differential pressure.

Elon meant that the difference between the internal and external pressure, during the test, was twice as much of a pressure differential as being in a hard vacuum. So they probably just pumped up the inside of the suit to three atmospheres; that's the easiest way to do it. Of course, they could have pumped the inside to 2.5 atmospheres and then pumped the outside down to 0.5 atmospheres. Same difference.

In terms of pressure differential I'm sure three atmospheres would be fine, but there may be other factors that can only be tested in a near vacuum environment. 

Edited by RCgothic
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37 minutes ago, RCgothic said:

In terms of pressure differential I'm sure three atmospheres would be fine, but there may be other factors that can only be tested in a near vacuum environment. 

In which case they could well have pumped down the surroundings to near-vacuum and then pumped up the inside of the suit to two atmospheres.

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3 minutes ago, CatastrophicFailure said:

Ugh, that fog looks delicious. I'd settle for any kind of moisture here.  :(

IIRC, it was a foggy launch like this that led to one of the landing failures, ice in the landing gear mechanism or the like. Have they remedied that vulnerability yet?

 

Perhaps you should drop by south east Texas, then.

152721WPCQPF_sm.gif

The facility in Brownsville better be built hurricane proof. (Yes, I know Harvey is only a tropical storm right now, and yes, I know it's supposed to hit North of Brownsville, but just sayin'.)

Anywho, the launch window ends one minute before I get out of school. Curses, foiled again...

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21 minutes ago, Silavite said:

Anywho, the launch window ends one minute before I get out of school. Curses, foiled again...

My son finishes lunch at 12:50 (launch time here in Mountain states), and he was gonna ask his teacher to miss 10 min of recess and pull it up on the TV in the classroom.

 

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Stage separation and MVac ignition. Really, really beautiful shot of MVac ignition from underneath.

Looks like it is running the older grid fins -- probably recycled from an earlier launch? This is a new booster but they can reuse grid fins.

S2 telemetry rather than S1.

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