What is the cost to NASA per launch to ISS of Starliner vs Crew Dragon?
According to a 2019 report by NASA's Office of the Inspector General (OIG), the launch costs are (in million\$):
cost per astronaut
cost per launch
SpaceX Crew Dragon
Boeing CST-100 Starliner
So, out of the three vehicles currently being used to ...
Crew Dragon uses the regular Draco thrusters for the deorbit burn, and in fact for any burn during a regular flight. The Superdracos are only used for launch escape.
The main reason is that the Superdracos are too powerful. A deorbit burn with the Superdracos takes only a couple of seconds, which means that if they burn a little bit too long or too short, ...
Say a Falcon 9 experiences an in-flight failure where four core engines shut down prematurely. Would it still be feasible to jettison the upper stage and attempt to reach orbit, while trying to land the booster?
It's unclear to me, given the phrase "attempt to reach orbit", if you mean discard the upper stage or separate it as usual. As Jörg W ...
It uses the cold nitrogen gas RCS thrusters. Sometimes, you can see them firing shortly before second stage engine startup.
Elon Musk has talked about using the ullage gas vents as RCS thrusters and for propellant settling as well. He mentioned they are already using them to help deorbit the second stage. Super Heavy will not have separate RCS thrusters, it ...