Why do spacecraft reenter at such high speed?
Couldn't they reenter slower?
Teach me about this pls. Is it gravity? I can't see gravity being responsible for causing 20,000 MPH speeds within 150 miles. Not all that is out of atmosphere, so it's not because of zero resistance.
It is gravity and the fact that they are going fast to begin with. What else would it be things just don't magically get really fast for no reason.
So they could slow down with rockets before reentry.
Would it save weight in lieu of needing thermal protection?
They'd have to bring a lot more fuel to slow down.
Which makes the rocket much bigger.
Which weighs less? A sweater or ten gallons of gasoline? (30L of petrol)
No that would probably end up costing more than just a bunch of ceramics
In order to land a rocket back down like how space X did then you would get more fuel to slow yourself slightly but not to remove the need for thermal protection because thats just pointless.
Cost=/=lives
The average life is worth 7 million according to the CDC. I imagine an astronauts life is worth much more.
IIRC the Orion reentered at like 20,000 MPH. That's mach 27. It was turning atmospheric gasses into PLASMA.
That's ridiculous.
Most astronauts don't die on re-entry because of heat shielding retard. It is just more cost effective to shield them from what kills them rather than spent far more using shittons of fuel to do something that isn't even worth it to do because it achieves pretty much the same result at a lesser cost.
In order to be in orbit they move at *VERY* high velocities, (they're not just floating in space, but flying/(actually falling), around it as fast as they could possibly fall.)
When you reenter at that speed, the atmosphere is basically like it's jerking your space-penis off with sandpaper at extremely high speeds. thus; it gets warm as fuck. (and if you were exposed, you'd probably get some gnarly burns)
Slowing it down would require rockets, which would require fuel, which would be heavy, which would require more space and bigger rockets to get you into space in the first place...
not very cost-effective. Cheaper with heat-shields
Dude a piece of FOAM killed the Columbia during reentry.
If they were able to reenter slower it wouldn't be a problem.