Re: Does it open at the front?
> Then attach a small Payload Assist Module send it to the Sun
Although it seems to be "downhill" to the sun it is as hard to slow an object down from Earth's orbital velocity so it can "fall" into the sun as it would be to launch it from the sun to Earth orbital velocity.
That's the problem with returning stuff from orbit to Earth. You have to make stuff go really fast horizontally to make it to orbit and so you have to spend the same energy/fuel to get it to stop orbitting.
The Shuttle and Apollo capsules used friction with the atmosphere to dump this speed, but a returning SpaceX rocket (or that junkyard rocket from the 70s TV show) needs to carry 2x as much fuel to use engines slow down.
This means that the 2nd stage weighs 2x as much, and so the first stage needs to be bigger to lift it, then the first stage needs to be even bigger to lift that extra fuel, which takes more fuel - that way madness (and the Saturn V) lies