Yes, first and second stages fall back to Earth. Normally the third stages go into orbit. Then the spacecraft separates from the third stage. The third stage may stay in orbit for a couple of days - but is in a really low orbit and it falls back to Earth under atmospheric drag and burns up in the atmosphere - except in case of Moon or interplanetary launches when third stage usually goes into orbit around the sun.
These are all expensive intricate complex machines.
As some people have said - it is a bit like building a 747, flying it once in a flight that destroys the entire plane except the pilot's cabin - and you bail out of it when you get to your destination in a small capsule attached to the front of the jet.
(it flies without passengers except in the pilot's cabin)
Then you build another 747 for your next flight across the Atlantic. And another and another, and you keep doing this several times a year.
Is no wonder spaceflight is so expensive at present.
With some spaceships sent to Mars and elsewhere - the third stages themselves reach escape velocity and go all the way to Mars. They are "trajectory biased" away from Mars to make sure they don't hit the planet for planetary protection reasons.
In the case of Apollo moon flights, then some of the third stages became mini NEO type asteroids in independent orbits around the sun.
The third stages need to go into orbit because you need many kilometers per second of delta v to get into orbit - and even more to get to Mars or the Moon - so - you need big rocket engines to carry all that fuel - and then you don't want to carry all that weight with you to your destination because your fine course corrections will use only tiny amounts of fuel left in the crewed section of the spaceship - so you have to separate from the final stage - and leave it in orbit around the Earth or the Sun as appropriate.
There are exceptions - the Indian MOM Mars spaceship was launched on a much less powerful engine - and used flybys of Earth and many boosts to get onto its interplanetary trajectory - so its final stage I'm pretty sure didn't go to Mars.
This is the launch sequence for the Soyuz, which is used to take astronauts to the ISS
And more details here
There are many ideas for ways to deal with this - Elon Musk's plans are most advanced at present. This test early this year was very impressive
But he has a fair way to go before his spaceships can be human certified - though already using them for supplies to the ISS.
It's not impossible that other approaches might beat him to it.
Such as the Skylon
Artist's concept of it taking off into orbit
and perhaps a little further down the road if it works:
orbital airships
and
Maglev tracks boosting ships to orbital velocities
And are many other ideas - suggested - some in the past, that nearly happened but were broken off such as NASA's
One of the most developed ideas to date is the Delta Clipper. It too could take off - and then land vertically - just like the SpaceX rocket - but this is back in 1995, nearly 20 years before Space X.
DC-X Flight 8
It was only intended as a proof of principle, and wasn't capable of going into orbit at this stage. But eventually it could have become a fully automated, reusable, single stage to orbit space shuttle for unmanned cargos - and it could also take humans - who wouldn't need to pilot it as it was fully automated.
However NASA eventually cancelled the project (after a crash) - as they have with so many projects. And then started another more ambitious similar project - but then cancelled that one also.
For more about this:
Projects To Get To Space As Easily As We Cross Oceans - A Million Flights A Year Perhaps - Will We Be Ready?
These are all expensive intricate complex machines.
As some people have said - it is a bit like building a 747, flying it once in a flight that destroys the entire plane except the pilot's cabin - and you bail out of it when you get to your destination in a small capsule attached to the front of the jet.
(it flies without passengers except in the pilot's cabin)
Then you build another 747 for your next flight across the Atlantic. And another and another, and you keep doing this several times a year.
Is no wonder spaceflight is so expensive at present.
With some spaceships sent to Mars and elsewhere - the third stages themselves reach escape velocity and go all the way to Mars. They are "trajectory biased" away from Mars to make sure they don't hit the planet for planetary protection reasons.
In the case of Apollo moon flights, then some of the third stages became mini NEO type asteroids in independent orbits around the sun.
The third stages need to go into orbit because you need many kilometers per second of delta v to get into orbit - and even more to get to Mars or the Moon - so - you need big rocket engines to carry all that fuel - and then you don't want to carry all that weight with you to your destination because your fine course corrections will use only tiny amounts of fuel left in the crewed section of the spaceship - so you have to separate from the final stage - and leave it in orbit around the Earth or the Sun as appropriate.
There are exceptions - the Indian MOM Mars spaceship was launched on a much less powerful engine - and used flybys of Earth and many boosts to get onto its interplanetary trajectory - so its final stage I'm pretty sure didn't go to Mars.
This is the launch sequence for the Soyuz, which is used to take astronauts to the ISS
And more details here
There are many ideas for ways to deal with this - Elon Musk's plans are most advanced at present. This test early this year was very impressive
But he has a fair way to go before his spaceships can be human certified - though already using them for supplies to the ISS.
It's not impossible that other approaches might beat him to it.
Such as the Skylon
Artist's concept of it taking off into orbit
and perhaps a little further down the road if it works:
and
Maglev tracks boosting ships to orbital velocities
And are many other ideas - suggested - some in the past, that nearly happened but were broken off such as NASA's
One of the most developed ideas to date is the Delta Clipper. It too could take off - and then land vertically - just like the SpaceX rocket - but this is back in 1995, nearly 20 years before Space X.
DC-X Flight 8
It was only intended as a proof of principle, and wasn't capable of going into orbit at this stage. But eventually it could have become a fully automated, reusable, single stage to orbit space shuttle for unmanned cargos - and it could also take humans - who wouldn't need to pilot it as it was fully automated.
However NASA eventually cancelled the project (after a crash) - as they have with so many projects. And then started another more ambitious similar project - but then cancelled that one also.
For more about this:
Projects To Get To Space As Easily As We Cross Oceans - A Million Flights A Year Perhaps - Will We Be Ready?
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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