Define “sustainable rocket”. There are greener fuels, like hydrogen peroxide, but I don’t think they give enough push to get to orbit.
But if you’re willing to drop the “rocket” part, you can remove the propellant entirely, and use a railgun or spinlaunch system. (Strictly speaking you’ll still need some kind of propellant for corrections and orbital maneuvering, but you’re not burning a fuckton of propellant just to beat gravity.)
There is also the question of the reusability of the rocket itself, but SpaceX and others have fairly well proven that by now.
The fuel is the least concern. They’re using H2+O2, which burns to water and can be completely created by using the excess solar energy during peak times of the day. The costly/unsustainable thing is the huge rocket that is destroyed each launch and must be completely rebuilt from scratch each time.
Define “sustainable rocket”. There are greener fuels, like hydrogen peroxide, but I don’t think they give enough push to get to orbit.
But if you’re willing to drop the “rocket” part, you can remove the propellant entirely, and use a railgun or spinlaunch system. (Strictly speaking you’ll still need some kind of propellant for corrections and orbital maneuvering, but you’re not burning a fuckton of propellant just to beat gravity.)
There is also the question of the reusability of the rocket itself, but SpaceX and others have fairly well proven that by now.
Not for manned launches though. Unless the goal is to send 280kg of meat paste to orbit.
The fuel is the least concern. They’re using H2+O2, which burns to water and can be completely created by using the excess solar energy during peak times of the day. The costly/unsustainable thing is the huge rocket that is destroyed each launch and must be completely rebuilt from scratch each time.
No one but SpaceX has proven they can do it so far, Blue Origin has only landed one, but hasn’t reused it yet. They’re close, but not quite there yet.