Falcon Heavy as a TLI payload of 16,800kg. A fully decked Orion spacecraft weighs 33,446kg. Really the only alternative to SLS for Artemis would be Starship but that hasn't even achieved orbit yet (meanwhile SLS already did a successful lunar orbit and return).
I’m not happy with this argument because the Orion comes in two modules. It’s designed to go in SLS but each module separately can be launched by Falcon Heavy.
In view of the launch economics, this argument still doesn’t make sense of SLS.
>but each module separately can be launched by Falcon Heavy.
How do you know that they can feasibly be launched separately? Do you think NASA would have asked for a launch vehicle the size of SLS if could have done a manned lunar mission with something less then half its size?
>Saturn V was less powerful than SLS - but it could send an entire mission in a single launch. Capsule, lander and all.
That's just not true. Saturn V had a paylod of 43,500kg to TLI. Only the largest configuration of SLS(Block 2) exceeds that with 46000kg. A Falcon Heavy is far below that.
Huh, I overestimated SLS? My bad - I think I must have used Block 2 numbers by accident. Thanks for the correction.
My point stands though: no Artemis mission has plans to launch a full Apollo style capsule + lander stack. Artemis HLS, SpaceX and Blue Origin versions both, flies entirely on its own. So what's required of both SLS and any would-be SLS replacement is a far less demanding mission than what Saturn V has done in the past.
Which calls into question: what SLS is even for? Does it add value to the mission, or is the mission subtracted from to justify adding SLS to it?
