Comment by pfdietz

1 day ago

Why make an SSTO when you can make a TSTO? First stage recovery is a solved problem and will always greatly relax the engineering problems over making a SSTO.

Because of course SSTO has benefits over TSTO, simplicity of operation being one example.

  • The argument for SSTOs was that staging was too scary. But experience since then shows this argument was bogus. Staging can be made highly reliable.

    Even a small amount of delta V provided by a first stage makes the job of the "almost SSTO" second stage much easier. And a low delta V first stage can be rugged, with high high safety factors, and is easy to recover at the launch site.

    Put another way: if you have an SSTO, its payload increases dramatically if you stack it on a very low performance recoverable first stage.

    I don't see any way SSTOs are going to be preferable to TSTOs, especially if the SSTO has to use hydrogen to get off the ground.