It is probably primarily an engineering mission--with goals to see if it can be done, how efficiently it can be done, and what can be learned along the way.

It is similar in this respect to SpaceX or Virgin Galactic or Blue Origin. The science of rocket engines is pretty well understood, but it's still an interesting problem to optimize.

To some extent future science depends on future engineering, so advances in engineering can still have scientific value.

Here's some ideas. I have no idea if anyone is working on it.

1. Telescope

2. Dark matter research

3. Effects of radiation in low atmosphere environment

4. Remote habitat research

5. Testing unmanned rocket/vehicle landings and launches