Dragon XL (or equivalent Starship) as space tug for module delivery to Gateway?

[Robotbeat]

For that matter, I wonder if the winner of the NASA ISS deborbit RFI might also be a candidate tug?

such a tug would have a lot of delta-v and thus could in principle do multiple missions.

[shintoo]

Fun discussion idea

In my mind, there are a few scenarios in terms of what is available for module delivery in... no particular order:

1. EUS is available and Orion delivers as planned.

2. Launch on other LV (FH/Vulcan/whatever) with a third stage to bring the module near Gateway. Orion/DXL/etc picks up and docks.

3. Launch on other LV with a tug (Cygnus/whatever based) that docks the module itself. No dependency on Orion/etc. being at the gateway during delivery. (Module may even have a loiter time if the tug provides good power)

4(?) Is there any way HLS could include a Gateway module in its cargo? Would certainly be entertaining watching that ballet.

Of all the options, I really like either SLS delivering a module via Orion, or HLS delivering a module via intricate choreography. These vehicles are already planned to visit Gateway, so they are simpler paths forward. I would rather have HLS store surface cargo than a gateway module though, since I still am of the opinion that surface cargo is far more valuable than more Gateway space.

I guess I am saying, if EUS is cancelled, I am perfectly fine with Gateway forever being just PPE+HALO. The current planned architecture is that Gateway is the primary outpost, and surface elements in the near term are secondary. I'd rather that be reversed - small orbital station, larger surface base. But if we can build out both (EUS and HLS both successful), why not.

[DanClemmensen]

4(?) Is there any way HLS could include a Gateway module in its cargo? Would certainly be entertaining watching that ballet.

4.1) HLS docks with module in LEO and carries it to Gateway in this configuration, so it does not take up internal cargo space. I don't particularly like it, but it's simple by comparison.

[TheRadicalModerate]

4(?) Is there any way HLS could include a Gateway module in its cargo? Would certainly be entertaining watching that ballet.

4.1) HLS docks with module in LEO and carries it to Gateway in this configuration, so it does not take up internal cargo space. I don't particularly like it, but it's simple by comparison.

If you're going to use a Starship, then a cargo Starship with some sort of chomper-like deployment mechanism can get to NRHO easily on two tankers' full of prop, dock the module (which can be up to 80t), and return straight to EDL.

(O/T, but probably an interesting topic:  What kind of payload bay doors would you need to dock a module with the docking ring on the outer end of the cylinder?  Could you safely use a chomper with a tilt-out PAF platform?  Kinda weird dynamics to do the docking, and keeping the open chomper out of the way isn't trivial.)

A modified Dragon only makes sense for BEO module deployments if it's being launched on an FH.  IIRC, an FHE can get about 15.5t to a BLT-like TLI.  That takes about 80m/s of delta-v to enter NRHO and perform the RPOD.  That would limit your Dragon bus and its payload to about 15.1t dry, and would need about 400kg of MMH/NTO.  That's probably something like a 13t payload, which would handily beat an SLS Block 1B co-manifest.

[meekGee]

I don't think Gateway is needed at all, but If we need a station in NRHO, then I cannot get interested in any scheme that uses a Starship to support it. If you need a Starship, then the Starship should replace the Gateway, not just support it. Take all the interesting bits from each module design and design them all into one Starship.

Again, SpaceX is not the Taco Bell of the space industry

Agreed. A custom Starship is not the answer to life, the universe, and everything. But If your concept depends on a custom Starship to service Gateway, then you may as well depend on a different custom Starship to replace Gateway. As I said, my vote is for no Gateway at all.

Yup.

You're watching the evolution of new capability vs. inertia.

Gateway was designed with a whole different transportation system in mind.