For those of you able to make it all the way through the 3h webcast video of the September lunar exploration industry briefing day there is a bit at the end that makes for interesting what-if pondering
The Altair lunar lander project office deputy manager Clinton Dorris can be heard referring to “marginal” trades when the panel was asked about the idea of using Altair as a hopper to extend sorties far from the outpostIt is not to hard to think about why a pressurised rover wins out over this idea, for example the risks involved in launch and landing, even for suborbital flights from one part of the Moon to another. But a rover has to have a much more limited distance, and I think that its range is also limited due to the safety need for astronauts to be able to walk back to the outpost
NASA’s exploration systems mission directorate associate administrator Doug Cooke says in the video that they “talked about it…[but]…you really need [in-situ resource utilisation] to do it.”
Not to mention the fact that you will probably need to redesign the Altair significantly
I guess you could use a two-week sortie Altair but remove the ascent module engines, unless anyone thinks you can use the ascent module as the hopper but surely you would have to add landing legs?
I think you would want the descent module (DM) as well and I think that that is sort of referred to when they talk about refuelling during the very brief discussion in the video. With the descent module you have plenty of fuel and maybe could include, with a hopper version, additional resources for power and air to breathe
For what goes on top of the DM I think you might want to use a modified habitat module. As the DM is supposed to be able to land up to 17,000kg (previously we have heard 14,000kg but in thr video 17 is mentioned) then that is your boundary for a habitat module for the outpost
That habitat module, with built in anti-dust airlock, could just as easily be a lab and maybe the same module doubles up for the presssurised section of the rover? Rather like today’s cars the wheel base supports a range of optional chassis
So beyond the cargo, sortie and outpost variant landers there could be a fourth version, a hopper, landed and designed for ISRU. Such a vehicle could enable short sorties to the mid-latitude regons that NASA is realising it is hard to get to with Altair
