Using Deep Space Gateway to Enable Lunar Exploration

The current administration has put forward their support for a manned lunar landing program. Basing a reusable lunar lander at the DSG could allow for a lower cost way to achieve this goal, without sacrificing the current architecture. So here is my plan. Some aspects of it are borrowed from Boeing designs for a reusable lunar lander architecture (http://bit.ly/2lg6bUJ). It involves only two new pieces of hardware:

-The Reusable Lunar Module (RLM) -The Lunar Transfer Stage (LTS)

Both pieces of hardware use storable, hypergolic propellants. This is to maximize reliability, and to loosen up some of the time constraints that cryogenic propellants might present. If SLS can only fly one or two flights a year, that will almost certainly limit the lunar campaign to one landing a year.

The RLM is designed for a crew of 2 or 3, with a stay of around 7 days on the lunar surface. Like the LTS, it is powered by a staged combustion hypergolic rocket engine with an Isp of 325s. The Russians have built many engines of this quality (potential international collaboration?). It has a dry mass of 6000 kg (this is just without propellant, I'm assuming that cargo, consumables, etc, fit into the 6000 kg), and fully fueled, masses 24000kg.

The LTS is a simple stage with 18000 kg of fuel, and 2000 kg inert mass. It is designed so that it can be launched to DSG by a fully expendable Falcon Heavy.

After the initial round of SLS flights to assemble DSG, an Orion would fly to DSG with a mostly empty RLM. The extra 4000kg or so of propellant would be used by the crew to perform maneuvering tests of the lander. After the crew returned to Earth, two falcon heavy launches would each send an LTS to the DSG. One would rendezvous with the RLM and transfer 18000 kg of propellant to it. The second would be docked onto one of the free nodes of the DSG. When the next crew arrives, the landing crew would board the RLM, undock from DSG, and rendezvous with the fully fueled LTS. The LTS would propel the RLM to lunar orbit, where it would separate and land on the surface. After the end of surface operations, the RLM would rendezvous with the LTS in lunar orbit, and the remaining propellant in the LTS would carry the now empty lander back up to the DSG. The LTS stages would be discarded at the end of the mission. For longer term lunar mission, or lunar bases, an RLM derived cargo lander could be launched by a single SLS directly to the lunar surface. Such a lander could land around 10 tons of cargo on the Moon, enough for a habitat, large rover, etc.

While this mission design may not be as reusable, or as capable as others, I believe that something like this could be quickly and cheaply developed, and this architecture never requires more than 2 SLS flights a year, though it could be accomplished at 1 a year as well. The use of falcon heavy for the refueling operations allows for a lower cost per mission than adding one or two more SLS flights into the mix. What do you think?

Submitted October 26, 2017 at 02:28PM by Prolemasses http://ift.tt/2yOVCuI