“The lateral propulsion system provides highly responsive, multi-axis control with maximum reliability but with inherently low, throttleable thrust. This lateral propulsion system can be a pressure fed, hypergolic system derived from existing robust engines. If technology matures sufficiently, a LO2/LH2 system could be utilized for enhanced performance. The throttleable lateral landing thrusters allow precision control of the final descent and translation rates. Since nearly all the work of descent will be performed using the high-efficiency RL10 engines, the system has a low gross weight. Even substantial hover and final descent durations using the lateral thrusters do not demand onerous propellant burdens.
The ability to rapidly maneuver is a clear advantage enabling selection of an optimal landing site. The distribution of lateral thrusters around the lander enables management of widely varying centroid locations which occur from mission to mission. It also permits control over residual propellant slosh behaviors as the vehicle maneuvers. The loss of a single thruster has minimal impact on system behavior, providing increasing system reliability.”

Another item of note is that it makes surface access easier, since they are closer to the ground. And it also allows for an unobstructed view of the surface when landing.

Not sure if the design could allow for lift off as well, though I figure if it can allow for hovering capability, lift off isn’t too much of a stretch.

For the Moon? I guess I don’t know what the advantages of such a system are.

I’ve seen footage of DCX in action and it seemed quite the vehicle. The thing was made to fly horizontal at times, IIRC. How nice it would be to resurrect that project for a sort of universal lander (as it seems it ought to be able to operate in both atmosphere and vacuum).

In addition to a DCX based concept for a reusable single stage lunar lander, how about a dual thrust axial lander?

There is nothing “miraculous” involved in it; it is simply a technology that we need to mature. The fact is that in space vehicles since Apollo, cryogens have been moved from storage tanks to fuel cells. This indicates that no physical principles are violated by such transfer. We need to be able to move propellant, store it, tank it and use it throughout cislunar space and eventually, this skill must be mastered and become a part of the infrastructure of a space transportation system.

You are correct — I was mistaken. Morpheus does use LOX-methane and was conceived as a way to deliver payloads autonomously to the cislunar localities. Mighty Eagle does not utilize cryogenics but uses a monoprop hydrogen peroxide system. It was primarily designed to validate hazard avoidance software for robotic landers.

It is a wonderful fantasy that Musk has taken full advantage of. He promises much but has in reality delivered little. SpaceX has taken cargo to the ISS at more cost per pound than the shuttle and is now launching satellites for profit (subsidized by those taxpayer dollars intended for a “cheap astronaut taxi.” ) Landing back the first stage is not such a remarkable achievement compared to the space shuttle that landed back the second stage engines, fully equipped space labs, and up to 8 astronauts.

“The greatest value to be realized from a reusable cryogenic space vehicle would come from developing a version that is permanently based in space, one that is not subjected to the extreme thermal environments of Earth orbital re-entry.”

In my view the main difficulty in building such a cycler-type vehicle is this recurring theme of transferring propellants from some kind of miraculous gas station in space. Such a scheme is a mess any way you look at it. I submit launching propulsion modules consisting of propellant tanks and engine/s from the Moon as the likely solution. A lunar lander would lift such a module from the Moon and deliver it to the vehicle while taking on an empty module (and eventually passengers) for return to the lunar surface- where the module would likely be very slowly and meticulously refueled from an ISRU facility. Such a module might be pressure-fed which would make for a much longer and more trouble free service life than a turbopump fed system (for a significant penalty in performance).

Yes, I know about both of those projects, but both use storable propellants, not cryogenics.

Three Points:

(1) The important point is the technology development. If you want a less capable version of the BE-3 or BE-4 the existence of the BE-3/BE-4 makes that much easier. Note that I am not trying to rule out use of a new variant of the RL-10, but now there are new options. The BE-3/BE-4 have been designed from the start to be compatible with Additive Manufacturing (3D Printing) and thus may be the best progenitors of engines manufactured on the Moon.

(2) If a BE3/BE4 lander is too big for a single launch of a Block I SLS, it could be launched and assembled in LEO. That should be no more complicated than the LEO rendezvous/docking contemplated in Constellation Systems for each lunar mission and would give you a reusable lander good for multiple missions.

(3) Absent a specific design study it is not really known what the dry mass of a BE3/BE4 Lunar Lander would be. It might not exceed the capabilities of the Block I SLS.