Yes, some sort of cargo deck at the top-center of the vehicle would need to be arranged for, in the deep-space-ready version. Are the people who are designing it, thinking in terms of Morpheus being an uncrewed/just-cargo type lander, or do they favor its use as a crew-transport lander, as well————— if they can work out the details of it having a cabin put on top? Spaceflight concepts like this, being put into some action, are all very exciting to see! Some kind of eventual lander vehicle is going to be a must, for the future history of human space exploration & space resource utilization, in the next few decades. That is if NASA & the American government ever regain their long-time-ago bravery & daringness, to pursue the doing of majestic things!

https://en.wikipedia.org/wiki/Project_Morpheus#mediaviewer/File:Project_Morpheus_Lander_in_free_flight.jpg

Put 3 of them together is a triangle to make the 6 tonne payload lander. The cargo deck being in the centre.

The crew might number three or four astronauts, depending on the projections for the cabin size. A lunar roving vehicle would be a must, per mission, in my view; and even as an open-space jeep car, like on Apollo, it should be able to carry all the crew members, on its traverses. Either a new, unfoldable car could be brought for each mission, or maybe a single car could be reused on another landing, if the distance between sites was not too faraway. [It could be designed to drive overland by remote guidance, and be sent to another spot, to be reclaimed by a different crew. Provided that the time spans between the landings also aren’t all that long. Such driving vehicles would need to have a long-enough operating life, under the harsh Lunar conditions.] At a outpost location, the rovers could perhaps be parked under some sort of tent or semi-shelter covering, between expeditions, so that they can endure the airless, temperature-swinging environment better.

The Morpheus lander concept sounds fairly good. It might make for a viable alternative to the Altair L-SAM. But I have yet to see a visualization or diagram of it. The lunar lander that eventually gets approved & flies will be a very important key-element to getting this great, second-round enterprise started. The deluded cowards who terminated Project Constellation in 2010, were all adamantly against NASA building ANY lander. As if a space-faring civilization could ever be built without dealing with one. I mean, with what are you going to use for ferrying astronauts & supply cargoes to a planetary surface, once you arrive at the destination planet’s “harbor”————its low orbit zone?

Now, if the disabling problem would be with the orbiting CEV, something that compromises its ability to leave lunar orbit & return to Earth, then any rescue mission sent by mission control would be more involved. If there were to be a Command Module Pilot flying the solo vigil, obviously he/she would need rescuing as well; (if during a preliminary sortie, if that kind of flight plan is used, at the beginning test-flights). Some arrangement for a deliberate crashing of the disabled vehicle, after it had been vacated, for later on, might need to be put into work, once the vehicle is checked more closely; perhaps through a close flying-in-formation next to it. (Or maybe two Orions might be capable of docking to each other, with or without a specialized docking module. Remember all that earlier NEO-reaching talk, that was floated around NASA, in the recent past, depicting such a two-craft flying arrangement?)

In any event, if the regular expedition’s CEV had been left crewless, as would happen during a typical outpost mission, and it is still the disabled spacecraft, then the rescue operation would focus on bringing the stranded-on-the-surface crew a new such craft. (With or without an extra lander. They may be able to skip that, if the main crew’s lander, already on the Moon, was working alright. The rescue CEV would need to be capable of then, dropping into low lunar orbit, by itself; with or without a distinct deceleration-stage craft. I recall the Constellation plan calling for it needing an L-SAM in order to reach lunar orbit.) Maybe the rescue CEV would have an extra crewman, to personally co-ordinate the needed maneuvers, or maybe it would be able to fly there unmanned. I would predict that such a rescue mission should probably have an extra astronaut on board, for it. Again, this large thought-experiment is meant to try to foresee some of the flight-plan detail involved in a renewed round of manned Lunar exploration.

Each astronaut requires 30.60 kilograms/day/astronaut consumables (ref: http://www.nasa.gov/audience/foreducators/stseducation/materials/Sustaining_Life.html)

So a single lander can supply consumables for 2000/30.60 = 65.3 days for one astronaut.

A Morpheus can act as an ascent stage by lifting a small cabin to lunar orbit.

He also noticed that by joining 3 together they can land 6 tonnes. That is sufficient to land the ascent stage. It is also sufficient for a small habitat or a manned rover. Mining equipment can be designed to fit this size and mass restriction.

The main crew-landing vehicle would not necessarily need to have an endurance-time range of much longer than this, because with the freighter transport of habitation modules to the surface, one-way & unmanned, the crew could rely on the supplies brought on board these lander-types, and spend a sizeable portion of their on-surface time inside its crew cabin, thus lowering the burdens initially put on the landing craft which they arrived in. Since the unmannedly-sent version of the lander would not have ascent capability, obviously the other lander type would be needed for departing from the Moon, at the end of the outpost stay. A lot of the specifics of this plan, depend on the precise size, volume & configuration of the next crew-landing vehicle.

Contemplating on an Altair-class L-SAM vehicle, one can envision a highly versatile & well-sized lunar lander, which could serve the functions of main crew transporter to a base camp————-as well as a stand-alone vehicle for an independent sortie landing; either at the beginning of our flight manifest, or later on, when surveying a particular area of the Moon would prove scientifically valuable, without having to emplace a base module at the particular site. Whether one or two of these outpost-type landers would be needed, to get all of the necessary equipment & provisions to a particular mission site, would depend on just how much cargo can be brought on board, and just how long the surface stay is planned to last.

An additional consideration would be in the possible rescue of a stranded or in-trouble team of astronauts, on the surface. Either an under-crewed sortie L-SAM could be sent to rescue them, or perhaps an ascent-capable outpost-type L-SAM could be sent out & down to the surface location, uncrewed, to save an astronaut team who’d lack a viable ascent vehicle to get home. Maybe a crewman or two could ride a specially-designed Orion CEV, to low lunar orbit, to assure the ease in their return, to an Earth-bound vessel. Maybe one crewman would ride the rescue lander and another the orbiter, during such a special rescue mission; or some variation to that effect.

Of course the CEV orbiter would then have to be able to accommodate the additional crewmen somehow, either with additional seats & spaces and/or maybe the lunar lander ascent stage could be specially brought along, on the Earth-ward journey, so as to have some further expanded room, and then it could be jettisoned right before atmospheric reentry; kind of like what Apollo 13 did, in 1970. That idea would require a double-vehicle departure from low lunar orbit; and inevitably the CEV would have to have the crew-cabin space for the extra crew-members, via extra couches, for at least the reentry phase. But all this thinking-ahead thought exercise shows that a new manned Lunar enterprise can indeed have a great deal of versatility to it; to handle both emergencies and an expanded scope of operations.

A practical tug will need to push 5-10 tonnes of payload from LEO to GEO, returning empty. The same engines can be used (if they can survive the long burn) but space rated parts will have to be used and big fuel tanks fitted. Navigation will have to perform automated docking.

Indeed the Space Tug or OTV was intended as a forerunner to the new lunar lander, if it had flown. The amount of power needed to reach geo-stationary orbit and reaching low lunar orbit was deemed as not being that big of a difference, hence there were magazine articles that spoke about upgrading a Space Tug into a lunar vehicle. Of course all that was assuming that the next major LEO space station that the United States put up, was going to involve in-orbit refueling ports, and that reusability & Earthian aerobraking for returning craft was going to come to pass.

As it turned out, the ISS was NEVER going to be used as an embarking point for reaching the Moon, nor other cislunar points in space. (It’s very orbit is not conducive to that idea, anyway.) Indeed the ISS turned out to be a gigantic dead-end; having been created mainly as a post-Cold War bilateral high-technology activity, to hopefully keep the post-Soviet-era Russian scientists busy & occupied, so that they wouldn’t engage in black-market weaponry & such. Hence, the U.S. remained safely & stagnantly perched in LEO, with next-to-no-hope of getting itself out of that grind. Man, all those decades of opportunity & possibilities that we missed!!!!

The concept of the space tug vehicle could certainly be revived & updated in the future, as you point out. Perhaps they will get built & flown once we have a firm foothold on the Moon, via a major lunar base; when lunar resources are being mined & processed. To be seen, just how beyond-LEO spaceflight strategies unfold and develop.

With a maximum dry weight of 20 tonnes a reasonable sized chemical tug could have been built, using say one or more RL-10s for the main engine.

Experimental nuclear engines could have been lifted to orbit on the Shuttle.

These tugs could still be built, possibly using methane engines.