One of the things that I keep coming back to about EELV derived lunar missions, is that while there are a lot of interesting possibilities out there, and they are likely to be a lot cheaper than the ESAS architecture, they’re still very expensive. Compared to the price points that you’d really need to get to in order to have real cislunar commerce, even EELVs are completely unrealistic. The fairly obvious conclusion I keep coming back to is that until you have lower cost launch to orbit (ie sub $1k/lb), lunar commerce is a real challenge–maybe not impossible, but a challenge. In other words, you really need low-cost space access (probably in the form of truly reusable space transports) before most lunar business plans can be closed.
One thing that Lockheed (or Boeing) could do to help catalyze things would be to make a line of relatively low-cost propellant tanker modules for on-orbit propellant delivery. These could be as simple as a propellant tank with a standardized docking interface (and with standardized fuel interconnects), or possibly could have a small guidance package on-board. Just enough so that between the package and the launch vehicle upper stage, the propellants can either be delivered to a location where a tug can bring them in to the propellant depot, or enough to allow the generic tank module to do the rendezvous and close approach itself. Put that technology on the shelf so that any launch company that can put stuff into orbit can buy a version of the tanker module and launch it on their vehicle. Spend the money and time with ITAR lawyers to make sure that you can get at least some of the friendly international space programs (like Arianespace, and the Japanese launch companies) on board with the project.
Just by demonstrating the concept, setting a reasonable standard, and selling generic tugs (with scalable tanks depending on the launch capacity of the vehicle in question), you remove most of the technical risk for those companies to do on-orbit propellant deliveries. While that doesn’t remove all the hurdles between where we are right now, and largescale orbital and cislunar commerce, it provides a good start. Once that technology is on the shelf (or in development), it makes it easier for other people to innovate.
Maybe somebody will contract with Lockheed to have them deliver a “used” Centaur stage back to LEO after dropping off a commercial satellite. Have it refilled, and checked out at a Bigelow Sundancer station, and then turn it into a small orbital propellant depot. NASA claims they’d buy propellants on-orbit for topping off the EDS/LSAM, if it becomes commercially available. They really do need the capability, because without it, their odds of losing a mission from launch delays is pretty high, what with the LSAM and EDS only being designed for 15 day loiters before they start cutting into margins. With it, they can really boost their lunar surface capacity (possibly as much as double the cargo mission payload). And even at the crazy price that EELVs go for these days, it would be a lot cheaper to top off EDS than to launch two Ares V missions, with two EDS’s, and two landers.
Some large NASA missions (like JIMO for instance) could really benefit from being able to have their Centaur upper stage topped-off in orbit. That would allow the thing to fly on an existing booster, without having to sacrifice any capabilities.
Another potential market for LEO propellants might be if some other country wanted to do lunar missions on the cheap. Not everyone has drunk the ESAS koolaid. Maybe the Europeans, or Russia, or China, or India could become interested in licensing or buying outright the tanker modules, and then doing their own manned lunar missions using a much more affordable archetecture. You could land two guys on the moon using only two refueled centaur stages. India for instance could probably do a manned lunar mission using their own launchers. Or if they’re saavier than that, they’d build their own lander and capsule, and launch them, but then buy a used Centaur on orbit, and buy “commodity” on-orbit propellant to fuel that and their lander. If you aren’t NASA, and you’re merely trying for the most affordable way of doing a lunar mission, you’ll buy your propellant from whoever wants to ship it.
Or maybe someone could buy a “used” Centaur, and use it as a semi-reusable tug for sending paying customers on around the Moon joyrides. Use it a few times, and then discard it and buy another “used” Centaur. Judging from the medium flight-rate ticket price of an Atlas V 401, I’d be surprised if a new Single Engine Centaur stage was worth more than $15M–If you bought it used on-orbit, it could probably be had for a song. A refueled Centaur stage (stock, not Wide Body) could send 30klb on an Apollo-8 style free-return trajectory with separation after the TLI burn, and the Centaur doing a second firing to return itself to LEO for reuse.
I could probably think of other ideas, but I think that Lockheed or Boeing could do fairly well for themselves by field-demonstrating orbital propellant transfer, and developing and selling/liscensing a generic propellant tanker module.
What do you guys think?