Dubbed the "Cislunar 1,000 Vision," an initiative outlined by American launch provider ULA foresees a self-sustaining economy that supports 1,000 people living and working in Earth-moon space roughly 30 years from now. The basic outline is to develop re-fueling capability in Earth-moon space, perhaps by propellant made using water extracted from the moon or asteroids. This, in turn, will make it more economically feasible to get to destinations more distant. From the Space.com article: [space.com]
For example, a rocket could carry just enough fuel to get to low Earth orbit and then refuel its upper stage in space to get a payload to the much more distant geosynchronous transfer orbit.
"I can potentially do that whole mission cheaper if I can get propellant cheap enough in low Earth orbit," Sowers said. George Sowers is vice president of advanced programs for Colorado-based ULA.
The concept stems from an analysis and ongoing technical work by United Launch Alliance (ULA) involving a souped-up Centaur rocket stage called ACES (Advanced Cryogenic Evolved Stage), a tanker called XEUS, and a "kit" that augments an ACES stage, allowing the vehicle to land horizontally on the lunar surface and be stocked with moon-mined fuel for transport.
ULA will solicit proposals for ACES' upper-stage engines, tapping the technologies of aerospace companies such as Aerojet Rocketdyne, XCOR Aerospace and Blue Origin. And the U.S. Air Force is supporting some ACES work under rocket propulsion system contracts, Sowers said.
"There's a lot of activity ongoing," he said, "and we're designing a Vulcan booster to accommodate the ACES upper stage."
Vulcan is ULA's next-generation launch system. [Vulcan Rocket: ULA Unveils New Modular Launch System (Video) [space.com]]
"Once we have ACES flying, sometime in the early to mid-2020s, we would be in a position to utilize space-provided propellant," Sowers said.
"For the most part, the only potential customers for space-based fuel have been space agencies. But their timelines keep shifting, their budgets keep getting reappropriated and the political will to enable this kind of activity 'gets bogged down in bureaucratic zombie zones,' [mining technologies and robotics provider Dale] Boucher said. [,,,] "the ULA plan enables commercialization in deeper space and provides risk reductions for space-agency-sponsored missions."