An international team headed by Lockheed Martin hopes to parlay a modular “general-purpose space utility vehicle” it has proposed for NASA’s second-round commercial-cargo competition into a human-spaceflight services business ranging from low Earth orbit (LEO) to Mars.

Dubbed “Jupiter” for one of the locomotives that met in the Utah desert to complete the U.S. transcontinental railroad, the proposed vehicle would marry the spacecraft bus Lockheed Martin Space Systems Company builds for its interplanetary probes with a robotic arm supplied by Canada’s MacDonald Dettwiler Associates (MDA) and a pressurized module built in Italy by Thales Alenia Space.

For cargo deliveries to the International Space Station under NASA’s second Commercial Resupply Services (CRS-2) work package, the Jupiter spacecraft bus and robotic arm would remain in orbit indefinitely after launching on an Atlas V with the first in a series of cargo modules attached. Identical cargo modules filled with pressurized and unpressurized supplies and station gear would arrive periodically after that on Atlas Vs, using the launchers’ Centaur upper stages to rendezvous with the Jupiter bus.

The Jupiter’s Canadian robot arm would grapple the arriving cargo module and attach it to the Lockheed Martin bus, which would move it into position to be grappled and berthed by the station crew. Astronauts would use the station’s larger robotic arm for the job, just as they receive cargo deliveries from the Orbital ATK Cygnus and SpaceX Dragon commercial cargo carriers flying under CRS-1 today.

The Italian-built module would remain berthed at ISS for the crew to unload and refill with trash. It would be discarded for destructive reentry after several months, and replaced with a fresh load of cargo arriving in a new module delivered by the Jupiter. But under Lockheed Martin’s ambitious plan, that would just be the beginning.

“What we’re envisioning here is something that we think has commercial application well beyond ISS,” says James Crocker, vice president and general manager for the space systems company’s new international unit. “In fact, on these missions themselves, one of the things we have put in our proposal is how we will reduce the cost to NASA and share the profits with NASA for commercial use of this.”

Just as NASA and its space-exploration partners envision a stepwise route to land human “pioneers” on Mars, the Jupiter partners see themselves providing commercial cargo and other services—including human habitats—at each step along the way. Crocker compares the idea’s commercial potential to the railroad cars that sent U.S. foodstuffs to East Coast ports for shipment to Europe in the 19th Century.

Jupiter was the name of the first eastbound Central Pacific Railroad locomotive to travel the completed transcontinental rail line. The spaceborne Jupiter vehicle could play the same role for the inner Solar System, says Crocker.

“Picture a future of interplanetary shipping lanes to the Moon and to Mars, with autonomous vehicles carrying supplies and scientific instruments and construction materials for habitats, robots in orbit for fueling, repairing, respositioning satellites,” he says. “Picture commercial hosted payloads, cubesats by the hundreds that would share space on this vehicle with perhaps NASA Earth-observing instruments, turning a profit and reducing the cost of supplying the station in orbit, but more importantly laying the foundation for a true commercial business in space.”

To that end, Lockheed Martin has made a “very substantial” but unspecified investment in the project, Crocker says. A win in the CRS-2 competition will hasten the development, including the addition of solar-electric propulsion for missions beyond LEO, but the team plans to continue the work with or without the ISS cargo contract, he says.

At least four other companies have entered the CRS-2 competition, which calls for delivery of 15,000 kg (33,000 lb.) of pressurized cargo and 2,000 kg of unpressurized “upmass” from the expiration of the initial CRS contracts after 2016. Incumbents Orbital ATK and SpaceX are in the running. Sierra Nevada plans to enter a variant of the Dream Chaser lifting body it unsuccessfully proposed for NASA’s commercial crew program, and Boeing has entered a cargo version of the CST-100 capsule that was a winner in the commercial crew competition. Blue Origin, which also is developing an orbital vehicle that may be suitable, won’t say if it bid on CRS-2.

Lockheed Martin and its partners have cobbled together the Jupiter “exoliner” from a lot of flight-proven hardware. NASA is flying the basic spacecraft bus at Mars on the Mars Reconnaissance Orbiter and Mars Atmosphere and Volatile Evolution probes, on the Juno spacecraft approaching Jupiter, and on the Origins Spectral Interpretation Resource Identification Security Regolith Explorer asteroid sample-return mission set for launch in September 2016.

Lockheed plans to keep the bus and arm operating indefinitely by launching more of its hypergolic fuel in spherical tanks housed in a ring-shape structure at the end of the cargo module that berths with the bus. The unit also can carry fluids to the ISS.

Between the fluid ring and the pressurized module is an open space comparable to the “trunk” on the SpaceX Dragon, where unpressurized cargo destined for the station’s exterior can be carried. Crocker says Lockheed Martin has developed a 9U cubesat dispenser for the open space to accommodate secondary payloads at the smallest end of the size scale, although much larger birds can be accommodated for ridesharing.

“On the first mission, of course, we carry the Jupiter module up,” he says. “This whole stack is rated to carry the Jupiter module, so we could actually launch satellites as large as Jupiter on future missions. Now we’d have to add a strap-on [booster] to the Atlas to do that, but that’s millions of dollars—it’s not tens of millions of dollars—so we can launch satellites as large as Jupiter and as small as a cubesat.”

Adding solid-fuel strap-ons also adds altitude to the orbits Jupiter can reach, although the CRS-2 concept is optimized “with a lot of margin” for the low ISS orbit to save money. For missions to geostationary orbit and beyond, the company has a concept it calls “Jupiter Electric” that uses solar-electric Hall thrusters designed as an upgrade for the Lockheed Martin A2100 commercial satellite bus.

“The only addition to this is the A2100 Hall-current thruster packs that we put on,” Crocker says. “It would actually be more packs than are on our A2100, but those are being designed, built and flight qualified right now.”

To power the spacecraft and its electrical systems, including the Hall thrusters, plans call for two or four fold-out solar arrays based on the lightweight Lockheed Martin arrays in use on the ISS since its P6 truss element was installed in December 2000. That sort of heritage is clearly a selling point for the CRS-2 proposal.

“This is real space,” says Crocker. “It’s a real interplanetary spacecraft; it’s a real ATV; it’s a real robotic arm; it’s a real refueling system, and the electrical portion of this is basically our commercial A2100 Hall-current thruster system, with the arrays that you see. If you’re trading weight and power, there’s a reason the station arrays are like that.”

With the modular approach, the heritage hardware used on Jupiter would be “extensible” to Mars, says Crocker, using a buzzword popular in human-exploration circles (AW&ST June 23, 2014, p. 44). The team is working on rigging the pressurized-cargo section as a habitat. Crews could use it at a human-tended deep-space outpost in one of the stable orbits near the Moon—distant retrograde orbit or the Earth-Moon L2 Lagrangian point—that NASA is eyeing as a “proving ground” for Mars-exploration vehicles, and Crocker says the Jupiter hardware also could serve a resupply function there or for bases on the lunar surface. “If we didn’t see a market for this beyond the space station, we wouldn’t be investing the kind of dollars we’re investing in it,” he says.

Crocker says the idea has gone over well with “venture capitalists and commercial operators who really are looking for low-cost access for satellites to space,” as well as within his own company and with its international partners.

“We’ve had discussions about what other countries have a very strong interest in lunar return, going back to the Moon,” says Crocker, an experienced space-exploration engineer responsible for standing up Lockheed Martin’s new international space unit. “We’ve had a lot of discussions with our industry partners and other folks who are interested.”

The space station is the key for now—a place to refine the systems needed for the push deeper into the Solar System that the Jupiter partnership hopes to commercialize.

“It would be very difficult to afford to do this if it weren’t based on the CRS as the foundation,” Crocker says. “So I would say that while I think that ultimately this vehicle will get built, without CRS-2 as a foundation, it would be pushed way out.”