The success of the SpaceX/Dragon resupply mission to the International Space Station has not been lost on Ad Astra Rocket Co., a seven-year-old venture focused on the development of advanced electric plasma propulsion systems for commercial in-space transportation.

“That is the proof in the pudding,” says Jared Squire, Ad Astra’s senior vice president for research, of the nine-day SpaceX pathfinder mission nurtured by NASA’s Commercial Orbital Transportation Services (COTS) program. “That type of relationship works.”

Ad Astra envisions a similar NASA initiative to foster the next step beyond orbital cargo missions — the private sector delivery of supplies to the Moon’s L-1 and L-2 Lagrange points, asteroids and to Mars orbit powered by the company’s Variable Specific Impulse Magnetoplasma Rocket (Vasimr) in support of future human deep-space exploration.

Squire is not prepared to suggest a figure, but COTS will channel $396 million to SpaceX as a development partner. Hawthorne, Calif.-based SpaceX, founded by billionaire Elon Musk, expects to begin regular cargo delivery missions to the station later this year under a $1.6 billion, 12-flight NASA contract signed in late 2008.

“We are thinking of something similar,” Squire says. “If you have the surface-to-orbit capability in a reliable way, now you need an orbital transfer vehicle — a vehicle that can take large payloads and deliver them wherever in space efficiently. Electric propulsion in general has a capability to do that, and in the near term solar-electric has a lot of potential.”

In addition to deep-space deliveries, Ad Astra is looking at a Vasimr-powered spacecraft for the removal of menacing orbital debris.

The technology is the brainchild of Franklin Chang-Diaz, Ad Astra CEO, who nurtured the project while a grad student in physics at Massachusetts Institute of Technology and then as an astronaut at NASA’s Johnson Space Center.

In late May, Ad Astra and NASA expanded a five-year-old Space Act Agreement (SAA) focused on further Vasimr development to begin the safety, reliability and mission assurance phase of the project. The amendment commits the equivalent of one full-time NASA expert to the safety process in exchange for an agency knowledge gain in the technology.

The long-running SAA, which does not involve an exchange of funds, is leading toward the launch of a 200-kw Vasimr prototype to the space station or an independent orbiting free-flyer in the 2015 timeframe for a three-year checkout of performance and reliability, Squire says.

The notional launch target has slipped a year and remains vulnerable to NASA budgeting and the future of the station’s status as a national laboratory. While Ad Astra has not committed to a launch provider, Orbital Sciences Corp. appears to provide the best match. Orbital Sciences represents NASA’s second COTS partner, and is developing the Cygnus/Antares system for that mission. A test-flight success similar to SpaceX’s will make Orbital Sciences eligible for $1.9 billion under an eight-flight ISS supply mission agreement with NASA, also awarded in 2008.

Like SpaceX, Ad Astra envisions a future role in human space transportation. Theoretically, a nuclear-powered version of Vasimr could speed a human crew to Mars in 39 days, versus 7-10 months with conventional propulsion.

The VF-200-1 prototype envisioned for the space station would operate under battery power — perhaps something similar to the battery specified for the sporty electric Tesla roadster, another Elon Musk initiative. Even with vast solar power, the station’s electrical grid could not meet Vasimr’s sustained power demands, Squire says.

From there, Ad Astra would look to advanced space solar power for electricity. Vasimr outperforms its chemical rivals by heating a gas fuel to super-high temperatures with focused radio waves. The resulting plasma is contained and directed with a protective magnetic field generated by superconducting magnets.

In ground vacuum-chamber testing, Ad Astra has relied on argon as a fuel source. But a switch to heavier krypton, which offers higher thrust at lower specific impulse under power limitations, is being evaluated.