NASA - National Aeronautics and Space Administration

AD ASTRA ENGINEERS POSITION THE 200 KW VASIMR® PROTOTYPE PLASMA ROCKET ENGINE IN THE COMPANY S LARGE VACUUM CHAMBER TO PREPARE FOR FULL POWER TESTING. THE ENGINE WAS DEVELOPED THROUGH A PARTNERSHIP BETWEEN AD ASTRA AND NASA JOHNSON SPACE CENTER. By Tim Glover Ad Astra Rocket Company

Michele Brekke NASA Johnson Space Center

The recent interest of commercial and government entities in sending payloads to the moon has generated a substantial, ongoing demand for costeffective transport from lowEarth orbit to the lunar surface.

One technology that may make lunar transport more economically affordable is being developed by Ad Astra Rocket Company through a partnership with NASA’s Johnson Space Center (JSC) – the Variable Specific Impulse Magnetoplasma Rocket (VASIMR®) engine. Ad Astra’s models indicate that the VASIMR® technology could economically meet the needs of this emerging market.

Ad Astra is based in Webster, Texas, where it has its main laboratory and corporate headquarters and is led by founder Franklin ChangDiaz, a seventime space shuttle astronaut and rocket scientist. Ad Astra also owns and operates Ad Astra Rocket Company inCosta Rica. ChangDiaz developed the VASIMR® concept while with NASA’s astronaut corps. After leaving NASA, he established Ad Astra and partnered with NASA to license, develop and commercialize the technology. As company CEO, ChangDiaz has directed the technology maturation that comprises the company’s intellectual property portfolio.

In his July 8, 2009, testimony to the U.S. Senate Committee on Commerce, Science and Transportation, NASA's new administrator, Charles Bolden, said this of Ad Astra's leader,“Franklin ChangDiaz, who is my idol, another astronaut who now is in the entrepreneurial space business, has a plasma rocket engine that if it works, and I operthink it will, will take us to Mars in 39 days instead of eight to 11 months. NASA provided him a very small stipend to get started and to bring his project to what we call the technology readiness level one, two and three. And now he's at the point where it's ready to fly. But he has done that with what they call venture capitalists, private investors.”

Ad Astra entered into its first agreement with JSC in 2005, receiving the use of onsite lab space for the initial development of the VASIMR® engine. NASA also provided an engineer, who assisted with facility safety and the development of the superconducting magnets used in the technology. The VASIMR® engine operates by heating argon gas to extremely high temperatures with radio waves in a strong magnetic field. Propulsion is produced as this energized plasma escapes along the magnetic field lines. The argon plasma at the core of the VASIMR® engine reaches temperatures nearly as high as those within the sun – millions of degrees Fahrenheit. At this high temperature, the engine ejects its propellant at speeds more than 10 times those of the best chemical rockets, which makes the rocket significantly more efficient than conventional rockets and even more efficient than highefficiency electric thrusters.

Use of the highly efficient VASIMR® engine could make lunar base support more economical by greatly reducing the mass of propellant required to transfer payloads from lowEarth orbit to lowlunar orbit. It also should accelerate planetary exploration by reducing flight times and by increasing the mass that can be delivered to other planets with existing launch vehicles.

Ad Astra has, through a privatization agreement with NASA, obtained an exclusive license to the original VASIMR® patents, thereby positioning itself as the premier developer for an electric rocket technology that may one day take mankind to Mars and beyond.

A New Type of Agreement
There is now in place an openended agreement that allows NASA to establish specific tasks as the VASIMR® technology and product line mature. JSC is providing Ad Astra with parttime liaison support to facilitate dialogue with subject matter experts. This support facilitated the most recent negotiations with NASA and the International Space Station (ISS), laying the groundwork for the partnership agreement to have the new plasmabased propulsion technology installed and tested on the ISS.

This is the first such agreement for a privately funded payload on the ISS exterior, and it represents an expansion of NASA’s plans to operate the U.S. portion of the space station as a national laboratory. (See article about the ISS National Laboratory on page 57.) The Space Act Agreement for the VASIMR® ISS project specifically describes it as the pathfinder project for external payloads under the National Lab program.

NASA and Ad Astra envision that the VASIMR® engine will be launched to the ISS and tested, for the first time, in the vacuum of space. The Space Act Agreement allows for the feasibility assessment of this venture, ranging from what vehicles will be used to transport the payload (approximately the size of a small car), to how to provide power to run the test firing.

As conceived at present, the engine will be attached to a truss of the space station, where ISS electrical power will be used to tricklecharge a large battery bank. This unique space station payload will operate in 10minute, 200kilowatt pulses, directing its thrust slightly off the center of the ISS’s mass and imparting a small torque on the station with each firing. Detection of this small torque by existing ISS equipment will serve as a direct measurement of the VASIMR® thrust, making the entire ISS a sensitive thrust stand.

Once continuous megawatt power levels become available through either solar or nuclear space power plants, the VASIMR® technology could emerge as a great enabler of manned flights to Mars, due to the reduced flight times made possible by its continuous thrust and high exhaust velocity.

Possible commercial applications include reboost of space stations in lowEarth orbit to cancel the effects of atmospheric drag. Simple cost models demonstrate that continuous thrust by a VASIMR® thruster would keep stations in orbit at much lower cost than periodic reboosting with chemical rockets.

The partnership between Ad Astra and NASA’s Innovation Partnerships Office allows Ad Astra to gain situational awareness of NASA’s commercial space concepts, with the IPP Office as a resource to the company. Meanwhile, NASA is able to stay abreast of commercial space propulsion concepts and to better understand commercial business practices.

Tim Glover is director of development for Ad Astra Rocket Company, and Michele Brekke is director of the Innovation Partnerships Office at NASA’s Johnson Space Center. For more information contact Tim Glover at tim.glover@adastrarocket.com. Please mention that you read about it in Technology Innovation.