Ad Astra Begins Work on NASA Contract for VASIMR Deep Space Engine

VASIMR Propulsion at ISS Credit: As Astra Rocket Company

VASIMR Propulsion at ISS
Credit: As Astra Rocket Company

It’s certainly not warp drive, but one of the more exciting concepts for deep space propulsion is a making a significant step towards development with the following press release from Ad Astra Rocket Company. (comments follow)

PRESS RELEASE 081015, August 10, 2015 Ad Astra Rocket Company and NASA move to execution phase of NextSTEP VASIMR® partnership [Webster, Texas – for immediate release]

Ad Astra Rocket Company and NASA have successfully completed contract negotiations on the company’s Next Space Technology Exploration Partnerships (NextSTEP) award, announced on March 31, 2015, and now enter the execution phase of the project. The parties executed the contract, a three-year, fixed price agreement, on August 7, 2015 for a total value of just over $9 million. The agreement is structured as a one-year contract with two additional one-year extensions based on the accomplishment of mutually agreed upon progress milestones. NASA’s Advanced Exploration Systems Program sponsors NextSTEP awards in a 50/50 cost partnership with industry. Under this award, Ad Astra will conduct a long duration, high power test of an upgraded version of the VX-200™ VASIMR® prototype, the VX-200SS™ (for steady state), for a minimum of 100 hours continuously at a power level of 100 kW. These experiments aim to demonstrate the engine’s new proprietary core design and thermal control subsystem and to better estimate component lifetime. The tests will be conducted in Ad Astra’s large, state-of-the-art vacuum chamber in the company’s Texas facility.

Since its inception in 2005, Ad Astra has continued to advance the technology readiness level (TRL) of the VASIMR® engine almost exclusively with private funding. This funding enabled the company to complete more than 10,000 successful high power firings, demonstrating the engine’s excellent reliability and performance (6 N thrust, 5000 sec Isp at greater than 70% efficiency) with no measurable signs of engine wear.

To optimize company resources, these tests were of short duration (less than 1 minute), but sufficiently long to reliably establish the rocket’s performance and measure thermal loads. Now, a longer duration test is needed to validate the new rocket core design for extended operation in space. Going forward in partnership with NASA under the NextSTEP award, Ad Astra continues the technology maturation of the VASIMR® to a TRL level greater than 5, a step closer to flight.

“We are proud of our accomplishments and thrilled by this announcement, which gives us a big boost toward space,” said Dr. Mark D. Carter, Ad Astra’s Sr. VP, Technology Development. “I am proud to be a be part of this project, an example of a progressive commercial-NASA partnership, seeking to advance the United States’ electric propulsion capability for the future of spaceflight,” said Dr. Jared P. Squire, Ad Astra’s Sr. VP, Research. Drs. Carter and Squire are leading the project at Ad Astra as Principal and Co-Principal Investigators respectively.


Short for Variable Specific Impulse Magnetoplasma Rocket, VASIMR® works with plasma, an electrically charged gas that can be heated to extreme temperatures by radio waves and controlled and guided by strong magnetic fields. The magnetic field also insulates nearby structures so exhaust temperatures well beyond the melting point of materials can be achieved. In rocket propulsion, the higher the temperature of the exhaust gases, the higher their velocity and the higher the fuel efficiency. Plasma rockets feature exhaust velocities far above those achievable by their chemical cousins, so their fuel consumption is extremely low.


A US Delaware corporation established in 2005, Ad Astra Rocket Company is the developer of the VASIMR® engine, an advanced plasma space propulsion system aimed at the emerging in-space transportation market. Ad Astra also owns and operates supporting research and development subsidiaries in the US and Costa Rica. Through its subsidiaries, the company also develops earthbound high technology applications in renewable energy, advanced manufacturing and applied physics. Ad Astra has its main laboratory and corporate headquarters at 141 W. Bay Area Boulevard in Webster, Texas, USA, about two miles from the NASA Johnson Space Center

End Release

Note: Ad Astra’s VASIMR technology has been subject to withering criticism over the years, including from the always voluble Robert Zubrin who went as far as to call it a “hoax” in this 2011 Space News editorial.

The problem is not with the VASIMR concept itself, which, as the press release notes has been clearly demonstrated in the lab, but instead with the absence of a suitable power source in space. VASIMR has the capacity to produce some stunning specific impulses at a thrust significantly higher than that produced by solar electrical ion engines. The trade-off is that the mass of the solar panel array required to power VASIMR is such that it negates much of the benefits. For example the International Space Station has 8 solar “wings” each capable of producing a maximum output of 32.8 kw, meaning that at present it would take something similar to the station’s acre of solar panels to provide the power for the 200 kw engine Ad Astra is currently testing. Foreseeing just that possibility, NASA and Ad Astra signed a Space Act Agreement in 2008 with the goal of eventually testing VASIMR  aboard the Station, where it could prove beneficial in counteracting drag.

ISS, with its enormous solar array however, is a rather unique asset, and one consistent point made by critics is that it may be the only place where VASIMR has a near-term future. As you might expect, Ad Astra takes a very different view, and has proposed a variety of possible missions such as orbital debris removal and asteroid re-direct. One of the most interesting however, is a mission concept which would see a VASIMR equipped reusable space tug fly closer to the sun in order to take advantage increased solar efficiency, and then fling robotic craft towards the outer solar system at much higher velocities, and thus shorter cruise times, than is presently achieved.

While those applications are still a ways off, and in the latter case certain elected officials are hostile towards anything which is perceived as threatening SLS, every advance in solar conversion efficiency or in the development of lower mass space solar arrays is also an advance for VASIMR. And, as the program name implies, NextSTEP is by definition a forward-looking effort. In other words, this is exactly the sort of thing NASA should be doing.

Along those lines..

There is an obvious alternative to VASIMR’s power problem; a compact space-rated nuclear reactor would neatly solve the issue, but regrettably there is no funded effort currently underway to develop one. That fact however, speaks to a none-to0-surprising lack of leadership in successfully arguing the case for a core technology widely understood to be essential for a permanent future in space.

YouTube Video of VASIMR Presentation to ISS R&D Conference




Posted in: Advanced propulsion

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