Monday, February 27, 2017

VASIMR Moves Forward; Franklin Chang-Diaz Remains Unbowed

          By Brian Orlotti

The Ad Astra Rocket Company's (AARC) variable specific impulse magneto-plasma rocket engine (VASIMR) has reached a major milestone towards fulfilling its NASA contract. As outlined in the February 23rd, 2017 ArsTechnica UK post, "NASA’s longshot bet on a revolutionary rocket may be about to pay off," VASIMR has been fired at 100kW for 10 seconds and at 50kW for one minute.

Now, reaping the fruits of perseverance after years of criticism, the engine’s designer stands on the verge of opening up more of the solar system to humanity.

Of course, the company still has much to do. 

In 2015, under NASA’s NEXTSTep program, AARC was awarded a three-year, $9Mln USD ($11.8Mln CDN) contract. To fulfill the contract, AARC must fire VASIMR for 100 hours at a power level of 100 kilowatts by 2018.

The VASIMR engine uses radio waves to heat and ionize a propellant (currently, argon gas), turning it into into a plasma, which is then accelerated by magnetic fields to generate thrust. The plasma provides a constant and efficient thrust, building up speed over time.

VASIMIR’s primary advantage over traditional chemical rockets is efficiency; various studies have concluded that a VASIMIR engine would use up to 90% less fuel while carrying equivalent tonnage to chemical rockets. This efficiency could greatly reduce mission costs, significantly improving the economics of spaceflight.

VASIMR is the creation of Dr. Franklin Chang-Díaz, a former NASA Space Shuttle astronaut with seven missions under his belt. In 1969, Chang-Diaz, speaking almost no English at the time, immigrated to the United States from Costa Rica to finish high school. He then earned a doctorate in plasma physics from the MIT. As of 2014, Chang-Díaz is on record (tied with Jerry Ross) for the most spaceflights. Photo c/o AARC.

In 2005, Chang-Diaz founded AARC in Houston, TX to privatize the VASIMIR engine after years of development work at the Massachusetts Institute of Technology (MIT) and NASA. In 2013, AARC ran a successful Kickstarter campaign to raise funds for developing a documentary about VASIMR, with 603 backers pledging over $76,746 USD (over $100K CDN).

A key Canadian connection to VASIMR exists. Nautel Ltd., a Nova Scotia-based firm specializing in AM/FM transmitters and radio navigational aids, built the solid-state radio emitters used in VASIMIR to heat the xenon gas into plasma. 

Nautel is also known for being the first company to develop a commercially available fully solid state broadcast transmitter and was first profiled in the November 7th, 2009 post, "Our Next Real Canadian Rocket Scientists."

Of course, Chang-Diaz has faced various challenges working toward his goals. For the past several years, he has also been engaged in a bitter, but mostly one way feud, with Mars Society President Robert Zubrin.

Zubrin penned an acidic July 11th, 2011 SpaceNews article titled, ‘The VASIMR Hoax,’ in which he referred to VASIMR as a “hyper drive” and a “hoax” which “must be exposed.” Zubrin has frequently used invitational "debates" at Mars Society conferences to question the capabilities of VASIMR, using Chang-Diaz’s absences as pretexts to slander him.

As outlined in the August 1st, 2011 Space Review article "VASIMR and a new war of the currents," Zubrin, in typically chauvinist and histrionic style, has often attacked VASIMR on technical and ideological grounds.

Zubrin’s main criticisms of VASIMR are that it is less efficient than other types of electric thrusters, requiring unrealistically efficient power sources, and that electric propulsion is unnecessary to reach Mars (and therefore should not be funded).

Chang-Diaz has kept his poise throughout, never stooping to Zubrin’s level. In the Ars Technica article, Chang-Diaz does admit that large but manageable solar arrays would be needed to provide the 1 megawatt of energy needed to power VASIMR.

However, this assumes solar energy levels at Earth’s distance from the Sun. Because solar energy quickly decreases beyond Mars, a solar-powered VASIMR will only be viable within the inner Solar System. Within these limits, however, the technology would still retain its advantages over chemical propulsion.

For travel beyond Mars, Chang-Diaz frankly admits that a nuclear power source will be needed to bring VASIMR to its full potential.

William Ernest Henley from his short poem "Invictus." Graphic c/o izquotes.

Over the years, Chang-Diaz has persevered with his creation through trying obstacles; the endless hustle of fundraising, NASA politics and the parochial pedantry of the space advocacy movement.

In addition, the fact that his goals are nearing fruition amidst a rising tide of hatred and intolerance in the US toward immigrants, particularly Spanish-speaking ones, is of no small significance.

His story is an example of the energy and enlightenment that immigrants bring to other lands.
Brian Orlotti.

Brian Orlotti is a network administrator at KPMG and a regular contributor to the Commercial Space blog.


  1. Hello Brian,

    Just wanted to do some edits for narrative, scientific, and technical precision.

    1) It's best to use the word "approximately" $9Mill USD, as the exact amount goes a little over but still under $10mill.

    2) In your paragraph discussing Nautel, the word "xenon" must be replaced with "argon". The VASIMR® engine heats ARGON gas into plasma.

    3) Discussion on Dr. Robert Zubrin...You might also want to add that Dr. Zubrin has never been to or visited our lab facilities in Houston.

    Subsequent paragraphs on solar power,

    4) The VASIMR® engine can operate effectively at less than 100kw. There's no absolute essential need for the 1 megawatt of energy for it to be able to function adequately.

    5) Additionally, a solar-powered VASIMR® engine can also travel to Mars at 200kw for cargo missions. It is human transportation to Mars in a solar-powered VASIMR® engine that would require higher power.

    6) At the end of your piece, yes, for travel beyond Mars, a nuclear power source will be needed, however this doesn't mean that the VASIMR® engine is not useful for solar-powered missions to Mars that could perfectly use the VASIMR® engine.

    7) Lastly, please be advised that VASIMR® engine is a registered trademark. It cannot be used as a noun only. It must be placed as an adjective in writing and with appropriate referencing. It's important to ensure an accurate representation and respect of the integrity of the brand and the registration.

    Please update all the proper name references as appropriate.

    "VASIMR® engine"
    "VASIMR® technology"
    "VASIMR® motor"
    "VASIMR® propelled-missions"

    Monica Hernandez Quijano (
    Global Communications Manager
    Ad Astra Rocket Company

    1. Some of the specifics of this article (such as the amount of money provided under NASA’s NEXTSTep program and the use of xenon as the propellant) were referenced in the Ars Technica post we mentioned in the article.

      But it's also worth noting that the Ad Astra Rocket Company website at states explicitly that VASIMR can use a variety of different fuels.

      According to the website, "The VASIMR® engines are capable of using almost any gas or substance with a high vapor pressure as a propellant. However, some gases are better suited to forming plasma than others, and the gas’ mass also plays an important role in rocket performance. For missions near Low Earth Orbit (LEO) and the moon, argon and krypton gas have the highest performance for a 200 kW VASIMR®. However, for missions that are much farther away, e.g. Mars or Jupiter, lighter gases are more desirable and give VASIMR an optimum performance in these cases."

      We're happy to update the post as new information becomes available.

      Chuck Black/ Editor


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