|Franklin Chang-Diaz. Photo c/o Ad Astra Rockets.|
by Brian Orlotti
Ad Astra Rockets, the Houston-based company founded by a former NASA astronaut to develop a new type of space propulsion, is raising money via Kickstarter to make a documentary explaining the technology.
"Our goal is to produce a full-length video, full of stunning animations that describe the way in which we intend to use our technology to transform space transportation," Franklin Chang-Diaz, retired NASA astronaut and founder of Ad Astra Rockets, said in the Houston-based firm’s Kickstarter video describing the planned documentary.
Chang-Diaz holds a doctorate in plasma physics from the Massachusetts Institute of Technology (MIT) and became an astronaut in 1980, flying on seven NASA space shuttle missions. He founded Ad Astra in 2005 to work on the Variable Specific Impulse Magnetoplasma Rocket (VASIMIR).
|VASIMR is a high efficiency plasma drive with the interesting ability to "shift gears" by trading exhaust velocity for thrust and vice versa. For more details, check out the March 1995 NASA technical paper Rapid Mars Transit with Exhaust Modulated Plasma Propulsion and the 2004 MarsWeek Conference paper VASMIR: Express Flight to Mars. Graphic c/o Atomic Rockets website.|
The VASIMIR engine uses radio waves to ionize and heat a propellant 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 main 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.
The technology does have disadvantages. VASIMIR’s low thrust-to-weight ratio and its need for a vacuum to operate make it unsuitable for launching payloads from Earth’s surface.
Chang-Diaz has pitched VASIMIR as a breakthrough technology that would enable a crewed mission to reach Mars in less than 40 days, compared to 2.5 years using chemical rockets. VASIMIR’s ‘always-on’ ability (i.e. constant thrust) would greatly reduce travel time and, by extension, mission risk. But Ad Astra's founder forsees many other applications for VASIMIR, including:
- Orbital reboosting of space stations
- Lunar cargo delivery
- Satellite repositioning, refueling, maintenance and repair
- Cleanup of ever-growing ‘space junk’
- Ultra-fast deep space robotic missions
VASIMIR is not without its critics, however. For the past few years, Chang-Diaz and VASIMIR have been engaged in a feud with Mars Society President Robert Zubrin (a first outlined in the August 1st, 2011 Space Review article ‘VASIMIR and a new war of the currents’). Zubrin, a nuclear & astronautical engineer, has attacked VASIMIR on various technical and ideological grounds. In his acidic July 11th, 2011 Spacenews article ‘The VASIMIR Hoax,’ Zubrin referred to VASIMIR as a “hyper drive” and “hoax” which “must be exposed”.
|This book, outlining interesting lessons from the past, is also useful for understanding space advocacy issues today. It's freely available, in PDF format, from the National Space Society (NSS) website.|
Zubrin’s main criticisms of VASIMIR are that it is less efficient than other types of electric thrusters now in use, requiring unrealistically efficient power sources, and that electric propulsion is not necessary to reach Mars (and so its development should not be funded). To his credit, Chang-Diaz has kept his poise throughout, never stooping to Zubrinesque histrionics, but calmly addressing criticisms point-by-point an in this press release on the Facts About the VASIMR Engine and its Development, from the Ad Astra Rocket website.
The VASIMIR feud seems to be a reflection not so much of the technology itself but rather of the weakness and ineffectuality of traditional space advocacy groups. We see the same tired parochialism; the endless squabbling over the thin slices of a shrinking pie rather than the coming together to grow the pie.
For all its flaws, VASIMIR is a technology that has, clearly, captured the imagination (and dollars) of many. Ad Astra's Kickstarter campaign has seen impressive results.
Over 33 days from July 9th - August 12th, 2013, Ad Astra Rockets surpassed its $46,000 USD goal, receiving over $76,000 in pledges as of early Monday morning (August 12th). With this new influx of funds, Chang-Diaz can now spread the word on VASIMIR to a larger audience. Kickstarter is to Chang-Diaz what Collier’s was to Von Braun.
Winning the public’s hearts and wallets will achieve more than sectarianism ever will.
|In the 1950s, Collier's Magazine published a series of articles on how "Man will Conquer Space Soon," based on the plans of Willy Ley, Werner von Braun and others, which helped popularize the idea of space travel and led directly to the Apollo program.|