This coming January, Ad Astra Rocket Company will test the VX-200, a full-scale ground prototype of the variable specific impulse magnetoplasma rocket (VASIMIR), first conceived in 1979 by the company's president and CEO, astronaut and plasma physicist Franklin Chang Diaz. The rocket is an attempt to improve on current space-propulsion technologies, and it would use hot plasma, heated by radio waves and controlled by a magnetic field, for propulsion. Chang Diaz believes that the system would allow rockets to travel through space at higher speeds, with greater fuel efficiency.

If the prototype demonstrates sufficient efficiency, thrust, and specific impulse on the ground, the next step will be the VF-200, a flight version of the rocket. Ad Astra plans to fly the VF-200 to the International Space Station, where it would help maintain the space station's orbit. If all this goes according to plan, Chang Diaz hopes to eventually build VASIMIRs that could travel to Mars and beyond. In advance of his appearance at the Emerging Technologies Conference this week, Technology Review talked with him about the near future of space exploration.

Technology Review: The United States now uses decades-old technology in its spacecraft. In what ways do you think the technology needs to be improved?

Franklin Chang Diaz: I've always said that in order for us to conduct a serious space-exploration program, we need to develop two things: power and propulsion. Power in space is still severely limited. Mainly, we use solar power. This is fine as long as we stay near the sun, but the issue remains that for Mars and beyond, we will need to develop nuclear electric power. If we don't, we might as well quit. We're not going to get anywhere without it.

Propulsion is the other pillar which I think is lacking. We have been going into space in venerable rockets--the technology has changed little, and will not be sufficient for us to go to Mars and to go beyond Mars.

TR: How do your ideas of power and propulsion apply to sending people to Mars?

FCD: Trips to Mars are prohibitively long and would expose the travelers to very high levels of radiation. I came to realize after my [NASA] flights that space is a tough place to be. If you're going to spend months and months drifting from one planet to another, then, like [former astronaut] John Young says, you're going to spend half the time looking out the window to the place that you came from, and the other half looking out the window to the place that you're going. They're both going to be little points of light, and you're going to discover what loneliness is all about. I think that pretty much sums it up: space is a vast void, and you're really going to have to travel fast if you're going to have any chance of surviving. I also would not want to send people to Mars on a fragile and power-limited ship. If you send people that far, you have to give them a fighting chance to survive, and the only way you can do that is if you have ample supplies of power. Power is life in space.