Mars, and Step on It
When it’s not the journey but the destination that counts.
- By Michael Klesius
- Air & Space magazine, September 2009
(Page 2 of 4)
Millis has compiled the results of the Breakthrough Propulsion Physics Project and related work into a book of technical articles, The Frontiers of Propulsion Science, and members of the Tau Zero Foundation continue to exchange ideas and debate strategies, though a program no longer exists to fund experiments and observation. “We talk among ourselves and encourage each other to launch into projects,” says Millis, “and we’ve been very successful with that, even without money.” One member, for example, is revisiting the British Interplanetary Society’s Daedalus program. Daedalus is a 1970s effort to invent a practical starship powered by nuclear fusion, the process in which extreme pressures and temperatures cause the nuclei of atoms to join, releasing energy. The society is holding a symposium this month to reconsider the idea in light of the advances in relevant technologies made over the past 30 years.
“I think back to the era of Dirac and Schrödinger and Einstein,” says Millis of the great theoretical physicists of the early 20th century, Paul Dirac and Erwin Schrödinger, who shared a Nobel Prize in 1933 for groundbreaking work in quantum mechanics. “When they were having their pivotal meetings and sometimes heated debates, they weren’t being funded for that work. They were just doing it because that’s what they did. And they made significant advances.
“And I’m thinking to myself, Well, it would be great if we got funding, but even if we don’t, when we talk amongst ourselves and debate things and encourage each other to write papers, we’re going to make progress.”
Millis estimates that, based on the energy needs as we understand them now, the first true interstellar mission won’t happen for another two centuries. And he chuckles at a common paradox voiced in his field: It’s useless to launch an interstellar mission, because future spacecraft, benefitting from technological advances, will overtake those launched earlier.
But he’s far from cynical.
“I grew up watching Apollo, and the systematic and well-thought-out march to that. And they did it. When you look into pioneering topics, there are those people who don’t want to touch it because it’s too far out there. But if it’s mature enough for you to at least start asking the right questions, and you do an honest job, then you can be a pioneer.”
For now, traveling to the stars will have to wait; the challenges close to home are big enough. On a clear night, we glimpse five planets with the naked eye: Saturn and Jupiter, bitter cold gas giants with poisonous atmospheres; Mercury and Venus, furnaces that would incinerate us; and Mars, a planet of extremes. At least they are Earth-like extremes: desert barrenness, as frigid in winter as Antarctica. It is also wrapped in a thin atmosphere of carbon dioxide, but humans have to bring their own environments wherever they travel in space. And it’s close—roughly 36 million miles away at its closest approach.
With rockets fed by liquid oxygen and liquid hydrogen, it would take us a little longer than a year just to get to Mars and back—200 days each way. The long-term exposure to radiation on such lengthy missions could endanger the astronauts.
Bill Emrich, a propulsion engineer at NASA’s Marshall Space Flight Center in Huntsville, Alabama, is one of the people pondering how to get to Mars a lot faster. In 2003, the Marshall center started work on the Propulsion Research Laboratory, where Emrich could investigate powerplants that would cut the transit time to Mars from 200 days to 100.