The launch window for NASA’s next Mars mission opens on Nov. 18 — in two weeks the spacecraft will hopefully be on its merry way to investigate the atmosphere of the infamous Red Planet.
MAVEN (short for Mars Atmosphere and Volatile EvolutioN) was largely spared the furloughs from the government shutdown because its launch is very much a matter of precise timing, and if they don’t go now, well, the next time the mission can fly in its current configuration will be 2016. Loyal Our Space readers will know that time is money in spaceflight. Miss your launch window and the same trip could take far longer and would take a lot more fuel to get there. More fuel means more weight, which means a bigger rocket, which in turn means more money.
But if all goes well MAVEN will make its first hop in the early afternoon. Once in space it will embark on a quiet cruise, coasting along in the direction where Mars will be in September 2014. And then it slow down enough to be captured by Mars’ gravitational pull and enter an elliptical orbit, which will bring it to a mere 92 miles above the planet’s surface several times before whipping out into space again.
For a spacecraft exploring the tenuous atmosphere of a planet those entry-and-exit orbits are pretty exciting: scientists will be able to explore changes in atmospheric pressure in greater detail and to far greater distances than a boring ole’ circular orbit would allow.
Why do we care what the air on Mars is like? You and I will probably never take a vacation there, so why bother?
It’s a fair question. But the little kid next door who will grow up to be a Mars explorer may beg to differ! And it’s not just all about us, either.
Unlike the Earth, Mars lost its magnetic field a long time ago. No magnetic field means no protection against the ferocious solar wind and those nasty charged particles the sun ejects at mind-boggling speeds on a constant basis. And that means it can rip the atmosphere right off a planet. Less air means also less barometric pressure. Less barometric pressure means water boils at far lower temperatures that what we’re used to. Water vapor hangs around in the atmosphere, and — you guessed it — there it goes, bye-bye, Gone With The Solar Wind.
We all know Mars is a very dry place these days. We also know it was once fairly wet. The Phoenix Lander discovered frozen water ice near the north pole a few years ago, so there’s still a little bit left. So part of what MAVEN is trying to figure out is estimate the rate at which the Martian air and water vapor are being pulled off the planet. And remember, future explorers (like the perky kid next door) will be very happy if they don’t have to haul massive quantities of water along (water is heavy, more weight means more fuel, more fuel means more money, yadda yadda, you know the drill by now).
But it will also give us a good idea of what might be in store for our own fair planet, if and when its magnetic field fails.
Of course, we’ll probably have messed it up for good long before that happens. As human beings, we’re not being very responsible caretakers of our home planet most of the time. We’re all guilty of that.
So, good luck and godspeed, MAVEN! Catch you on the flip side.
Meanwhile, check out the MAVEN website at http://www.nasa.gov/mission_pages/maven/main/index.html
Beate Czogalla is the Professor of Theater Design in the Department of Theatre and Dance at Georgia College & State University. She has had a lifelong interest in space exploration and has been a Solar System Ambassador for the Jet Propulsion Laboratory/ NASA for many years. She can be reached at email@example.com