NASA's Maven orbiter entered Martian orbit on Sunday after a journey of 10 months and 442 million miles, opening the way for a mission that could reveal what happened to the Red Planet's air and water.
The $671 million mission is designed to study Mars' upper atmosphere for one Earth year. But if Sunday's engine firing had gone awry, all that money and work would have gone for nothing. Fortunately, the bus-sized spacecraft's six rocket engines did the job, although mission managers reported that it took slightly longer than the planned 33 minutes.
Because of the distance between Earth and Mars, the readings confirming a successful burn were received at Maven's mission control center near Denver about 12.5 minutes after the spacecraft shut down the engine. Team members had brought peanuts and Mars candy bars to the Lockheed Martin facility as good-luck treats.
"Congratulations, Maven is now in Mars orbit," Dave Folta, mission design and navigation lead, told the team. That long-awaited word sparked an eruption of applause and hugs.
The University of Colorado's Bruce Jakosky, principal investigator for the Maven mission, noted that it's taken 11 years of planning to get the spacecraft to Mars. "I think my heart's about ready to start again," he said during a post-burn news briefing.
Sunday's maneuver put Maven into a highly elliptical pole-to-pole orbit, ranging in altitude from 236 miles to 27,700 miles (380 kilometers to 44,600 kilometers). Over the next several weeks, additional maneuvers will put the spacecraft into the prescribed orbit for its science mission, which will range as close as 77 miles (125 kilometers).
How Mars lost its mojo
Maven's name comes from an acronym that stands for Mars Atmosphere and Volatile EvolutioN. The spacecraft's observations are expected to help scientists figure out how Mars lost most of its atmosphere over the course of billions of years — a phenomenon that turned it from a world with liquid water that could have sustained life to the cold, dry planet we see today. Mars' current atmosphere, dominated by carbon dioxide, is only 1 percent as dense as Earth's.
Scientists suspect that storms of charged particles from the sun stripped off molecules from the upper atmosphere. Maven will measure the current rate of atmospheric loss — valuable data that will be factored into computerized climate models for Mars.
"We measure these things today even though the processes we're interested in operated billions of years ago," Jakosky explained during a briefing last week.
Maven won't just be answering questions about ancient Mars. The planet appears to be going through an upswing in dust storms, said Richard Zurek, chief scientist for the Mars Program Office at NASA's Jet Propulsion Laboratory. Maven is arriving "just in time to see the imprint of that on the atmosphere of Mars," Zurek said during a Planetary Society webcast.
In a statement, NASA Administrator Charles Bolden said Maven's findings about the Martian environment will "better inform a future mission to send humans to the Red Planet in the 2030s."
Comet encounter ahead
On Oct. 19, Maven will be on hand for Mars' close encounter with Comet Siding Spring, which is due to come within 82,000 miles (132,000 kilometers). The comet isn't expected to damage NASA's orbiters or rovers, but Maven will be well-placed to measure the effect of cometary debris on the atmosphere.
In addition to its scientific studies, Maven is due to serve as a backup relay satellite for NASA's Curiosity and Opportunity rovers, as well as the InSight lander that's due for launch in 2016. The space agency's two existing relays, Mars Reconnaissance Orbiter and the Mars Odyssey orbiter, already have exceeded their design lifetimes.
Maven is also carrying a "best-of" DVD encoded with digitized files for 100,000 names of Earthlings, 377 student art projects and more than 1,000 haiku poems — all collected as part of the mission's outreach activities.
On Tuesday, India's Mars Orbiter Mission spacecraft is due to join the armada of spacecraft at Mars — an armada that also includes the European Space Agency's Mars Express orbiter. The MOM orbiter, also known as Mangalyaan (Hindi for "Mars-Craft), will conduct complementary studies of the Martian atmosphere as well as the planet's surface.
Unlike Maven, MOM can make detailed measurements of atmospheric methane — which some scientists see as a potential indicator of biological activity on Mars.