A NASA robotic spacecraft fired its braking rockets on Sunday, ending 442 million miles to put itself into orbit around Mars and begin a hunt for the planet's lost water.
After traveling for 10 months, the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft fired its six rocket thrusters, trimming its speed from 12,800 mph to 10,000 mph.
The 33-minute engine firing left MAVEN in the clutches of Mars' gravity as it flew over the planet's north pole and slipped into a looping 236-mile by 27,713-mile high orbit.
"I don't have any fingernails anymore, but we made it," Colleen Hartman, NASA deputy director for science at Goddard Space Spaceflight Center in Greenbelt, Md., said during a NASA Television broadcast of MAVEN's arrival.
Flight control teams burst into cheers and applause as radio signals from MAVEN confirmed it was in Mars orbit at 10:25 p.m.
Over the next several weeks, MAVEN will lower its altitude until it reaches its 93-mile-by-3,900-mile operational orbit.
That’s when the real work will begin for the $671 million mission.
Flight controllers in Colorado will spend the next six weeks adjusting Maven's altitude and checking its science instruments. Then Maven will start probing the upper atmosphere of Mars. The spacecraft will conduct its observations from orbit. As long as a school bus, from solar wingtip to tip, and as hefty as an SUV, the craft is not meant to land.
Scientists believe the Martian atmosphere holds clues as to how Earth's neighbor went from being warm and wet billions of years ago to cold and dry.
MAVEN will study how the solar wind strips away atoms and molecules in the planet's upper atmosphere, a process that scientists believe has been underway for eons.
"By learning the processes that are going on today we hope to extrapolate back and learn about the history of Mars," MAVEN scientist John Clarke, with Boston University, said in an interview on NASA Television.
The planet's surface is riddled with what appear to be dry riverbeds and minerals that form in the presence of water.
But for water to pool on the planet's surface, its atmosphere would have had to be much denser and thicker than it is today. Mars' atmosphere is now about 100 times thinner than Earth's.
Scientists suspect Mars lost 99 percent of its atmosphere over millions of years as the planet cooled and its magnetic field decayed, allowing charged particles in the solar wind to strip away water and other atmospheric gases.
Learning about how Mars lost its water is key to understanding if the planet most like Earth in the solar system ever could have supported life.
This is NASA's 21st shot at Mars and the first since the Curiosity rover landed on the red planet in 2012. Just this month, Curiosity arrived at its prime science target, a mountain named Sharp, ripe for drilling. The Opportunity rover is also still active a decade after landing.
All these robotic scouts are paving the way for the human explorers that NASA hopes to send in the 2030s. The space agency wants to understand as much about the Red Planet as possible before it sends people there.
The MAVEN mission is scheduled to last one year. The spacecraft joins two other NASA orbiters, two NASA rovers and a European orbiter currently working at Mars. A seventh Mars probe owned by India is scheduled to arrive on Wednesday.
Al Jazeera and wires services