Washington, Feb 12 (IANS): NASA's atmosphere-sniffing Mars Atmosphere and Volatile Evolution (MAVEN) mission has embarked on a new campaign to tighten its orbit around the red planet to become a data-relay satellite for the US space agency's Mars 2020 rover.
The operation will reduce the highest point of the spacecraft's elliptical orbit from 6,200 kilometres to 4,500 kilometres above the surface, according to NASA's Goddard Space Flight Center.
NASA engineers will begin lowering the lowest part of the spacecraft's orbit into the Martian upper atmosphere over the next few days by firing its thrusters.
Taking the advantage of drag of the Mars' upper atmosphere, NASA engineers over the next few months, will slow the spacecraft gradually, orbit by orbit, Xinhua news agency reported on Monday.
The orbit of the four-year-old spacecraft MAVEN will not be drastically shorter than its present orbit, but even this small change will significantly improve its communication capabilities.
"It's like using your cell phone. The closer you are to a cell tower, the stronger the signal," said Bruce Jakosky, MAVEN principal investigator from the University of Colorado, Boulder.
Also, coming in about 1,500 kilometres closer will allow the orbiter to circle Mars more frequently -- 6.8 orbits per Earth day compared with 5.3 previously -- thus communicating with the Mars rovers more frequently.
At unoccupied time, MAVEN will continue to study the structure and composition of the upper atmosphere of Mars.
"The MAVEN spacecraft has done a phenomenal job teaching us how Mars lost its atmosphere and providing other important scientific insights on the evolution of the Martian climate," said Jim Watzin, director of NASA's Mars Exploration Programme.
The MAVEN has completed its two-year mission but its fuel allows it to last through 2030, NASA said.
The orbiter carries an ultra high-frequency radio that allows it to relay data between Earth and rovers or landers on Mars, including the Curiosity rover.
According to the US-based space agency, the spacecraft will circle Mars at this lower altitude about 360 times over the next 2.5 months, slowing slightly with each pass through the atmosphere.