Indian, US spacecraft arrive at red planet on separate missions

NASA's MAVEN spacecraft began orbiting the red planet on Sunday, on a mission to study how climate changed over time from warm and wet to cold and dry.

The unmanned orbiter has traveled more than 10 months and 711 million km to reach Mars for the first detailed look at the planet's upper atmosphere.

"Wow, what a night. You get one shot with Mars orbit insertion, and Maven nailed it tonight," NASA project manager David Mitchell said.

The data from the Mars Atmosphere and Volatile Evolution spacecraft aims to help scientists understand what happened to the water on Mars and the carbon dioxide in its atmosphere several billion years ago.

How Mars lost its atmosphere is one of science's biggest mysteries. The answers could shed light on the planet's potential to support life - even if that was just microbial life - long ago.

MAVEN's findings are also expected to help add to knowledge of how humans could survive on a future visit to Mars, perhaps as early as 2030.

"Mars is a cool place, but there is not much atmosphere," said John Clarke of the MAVEN science team.

"It is very cold - well below zero. The atmosphere is about half a percent of what we are breathing," he said.

"But we know that Mars could change, and it was probably different in the past. There is a lot of evidence of flowing water on the surface from Mars's ancient history."

MAVEN will now enter a six-week phase for tests, before starting a one-year mission to study the gases in Mars' upper atmosphere and how they interact with the sun and solar wind.

"We are looking at early November as the official start of science," said Maven's principal investigator Bruce Jakosky.

Much of MAVEN's year-long mission will be spent circling the planet 3,730 miles above the surface.

Meanwhile, India's Mars Orbiter Mission entered the planet's gravitational sphere of influence on Monday ahead of its scheduled orbit insertion on Wednesday, the Indian Space Research Organization announced on its Facebook page.

The spacecraft was within 540,000 km of Mars' gravity, it said.

Xinhua - AFP

(China Daily 09/23/2014 page10)