[meteorite-list] Rocket Burn Puts Indian Probe on Course to Mars

[Ron Baalke]

http://www.spaceflightnow.com/pslv/c25/131130departure/

Rocket burn puts Indian probe on course to Mars
BY STEPHEN CLARK
SPACEFLIGHT NOW
November 30, 2013

India's first robotic Mars probe set sail for the red planet Saturday 
with a vital rocket burn to catapult the spacecraft out of the realm of 
Earth's gravity and into interplanetary space.

The Mars Orbiter Mission, India's first Mars probe, is due to enter orbit 
around the red planet on Sept. 24, 2014, two days after NASA's MAVEN Mars 
probe arrives.

Saturday's crucial maneuver was timed for the precise moment necessary 
to send the spacecraft toward Mars, and it had to go off without a hitch.

India's space agency said the orbiter's burn was successful, with the 
spacecraft's main engine firing more than 22 minutes starting at 1919 
GMT (2:19 p.m. EST) to gain speed and break free of Earth's gravitational 
influence.

"Following the completion of this maneuver, the Earth orbiting phase of 
the spacecraft ended. The spacecraft is now on a course to encounter Mars 
after a journey of about 10 months around the sun," the Indian Space Research 
Organization said in a written statement.

The $72 million mission has a trip of more than 400 million miles ahead 
of it. The probe will fly halfway around the sun while moving out toward 
the orbit of Mars, intercepting the red planet Sept. 24 for another major 
rocket maneuver to place itself into orbit.

If the probe arrives successfully, India's space agency will become the 
fourth entity to have a mission reach Mars. The United States, Russia 
and the European Space Agency have already done it.

The Mars Orbiter Mission launched Nov. 5 on India's Polar Satellite Launch 
Vehicle, the smaller but more reliable of the nation's two rockets.

The PSLV was not powerful enough to put the nearly 1.5-ton spacecraft 
on a direct trajectory to Mars. Instead, engineers devised a departure 
profile that put the probe into an oval-shaped orbit around Earth and 
used its on-board engine to gain speed and altitude throughout November, 
eventually generating enough energy to escape the planet's grasp.

Indian controllers used the time to activate the spacecraft's systems 
and research payloads, including the mission's camera which snapped a 
photo of Earth. All systems on the spacecraft are performing well, according 
to ISRO.

The decision to launch on the PSLV removed the risk of launching on India's 
larger failure-prone Geosynchronous Satellite Launch Vehicle, which could 
have put the mission immediately on the path to Mars.

But it also raised other risks.

The probe repeatedly passed through Earth's Van Allen radiation belts. 
Indian officials mitigated the threat by beefing up the craft's computers 
with radiation shielding.

And it meant the probe had to carry more propellant, leaving less room 
for scientific instruments and decreasing the fuel left over to survey 
Mars once it arrives there.

The Indian mission carries about 33 pounds, or 15 kilograms, of scientific 
instrumentation.

Operating from a perch taking the spacecraft from just above the Martian 
atmosphere to a peak altitude of nearly 50,000 miles, the Mars probe will 
observe the planet with five science instruments, gathering data on the 
history of the Martian climate and the mineral make-up of its surface.

The mission carries a color imaging camera to return medium-resolution 
pictures of the Martian surface, a thermal infrared spectrometer to measure 
the chemical composition of the surface, and instruments to assess the 
Mars atmosphere, including a methane detector.

Scientific assessments of methane in the Martian atmosphere have returned 
mixed results.

Methane is a potential indicator of current microbial life on Mars, but 
some types of geologic activity can also produce trace levels of the gas.

Following up on detections from ground-based telescopes and Europe's Mars 
Express orbiter, NASA's Curiosity rover measured no methane in the Martian 
atmosphere when it sucked air into its internal instrument suite on several 
occasions since landing in August 2012.

But India says the Mars Orbiter Mission's prime purpose is technological, 
not scientific.

"First and foremost, India should be able to orbit a spacecraft around 
Mars," ISRO chairman K. Radhakrishnan told India's NDTV television network 
before the mission's launch. "We are moving from Earth's orbit to the 
orbit of Mars through a long cruise phase around the sun."

The mission's ground team plans several course-correction burns over the 
10-month trip to Mars, with the first set for Dec. 11. The midcourse maneuvers 
will tweak the probe's trajectory to arrive at Mars at the right time 
and in the correct position in September 2014.