India's Mars Orbiter Successfully Completes Test Firing on Eve of Entering Mars Orbit
September 22, 2014 • 9:37AM

India's Mars orbiter, which is scheduled to be captured by Mars' orbit on Wednesday, September 24th, carried out a critical test earlier today when its engine was successfully fired for 4 seconds, after having been idled for 300 days, en route to Mars. In order for the spacecraft to be slowed down to be able to be captured into orbit by Mars' gravity, the engine must burn for 24 minutes and 14 seconds on September 24. Today's test guaranteed that the engine is responding correctly.

There is a "Plan B," should the engine fail to light. The spacecraft also has a set of eight small thrusters, which were used to make small trajectory adjustments during cruise, and would be used to adjust the spacecraft's orbit around Mars, but which could be used for orbital insertion if the engine fails. This would save the mission, but is not optimal, since it would use up fuel that otherwise is needed during orbital science operations.

All of these maneuvers must be done automatically by the spacecraft, as the communications delay between Earth and Mars is more than 12 minutes. On September 17, the final commands were uploaded to the spacecraft, and now everyone can only wait. NASA's Deep Space Network of large antennas will provide tracking for the Indian craft.

Prime Minister Modi will watch every maneuver at India's Spacecraft Control Center, beginning with the reorientation of the orbiter a few minutes before 7 am, and wait for confirmation shortly after 8 am that the satellite is in orbit around Mars. He will then address the Indian Space Research Organization team, as he had previously done as Chief Minister of Gujarat.

On Sunday, NASA's MAVEN spacecraft, another Mars orbiter, successfully entered Mars' orbit after a 10 month journey over 442 miles. According to Charles Bolden, NASA's Administrator,

“As the first orbiter dedicated to studying Mars’ upper atmosphere, MAVEN will greatly improve our understanding of the history of the Martian atmosphere, how the climate has changed over time, and how that has influenced the evolution of the surface and the potential habitability of the planet.

“It also will better inform a future mission to send humans to the Red Planet in the 2030s.”