Mars Orbiter's liquid rocket motor test-fired successfully - Livemint

Scientists and engineers from Isro monitor India’s Mars Orbiter Mission at the Isro Spacecraft Control Centre, Peenya, Bangalore. Photo: PTI

New Delhi: The Indian Space Research Organisation (Isro) successfully test-fired the liquid rocket motor on the Mars Orbiter for the first time since December for four seconds, gearing up for Wednesday when the spacecraft will be inserted into a Martian orbit.

Prime Minister Narendra Modi will witness the insertion at the Spacecraft Control Centre at ISRO Telemetry Tracking and Command Network (ISTRAC) in Bangalore on Wednesday. “Yes. The Prime Minister will be present at the centre on Wednesday when the operation is going on. This is the information we have,” ISRO scientific secretary Koteswara Rao told Press Trust of India.

“The spacecraft is healthy. It has completed 98% of its journey to Mars and we are now prepared for that crucial operation to take place on 24 September morning,” Isro chief K. Radhakrishnan said, expressing joy after the engine of the Mars Orbiter was reignited.

“Main Liquid Engine test firing on Mars orbiter spacecraft successful: we had a perfect burn for four seconds as programmed. The trajectory has been corrected,” Isro announced on Monday.

The success came even as the unmanned probe today entered the Mars Gravitational Sphere of Influence. “Our navigators’ calculations show that Mars Orbiter Mission has entered the Gravitational Sphere of Influence of Mars,” Isro said.

The orbiter on Monday entered within 580,000km from Mars in a hyperbolic trajectory after which the fourth trajectory correction manoeuvre took place and then the main liquid engine was test-fired for 3.968 seconds. The motor was last used in December when the spacecraft was set on trajectory to arrive at Mars.

Monday’s development took place even as National Aeronautics and Space Administration’s (Nasa’s) orbiter Maven (Mars Atmosphere and Volatile Evolution) was successfully inserted into the Martian orbit. Isro and Nasa’s Jet Propulsion Centre were on a teleconference call to ensure there will be no interference to the other’s mission and that the timings have been adjusted accordingly.

Isro’s 1,340kg Mars Orbiter was launched aboard the polar satellite launch vehicle (PSLV-C25) on 5 November from the Satish Dhawan Space Centre in Sriharikota.

On 24 September, after the Orbiter completes a 300-day journey from Earth, it will be inserted into a Mars orbit. A microprocessor-based control system of the spacecraft will act as its electronic brain during the communication gap from Earth, which on Monday stood around 12 minutes.

Just before reaching Mars’ capturing orbit, forward rotation for the orbiter will begin at 6.56am, after which the 24-minute Mars orbit insertion burn will start consuming propellant weighing 249.5kg.

During this phase, the rocket will be hidden from Earth’s view when its speed will be reduced to 1.6km per second by firing the liquid motor on the spacecraft. The ground station support during the manoeuvre will be provided by the Indian Deep Space Network in Bangalore, and from the US, Spain and Australia, which will establish communication with the dish antennae (with a diameter of 2.2 metres) in the Orbiter, which will eventually send scientific data.

The Orbiter is carrying five scientific payloads weighing 15kg, which will observe the Martian surface, atmosphere and exosphere extending up to 80,000km for a detailed understanding of the evolution of the planet by observing its geologic and biogenic processes. The payloads consist of a camera, two spectrometers, a radiometer and a photometer.

The primary objective of the Mars Mission, however, is to prove India’s technological capability to reach the Red Planet and carry out scientific observations.

Probes to Mars have a high failure rate. Of the 51 missions so far, only 21 have succeeded. A similar mission by China failed in 2011.

PTI contributed to this story.