Indian Mars orbiter’s fourth burn in earth orbit only partially succesful

The Indian Mars Orbiter Mission met its first setback last night when the planned 4th burn in earth orbit was achieved but did not or could not impart the extra velocity that was planned. The orbit rose from about 71,000 km (apogee) to 78,000 km instead of the planned 100,000 km. A supplementary burn is planned for the early hours of 12th November (burns are scheduled for when the spacecraft is near perigee and within clear and easy range of tracking stations).
The current position of the spacecraft is between India and Saudi Arabia

ISRO Press Release:

In the fourth orbit-raising operation conducted this morning (Nov 11, 2013), the apogee (farthest point to Earth) of Mars Orbiter Spacecraft was raised from 71,623 km to 78,276 km by imparting an incremental velocity of 35 metres/second (as against 130 metres/second originally planned to raise apogee to about 100,000 [1 lakh] km). The spacecraft is in normal health. A supplementary orbit-raising operation is planned tomorrow (November 12, 2013) at 0500 hrs IST to raise the apogee to nearly 1 lakh km. 

During the orbit-raising operations conducted since November 7, 2013, ISRO has been testing and exercising the autonomy functions progressively, that are essential for Trans-Mars Injection (TMI) and Mars Orbit Insertion (MOI).  

During the first three orbit-raising operations, the prime and redundant chains of gyros, accelerometers, 22 Newton attitude control thrusters, attitude and orbit control electronics as well as the associated logics for their fault detection isolation, and reconfiguration have been exercised successfully. The prime and redundant star sensors have been functioning satisfactorily. The primary coil of the solenoid flow control valve was used successfully for the first three orbit-raising operations. 

During the fourth orbit-raising operations held today (November 11, 2013), the redundancies built-in for the propulsion system were exercised, namely, (a) energising the primary and redundant coils of the solenoid flow control valve of 440 Newton Liquid Engine and (b) logic for thrust augmentation by the attitude control thrusters, when needed. However, when both primary and redundant coils were energised together, as one of the planned modes, the flow to the Liquid Engine stopped. The thrust level augmentation logic, as expected, came in and the operation continued using the attitude control thrusters. This sequence resulted in reduction of the incremental velocity. 

While this parallel mode of operating the two coils is not possible for subsequent operations, they could be operated independently in sequence.

Mangalyaan current position 20131111 0830CET

Mangalyaan current position 20131111 0830CET

TOIThe first orbit-raising manoeuvre of India’s Mars Orbiter Mission was performed at 01:17 hrs Indian Standard Time (IST) early on November 07, 2013) when the 440 Newton Liquid Engine of the spacecraft was fired for 416 seconds by commanding it from Spacecraft Control Centre (SCC) at Isro Telemetry, Tracking and Command Network (ISTRAC) at Peenya, Bangalore. With this engine firing, the spacecraft’s Apogee (the farthest point to Earth) was raised to 28,825km.

The second orbit raising manoeuvre of MOM was at 02:18:51 hrs(IST) on Nov 8, 2013.The change observed in Apogee was from 28,814km to 40,186km. 

The third orbit raising manoeuvre of Mars Orbiter Mission spacecraft, starting at 02:10:43 hrs on Nov 09, 2013, was successful. The change observed in the Apogee was from 40,186 km to 71,636km.


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One Response to “Indian Mars orbiter’s fourth burn in earth orbit only partially succesful”

  1. UPDATE! Indian Mars orbiter supplementary firing successful | The k2p blog Says:

    […] Indian Mars orbiter’s fourth burn in earth orbit only partially succesful […]

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