Thursday, May 2, 2013

Martians! Here we come!



The Mars mission, India's first ever to a distant planet was announced by our Prime Minister Dr. Manmohan Singh during India's 66th Independence Day celebrations. This was to be a considerable challenge to our burgeoning space program considering the fact that even countries with established space programs such as the Russia Federation have found it difficult to achieve much success when it comes to the red planet.

But ISRO on the other hand has things going right for them on the deep space exploration side of the things. Buoyed by the success of Chandrayaan 1 and the impeding launch of Chandrayaan 2 missions to our moon, the scientists at ISRO are confident of achieving yet another feat with Mars mission.

The mission itself has always been short of details except for the occasional new reports saying that the orbiter is on schedule for a 2014 launch. Every piece of information that can be found on this mission is indeed valuable. There are certain titbits from mission that we would like to share.

  • The Mars orbiter will be placed in an elliptical orbit of around 500 X 80,000 km around the red planet. It is much more difficult to put an orbiter into a circular orbit. A circular orbit requirement would require a significant increase in the fuel carried by the orbiter and hence its weight. It would also make the procedure of achieving the required orbit much more complex. The orbiter would first be inserted into an elliptical orbit. Then through a series of burns the apoapsis would need to be reduced to achieve a circular orbit. An elliptical orbit on the other hand reduces the complexity but doesn't make it any more easier to achieve.

  • The orbiter will be launch by the PSLV-XL, the same version which launched the Chandrayaan 1. ISRO understandably wants to go with the proven workhorse as opposed to the GSLV even if it means much stringent weight limitations of the orbiter. This might also be one of the reasons for choosing an elliptical orbit as a circular orbit means more fuel which in turn means more weight. The PSLV should be capable of sending a orbiter with ~200 kg of space for instruments  to the Martian orbit.     

  • The orbiter would need around 300 days to reach Mars and is supposed be launched during October-November 2013. The launch window is very important since missions to Mars can be launched when Earth and Mars are relatively close to each other. This window occurs only once every 26 months. So, miss this window and the mission will have to wait for another 2 years.

  • The orbiter is supposed to carry very few instruments, considering the weight limitations and all the instruments are planned to be Indian. The goal of the mission to establish the capability to send orbiters to Mars, so if this mission is successful much bigger missions may follow.
There are a lot of challenges in this mission. Some more intimidating than others but all of which have to be overcome for success. Some of the significant challenges as mentioned by ISRO are

  • The spacecraft needs shielding from the radiation in the Van Allen belt and also the deep space radiation. The spacecraft will have a significant and prolonged exposure to radiation so it needs augmented radiation shielding.  

  • There is a communication delay of ~20 mins between Earth and Mars. This is due to enormous distance that varies between 55-385 million kms between the two bodies. Compare this with the 2 second communication delay between the Earth and the Moon which are separated by 384,000 kms.

  • The propulsion system of the spacecraft needs to be robust and reliable. The spacecraft propulsion system will remain dormant for almost 300 days when the spacecraft is travelling from Earth to Mars. Then once it is close to Mars, the propulsion system has to work exactly as it should to insert the spacecraft into orbit around Mars.

  • The most challenging phase is certainly inserting the spacecraft into orbit around Mars. The room for error in this phase is minimal and could result in the spacecraft being lost in the depths of space. This critical event will ensure whether the mission is a success.
 ISRO has a daunting task ahead of it to ensure that this mission goes as planned given such a large number of variables involved. There are scientists who are working day and night to ensure just that. So, wishing success for ISRO with this challenging mission that is set to boost India's image in the world to new heights.

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