ISRO has received the scientific proposals and the institutions whose proposals are shortlisted will make presentations in front of the Advisory Committee for Space Science Responding to Indian Space Research Organisation’s (ISRO’s) call for scientific proposals for participation in the Mars Orbiter Mission (MOM)-2, nine Indian institutions including ISRO have submitted details of experiments that could be carried out on or around Mars. The mission is expected to be launched either in May-June 2020 or July-August 2022, on board the more powerful rocket – the geostationary satellite launch vehicle (GSLV) Mark III, which is also scheduled to launch the country’s second mission to Moon, Chandrayaan-2, around late 2017 or early 2018. Although ISRO refrained from divulging details of the proposed scientific experiment for MOM-2 – or even the institutions submitting them – ISRO’s chief spokesperson Devi Prasad Karnik told Bangalore Mirror, “The proposals give a summary of the scientific studies which can be done about Mars. Many of the proposals also include the type of experiments required to undertake these studies.” Although ISRO did not specify details, one gets a fair idea about what they could be from ISRO’s Announcement of Opportunity (AO) which was put up on the space agency’s website in May while calling for Indian scientific institutions to submit the proposals. It states: “Future Mars missions are focusing on in situ surface/subsurface probing by landers and rovers, with orbiters continuing studies of Martian surface and sub-surface (from space) and also serving as continued communication link to Earth. An orbiter mission with focused science objectives can provide valuable global Mars science…” ISRO’s Space Science Programme Office has received the scientific proposals and the institutions whose proposals are shortlisted will make presentations in front of the Advisory Committee for Space Science (ADCOS). Which experiments would finally go on the mission will be decided by the ADCOS. MOM-2 (also called Mangalyaan-2) is being planned as a landing mission wherein the orbiting spacecraft will release another vehicle (the lander) towards the surface of the red planet and make a touchdown. The lander is also being planned to carry a small robotic rover which would be designed to exit the lander and around the Martian surface in a limited area and time to explore the surface, while constantly sending data back to the orbiter, which in turn would relay that to ISRO’s receiving stations. The MOM-2 will be orbiting in a highly elliptical orbit of 5,000 Km at its farthest distance from the Martian surface and 200 Km at its closest approach.
GSLV, IT IS!
ISRO has confirmed that MOM-II would be launched on board the GSLV Mark-III rocket, which is much more powerful than the polar satellite launch vehicle (PSLV) rocket that launched India’s first unmanned mission to Moon, Chandrayaan-I in October 2008 and MOM-I in November 2013. Karnik said the mass of the payload carried on the MOM-II mission would depend on several aspects “like the overall scientific objectives of the mission and hence the orbit geometry, propellant budget etc. It (the total weight of experiment payload from these institutions, apart from ISRO’s) could also be less than 100kg.” However, as the MOM-II spacecraft would be much heavier than the current MOM, which is operational around Mars, the natural option for ISRO will be the GSLV to launch MOM-II. The MOM-I spacecraft weighed 1,350 Kg while Chandrayaan-I weighed 1,380 Kg; but Mangalyaan-II will have a much heavier payload to be lifted considering a lander and a rover would be included. Such a heavy payload cannot be lifted by a PSLV rocket because it is not powered by a cryogenic engine, while GSLV Mark-III is. The powerful cryogenic rocket engine will power the third –and uppermost – stage to carry the MOM-II spacecraft with the required thrust all the way to
Mars, which at its closest is 54.6 million Km. The engine uses cryogenic fuel or oxidiser, both of which are gases liquefied and stored at very low (cryo) temperatures. These engines were considered crucial for US’ National Aeronautics & Space Administration (NASA) succeeding in reaching Moon using its Saturn V rocket. Initially it was the GSLV which was planned to carry Chandrayaan-I and Mangalyaan-I. But in the absence of a cryogenic engine to power the rocket, besides a string of earlier failures (GSLV had four launch failures out of just 10 launches), these missions were launched using an enhanced version of the PSLV, ISRO’s workhorse launcher that has recorded a success rate of 94.60 per cent (just two failures) in 37 launches since September 20, 1993.
ISRO scientists are now confident of using the GSLV Mark III rocket for the Chandrayaan-II and MOM-II. It took four years after the 2010 debacle (two back-to-back failures of GSLV) for ISRO to successfully launch the GSLV on January 5, 2014 using India’s indigenously-built cryogenic engine. It successfully launched the GSAT-14 satellite. The GSLV-D5 rocket – the second flight with an indigenous cryogenic engine – launched the GSAT-14, the 23rd geostationary communication satellite built by ISRO. This was followed by two successful GSLV launches on August 27, 2015 (GSLV-D6) and September 8, 2016 (GSLV-F05), which was the first operational flight of the Mark-II version of GSLV that also used an indigenously built cryogenic engine. The string of successes has now infused confidence among the scientists to go for a GSLV rocket to launch mega missions.