Aiming for the moon: Measuring India’s leap
- Going behind the scenes of the halted ‘Chandrayaan-2’ mission, Lounge takes a closer look at India’s relationship with the moon
- The Apollo 11 landings had a key impact on India’s space programme too. Isro was incorporated barely a month after the iconic moon mission.
It was called off 56 minutes before the launch. That means everything was going fine till the last stage," says Ajay Lele, senior fellow at the Institute for Defence Studies and Analyses, Delhi.
The launch of Chandrayaan-2, India’s second lunar mission, scheduled for 2.51 am on 15 July, was postponed when scientists at the Indian Space Research Organization (Isro) detected a technical snag in the launch vehicle system minutes before lift-off. “Revised launch date would be announced later," the space agency tweeted at 2.37 am. Isro now says Chandrayaan-2 is scheduled to launch from the Satish Dhawan Space Centre in Sriharikota at 2.43 pm on 22 July.
“Even the filling of fuel was done for the cryogenic stage, which is the toughest (part), so there could be some parameter that was not as planned. It is commendable that Isro detected it and halted the countdown," says Lele. Isro has not yet officially disclosed the nature of the glitch, though some news reports have indicated that the main cryogenic engine failed to build pressure due to helium gas leakage, possibly due to a malfunction of the nipple-joint valve in the plumbing.
If the Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk III) carrying Chandrayaan-2 had taken off as scheduled, the mission payload would have been injected into an Earth parking orbit soon after the launch. A series of orbital manoeuvres would have been carried out to raise its orbit and put Chandrayaan-2 on a lunar transfer trajectory.
Once it entered the moon’s sphere of influence—where the celestial body’s gravitational influence comes into play—the on-board thrusters would have slowed the spacecraft for a “lunar capture". The Vikram Lander would have detached from the orbiter on landing day and it would have soft-landed near the lunar south pole in September.
But India missed its date with the moon as well as the opportunity to launch Chandrayaan-2 along with the 50th-year commemoration of the historic Apollo 11 mission that placed the first human beings on the moon on 20 July 1969.
This, however, isn’t the first time that a mission has had to be aborted hours before launch in India or elsewhere. In August 2013, Isro had called off the launch of GSLV D-5 when a fuel leak was detected in the system. The GSLV rocket was powered by indigenously developed cryogenic engines. The launch was postponed to January 2014.
Such foresight is crucial not only for the safety of the spacecraft but also the astronauts on board, in the case of manned missions. For instance, in October 2018, a rocket malfunction forced the Russian Soyuz rocket carrying a US-Russian crew to the International Space Station to make an emergency landing, minutes after lift-off. The crew capsule fell back to the earth in a ballistic re-entry, with the crew safe.
The GSLV Mk III is India’s most powerful rocket. Armed with a cryogenic engine, it is capable of launching the 4-ton class of satellites into the geosynchronous transfer orbit. Isro has, however, encountered technical difficulties with the GSLV in the past. Earlier flights—GSLV-F02 on 10 July 2006 and GSLV-D3 in April 2010—could not accomplish their mission objectives due to technical problems. In fact, the latter was also aborted hours before launch.
In the GSLV-D3, the problem was the Cryogenic Upper Stage (CUS) engine, which had been indigenously developed after decades of research and is critical for powerful rockets like the GSLV Mk III, which deliver heavier payloads. Until then, GSLV flights used Russian Cryogenic Stages.
A failure analysis committee set up by Isro found that the main CUS engine had failed soon after ignition. The agency then modified the GSLV and successfully launched the vehicle on 5 January 2014.
Scientists believe the stakes are so high that a greater measure of caution is called for with Chandrayaan-2, the most complex mission undertaken by Isro. “Those 15 minutes (of its soft landing) would be terrifying. Even a single second should not go against the plan," Isro chairman K. Sivan had said in June.
According to the space agency, Chandrayaan-2 will mark a paradigm shift in the approach to lunar expeditions. The agency had upgraded the rocket from GSLV Mk II to Mk III and it is also expected to carry the country’s first manned mission to space, Gaganyaan, planned for 2022.
With the now missed 15 July launch, Isro had aimed to touch down on the moon’s south polar region when the lunar day begins on 6 September. But experts and media reports claim that even with the rescheduled launch date, it is still possible to achieve the original landing date. There has, however, been no official statement from the space agency on this yet. “If the September landing is missed, Isro would have to target landing when the next (lunar) day begins, (or) roughly after 28 earth days," says Nirupam Roy, an assistant professor at the Indian Institute of Science, Bengaluru.
Choosing the right launch window is critical for lunar missions. In the case of Chandrayaan-2, the September landing is important since it marks the beginning of a 14-day period when there will be daylight on the moon, needed for the lander and rover to conduct scientific experiments.
This is why whenever a spacecraft has to rendezvous with another body, the launch must be timed carefully.
The intersection of Chandrayaan-2 and the moon’s path has to be predicted accurately, so that when the mission module approaches the farthest point from Earth (an apogee), the on-board thrusters could fire precisely to reduce its velocity for a lunar capture.
The First Moon Mission
If there’s one thing space flight missions have shown us in the 50 years since Apollo 11 (and even earlier), is that even the minutest of changes in force, exhaust velocity, atmospheric or exhaust pressure and any other important parameter can have unexpected results for any mission.
Even Chandrayaan-1, India’s first mission to the moon, which also carried payloads developed by other countries, experienced small, technical glitches before finally launching on 22 October 2008. The mission was a success—data from Chandrayaan-1’s Moon Mineralogy Mapper experiment showed evidence of water in the moon’s exosphere, and on its surface and sub-surface. The mission also carried out detailed mineral and chemical composition studies of the lunar surface. The Mars Orbiter Mission in 2013-14 was yet another feather in the cap of the Indian space programme.
Jahnavi Phalkey, the founding director of Science Gallery Bengaluru, a space for collaboration between science, the arts and design, reiterates that these missions run on very complex systems and the halted launch is by no means a misstep. She says the journey of India’s space programme leading up to Chandrayaan-2 is the most successful story of an Indian state-funded project.
Phalkey explains how the space programme has built on its strength—recruiting engineers, scientists and researchers from government engineering colleges. “They (Isro) have worked hard on it, finessed certain things and become experts at budgets which are incomparable," adds Phalkey.
The Apollo 11 landings had a key impact on India’s space programme too. While the Indian National Committee for Space Research (Incospar) was set up in 1962, Isro was incorporated barely a month after the iconic moon mission. Today, it is one of the six largest space agencies, with a mission of sending an Indian into space in 2022.
“Globally, it (the Apollo 11 mission) was certainly an inspirational moment. One might look at only how (former Isro chairman) Vikram Sarabhai thought about it. The one thing I have always found quite sobering when looking at his writings or the approach of his colleagues to space research is that they somehow never lost focus of what advanced space research was supposed to do for India," says Phalkey. “They (Sarabhai and his colleagues) realized its importance at that point of time, but their eyes were always on taking other agendas forward: which were that of well-being, better livelihood, mass education and development in India," she adds.
Reacting to the moon landings, Sarabhai was quoted in The Times Of India on 22 July 1969 as saying that “our perspective of the universe must alter fundamentally when we understand how the solar system and the important objects in it were created....The impact of this should be as significant as when man learnt that the world is a sphere and that it is not at the centre of the universe."
In her book Vikram Sarabhai: A Life, Amrita Shah writes that the Indian space programme “broke the mould". While the Russians, Americans and Germans had been working on rocket technology since the 1900s, their impulse continued to be aggressive. Even the “scientific experiments and studies carried out on rockets" were linked to military applications, she writes. But from the very beginning, Shah adds, the thrust of the Indian space programme was peaceful.
While Sarabhai’s ambitions for the space programme were creating a sensation globally, his focus was primarily national, writes Shah. “Vikram believed that many benefits would accrue from the very existence of the space programme itself. In a paper on Space Activity For Developing Countries published in the science and technology series of the American Aeronautical Society of California in 1966, he talked about its potential to stimulate growth in advanced fields such as electronics, chemicals, cybernetics and in materials engineering…. This was Vikram’s dream: linking technology with development," Shah writes.
Testing the limits
As India prepares for its second lunar mission, it is important to remember that Apollo 11 wasn’t the first mission in the Apollo programme. While it was designed to land astronauts on the moon and bring them back safely, some—like Apollo 7 (1968) and Apollo 9 (1969)—were manned Earth-orbiting missions that tested the command and lunar modules, two critical components for the missions. The six crew missions that did end up landing on the moon—and the 12 men that walked on its surface—gave the scientific community a wealth of information and data that is useful even today. According to US space agency Nasa, the six missions that landed on the moon brought back almost 400kg of lunar samples.
Poshak Gandhi, an astronomer with the School of Physics and Astronomy at the University of Southampton, says these lunar rock samples helped the scientific community learn more about the origin and composition of the moon and the solar system. “For example, it is now believed that the moon was created out of the impact of a giant collision between proto-Earth and another massive body in the early solar system. Furthermore, the lunar ranging experiments left on the moon still routinely bounce lasers sent from Earth to measure the distance to the moon with a superb precision of about 1cm. These distances can be used to test Einstein’s theory of gravity," explains Gandhi, on email.
Even though Apollo 11’s legacy has been repeatedly questioned, Phalkey feels it was “the idea of science as a reason of state", citing Ashis Nandy from his book Science, Hegemony And Violence: A Requiem For Modernity (1983), which attempts to describe the true importance and legacy of the 1969 moon landing and the missions that followed.
This was the first time a nation’s ambitions had been articulated in terms of science and technology. She says, citing Nandy again, that “before that, it was either military might or wealth. ‘We want to put a man on the moon’ was the articulation of a country’s goal for the first time in terms of science and technology. That was the most important thing."
To reiterate the essence of Sarabhai’s seminal paper published in 1966, our space ambitions can go hand in hand with social welfare and development. And so, every small step towards the moon, with Chandrayaan-1 and 2, is a giant leap for India’s ambitions — on the ground and beyond.
FIRST PUBLISHED20.07.2019 | 08:15 AM IST
TOPICSChandrayaan 2 | Chandrayaan 1 | Isro | NASA
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