HomeINDIAGaganyaan: Countdown to India’s Biggest Space Mission to Date
December 19, 2018
Gaganyaan: Countdown to India’s Biggest Space Mission to Date
On November 14, scientists from the Indian Space Research Organisation (ISRO) waited impatiently as anxious minutes ticked away on the clock. The launch of the 3,423-kg satellite GSAT-29 from its launch pad at Sriharikota, Andhra Pradesh, had been delayed due to the incoming Cyclone Gaja. When the ‘Bahubali’ rocket finally took flight at 5:08 pm and precisely placed the heavyweight satellite into orbit 16 minutes later, a huge sigh of relief followed.
The rocket was ISRO’s Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk III). What is so special about it?GSLV Mk IIIis no ordinary rocket; it has been chosen to carry over a billion dreams when it takes off on India’s maiden human spaceflight mission: Gaganyaan. On August 15, 2018, Prime Minister Narendra Modi announced that India would launch its first human mission in 2022, the country’s 75th year of Independence. The three-stage heavy-lift launch vehicle, GSLV Mk III, has been picked for the mission that will send three astronauts into the low-earth orbit of 300-400 km for seven days.
The sky is no more the limit
Last week, on December 13, thefirst tourism spaceshipby Virgin Galactic successfully reached the space boundary. Other private companies like Blue Origin and SpaceX also plan to execute human spaceflight missions as early as next year. “The future prospect of commercialisation of manned space missions is tremendous, and India definitely should look for its share in this domain”, says Dr Saurabh Das, faculty at Center of Astronomy, Indian Institute of Technology Indore. A 90-minute flight aboard Virgin’s suborbital mission, for instance,costsaround ₹1.8 crore, and more than 600 people have already paid the deposits.
More than five decades since the Soviets put the first man in space way back in 1961, only three nations have been able to achieve the feat: the USA, Russia and China. Post-2011, however, only Russia and China have retained human spaceflight capabilities, as the US saw a push towards private space flights after the retirement of the US Space Shuttle series.
If successful, Gaganyaan will make India the world’s fourth country to have successfully placed a human in space. “A healthy space programme has to evolve from challenge to challenge. After the successful execution of missions like Chandrayaan and Mangalayaan, a crewed programme is the next step that shows capability beyond what ISRO has achieved so far,” says Dr Jayant Murthy, Senior Professor at the Indian Institute of Astrophysics.
Building on the success of individual missions, a constant push in advancing science and technology is extremely important for the growth of a nation. However, the ephemeral interest in any mission may lead to ignoring the basic science that underpins space explorations. “In practice, individual missions are always given priority over the sustained buildup of expertise,” warns Dr Murthy. Experts, therefore, continue to emphasise the importance of promoting basic science and technology, including large-scale experiments and non-human space explorations.
Key things to focus
What makes human spaceflight such a huge challenge? Three major aspects: adjusting to the space environment, getting the hardware, software and other mechanics right, and overcoming complications related to launch and reentry.
The Indian Air Force’s Institute of Aerospace Medicine in Bengaluruwill be taking careof how astronauts would survive in the space environment. ISRO’sproven track recordandinternational collaborationsalso give much confidence in mechanical and safety-related matters. Therefore, the biggest challenge lies in the successful management of launch and reentry.
To date, there have been 19 deaths during spaceflight in history (of over 100 space mission-related deaths overall). Sixteen of these were associated with spacecraft launch and re-entry. While ISRO possesses immense experience in launching, atmospheric re-entry is a different ball game altogether.
Ultimate challenge of re-entry
“The most important and critical challenge for any mission is the entry into the atmosphere. The control, navigation and communication during this phase are very complex and any mistake will have catastrophic effects on the mission,” says Dr Das.
The Space Shuttle Columbia Disaster in 2003 that killed Kalpana Chawla and six other astronauts during re-entry serves as a reminder of risks involved. The typicalspeedat which a spacecraft starts to re-enter the atmosphere is around 28,000 kilometres per hour— just below the minimum speed required to stay in Earth’s orbit.
The heat produced due to compression of gases during re-entry is so great that it ionises or breaks the gas molecules around the spacecraft. Ionising essentially means acquiring a charge. The electrical charge produced around the spacecraft is so strong that it blocks radio frequency waves used for communication. However, with recent technological advancements, there arewaysto mitigate this communications blackout.
In addition, a special shield is necessary to keep the spacecraft intact at temperatures of over 1600°C during re-entry. The Russian Soyuz, Chinese Shenzhou, and all the earlier US spacecraft used heat shields made of special ceramic materials designed to slowly burn away during re-entry. The US Space Shuttle started the use of special silicon tiles to withstand heat.
Indian scientists have also followed suit anddeveloped lightweight silicon tilesto coat the spacecraft. In fact, ISRO has beenpreparingfor the manned mission by developing the required technologies since 2004. The most critical of these are the Crew module Atmospheric Re-entry Experiment (CARE), successfully tested in December 2014, and the Crew Escape System, successfully tested in July 2018. While the former technology can bring back the astronauts safely, the latter provides a safe escape to astronauts in the event of a launch abort.
Why send humans to space?
Back in the 1960s, Vikram Sarabhai—the founder of ISRO and the father of India’s space programme—had said that India did not fancy competing with advanced economies in planetary exploration or manned space flight. However, within half a century, we have accomplished planetary explorations like Mangalyaan and are eyeing crewed missions. The future will inevitably involve the space age and experts say that India should not be left behind, especially when we have all the technologies to make it happen.
“In future, the exploration of the exoplanets and ultimately finding an alternative to Earth will be crucial for the survival of the human race. Gaganyaan will make India one of the few leading countries in the space age. It is only a first step towards manned space missions. The success of this mission will give enough confidence to the country to look for exploration beyond Mars”, explains Dr Das.
Chairman of ISRO Dr K. Sivan summed it up in aninterviewto the BBC, “If colonies have to be set up outside Earth for the human civilisation, how can India, one of the oldest civilisations, be left behind and wanting?”