AMID INDIA’s preparations for a manned space mission, the recent failure of a Russian rocket launch has served a reminder of the perils and technological challenges involved in every space flight. The fact that both astronauts on board survived the failure, on the other hand, has been hailed as an example that underlines the safety measures that were in place. How are Indian scientists progressing on astronaut safety?
On October 11, the failure of the Russian rocket Soyuz FG led to the abortion of Expedition 57 to the International Space Station. On board the Soyuz MS 10 mission were Alexey Ovchinin of Roscosmos and Nick Hague of NASA. When the failure was detected at an altitude of 50 km, an emergency operation was carried out to separate the crew module. The astronauts landed on Earth some 402 km from the launch site at the Russian Baikonur cosmodrome.
It was the first mid-flight failure of a Soyuz rocket since 1975, when a mission was aborted after the second stage failed to fire while was climbing to leave Earth’s atmosphere, with crew on board.
Since the first successful human space flight in 1961 by Yuri Gagarin, 18 astronauts (13 Americans, 4 Russians, 1 Israeli) have lost their lives on space missions. The rocket, the crew module and all systems involved require a “human ratings certification” before they can be used to send a human into space.
ISRO at work
The Indian Space Research Organisation is preparing to become the fourth country to launch a human into space — after Russia, the US and China. Its Gaganyaan mission was given a 2022 deadline by Prime Minister Narendra Modi on August 15.
“We are now moving rockets from a mission-critical nature to a safety-critical launch nature, where the human being comes into play in a rocket — where human life becomes more important. We need to build safety critical features into rockets,” S Somnath, director of ISRO’s Vikram Sarabhai Space Centre, said recently while providing an overview of ISRO’s early plans. Somnath is a key figure in the development of the GSLV Mk III rocket, which will be used for the manned mission.
“The crew escape system is crucial to the mission. The principle here is that you can have a less reliable rocket but you need a highly reliable crew escape system,” Somnath said. “The most important part of a human space flight is the ability to detect an imminent danger and take action to abort the mission. We need to have systems for this. We need onboard intelligence to see what is happening around and take action if anomalies develop.”
A NASA manual on human ratings of space systems, available in the public domain, underlines the difference between the development of systems for human space flights and missions with robotic payloads. “A human-rated system accommodates human needs, effectively utilizes human capabilities, controls hazards and manages safety risk associated with human spaceflight, and provides, to the maximum extent practical, the capability to safely recover the crew from hazardous situations,” states the NASA procedural requirements document for human ratings of space systems.
While designing a rocket to launch any mechanical payload, scientists do not have to consider factors like the amount of heat generated, vibration caused or metallic changes in the payload capsule. For rockets meant to carry humans, all these factors will have to be brought within human tolerance levels.
Like ISRO, private space agencies like Elon Musk’s SpaceX and Boeing are working to develop human-rated systems that can be certified by 2019. SpaceX’s efforts to get a human ratings certification for its Falcon 9 (Block 5) rocket — which experienced an explosion on the launchpad in 2016 — offer insight on the technical challenges. “The rocket has to be designed to 25% above the worst case of the expected load in the case of a satellite launcher. For a human-rated launcher, it has to be designed 40% above the worst-case loads. That’s really difficult to do without making the rocket really heavy. That’s hardcore stuff,” Musk said in May, after the successful launch of a Falcon 9 rocket with improvements meant for human ratings certifications, such as higher heat resistance and backup electronics.
The Indian rocket
ISRO’s GSLV Mk III, which has undergone one experimental and one developmental flights, is expected to make 10 flights, including two in the form of an unmanned human space launch vehicle, before it finally launches humans in 2022.
Somnath says the GSLV was designed keeping in mind human flight in the future, so it will not need major tweaking. “When the GSLV Mk III was designed in the 2000-2002 time-frame, one of the important aspects that we mentioned was that it must ultimately become a vehicle that takes a human to space. We were directed to keep the design conditions in such a way that acceleration, reliability, safety, vibration and other aspects are all addressed right at the design stage. This is why we are confidently speaking of a human space flight,” Dr Somnath said recently.
“The GSLV Mk III is an intelligent system with built-in redundancies, but for a final human rating the redundancies needed are of a higher order. We are working on it,” he said. “Various aspects of this have already been addressed — the environment, the margins on the hardware, the interface with the launchpad, the redundancy on board and the checking out and clearing the rocket for launch. We are now discussing the algorithms that will go inside in terms of instrumentation and process in a computer and see if we can abort a mission without causing damage to the crew. This aspect is under review and we will be coming out with an architecture where the time-span available is so short.”
While ISRO is confident, some experts have sounded a note of caution. “Any serious follower of ISRO’s programme will understand the huge divide which exists between projections and reality in space technology and space processes. Space operations being glamorous can hide failures against the backdrop of stunning successes,” Air Vice Marshal (retd) Pankaj Tyagi said at an event last month. “While creating perceptions and hype through media management is very important to inspire people, it is also important to reduce knowledge gaps and optimise resources, especially when a human is on board a rocket.”