Lack of access to the cosmonaut training programmes would be a hindrance for ISRO's planned manned missions, explains Devangshu Datta.
The Ukraine war could lead to breakdowns in space exploration due to sanctions against Russia.
Apart from the complexities of maintaining the International Space Station, there is a host of other areas where Russia provides both equipment and science as also technology inputs.
This new scenario could lead to some setbacks for the Indian Space Research Organisation and others in the Indian aerospace sector.
It may also present some opportunities. Russia used to supply a lot of rockets to various space and satellite launch programmes, including those run by various European Union entities. Lack of access to the cosmonaut training programmes would also be a hindrance for ISRO's planned manned missions.
Even during the Cold War, there was cooperation in space between the two opposed super-powers, which carried out joint projects like the 1975 Apollo-Soyuz Project, which sent up joint crews. The International Space Station programme is a long-running cooperative project, of course.
Russia supplies rockets to ferry crews to the ISS and it also supplies rockets for many of the European Space Agency's programmes. And it plays a role in ensuring the ISS remains in stable orbit.
Private operators such as SpaceX can take over the ISS ferry tasks, perhaps, and many organisations will have to look to fill the gaps arising from Russia's exclusion.
Russia was key to enabling India to develop a grasp of cryogenic rocket technology, supplying engines while India struggled to overcome bans on 'dual-use' technology after the 1998 nuclear tests.
ISRO's manned mission ambitions are linked to Russia in terms of cosmonaut training, supply of space suits and other equipment, the design of habitable capsules, plus the training of personnel in space medicine, etc.
It may seem paradoxical that rockets, which have been around a long time, are among the trickiest things to make in the 21st century. Tipu Sultan, for instance, used rocket batteries back in the 18th century during his campaigns, and the German V-2 was devastatingly effective.
Most of the scientists and engineers in the V-2 design teams ended up in the Soviet Union, or the US. US President Dwight Eisenhower (himself of German descent) once asked if 'our Germans were better than their (Russian) Germans' during the space race.
Rockets work due to Newton's Third Law. You set fire to something and the hot exhaust is expelled through the rear end of the rocket, which is pushed forward by the equal and opposite reaction. So a rocket with an explosive warhead is relatively easy to design.
But a modern rocket, which is designed not to explode but to carry delicate instruments and even more delicate human beings to a precise destination, is much harder to design and fabricate.
It requires calibrated fuel mixes in special tanks, sophisticated guidance systems, and the use of complex alloys and composite materials to withstand surges in temperature and pressure.
The design complexities for manned vehicles are even higher -- humans must be protected against the huge gravity forces generated as a rocket accelerates. If the rocket is re-usable and/ or multi-stage, the design becomes yet more complex.
Rockets use different types of fuel. Diwali rockets use solid fuels like gunpowder variants, zinc-sulphur combinations, nitroglycerine, sugars, etc.
Liquid fuel rockets are also common. Cryogenic designs use gases, liquefied and stored at very low temperatures.
For example, a liquid oxygen-liquid hydrogen mix may be used. Hydrogen liquefies at minus 253 degrees Celsius and oxygen at below minus 183C. Semi-cryogenic engines use combinations of low-temperature liquefied gas, and kerosene at normal temperatures.
Cryogenics and semi-cryogenics offer desirable qualities by combining low weight and high impulse. But design is extremely demanding. The fuels must be stored separately at low temperatures and, once they ignite, 3,500C temperatures are generated in the combustion chamber. Catastrophic accidents can occur.
Just six countries -- the US, Russia, France, China, Japan and India -- have proven cryogenic engines.
It took ISRO over 20 years to develop the technology. It was about to test a semi-cryogenic engine design in Ukraine when the war broke out.
Skyroot Aerospace, a firm founded and led by former ISRO personnel, has successfully run the first tests on India's first privately developed cryogenic engine -- Dhawan-1, which uses LNG and liquid oxygen.
ISRO will have to become more aatmanirbhar (self-reliant). While its grasp of cryogenics could lead to a bigger role in the satellite market, it may have to work out new options in preparing for manned missions.
Few nations have expertise across the new range of technologies required to keep humans safe and healthy in space. This will be a delicate balancing act given geopolitical uncertainty.
