Shooting for the moon

In a 1950s novella by Robert Heinlein, a robber baron named Delos D Harriman does a lunar land grab. “The Man Who Sold the Moon” raises money to land a rocket there, by marketing giant advertising billboards, setting up broadcasting stations for TV networks, offering diamond-mining concessions, and so on. ISRO’s Chandrayaan-2 (C-II) — India’s second moon mission has purely scientific objectives. But the commercial returns from C-II could be huge, and more realistic than those imagined by Heinlein. 

In brief, Isro launched a big rocket (Bahubali) on Monday, July 22. If all goes well, Bahubali will push an orbiter into orbit around Luna by August 20. The orbiter will release a lander (Vikram), somewhere close to the unexplored South Pole on September 5-6. 

The lander will release a rover (Pragyaan). Pragyaan will explore and conduct scientific experiments. Pragyaan is scheduled to operate for 13.5 earth days, (one lunar day). All data will be transmitted back to ISRO’s ground station. The orbiter will continue to spin around, hopefully for at least a year.  

Doing this involves a grasp of many technologies. The cryogenic GSLV Mark-II rocket, Bahubali, will carry a payload of 4,000 kg roughly 380,000 km across space (actual distance travelled is much more). Cryogenic technology uses liquefied gases as rocket fuel. It’s very efficient. But it’s hard to build stable cryogenics. Just six countries have demonstrated this capability. 

The GSLV can put heavier satellites (or constellations of many satellites) into space. India took many years to develop stable cryogenic engines after being sanctioned after the Pokhran-II nuclear blasts in 1998. It used Russian cryogenic engines, bought before Pokhran-II. The reason for the sanctions: cryogenic engines can power long-range inter-continental ballistic missiles with nuclear warheads. ISRO is not into military applications but it 

doesn’t hurt to possess this capability. 

Second, the mission plan underlines Isro’s grasp of complex calculations. We’ve already seen this with Chandrayaan-1, and with the Mars Orbital Mission, Mangalyaan. First, ISRO will put Bahubali into an elliptical (egg-shaped) orbit around earth. That elliptical orbit will be tweaked to use earth’s gravity to help the rocket’s engines push it towards the moon. Then, it will be put into an egg-shaped orbit around the moon and that orbit will be tweaked to bring it closer to the lunar South Pole. The Mars Mission involved more complex calculations, with much distance to cover, and a less powerful engine.   

The lander will be released for a controlled landing and this is a new capability since Chandrayaan-1 fired a probe like a very large bullet. A landing on Luna is trickier than a landing on Mars because the moon is covered with metres-thick layers of dust in many places. 

The lander has to find a good spot and perform the landing autonomously. Light and electromagnetic waves travel at 300,000 km/ second in vacuum. A round-trip for data transmissions to the moon and back takes two to three seconds, which means this can’t be safely remote-controlled. 

ISRO demonstrated autonomous technology in the Mars orbiter. But a successful landing is harder to pull off. Pragyaan will roll out of Vikram after landing. Travelling at the glacial speed of 60 cm per minute, it will explore the surrounding area and conduct experiments. C-II hopes to find water, which may be stuck in pools near the pole. Pragyaan has to last one lunar day, for sure. It may or may not, survive the night that follows, with temperatures of minus 170°C.  

If all this works, or even if it doesn’t, ISRO plans future manned missions, while absorbing the technological lessons. Manned space missions are orders of magnitude harder. Keeping equipment functional in space is tough. Keeping humans alive, well and sane in space is much tougher. 

Space temperatures are extreme. A spot in direct sunlight could be at 130°C, while a spot in darkness is minus 170°C. Cosmic radiation can fry instruments and trigger cancer in unshielded human beings. Gravity swings between zero in space, to one-sixth of the earth on the moon, to very high (multiples of earth gravity) under acceleration. Food and water must be recycled. There has to be a way to return alive. 

Space exploration led to the development of many of the technologies that make 21st century civilisation possible. Our communication, entertainment and navigation systems depend on satellites. It’s enriched medical knowledge. The development of solar power, electronics and computers were hugely boosted by space exploration. Municipal water and waste recycling systems are based on space designs and so is our understanding of climate change. ISRO’s missions will help India gain capabilities in these respects. 

The moon itself could be a source of scarce minerals, or a convenient place to build rockets to explore other places. Nobody owns the moon, by the way. It belongs to everyone, according to The Treaty of Outer Space, which supersedes the ancient principle of ad coelum (cited by Heinlein) that states that the owner of land has rights to the air above, and the ground below. So planting the tricolour there metaphorically at least, is not just a matter of pride. It establishes a foothold for the future.