Small rockets are the next big thing

With Chandrayaan-2 heading towards the Moon, a slew of exciting projects is in the offing.

Rockets are generally perceived as fire-breathing leviathans that soar into the skies, but the space-scape is fast changing with innovations in both launch vehicles and satellites.

A Spanish company Zero 2 Infinity is offering to launch satellites not just to space, but also from space. The company’s idea is to take a rocket up to a height of about 22 km, beyond the edge of the Earth’s atmosphere in a balloon, and then fire it there for onward journey into the space.

The idea may sounds far-fetched, but is actually quite simple. Today, you build giant rockets because they need a lot of fuel to develop enough thrust to pull off from the Earth’s gravity. These rockets burn a third of their fuel to travel up to 30 km above the Earth. So, why not let a balloon do the work for the rocket?

Satya Chakravarthy, a professor of aerospace engineering at IIT-Madras, says that with a balloon-based launch “you can shave off a lot of weight of the rocket”.

Today, with giant strides in semi-conductor technology packing more computational power in small space, a need (and a market) for small, micro and nano satellites is emerging. In consonance, there is a need for smaller rockets.

India’s space agency, ISRO, has recognised this trend. That is why it is talking of a Small Satellite Launch Vehicle (SSLV) programme, to launch satellites as small as 500 kg — a quarter of the usual payload of a PSLV rocket.

While Zero 2 Infinite seems to have taken a big jump in launch technology, simpler solutions are at hand. If you can launch an Agni missile from the back of a truck, why not a rocket of a similar size, asks Chakravarthy, who is also the co-ordinator of the Chennai-based National Centre for Combustion Research and Development, a body set up jointly by IIT-Madras and the Indian Institute of Science Bengaluru.

Mobile (truck-borne) rocket launches, he says, are a no-brainer and will happen soon, he says. If you can do it on a truck, you can also do it on a ship-towed barge in the sea. The advantage of mobile launches is, you can micro-tune your launch site to match the orbit. A sea-based launch is not a new idea, though. In the 1990s, a company, Sea Launch, offered barge-mounted launches, but the company got into a financial crisis and went bankrupt.

A Chennai-based start-up that Chakravarthy is a technical mentor of, Agnikul Cosmos, is designing small (20-metre-tall) rockets that are modular. The company’s 20-metre rocket, Agnibaan, is basically a three-stage one, but has the flexibility to be two-stage one if the satellite is lighter. “We can also play around with the number of engines to add or reduce thrust,” says Srinath Ravichandran, Co-founder & CEO, Agnikul. Incidentally, Agnikul has received first stage funding from Speciale Invest, a venture fund.

Also, the rocket, made of an alloy of nickel, cobalt and copper, is to be 3D printed. With the modular design and 3D printed manufacture, Agnikul will be able to offer small satellite launch service at a fraction of the global costs, says Ravichandran. Agnikul’s initial launches will be from ISRO’s Sriharikota space centre. The Indian space agency, he says, has been very supportive.

3D printed rockets seem to be the in-thing. Rocket Lab, a Los Angeles-based, Khosla Ventures-backed, launch services company too has its 18-metre rocket, Electron, 3D printed. Rocket Lab has made seven launches.