Bengaluru-based space tech start-up Bellatrix Aerospace plans to test its propulsion technologies — systems that guide satellites to their destination — in space by 2023, and launch its "space taxi" service by 2024.
A space taxi, also known as an 'orbital transfer vehicle' (OTV), is a last-mile connector for satellites aboard rockets. Satellite propulsion systems, or thrusters, are the engines that keep satellites in orbit for their entire lifespan, which is approximately 10-15 years.
The engines assist satellites in space by allowing them to move from one orbit to another as well as manage other orbital parameters such as orientation, inclination, and so on.
The start-up has developed four different types of thrusters: hall thrusters, microwave plasma thrusters, nano thrusters and green propulsion systems. Different types of thrusters will cater to satellites ranging in size from nano to heavy.
The thrusters are also one-of-the-kind. The microwave plasma thruster, for instance, uses water as a fuel. Yashas Karnam, co-founder of Bellatrix Aerospace, told Moneycontrol that the company holds a global patent for the thruster and has received an order from the Indian Space Research Organisation (ISRO). He said that the hall thruster is propelled by the power available on satellites.
Founded in 2015 by Rohan M Ganapathy and Karnam, the company also concentrated on manufacturing launch vehicles (like Agnikul Cosmos or Skyroot Aerospace). However, given the high level of competition in the space launch vehicle market, it later decided to focus solely on developing satellite propulsion technologies.
The start-up has thus far raised $8 million in Series A funding and is in the process of securing additional funds. This funding will support the $75 million investment commitment made in partnership with the Karnataka government for the establishment of a research and development centre and manufacturing factory for space taxis and rocket propulsion systems.
Multiple test launches planned
Karnam said Bellatrix is planning multiple launches in 2023 to test its four propulsion technologies in space. He said that testing these thrusters would be very different from testing a rocket for space.
"A rocket launch lasts for about a maximum of 30 minutes. So all your systems should be designed, tested and qualified for maximum 30 minutes of operation. But for a satellite propulsion system, I have to design and qualify it for 15 years of operation in space," he said.
Moreover, the differences and complexities increase when developing satellite propulsion systems because the engines must operate in space. "So we need to test these engines in a vacuum," Karnam said, adding that the thrusters have already been tested in a simulated vacuum setup at the Indian Institute of Science in Bengaluru.
"We will be flying them on actual satellites and the test will go on for a couple of months once in space," he said.
The rocket market is crowded
The decision to pivot from its plans to manufacture a rocket (Chetak), to making propulsion systems for satellites was a tough one for Bellatrix Aerospace. "It's common for engineers to have a passion for making rockets. However, from the business standpoint, it is tough," Karnam said.
When Bellatrix started, there were only two companies in the world manufacturing rockets with payload capacities of less than 500 kg. "Today, as the market has been expanding, there are more than 230 companies," he said.
"So there is not enough market for 230 companies to do it. And if we had entered the market, we would only win if we offered cheap prices for launches despite building some of the best technologies. So our profit margins would have decreased," he said.
On the other hand, the lack of competition in the satellite propulsion systems market was appealing to Bellatrix, and gaps in existing technologies provided them with an opportunity.
"Traditionally satellites use hydrazine as a fuel for propulsion systems. This is a very toxic and carcinogenic chemical. People handling it would have to wear HAZMAT (hazardous materials) suits and there are a lot of regulations and restrictions around its usage," Karnam said.
"Even the plants (for making hydrazine) had to be close to the rocket launch site because it is a very unstable compound and sensitive to shock," he added.
Apart from the environmental concerns associated with the use of hydrazine, Bellatrix identified the need for fuel that is significantly lighter than hydrazine. "Most of your satellite weight goes behind fuel — because you have to carry fuel that will sustain the satellite for its entire 15-year life span," he said.
"So for instance, in a 5-tonne communication satellite, one would have to carry 3.5 tonne of just fuel, only 300 kg would be the useful payload. So instead of paying for the 300 kg, you are actually paying the cost of a 5-tonne satellite. And for launch vehicles, you have to pay per kilogram, thus taking costs higher," he explained.
Thus, according to Karnam, the start-up began looking at different solutions that were "cleaner, safer, and more efficient," and they zeroed in on technologies such as microwave plasma thrusters that use water as fuel, and so on.
"Everything that we have done was all built in-house at Bellatrix. And we have not just made the thruster but we have also made a lot of subsystems for it," he said.
Thruster subsystems include catalysts, thermal coatings, testing and calibration equipment, and so on. "All these were done to cut down costs, and take advantage in terms of the lead times that we can offer to our customers," he said.
Why space taxis?
The start-up is also manufacturing orbital transfer vehicles, or space taxis, which it plans to launch into space by 2024.
"Rockets carrying multiple satellites usually go to the orbital destination of the customer who pays the most. So our OTV would help the other satellites on the rocket reach the required orbit after it is deployed," Karnam said.
These OTVs would be mounted on the launch vehicle, and after it has travelled to the required location in space to deploy the primary satellite, the OTVs will assist the other satellites in travelling to their respective locations. "This would be much cheaper than taking a chartered flight," said Karnam.
By "chartered flight," Karnam refers to rockets that can be launched exclusively for the needs of one customer who plans to deploy a satellite at the time they choose (as opposed to ISRO's PSLV, which carries multiple satellites and launches sporadically each year.
The start-up currently has collaborations with rocket manufacturer Skyroot Aerospace, satellite infrastructure manufacturer Dhruva Space and space data analytics company SatSure.