Bengaluru-based Astrogate is working on technology that will make it easier for small satellites to send more data to earth stations at a faster speed than before. It hopes to change the face of space communication much like Jio changed the face of internet access in India.Krishna Reddy
Between now and 2027, the world will launch about 7,000 small satellites – that’s six times as many as we launched in the past decade. Small satellites are in fashion, so to speak, mainly because they are cheaper and faster to launch than their larger counterparts. Many of these are used to enhance internet connectivity in remote areas on Earth or study our planet’s climate.
The main purpose of such satellites is to collect and transmit data for researchers to analyse and work on. The sooner they get the data, the better. But that’s easier said than done. Because the satellites are small, they cannot transmit large amounts of data, and definitely not at high speeds.
The bigger problem, however, is that most ground stations (on Earth) are not equipped with the required hardware to receive large amounts of data sent by small satellites.
This is where Astrogate, a Bengaluru-based startup set up by IIT alumni Nitish Singh and Aditya Kedlaya comes in. Astrogate works in the area of optical communication and using that technology, has developed a device that helps small satellites send more data to ground stations or communicate better with nearby satellites - a space-to-ground link that functions as a low-cost optical communication solution.
The flight optical terminal device measures just 1U (U is a unit of measurement used, among other things, to measure payloads onboard satellites).
Co-founder and Director Nitish Singh explains,
“You need a faster mode of connection, which can send and receive data in a short span of time among the group of satellites in space (a ‘smallsat constellation’) or from satellites (in orbit) to ground stations. Here, the idea is to use laser as a mode of sending and receiving data with the help of optical communication, rather than using the conventional method.”
Given its size, the device can be fitted on any small satellite. More importantly, it can receive data at a speed of 150 mbps if fitted at a ground station. This is 10x faster than existing hardware.
When coupled with amateur telescopes used to view planets in space, or when coupled with an optical modem, the transmitter can send data at a speed of 150 mbps.
Nitish further explains,
“In space, small satellites are present in low earth orbit (LEO) and geostationary earth orbit (GEO). Now, satellites are in motion in LEO whereas in GEO, the satellites are stationary or motionless with respect to the Earth. We are developing an (optical communication) device that can be used in both, and measures 1U.”
The system works on a simple fundamental, it has two ends, one end sends the message and the other end receives it. Similarly, a satellite has a transmitter (sender) on it and a receiver on the ground station on earth to receive the data it sends.
The startup traces its origins back to another space-tech company which has been in the news for what was quite literally a ‘moonshot’ endeavour – Team Indus. That startup, founded in 2011, was in the news for being the only Indian company shortlisted for Google’s Lunar XPrize instituted in 2007.
Sadly, the XPrize was scrapped in 2018 when none of the shortlisted teams was deemed ready for the trip to the moon. Since then, Team Indus has become part of an American consortium shortlisted by NASA to fly scientific and commercial cargo to the moon in the next decade or so.
Nitish (28) and Aditya (29) were both a part of Team Indus. Nitish, an aerospace engineering graduate from IIT-Kharagpur, led Mission Planning and Operations team and oversaw systems engineering for the XPrize mission. Aditya, who is an alumnus of IIT-Guwahati, was working on its thermal design and analysis aspects.
It was during this time that Nitish zeroed in on the problems in space communication infrastructure and began thinking about how it could be improved.
In late 2017, the duo left Team Indus to work on solutions in the space communication sector. To get some guidance and expertise initially, Astrogate participated in the cohort accelerator programme organised by the LightSpeed Innovations in the US that year.
“In 2018, we began working on our prototype, which succeeded as we were able to send and receive data through an optical communication set up on ground. Later, we moved onto low-altitude UAV (unmanned aerial vehicles, aka drones) trials. These tests are more representative of how the satellites in motion will acquire the ground terminal and send data on optical links.”
A key challenge related to stable pointing. The laser beam, directed from the transmitter, proved to be too small to be detected correctly. It was crucial that this problem be solved because it is the laser that establishes the link between a receiver and a transmitter. Nothing short of pinpoint accuracy would work.
To counter this issue, the duo developed a system to track laser beams sent from the transmitter onboard the satellite.
As Aditya explains,
“We made sure the transmitter and receiver are in place on ground and won’t move even if an earthquake occurs. By the end of 2018, we achieved technological readiness by completing numerous tests and trials to test for link distances and tracking systems.”
Once the pointing system was perfected, Astrogate received interest for carrying out operational trials for high-speed connectivity in rural and remote areas in India. (The founders said they were not at liberty to disclose who they are working with on this.)
With prototype testing completed, the team of eight at Astrogate has started work on the flight model and qualification plan. The founders believe that their first module will be ready for flight by March 2020.
Next on the anvil is to get satellites to communicate better with each other. But that’s another story.