Two scientists at IIIT-Delhi are working on an algorithm that can predict trajectory of objects in space to determine if it is on a collision course with a satellite up to a month in advance

New Delhi: The space is cluttered with satellites — both functional and defunct. As more and more objects are launched into space, the probability of a collision increases. Two computer scientists at Indraprastha Institute of Information Technology-Delhi are now working on an algorithm that can predict if an object is on a collision course with a satellite up to a month in advance.

Using the algorithm, agencies like the Indian Space Research Organisation (ISRO) or the Defence Research and Development Organisation (DRDO) can monitor the safety of the vital Indian satellites and take preventive measures, if any, if these satellites are at risk of being hit by a stray piece of space debris.

“At least 20,000 pieces of space debris is present in the low Earth orbit. The speed at which some of these are travelling is 7 km/second. If they collide with any active satellite, the damage will be similar to a bullet shot,” Sanat K. Biswas, who developed the algorithm, said.

The US Department of Defence maintains a satellite catalogue on objects in Earth’s orbit. Its Space Surveillance Network tracks discrete objects as small as 2 inches (5 centimetres) in diameter in low Earth orbit and about 1 metre in geosynchronous orbit.

Currently, about 15,000 officially catalogued objects are still in orbit. The total number of tracked objects exceeds 21,000.

However, if an Indian satellite were at threat of collision, the country would depend on the US for information.

“We also do not know how this data is collected, or how accurate it is,” Biswas said.

Biswas is working with his colleague Arun Balaji Buduru to develop the algorithm.

The duo received research funding from the National Supercomputing Mission (NSM) for two years. The NSM funds are awarded by the Department of Science and Technology (DST), in collaboration with the Ministry of Electronics and Information Technology (MeITy).

How The Algorithm Works

Usually, to predict the path of each object in space, data on the past positions of the object is collected, based on which its future path can be predicted. This data on the historical positions of each of the over 20,000 pieces of debris is determined through ground and space-based telescopes.

During his PhD, Biswas developed an algorithm that requires a smaller number of sampling points or historical data to give an accurate prediction. The algorithm will be implemented using supercomputers that will have the ability to compute the pathways of thousands of pieces up to a month in advance.

“Our goal is to eventually give this information to an authority like the ISRO or the DRDO,” he said.

According to Milind Kulkarni, a scientist at the Department of Science and Technology who heads the NSM, the project aims to develop an indigenous computational tool for tracking space objects, thereby reducing India’s dependency on Combined Space Operation Centre (CSpOC) led by the US for collision alerts.

“It is anticipated that the processing time and thus computation resource requirement for calculating orbits and associated uncertainty of more than 20,000 space objects will reduce significantly by this novel approach,” Kulkarni said.