BENGALURU: It’s just not on city roads that we have to contend with traffic jams. Space scientists are worried over the increasing number of satellites in the lunar orbit, and more so in Earth’s orbit. This worry of an imminent “traffic jam” in space — mainly in the orbits of the Earth, Moon and (in future) Mars — found expression at the crossover session of the Sydney Dialogue at the Bengaluru Tech Summit on Friday. Indian Space Research Organisation (ISRO) Chairman K Sivan called for a collaborative approach in Space Situational Awareness (SSA) by tracking objects in orbit and predicting where they will be at any given time.
The ISRO chief particularly stressed on the importance of all space agencies collaborating with each other to track objects in space and mitigate threats of collisions or near-collisions, and stressed that the role of the QUAD (the USA, Australia, Japan and India) will be more significant in this regard.Sivan’s appeal gains significance in the background of a projected near-collision between India’s Chandrayaan-2 orbiter (CH2O) and Jet Propulsion Laboratory (JPL)/National Aeronautics and Space Administration’s (NASA) Lunar Reconnaissance Orbiter (LRO), both in the lunar orbit, and how it was avoided through data exchange and collaboration.
The extremely close conjunction between CH2O and LRO was expected to occur on October 20 at 11:15 am IST over the Lunar North Pole. A week prior to that, analyses by ISRO and JPL/NASA showed the separation between the two spacecraft will be less than 100 metres. The data exchange between ISRO and JPL/NASA highlighted the importance of undertaking a collision avoidance manoeuvre, and it was mutually agreed that CH2O will make the manoeuvre. The move was carried out at 8.22 pm on October 18, and CH2O’s modified orbit confirmed that there will be no further close conjunctions between the two spacecraft in the lunar orbit.
While there are just nine spacecraft currently in the lunar orbit, according to the Union of Concerned Scientists there are 3,372 big and small active satellites in the Earth’s orbit. This ushers an urgency for collaboration among various space agencies to avoid satellite collisions, more so in the Earth’s orbit than in the lunar or Martian orbits. Sivan said a comprehensive SSA was impossible in isolation, and collaboration with other space agencies was imperative.
Hiroshi Yamakawa, president, Japan Aerospace Exploration Agency, too admitted that transparency is important in sustainable use of outer space, and collaboration is imperative with space stations needing information from other countries on satellites and space debris. “Or else, due to heavy traffic, there may be a good chance of collision among satellites or space debris,” he said. Sivan suggested establishing a new observation facility in the southern hemisphere under the QUAD framework. The facility can leverage the countries’ unique geographical advantages and data shared among member states though a suitable mechanism, he said.