Express News Service
BENGALURU: The growing traffic in space is of serious concern to space scientists globally, with launch windows becoming tighter and a challenge. A bigger and attributing concern of space traffic management (STM) is increasing orbital debris (OD) that is posing a major threat to space launches and robotic missions. OD or space junk is any human-made object in orbit that no longer serves a useful function, and includes spent upper stages, retired spacecraft, mission related debris, fragments etc.
“The low earth orbit (LEO) has the highest concentration of debris. The mass in orbit has increased to 9500 metric tonnes,” said chief scientist for Orbital Debris, National Aeronautics and Space Administration (NASA), Dr Jer Chyi Liou. LEO is relatively close to the Earth’s surface, in the region below 2000km altitude.
In an exclusive interaction with TNIE on the sidelines of the workshop on space situational awareness (SSA) and space traffic management (STM) by Indian Space & Research Organisation (ISRO), the scientist said that as per the “current estimates of orbital debris, there are around 27,000 objects measuring 10cm and larger; 500,000 of those measuring 1cm and larger, and one hundred million of those measuring 1mm and larger”.
“The biggest threat is from objects measuring 1mm and below because they have the potential to pierce the propellant tanks of spacecraft. There is no data on the number of such objects in space. The thickness of the propellant tank is approximately 2mm. Because of the pressure, the tanks may explode, damage the spacecraft components and adversely impact the mission. A piece of OD measuring 0.4mm can pose a serious threat to astronauts during spacewalk,” he added. Due to the speed in space, even sub-mm debris poses a realistic threat to human spaceflight and robotic missions.
‘There is low compliance’
Liou said the problem of OD is getting worse, affecting space missions. “We need to comply with existing best practices on mitigation of OD studied by NASA in 1995, the US government in 2001 and Inter-Agency Space Debris Coordination Committee (IADC) in 2002, on preserving the near earth space environment for future generations. Unfortunately, there is low compliance,” he added. “More and more mass in the environment will have a cascading effect. It will lead to accidental collision, which will create more OD and more collisions.”
Liou said two incidents — China’s Anti Satellite test in January 2007, which used a missile to destroy an old weather satellite, and the collision between an inactive Russian communications satellite, designated Cosmos 2251, with an active commercial communications satellite operated by US-based Iridium Satellite LLC on February 10, 2009, had more than doubled OD. “Space is for everyone. We need to balance the benefits (of development) with the environment. We need to manage the side-effects for safer and sustainable space,” he concluded.
BENGALURU: The growing traffic in space is of serious concern to space scientists globally, with launch windows becoming tighter and a challenge. A bigger and attributing concern of space traffic management (STM) is increasing orbital debris (OD) that is posing a major threat to space launches and robotic missions. OD or space junk is any human-made object in orbit that no longer serves a useful function, and includes spent upper stages, retired spacecraft, mission related debris, fragments etc.
“The low earth orbit (LEO) has the highest concentration of debris. The mass in orbit has increased to 9500 metric tonnes,” said chief scientist for Orbital Debris, National Aeronautics and Space Administration (NASA), Dr Jer Chyi Liou. LEO is relatively close to the Earth’s surface, in the region below 2000km altitude.
In an exclusive interaction with TNIE on the sidelines of the workshop on space situational awareness (SSA) and space traffic management (STM) by Indian Space & Research Organisation (ISRO), the scientist said that as per the “current estimates of orbital debris, there are around 27,000 objects measuring 10cm and larger; 500,000 of those measuring 1cm and larger, and one hundred million of those measuring 1mm and larger”.
“The biggest threat is from objects measuring 1mm and below because they have the potential to pierce the propellant tanks of spacecraft. There is no data on the number of such objects in space. The thickness of the propellant tank is approximately 2mm. Because of the pressure, the tanks may explode, damage the spacecraft components and adversely impact the mission. A piece of OD measuring 0.4mm can pose a serious threat to astronauts during spacewalk,” he added. Due to the speed in space, even sub-mm debris poses a realistic threat to human spaceflight and robotic missions.
‘There is low compliance’
Liou said the problem of OD is getting worse, affecting space missions. “We need to comply with existing best practices on mitigation of OD studied by NASA in 1995, the US government in 2001 and Inter-Agency Space Debris Coordination Committee (IADC) in 2002, on preserving the near earth space environment for future generations. Unfortunately, there is low compliance,” he added. “More and more mass in the environment will have a cascading effect. It will lead to accidental collision, which will create more OD and more collisions.”
Liou said two incidents — China’s Anti Satellite test in January 2007, which used a missile to destroy an old weather satellite, and the collision between an inactive Russian communications satellite, designated Cosmos 2251, with an active commercial communications satellite operated by US-based Iridium Satellite LLC on February 10, 2009, had more than doubled OD. “Space is for everyone. We need to balance the benefits (of development) with the environment. We need to manage the side-effects for safer and sustainable space,” he concluded.
