Space Junk
Context:
Robots are playing a crucial role in removing the growing problem of space debris orbiting the Earth.
According to NASA, more than 9000 tonnes of space junk is currently orbiting Earth including 30000 pieces of at least 10 cm long travelling at orbital velocity. Even a small piece of junk could destroy a satellite or hit an astronaut doing a spacewalk.
The Global space economy is set to reach $ 1.8 trillion by 2035 from $ 630 billion in 2023.
Some of the missions
Astroscale’s Active Debris Removal Missions
- Astroscale, a space sustainability company, plans to launch a mission in 2026 to capture and remove two defunct UK-owned satellites using a lightweight version of the ISS robotic arm.
- It can grab old satellites and other space debris, then nudge them towards the earth’s atmosphere where they burn up.
- It has an arm cold “gripper” which uses magnets to latch on to space junk adjusting for speed, rotation and alignment in what its makers call a “complex space ballet” .
- Their ELSA-M mission successfully captured simulated debris in 2021 using a magnetic system.
- The upcoming Cosmic mission will target old satellites without special features for removal.
- Astroscale is also partnering with JAXA to inspect and remove a discarded Japanese rocket stage with their ADRAS-J spacecraft in 2025.
ESA’s ClearSpace-1 Mission
- The European Space Agency (ESA) plans to remove a spent rocket body from orbit in 2025 using a junk collector spacecraft built by Astroscale’s competitor ClearSpace.
- Zero Debris Charter: It is an initiative launched by the European Space Agency (ESA) aimed at achieving debris-neutrality in space by the year 2030.
SINTEF’s 3D Camera for Robotic Vision
- Norwegian researchers at SINTEF are developing a new 3D camera to provide robust and accurate robotic vision for space applications.
- The camera uses two lasers projecting a pattern onto the target, enabling triangulation and advanced data processing to build a 3D image.
- The camera is compact, energy-efficient, and provides detailed close-up images. It has been stress-tested to withstand the harsh conditions of space.
Indian Initiatives
- Project NETRA: India has initiated Project NETRA (Network for space object Tracking and Analysis) to safeguard its space assets from the growing threat of space debris.
- Objectives of Project NETRA:
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- An early warning system to detect debris and other hazards to Indian satellites.
- Give India its own capability in space situational awareness (SSA) like other major space powers.
- Spot, track and catalogue objects as small as 10 cm up to a range of 3,400 km and an orbit of 2,000 km.
- Eventually capture the geostationary orbit (GEO) scene at 36,000 km where communication satellites operate.
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- Debris Free Space Missions (DFSM): Starting in early 2025, it aims to enhance sustainability and reduce collision risks by selecting optimal orbital slots, budgeting fuel for post-mission disposal, and planning controlled re-entry or deorbiting trajectories.
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- The ISRO system for safe and sustainable space operations management (IS4OM) will lead the implementation of DFSM with support from the Department of Space.
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Kessler Syndrome, also known as the Kessler effect, is a theoretical scenario proposed by NASA scientist Donald J. Kessler in 1978. The syndrome operates on the principle that as the density of objects in low Earth orbit (LEO) increases, the likelihood of collisions also rises. Each collision generates additional debris, which in turn increases the chances of further collisions. This creates a domino effect, where the accumulation of debris can reach a critical threshold, leading to a situation where space operations become severely hindered or impossible.