Long-term evolution of the space debris population

Dr Hugh LewisAstronautics Research Group, Faculty of Engineering & the Environment

Space debris 101…

Space debris sources

Space debris population (1)

Data courtesy of NASA Orbital Debris Program Office

Space debris population (2)

Softball size or larger

( 10 cm)

~22,000 ~500,000 ~100,000,000

Total mass: ~6,500 tonnes(> 2,700 tonnes in LEO)

Marble size or larger

( 1 cm)

Ball-point pen tip( 1 mm)

≥ 10 cm debris population

ESA MASTER 2009 population seen in DAMAGE~30,000 objects ≥ 10 cm May 2009

View from the ISS

Simulated view from the ISS, with orbiting

objects from space-track

≥ 10 cm debris population

UN space debris mitigation guidelines1. Limit debris released during normal operations

2. Minimize the potential for break-ups during operational phases

3. Limit the probability of accidental collision in orbit

4. Avoid intentional destruction and other harmful activities

5. Minimize potential for post-mission break-ups resulting from stored energy

6. Limit the long-term presence of spacecraft and launch vehicle orbital stages in the low Earth orbit (LEO) region after the end of their mission

7. Limit the long-term interference of spacecraft and launch vehicle orbital stages with the geosynchronous (GEO) region after the end of their mission

Remediation• Even with good compliance with the commonly

adopted mitigation guidelines, the space debris population is likely to grow:

– Active Debris Removal• About 50 removals needed to prevent one collision• $1 – $3 billion per year

LEO mitigation & remediation

30% compliance

90% compliance

90% compliance with 5 removals per year

LEO mitigation & remediation

90% compliance

90% compliance

with 5 removals per

year

Chance of the same

result

1-in-50 1-in-2001-in-5

12

Summary• Compliance with debris mitigation guidelines is

currently low

– Even if compliance rates improve the debris population is likely to continue to grow:

• Catastrophic collisions every five to ten years• Impact on spacecraft operations

• Remediation of the debris environment

– Can help to limit the growth of the debris population:• Activity needs to be sustained (expensive!)• Catastrophic collisions will still occur• Success is uncertain• Challenges:

– Compliance, Consensus, Cooperation, Collaboration, Contributions

Thank you for your attention

Contact: hglewis@soton.ac.uk

Thanks to Holger Krag (ESA Space Debris Office) for permission to use the MASTER reference population, and J.-C. Liou (NASA Orbital Debris Program Office) for permission to use the satellite catalogue data