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1. Space Environment
Lecture 26 – Space Debris (Vol. 1)
In-situ measurements
Professor Hugh Lewis
SESA3038 Space Environment

2. Overview of lecture 26
• In this lecture we complete our look at space debris measurements,
focusing on in-situ measurements
– We look at how in-situ measurements help to complete our
understanding of the space debris population
– We look at space missions that have enabled us to gather in-situ data:
– LDEF, Hubble, ISS, Space Shuttle
– We also look briefly at the undesirable nature of in-situ measurements:
impacts on parts of the ISS and on an ESA satellite
– Finally, we see estimates of the small-size (microscopic) space debris
populations
Space Environment – Space Debris (Vol. 1)

3. Space Environment – Space Debris (Vol. 1)
SSA coverage
From NASA presentation to the UN COPUOS STSC Jan 2018
https://www.unoosa.org/documents/pdf/copuos/stsc/2018/tech-14E.pdf

4. In-situ measurements
• LDEF
• Hubble solar array
• Sentinel 1A
Space Environment – Space Debris (Vol. 1)

5. Space Environment – Space Debris (Vol. 1)

6. Space Environment – Space Debris (Vol. 1)
STS-114 High Velocity Impacts on Windows

7. Space Environment – Space Debris (Vol. 1)
Impacts on the ISS: Multi-Purpose Logistics Module

8. Space Environment – Space Debris (Vol. 1)
Impacts on the ISS:

9. Space Environment – Space Debris (Vol. 1)
Impacts on the ISS:
https://twitter.com/cmdr_hadfield/status/328920180241596417?lang=en

10. Impacts on the ISS
• Battery charger on the P6
truss segment of the ISS
https://twitter.com/SWGlassPit/status/1228431095525519361
Space Environment – Space Debris (Vol. 1)

11. In-situ measurements: Space Debris Sensor
• SpaceX-13, carrying resupply and NASA’s SDS, was launched to the ISS on 15 December
2017
• The SDS mission aimed to mature NASA’s in-situ measurement technologies and collect
data on the sub-millimetre debris population at the ISS altitude. It failed shortly after
deployment
• NASA is aiming to deploy SDS above 600 km altitude to fill the data gap on the millimetre-
sized debris
Space Environment – Space Debris (Vol. 1)

12. Impacts on spacecraft
• Sentinel 1A
• Solar panel impact on 23 August 2016
• Affected area is ~ 40 cm in diameter
• Impact on the back of the panel
• Sudden small power reduction at 17:07 GMT
• Small changes in orientation and orbit
• Debris particle few millimetres in size
• No impact on satellite operation
• See:
http://www.esa.int/Our_Activities/Observing_t
he_Earth/Copernicus/Sentinel-
1/Copernicus_Sentinel-
1A_satellite_hit_by_space_particle
Space Environment – Space Debris (Vol. 1)

13. Space Environment – Space Debris (Vol. 1)
Potential Shuttle Damage

14. Size distribution Space Environment – Space Debris (Vol. 1)
Graphic from “Orbital Debris: A Technical Assessment” (1995)

15. Overview of lectures 20 to 26
• In these lectures we have focused on the current state of the environment
and how this state has emerged from historical space activity and
fragmentation events.
• We have introduced the space surveillance network and new commercial
networks of sensors (radar and optical)
• We have seen how the different sensing technologies can be used to
characterise space objects (i.e. not just count them)
– This characterisation provides space situational/domain awareness
• Finally, we looked at how in-situ measurements help to complete our
understanding of the space debris population
Space Environment – Space Debris (Vol. 1)