Christophe Bonnal from @CNES now talking about Just-in-time collision avoidance for large derelict #spacedebris using clouds of particles #orbitaldebris2019
[I recall this exact concept being presented by Darren McKnight during the joint NASA-DARPA workshop in Chantilly in 2009. Will there be anything new here?]
Just need a delta-V of 3.5 mm/s along velocity vector to induce a miss distance of 1 km over 24 hours for an object of 100 kg [I think]. Also needs very accurate orbit data
Target mass < 2000 kg on next slide
7.7 mm/s on target of 1400 kg requires only 3 g [of] particles
Study looked at launch windows and phasing requirements to intercept targets in any orbit plane, with launch site close to the equator. Assumed launch at first opportunity of trace crossing. Need a group of launch sites.
Maximum size of particles 50 to 100 micrometres to avoid generation of new debris on collision with target. Optimal size 5 to 10 micrometres to induce sufficient velocity change.
Total particle mass of 10 kg. Selected 50 micrometre copper particles contained in 58 litre bladder tank pressurised using air or Nitrogen. Internal fluid to ensure good dispersion of copper particles
Air launched solution not capable, so use two-stage rocket (potentially reusable stages). Requires 100s trajectory adjustments by upper stage and 1 minute margin on launch time.
There is a third stage - for rendezvous. Note this is sub-orbital launch solution, so no long-term orbital debris created
Conclusions: 1 to 4 launch sites needed; relatively cheap solution but only works if we have improved knowledge of debris orbits
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