Craig Smith, EOS Space Systems; Steve Gower, Space Environment Research Centre; David Ball, Space Environment Research Centre Limited
Keywords: Colliions avoidance, photon pressure, high power lasers, adaptive optics
Abstract:
The Cooperative Research Centre for Space Environment Management and its participants, is developing a system to demonstrate remote manoeuvre of space debris using photon pressure for active collision avoidance. The Cooperative Research Centre operated by the Space Environment Research Centre (SERC) is comprised of participants from Industry (EOS Space Systems, Lockheed Martin Australia, Optus satellite Systems), Academia (Australian National University, RMIT University) and Government (National Institute of Information and Communications Research Institute, Japan and the Department of Industry, Commonwealth of Australia)
Debris on debris collisions in orbital space are now a significant contributor to the growth of the space debris population. Left unchecked there is the possible (probable) runaway cascade (Kessler Syndrome caused by such collisions in popular orbits, possibly rendering these valuable orbital slots unusable in the future.
To reduce the collision risk there have been a number of proposals for removal of large debris objects, mostly involving rendezvous with and capture of large debris objects. However, none of the debris removal capture plans are particularly affordable and none reduce the current collision risk, only future population growth.
Rather than remove debris from orbit we will demonstrate the ability to avoid collisions by making small orbit changes to one or both objects in a predicted collision so that the intersection in time and space does not occur. The objects remain in orbit but do not crash and generate more collision debris.
As the ability to effect orbit change with a ground based laser is likely to be small it is necessary to start with very accurate predictions of the orbit conjunction. These will be made using laser ranging systems to provide high accuracy tracking of the intersecting objects and advanced orbit propagation and conjunction models. When a collision prediction is confirmed it is proposed to make small changes to the debris object’s orbit (1mm/s change in along track velocity) using photon pressure from a ground based laser. Over time (24 hours) the small velocity change grows to a significant displacement and essentially de-phases the two orbits so that the two objects do not occupy the same space at the same time even though they remain in similar orbit geometry.
To effect an orbit change using photon pressure delivered from a ground based laser system, SERC and participants have augmented the EOS 1.8m SSA telescope with a high power (up to 18kW) CW laser and high order adaptive optics system including a sodium laser guide star module. These hardware components are coupled with developments in obit predictions, propagation, and atmospheric density modelling and conjunctions analysis. The laser and AO systems are now entering advanced stages on integration and alignment. The photon pressure remote manoeuvre system is scheduled to commence operations within the second half of 2019.
This paper will describe the method of engagement with the debris object and provide an overview of the system integration and results of photon pressure experiments to date.
Date of Conference: September 17-20, 2019
Track: Orbital Debris