190 likes | 357 Views
Optical surveys for space debris. Byeon Jae Gyu. What is space debris?. Space debris Non-functional, man-made objects in space Several meters in size like defunct satellites Centimeter and milimeter-sized debris created by explosion and collisions
E N D
Optical surveys for space debris Byeon Jae Gyu
What is space debris? • Space debris • Non-functional, man-made objects in space • Several meters in size like defunct satellites • Centimeter and milimeter-sized debris created by explosion and collisions • Very small particals like flakes, and solid rocket motor slag or dust • Low Earth orbit (LEO) • Region up to 2,000km altitude / about 20cm • Geostationary Earth orbit (GEO) • Around 36,000km altitude / about 0.1 ~ 1m • Geostationary transfer orbits (GTOs) • 2,000 ~ 36,000km altitude / larger than about 1m
What is space debris? • Simulated explosion in LEO
The USSTRATCOM catalogue • The USSTRATCOM catalogue • The US Strategic Command (USSTRATCOM), a military entity of the USA, maintains a catalog of about 9,000 known ‘large’ objects • Russia maintains a similar catalog • USSTRATCOM catalog, although generated for a different purpose and known to be incomplete, is extensively used in space debris research.
Radar observations • Radar is mostly used to survey the LEO region • Detection and tracking all objects larger than about 10-20cm • High altitudes is using optical telescopes of 1m aperture • Can dectct in GEO, have size of the order of 1m in diameter • NASA : the 36-m Haystack dish antenna in MA • ESA : German 34-m dish radar facility
Optical observations • LEO measurements form the NASA Liquid Mirror Telescope (LMT) • GEO survey result from the NASA CCD Debris Telescope (CDT) • The NASA funded Michigan Orbital Debris Survey Telescope (MODEST) • The TAROT telescope supported by the French space agency CNES • GEO and GTO observations from the ESA 1-m telescope
Protecting the space environment • We realize that space cannot be cleaned from debris with any technical means in near future • De-orbit larger objects • Ground-based high power lasers to perturb the orbits of small fragment forcing the fragments to reenter the atmosphere • United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS)