Dept. of AstronmyDept. of Astronmy

Optical surveys for space debrisOptical surveys for space debris

Byeon Jae Gyu

Dept. of AstronmyDept. of Astronmy

What is space debris?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 collisi

ons• 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

Dept. of AstronmyDept. of Astronmy

What is space debris?What is space debris?

Dept. of AstronmyDept. of Astronmy

What is space debris?What is space debris?

Dept. of AstronmyDept. of Astronmy

What is space debris?What is space debris?

• Simulated explosion in LEO

Dept. of AstronmyDept. of Astronmy

Why is space debris a problem?Why is space debris a problem?

Dept. of AstronmyDept. of Astronmy

Why is space debris a problem?Why is space debris a problem?

Dept. of AstronmyDept. of Astronmy

The USSTRATCOM catalogueThe 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.

Dept. of AstronmyDept. of Astronmy

Radar observationsRadar 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

Dept. of AstronmyDept. of Astronmy

Optical observationsOptical 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

Dept. of AstronmyDept. of Astronmy

Optical observationsOptical observations

Dept. of AstronmyDept. of Astronmy

Optical observationsOptical observations

Dept. of AstronmyDept. of Astronmy

Optical observationsOptical observations

Dept. of AstronmyDept. of Astronmy

Optical observationsOptical observations

Dept. of AstronmyDept. of Astronmy

ModelsModels

Dept. of AstronmyDept. of Astronmy

ModelsModels

Dept. of AstronmyDept. of Astronmy

Protecting the space environmentProtecting 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)