Geostationary Orbit Impact Detector
Internal Investment Budget
Adaptation, launch and operation of the GORID (Geostationary Orbit
Impact Detector) experiment. See also the presentation from the Final Presentation Days in
which were organised to report on the technology research in the
space environments and effects area.
Modification of the detector and the Russian EXPRESS spacecraft on which GORID is attached.
Building of electronic interface.
Launch and operation of GORID.
Delivery of GORID data to ESTEC.
GORID was launched on 26 September 1996. First impacts were detected on 3 November 1996.
Since 22 April 1997 GORID is in standard normal operation. The expected lifetime of the GORID/EXPRESS system is 5-7 years.
Information on the small-size meteoroid
and space debris environment can only by gained by the analysis
of retrieved spacecraft or spacecraft parts (only possible for relatively
low orbits) or by in-situ monitors in orbit.
Instruments to detect impacts from natural meteoroids
and man made space debris particles have been flown in Low Earth
Orbits (LEO) (e.g. on LDEF, EURECA, MIR, BREMSAT) and on interplanetary
missions (e.g. Giotto, Vega, Ulysses, Galileo, Hiten).
However, very little information on the particulate
environment for Earth orbits above about 600 km altitude is available.
Especially the space debris environment in the important geostationary
ring is largely unknown. Ground based detection in GEO is limited
to objects larger than about 0.5 m.
To obtain information on the submicron to millimetre
size particle population in GEO the GORID (Geostationary Orbit Impact
Detector) experiment was initiated. GORID is a joint project between
ESA, the Max-Planck Institute (MPI) für Kernphysik in Heidelberg,
the Scientific Production Association of Applied Mechanics (NPO-PM)
from Krasnoyarsk and the Novosibirsk State University (NSU). Main
objectives of the experiment are to:
- monitor the space debris environment in the geostationary orbit and its long term variation.
- monitor the meteoroid flux at 1 AU heliocentric distance , its dependence on the season and its long term variation.
- Investigate the small particle mass region of meteor streams and its relation to the position of the parent bodies.
- Act as a third point for simultaneous measurements with the corresponding Ulysses (out of the ecliptic) and Galileo (at Jupiter) instruments.
On 26 September 1996 the Russian Express-2 telecommunications
spacecraft was launched into geostationary orbit (GEO). The GORID
Cosmic Dust/Space Debris detector was included as a piggyback instrument.
The instrument consists of a plasma type detector and associated
electronics and is essentially identical to the Dust detectors flying
on the Ulysses and Galileo spacecraft.
The aperture size is 0.1 m2 and the instrument
is capable of detecting particles with a mass down to 10-14
g (velocity dependent). The detector is stationed at 80o
Eastern longitude. It has a fixed viewing direction which is 65o
away from the flight direction towards North.
A picture of GORID with its Gold coated
detecting surface is shown here:
The diameter of the detector opening
is 43 cm. The extracted parameters include particle mass, velocity
and crude impact direction. To some extend orbital debris and natural
meteoroids can be separated by the impact velocity which at the
GEO altitude is typically below 5 km/s for debris and higher for
During its first year of operation GORID has detected
between 0 and 12 events per day which have all the signatures of
hypervelocity impacts. It appears that many of the impacting particles, especially
those arriving during the local night times, are highly negatively
charged when they enter the detector. An interesting observation
which, if confirmed, could have important implications for the solid
particle environment in GEO.
A detailed analysis of the GORID data is ongoing.
The design life of the Express satellite is 5 to 7 years.
G. Drolshagen, H. Svedhem, E.
Grün, O. Grafodatsky, U. Prokopiev, In Situ Measurement of Meteoroids
and Space Debris in GEO, 48th IAF Congress, 6-10
October 1997, paper IAA-97-IAA.6.3.09, 1997.
G. Drolshagen, H. Svedhem, E.
Grün, O. Grafodatsky, V. Verhoturov, U. Prokopiev, V. Gusyelnikov,
In Situ Measurement of Cosmic Dust and Space Debris in the
Geostationary Orbit, Procedings of 2nd European
Conf. On Space Debris, Darmstadt, March 17-19, 1997.
Preparing for the Future, Vol. 7, No.
1, ESA, March 1997.G. Drolshagen, H. Svedhem, E. Grün, O. Grafodatsky, U. Prokopiev, Geostationary Orbit Impact
Enhanced Meteoroid/Debris analysis tool.
EURECA and HST solar array Post-Flight Impact Studies.
Standard In Situ Impact Detector (DEBIE).
G. Drolshagen and H. Svedhem, (ESA/ESTEC)
E. Grün, MPI f. Kernphysik (D)
O. Grafodatsky, NPO-PM, (Russia)
U. Prokopiev, Novosibirsk State University, (Russia)
Contact point at ESA: