Typically, radar measurements have been used for space debris in low Earth orbit (LEO), while optical measurements have been used for high Earth orbit (HEO).

B. Radar detection and measurement of orbital debris (FGAN)

Some measurement of small debris in LEO have been done using optical telescopes, but in general, radars outperform telescopes for measurements in LEO.

Some optical measurements of small debris in LEO have been done, but in general radars outperform telescopes for measurements in LEO.

For that purpose, mainly three modes of operations were developed first a tracking mode of operation to measure selected objects in low Earth orbit, in geosynchronous orbit and in geostationary transfer orbit.

It's a satellite which was all made of ice, and we measured it from orbit. Made of ice.

Additional orbital debris measurements in GEO are needed before more accurate risk assessments can be performed.

For that, mainly three modes of operation were developed a tracking mode of operation to measure selected objects in low Earth orbits (LEO), in geosynchronous orbits (GSO), and in geostationary transfer orbits (GTO).

The figure summarizes measurements in LEO near 500 km altitude.

A Tracking, Telemetry and Control (TT amp C) station is used to support polar satellites during the launch phase and when in service in their nominal orbits.

If an identified object is predicted to pass within the warning box near the orbiter (25 kilometres along the orbit and 5 kilometres both radial and out of orbital plane), the Space Surveillance Network is requested to make additional observations and use them to compute a more accurate orbit of that object.

These measurements are used to maintain the HEO part of the Space Command catalogue.

We can measure the speeds of these galaxies, their orbital velocities, and figure out how much mass is in this cluster.

With a view to further investigation of radiation conditions in orbit and to improving the resources available for space dosimetry, the micrometeorite situation along the flight track of the Mir station was monitored and the Spin 6000 experiment measuring gamma ray spectra in various parts of the orbital station was performed.

A total of 44 objects (including radar calibration satellites) were frequently measured and analysed resulting in estimates of size, shape, intrinsic motion, mass, orbit, and orbital lifetime.

Adjust the volume levels of all tracks

(i) Launch vehicle sub orbital stages should be equipped with tracking aids to permit monitoring of trajectories and prediction of impact points

To measure the small sized solid particle population in different orbits and on a more regular basis, a low resource standard in situ detector called DEBIE is under development.

Design of the orbit suitable for a debris observation satellite

Therefore, it is expected to contribute to an international cooperative project to measure the debris population in and around Geostationary Orbit (GEO).

Radar measurements of ARIANE upper stages in GTO will help to understand the generation of space debris due to fragmentation in these orbits.

(d) IDES is a semi deterministic model of the environment using detailed historical and future traffic models to provide short term and long term predictions of the orbital debris environment and the collision flux it presents to specific satellites.

A Tracking, Telemetry and Control (TT amp C) station is used to support polar satellites during the launch phase and when in service in their nominal orbits.

Detection of neutral particles in orbital altitudes and Technological demonstration.

Some preliminary measurements have been done to survey the region near GSO for debris objects smaller than 1 metre.

Some preliminary measurements have been done to survey the region near GEO for debris objects smaller than 1 m.

To make further progress we really need to look at the orbits of stars that are much further away.

Models have predicted that the orbital debris environment could exceed the meteoroid environment in certain regions of low Earth orbit.

After moving from its in orbit test location, INTELSAT 702 began commercial service on August 13, 1994, at longitude 359 degrees E., replacing the lower capacity INTELSAT 512.

The minimum diameter of observable objects was about 10 centimetres for LEO and 1 metre for geostationary satellite orbit (GSO).

An ever increasing measurement programme is essential towards understanding and controlling the growth in the future orbital debris environment.

It detected a large swarm of objects in near circular, 65 inclined orbits at an altitude of about 900 km (see figure 1).

In particular, future traffic scenarios and the application of mitigation measures will have a major influence on the outcome of model predictions.

Survey type NEO missions are dedicated to the detection, tracking (that is, orbit determination) and remote characterization (for example, determination of taxonomic type and surface albedo of NEOs).

A validation of model assumptions is mainly restricted to the small fraction of generated objects that exceeds the radar observation threshold of about 6 mm diameter in low Earth orbit (LEO).

To provide a large capacity data communications link from the Advanced Earth Observation Satellite (ADEOS), interorbit communication technology will be developed.

During FY 1994, NASA made significant progress in measuring, modeling, and mitigating the orbital debris environment.

It was inescapable that orbital debris would become an environmental issue requiring models and measurements to understand this new environment.

The limited number of large objects near GEO also permits the prediction of close approaches between operational spacecraft and tracked orbital debris in sufficient time to conduct an evasive manoeuvre.

In September 1996, the impact ionization detector Geostationary Orbit Impact Detector (GORID) was placed into GEO on board the Russian telecommunication satellite Express 12.

The following ESA geostationary satellites have been re orbited OTS 2 (orbiting 318 km above GSO), GEOS 2 (260 km), Meteosat 2 (334 km), ECS 2 (335 km) and Olympus 1 (due to a failure, this satellite has been left at orbit 213 km below GSO).

The precise range and range rate equipment (PRARE), operational on ERS 2, allows precise orbit calculations to be made and accurate corrections to radar altimeter measurements to be implemented.

A catalogue is a deterministic record of the characteristics of the orbital population that have been derived from measurements or records.

19. Current space surveillance systems cannot track objects in LEO with a radar cross section of less than 10 cm in equivalent diameter.

The number of orbital debris of less than 1 m in diameter near GEO is not well known.