Meteor (satellite)

The Meteor craft are weather observation satellites launched by the USSR. The Meteor satellites were designed to monitor atmospheric and sea-surface temperatures, humidity, radiation, sea ice conditions, snow-cover, and clouds.

Meteor 2-21

Meteor 2-21/Fizeau is the twenty-first and last in the Meteor-2 series of Russian meteorological satellites launched in 1993.

ILRS Mission Support Status: Satellite Laser Ranging (SLR) tracking support of this satellite was discontinued in October 1998. What makes Meteor 2-21 distinctive from the other meteorological satellites is its unique retroreflector array. Fizeau is named after a French physicist, Armand Fizeau, who in 1851 conducted an experiment which tested for the aether convection coefficient. SLR tracking of this satellite was used for precise orbit determination and the Experiment of Fizeau. The Experiment of Fizeau tests the theory of special relativity-that distance events that are simultaneous for one observer will not be simultaneous for an observer in motion relative to the first.

RetroReflector Array (RRA) Characteristics: The retro-reflector array consists of three corner cubes in a linear array with the two outer corner cubes pointing at 45 degree angles relative to the central cube. The central cube is made of fused silica and has a two-lobe Far Field Diffraction Pattern (FFDP) providing nearly equal intensities for compensated and uncompensated velocity aberration. Both outer reflectors have aluminum coating on the reflecting surfaces and near-diffraction-limited FFDPs. One of the end reflectors is made of fused silica with an index of refraction of 1.46 and should provide partial compensation of the velocity aberration. The other end reflector is made of fused glass with an index of refraction of 1.62 and should provide a perfect compensation of the velocity aberration.

SLR full-rate data from MOBLAS 4, MOBLAS 7, and Maidanak seem to confirm the presence of the compensating influence of the Fizeau effect. Resur-1, another Russian satellite launched in 1994, has 2 corner cubes reflectors with near diffraction-limited FFDPs, which were specifically designed for the continuation of this experiment. WESTPAC, a future SLR satellite, will verify indisputably the existence or otherwise of the Fizeau effect.

Instrumentation: Meteor-2-21/Fizeau had the following instrumentation on board:

1. Scanning telephotometer
2. Scanning infrared radiometers
3. Radiation measurement complex
4. Retroreflector array

Meteor 3

Launch of Meteor-3 on a Tsyklon-3 rocket

In the last days of the Cold War, Meteor-3 carried the second Total Ozone Mapping Spectrometer (TOMS) aloft as the first and the last American-built instrument to fly on a Soviet spacecraft. Launched from the Plesetsk, Russia, facility near the White Sea, on August 15, 1991, Meteor-3 TOMS had a unique orbit that presents special problems for processing data. Meteor-3 TOMS began returning data in August 1991 and stopped in December 1994.

Meteor 3-5

Meteor 3-5, launched in 1991, is in a slightly higher orbit than Meteor 2-21. It transmits on 137.300 MHz. Mechanically, it is similar to Meteor 2-21. Which satellite is in operation depends on the sun angles and consequently the seasons. Meteor 3-5 is usually the (Northern Hemisphere) "summer" satellite while 2-21 is in operation for approximately the half-year centered on winter.

Meteor 3-6/PRARE

The METEOR 3-6/PRARE satellite is the sixth in the Russian METEOR-3 series of meteorological satellites launched in 1994. These satellites provide weather information including data on clouds, ice and snow cover, atmospheric radiation and humidity. The Meteor-3 class of satellites orbit in a higher altitude than the Meteor-2 class of satellites thus providing more complete coverage of the Earth's surface. The Meteor-3 has the same payload as the Meteor-2 but also includes an advanced scanning radiometer with better spectral and spatial resolution and a spectrometer for determining total ozone content. Meteorological data is transmitted to four primary sites in the former Soviet Union in conjunction with about 80 other smaller sites.

ILRS Mission Support Status: Satellite laser ranging and PRARE data was used for precision orbit determination and intercomparison of the two techniques. ILRS tracking support of this satellite was discontinued on November 11, 1995.

Instrumentation: METEOR-3-6 has the following instrumentation on board:

1) Scanning TV-sensor 2) Visible light and infrared radiometers 3) Scanning infrared radiometer 4) Ozone Mapper 5) Precise Range and Range-Rate Equipment (PRARE) 6) Retroreflector array

RetroReflector Array (RRA) Characteristics: The retro-reflector array is a box wing annulus with a diameter of 28 cm and has 24 corner cube reflectors.

Meteor-3M

Meteor-3M satellite

Meteor-3M satellite atop its Zenit-2 launcher

The Meteor-3M series of satellites is to be an advanced series of polar orbiters with one 1.4 km resolution visible channel and a ten-channel radiometer with 3 km resolution.

The first of these, Meteor 3M-N1, was launched on December 10, 2001 at 17:18:57 UTC from the Baikonur Cosmodrome in Kazakhstan. The satellite is in a sun-synchronous orbit with an ascending node time of about 9 AM. An APT transmission was planned to only have a reduced resolution (2 km) visible channel data. The status of any APT capability on this satellite is unclear, but it is thought not to have an APT transmitter. No APT transmissions have been received from this satellite. SLR mission support began on May 1, 2002.

METEOR-3M includes the SAGE III (Stratospheric Aerosol and Gas Experiment) payload and other instruments designed to measure temperature and humidity profiles, clouds, surface properties, and high energy particles in the upper atmosphere. SAGE III is a gyrating spectrometer that measures ultraviolet/visible energy that will be used to enhance our understanding of natural and human-derived atmospheric processes by providing accurate long-term measurements of the vertical structure of aerosols, ozone, water vapor, and other important trace gases in the upper troposphere and stratosphere.

Secondary mission objective is the flight testing of the novel-type spherical retroreflector for precise laser ranging.

ILRS Mission Support Status: SLR will be used for precise orbit determination and retroreflector research.

Instrumentation: 1. SAGE III 2. Spherical retroreflector 3. Other weather monitoring instruments

RetroReflector Array (RRA) Characteristics: The retroreflector is a glass ball 60 mm in diameter, fastened in a holder providing observation from Earth at elevations more than 30° (the retroreflector field of view is centered in the Nadir direction). The spherical retroreflector with it holder is fixed to the METEOR-3M spacecraft. The expected return signal strength level is between LAGEOS and ETALON.

See also

• Soviet space program

External links

• Sputnik server
• NOAA description of Meteor
• SAGE III Meteor 3M
• SAGE III Meteor 3M platform
• NASA - Goddard Space Flight Center Scientific Visualization Studio
• NASA International Laser Ranging Service (ILRS)
  • NASA ILRS Meteor 3-6
  • NASA ILRS Meteor 2-21/Fizeau
  • NASA ILRS Meteor 3M