Encyclopedia Astronautica
GFZ-1


German earth geodetic satellite. 2 launches, 1995.04.19 (GFZ-1) and 1998.07.10 (WESTPAC). GFZ-1 was a geodetic satellite designed to improve the current knowledge of the Earth's gravity field.

The satellite, a passive system with no onboard sensors or electronics, was covered with retroreflectors that reflect laser beams sent from ground stations.

By measuring the round trip time of the transmitted light, the distance between the satellite and the station could be determined within approximately 1 centimeter. These measurements were used to determine variations in the rotational characteristics of the Earth and for measurement of the Earth's gravitational field. As the vehicle's orbit decayed, the satellite's orbital motion would also be used calculate to atmospheric densities. Deployed from the Mir space station, GFZ-1 was the first non-Russian satellite launched from Mir. GFZ-1 was developed in under 12 months and cost approximately $700,000 (including design, fabrication, test, and launch). Data collection, distribution and evaluation were coordinated by the project's scientists at the GeoForschungsZentrum Potsdam.

he satellite consisted of a spherical body made of brass with 60 corner cube reflectors distributed regularly over the satellite's surface. These retroreflectors were quartz prisms placed in special holders that were recessed in the satellite's body. External metallic surfaces were covered with white paint for thermal control purposes and to facilitate visual observation in space. The vehicle's size was limited by the maximum allowable dimensions of the Mir airlock (30 cm). The vehicle carried no electronics or sensors and was not attitude controlled.

The spacecraft carried no active payload. Science was performed using ground lasers to illuminate the vehicle's 60 retroreflectors. GFZ-1 was delivered to Mir on Progress M-27 and deployed from Mir on 19 April 1995.

AKA: Geo Forschungs Zentrum.
Gross mass: 22 kg (48 lb).
Height: 0.21 m (0.68 ft).
First Launch: 1995.04.19.
Last Launch: 1998.07.10.
Number: 2 .

More... - Chronology...


Associated Countries
See also
  • Soyuz The Russian Soyuz spacecraft has been the longest-lived, most adaptable, and most successful manned spacecraft design. In production for fifty years, more than 240 have been built and flown on a wide range of missions. The design will remain in use with the international space station well into the 21st century, providing the only manned access to the station after the retirement of the shuttle in 2011. More...
  • Zenit Zenit was to be a modular new generation medium Soviet launch vehicle, replacing the various ICBM-derived launch vehicles in use since the 1960's (Tsiklon and Soyuz). A version of the first stage was used as strap-ons for the cancelled Energia heavy booster. But it was built by Yuzhnoye in the Ukraine; when the Soviet Union broke up planned large-scale production for the Soviet military was abandoned (Angara development was begun as an indigenous alternative). Launch pads were completed only at Baikonur; those at Plesetsk were never finished and are planned to be completed as Angara pads. However the vehicle found new life as a commercial launch vehicle, launched from a sea platform by an American/Ukrainian consortium. More...

Associated Launch Vehicles
  • Soyuz Russian orbital launch vehicle. The world's first ICBM became the most often used and most reliable launch vehicle in history. The original core+four strap-on booster missile had a small third stage added to produce the Vostok launch vehicle, with a payload of 5 metric tons. Addition of a larger third stage produced the Voskhod/Soyuz vehicle, with a payload over 6 metric tons. Using this with a fourth stage, the resulting Molniya booster placed communications satellites and early lunar and planetary probes in higher energy trajectories. By the year 2000 over 1,628 had been launched with an unmatched success rate of 97.5% for production models. Improved models providing commercial launch services for international customers entered service in the new millenium, and a new launch pad at Kourou was to be inaugurated in 2009. It appeared that the R-7 could easily still be in service 70 years after its first launch. More...
  • Soyuz 11A511U Russian standardised man-rated orbital launch vehicle derived from the original R-7 ICBM of 1957. It has been launched in greater numbers than any orbital launch vehicle in history. Not coincidentally, it has been the most reliable as well. After over 40 years service in Russia, ESA built a new launch pad at Kourou which will keep it in service from three launch sites in three countries well into the mid-21st Century. More...
  • Zenit Zenit was to be a modular new generation medium Soviet launch vehicle, replacing the various ICBM-derived launch vehicles in use since the 1960's (Tsiklon and Soyuz). A version of the first stage was used as strap-ons for the cancelled Energia heavy booster. But it was built by Yuzhnoye in the Ukraine; when the Soviet Union broke up planned large-scale production for the Soviet military was abandoned (Angara development was begun as an indigenous alternative). Launch pads were completed only at Baikonur; those at Plesetsk were never finished and are planned to be completed as Angara pads. However the vehicle found new life as a commercial launch vehicle, launched from a sea platform by an American/Ukrainian consortium. More...
  • Zenit-2 Ukrainian orbital launch vehicle. Two-stage version that continued to be used for launch of Russian military satellites tailored to it after the fall of the Soviet Union. More...

Associated Manufacturers and Agencies
  • GFZ German manufacturer of spacecraft. Geoforschungszentrum, Potsdam, Germany. More...

Associated Programs
  • Mir The Mir space station was the last remnant of the once mighty Soviet space programme. It was built to last only five years, and was to have been composed of modules launched by Proton and Buran/Energia launch vehicles. These modules were derived from those originally designed by Chelomei in the 1960's for the Almaz military station programme. As the Soviet Union collapsed Mir stayed in orbit, but the final modules were years late and could only be completed with American financial assistance. Kept flying over a decade beyond its rated life, Mir proved a source of pride to the Russian people and proved the ability of their cosmonauts and engineers to improvise and keep operations going despite all manner of challenges and mishaps. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.

Associated Launch Sites
  • Baikonur Russia's largest cosmodrome, the only one used for manned launches and with facilities for the larger Proton, N1, and Energia launch vehicles. The spaceport ended up on foreign soil after the break-up of Soviet Union. The official designations NIIP-5 and GIK-5 are used in official Soviet histories. It was also universally referred to as Tyuratam by both Soviet military staff and engineers, and the US intelligence agencies. Since the dissolution of the Soviet Union the Russian Federation has insisted on continued use of the old Soviet 'public' name of Baikonur. In its Kazakh (Kazak) version this is rendered Baykonur. More...

GFZ-1 Chronology


1995 April 19 - . 21:50 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC1. LV Family: R-7. Launch Vehicle: Soyuz 11A511U.
  • GFZ-1 - . Mass: 20 kg (44 lb). Nation: Germany. Agency: GFZ. Program: Mir. Class: Earth. Type: Geodetic satellite. Flight: Mir EO-18. Spacecraft: GFZ-1. Decay Date: 1999-06-23 . USAF Sat Cat: 23558 . COSPAR: 1986-017JE. Apogee: 387 km (240 mi). Perigee: 380 km (230 mi). Inclination: 51.6000 deg. Summary: Geodetic; carried retroreflectors for ground laser ranging; delivered to Mir on Progress M-27 and deployed from Mir 4/19/95 ..

1998 July 10 - . 06:30 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC45/1. LV Family: Zenit. Launch Vehicle: Zenit-2.
  • WESTPAC - . Mass: 24 kg (52 lb). Nation: Australia. Agency: WPLTN. Manufacturer: RKA; EOS. Class: Earth. Type: Geodetic satellite. Spacecraft: GFZ-1. USAF Sat Cat: 25398 . COSPAR: 1998-043E. Apogee: 819 km (508 mi). Perigee: 815 km (506 mi). Inclination: 98.8000 deg. Period: 101.20 min. Formerly known as WPLTN-1, this geodesy satellite was a copy of Potsdam's GFZ-1 satellite, a sphere covered with laser retroreflectors, with a different `Fizeau' corner cube design. It serves as a target for the Western Pacific Laser Tracking Network (WPLTN) and is a joint project of Electro Optic Systems of Queanbeyan, New South Wales, Australia, and the Russian Space Agency. Diameter is 0.24m.

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