VENµS

Vegetation and Environment monitoring on a New Micro-Satellite (VENµS) is a near polar sun-synchronous orbit microsatellite. It is a joint project of the Israeli Space Agency and CNES. The project was signed upon in April 2005[5] and was launched on the 2nd of August 2017.[4] The microsatellite, which was set to cost the ISA US$20 million and CNES €10 million, was designed and built by IAI and Rafael under ISA's supervision.

VENµS
Mission typeEarth observation
Technology
OperatorISA/CNES
COSPAR ID2017-044B
SATCAT no.42901
Websitevenus.cnes.fr/fr
Mission duration4.5 years [1]
Spacecraft properties
BusISA[2]
ManufacturerIAI
Rafael
CNES
Launch mass265 kilograms (584 lb) (wet mass, of which 23 kg are fuel)[1]
Power800 watts[3]
Start of mission
Launch date2 August 2017 01:58:33 [4]
RocketVega
Launch siteKourou
ContractorArianespace
Orbital parameters
Reference systemGeocentric
RegimeSun-synchronous 2 day Earth repeating
Perigee altitude720 km (first phase) / 410 km (second phase)
Apogee altitude720 km (first phase) / 410 km (second phase)
Inclination98.27 degrees[2]
Main
NameRitchey-Chretien telescope[3]
TypeCassegrain reflector
Diameter0.25m[3]
Focal length1.75m[3]
Collecting area50 special interest sites
Instruments
Super Spectral Camera (VSSC),[2] Israeli Hall Effect Thruster (IHET) [3]

VENµS Insignia  

For the mission, CNES is responsible for supplying the superspectral camera and the science mission center. The ISA is responsible for the satellite control center, the technological mission and payload (Israeli Hall effect Thruster and autonomous mission), the spacecraft, and the launcher interface.[2]

History

A joint study to check feasibility of the program was done on the first half of 2005. Phase A started in 2005 and upon completion, a memorandum of understanding was signed between the ISA and CNES.[6] The satellite was originally planned to be launched in 2008;[5] however due to changes of the launchers and several delays, the launch date was pushed to 2 August 2017. It was launched via a Vega launcher from Guiana Space Centre together with Italian satellite OPTSAT-3000.[7][8]

Mission

The satellite has a scientific and a technological mission. Scientific mission requirements were defined by Centre d'Etudes Spatiales de la BIOsphère, France, and Ben-Gurion University of the Negev, Israel, and CNES.[2] Technological Mission requirement were defined by Rafael.[9]

Scientific mission

The satellite has a 2-day revisit orbit which allows constant viewing angles at constant Sun lighting angles. The unique combination is hoped to allow the development of new image processing methods. A set of at least 50 points of interest around the world were chosen to be scanned throughout the scientific mission. The points will be rescanned every 2 days for the entire duration of the mission where it will collect sensory and imagery data. Some of the objectives from the scientific mission are:

  • Monitoring and analyzing surface under various environmental and human factors
  • Develop and validate various ecosystem functioning models
  • Improve and validate global carbon cycle models
  • Define theoretical and practical methods for scale transfer
  • Collect and analyze data collected by the low spatial resolution sensors

The satellite is equipped with a Super Spectral Camera comprises a catadioptric optical system, a focal plane assembly with narrow band filters, and 4 detector units with 3 separate CCD-TDI array. Each array with separate operational and thermal control.

The satellite is also equipped with a Ritchey-Chretien telescope with a focal length of 1.75m and a diameter of 0.25m. The telescope's tube will be covered to protect it from pollution and dust which will deploy once in orbit.[3]

Technological mission
VENμS Hall effect thruster

In addition to its scientific mission, the satellite has a technological mission. The satellite is equipped with Israeli hall effect thrusters (IHET).[3] The mission is to demonstrate the thrusters' enhanced capabilities and autonomous mission operations which include:[10]

  • Orbit maintenance
  • LEO to LEO orbit transfer
  • Enabling imaging mission in a high drag environment - performing the scientific mission at an altitude of 410 km on an Earth repeating sun synchronous orbit

The technological mission is designed to use 16 kg of Xenon.

Platform

The satellite platform is based on the Israel Aerospace Industries OPSAT 3000 satellite platform.[11] Venus satellite will have dual propulsion system: Hydrazine for orbit insertion and Xenon for the technological mission.

Venus satellite mass is 265 kg (wet), of which 16 kg are Xenon and 7 kg are hydrazine.

Ground control station

The satellite is ground controlled by IAI in Israel; the Israel mission control is linked to two sub-stations in charge of each of the missions: The scientific mission is operated from Toulouse Space Center, France and the technology mission is controlled from the Technological Mission Center, Rafael, Haifa, Israel.[12]

See also

References
  1. "VENµS (Vegetation and Environment monitoring on a New MicroSatellite)". eoportal.org. Retrieved 23 May 2017.
  2. "Venus satellite". CNES. Retrieved 23 May 2017.
  3. Yoram Yaniv & Jacob Herscovitz. "VENμS". doi:10.1109/IGARSS.2010.5652087. S2CID 5994623. Cite journal requires |journal= (help)
  4. "Vega launcher achieves on-target deployment of Earth-imaging satellites". Spaceflight now. 4 August 2017.
  5. "CNES AND ISA TO WORK TOGETHER ON VENµS MISSION". CNES Press. Retrieved 21 November 2013.
  6. "JOINT CNES-ISA VENµS MISSION GETS UNDERWAY". CNES Press. Retrieved 21 November 2013. in April 2005, declaring the satellite to be built.
  7. "Venus satellite to be launched in July 2017". Israel Space Agency. February 1, 2017. Retrieved 28 February 2017.
  8. "Vega lofts two satellites on second launch this year". European Space Agency. 2 August 2017.
  9. Herscovitz, Jacob; Linn Barnett, Danna. "Decision Analysis for Design Trades for A Combined Scientific-Technological Mission Orbit on Venµs Micro Satellite". Proceedings of 17th Annual International Symposium–INCOSE, San Diego. 2007. Cite journal requires |journal= (help)
  10. "Systems Engineering in Venus Satellite" (PDF). Venus Project Manager. Retrieved 22 November 2013.
  11. "OptSat 3000". Israel Aerospace Industries. Retrieved 23 May 2017.
  12. Rainer Sandau; Hans-Peter Roeser; Hans-Peter Röser & Arnoldo Valenzuela (2010). Small Satellite Missions for Earth Observation: New Developments and Trends. Springer. p. 61. ISBN 978-3642035005.
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