March 30, 2017

Satellite

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SWOT (vue d'artiste) Credits: CNES

The SWOT satellite consists of:

  • a new type of spacecraft bus developed by Thalès Alenia Space and able to carry an 850 kg payload requiring 1550 W

  • a payload made up of the following main instruments:

    • The main payload, a Ka-band Radar Interferometer dubbed KaRIn (Ka-band Radar Interferometer), for plotting in 2D the topography of continental surface waters. It has been developed by NASA/JPL with a major contribution from CNES in the form of the radar radio-frequency unit (RFU)
    • The Poseidon-3C Ku-/C-band altimeter which will complement altimetry measurements for long wave ocean signals, enabling precise corrections of ionospheric effects on these signals (CNES contribution)
    • A radiometer designed to determine tropospheric water vapour content (NASA contribution); a key feature of the model developed for SWOT is that it will be able to take measurements in each of the KaRIn swaths by off-nadir pointing of 3°
    • A DORIS precise orbit determination system (CNES contribution)
    • A GPS system to complement DORIS for precise positioning of the satellite (NASA contribution)
    • A backscattering laser for precise calibration of the other instruments by analysing laser bursts fired from the ground and reflected by a set of mirrors aboard the satellite (NASA contribution)

The Mid-Class launcher is being provided by NASA. There was a choice of three possible launchers: Falcon 9, Antares or Atlas 5. NASA finally chose the SpaceX Falcon 9 rocket in late November 2016. The satellite will be launched from Vandenberg Air Force Base in the USA.

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Architecture of the SWOT satellite

Characteristics of the SWOT satellite

  • Mass of the spacecraft bus: 1,000 kg
  • Mass of the payload module: 850 kg
  • Electrical power: 1550 W
  • Solar array: about 32 m2
  • Mission duration: 45 months