June 29, 2021


SWOT (vue d'artiste) Credits: CNES

The SWOT satellite comprises:

  • a new type of spacecraft bus developed by Thales Alenia Space able to carry an 850-kilogram, 1,600-W payload

  • a payload made up of the following main instruments:

    • The main payload, a Ka-band radar interferometer dubbed KaRIn for plotting in 2D the topography of continental surface waters. KaRIn has been developed by NASA/JPL with a major contribution from CNES in the form of the radar radiofrequency 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 (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 acquire measurements in each of KaRIn’s 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 laser reflector 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 launcher supplied by NASA will be a SpaceX Falcon 9. The satellite will be launched from Vandenberg Air Force Base in the USA.


SWOT satellite architecture

SWOT satellite features

  • Spacecraft bus mass: 1,000 kg
  • Payload module mass: 850 kg
  • Electrical power: 1,550 W
  • Solar array: about 30 sq.m
  • Mission duration: 45 months
  • Thrust capacity for controlled re-entry at end of mission: 366 kg of N2H4