Author: Naomi Hartono

On March 9, the international Surface Water and Ocean Topography (SWOT) satellite’s main scientific instrument – the Ka-band Radar Interferometer (KaRIn) – returned to regular commissioning activities.

KaRIn was shut off in late January. Since then, the team has worked to analyze the situation and developed a plan to restore operations utilizing a backup KaRIn power unit. The backup unit was chosen to expedite the restoration of operations and to minimize overall risk to the mission.

The mission continues to monitor KaRIn, as well as overall operations, as it progresses with commissioning, calibration, and validation activities to ensure the performance of SWOT’s systems and science instruments in preparation for the planned start of science operations in July 2023.

After launching in December 2022, the international Surface Water and Ocean Topography (SWOT) mission started commissioning activities – the six-month checkout period before the scientific mission begins. Commissioning has included turning on all the science instruments, among them the main science instrument, the Ka-band Radar Interferometer (KaRIn), which engineers fully powered on in mid-January 2023. They received performance information, but in late January one of the instrument’s subsystems – the high-power amplifier – was unexpectedly shut down.

Engineers are working systematically to understand the situation and to restore operations, performing diagnostics and working with a test bed that simulates the KaRIn instrument on Earth. Once the KaRIn instrument is up and running again, the mission will continue with its commissioning and calibration activities – planned March through June – to ensure data accuracy in preparation for the beginning of science operations in July 2023.

Launched from Vandenberg Space Force Base in California, SWOT is a collaboration between NASA and the French space agency Centre National d’Études Spatiales, with contributions from the Canadian Space Agency and the UK Space Agency. SWOT will take high-resolution measurements of the height of water in the world’s oceans and freshwater bodies. It will provide insight into the ocean’s role in climate change and help communities monitor and plan for changes in water resources and the effects of rising seas.