Airbus has completed assembly of the CRISTAL ice-monitoring satellite and conducted initial deployment and launch-interface tests. ESA’s October 26, 2026 update reports that assembly finished in September at Friedrichshafen, Germany. Launch is targeted for late 2027 or early 2028.
CRISTAL stands for Copernicus Polar Ice and Snow Topography Altimeter. Its measurements are intended to extend observations of sea-ice thickness, snow covering that ice and changes in ice-sheet elevation.
The recent solar-array deployment test checked the interaction between mechanical hardware and the software sequence that opens the panels. A separate campaign with launch provider Avio checked the spacecraft’s fit on its launch adapter and the mechanism that releases it from the rocket.
ESA says the spacecraft will move to its Netherlands facilities and spend most of 2027 undergoing environmental tests. The deployment checks reported in October are completed activities; the environmental campaign is the next stage.
Measuring Ice and the Snow Above It
CRISTAL’s main instrument is the Interferometric Radar Altimeter for Ice and Snow, known as IRIS. Built by Thales Alenia Space, it operates at two radar frequencies: approximately 13.5 gigahertz in Ku band and 35.75 gigahertz in Ka band.
Radar altimeters transmit pulses toward Earth and measure the time taken for the reflected signals to return. Combined with knowledge of the satellite’s orbit, those measurements provide information about the height of the reflecting surface. New Space Economy’s explanation of satellite altimetry describes the basic measurement method.
Measuring sea ice requires more interpretation than measuring the distance to a single exposed surface. Snow lies above the ice, and radar can interact with different parts of that layered material. Snow depth also affects calculations that convert the height of ice above the surrounding sea into an estimate of its total thickness.
Using two frequencies provides additional information about those interactions. The Centre for Polar Observation and Modelling describes CRISTAL’s combined ice and snow measurements and its role in continuing polar observations.
The spacecraft also carries a microwave radiometer supplied by NASA’s Jet Propulsion Laboratory. Its measurements complement the radar observations.
Research Behind the Measurement Method
Research using existing satellites helps establish how the new mission’s measurements should be interpreted. A peer-reviewed study published in January 2026 examined observations from CryoSat-2, AltiKa and ICESat-2 collected between 2018 and 2023.
The study investigated the relationship between radar frequency, snow and ice conditions, and the height represented by a satellite measurement. It found that surface roughness affects the radar response, complicating a simple interpretation in which each frequency consistently identifies one particular boundary within the snow-and-ice layer.
Those findings concern observations from existing missions and supporting analysis. They are not measurements from CRISTAL, which has not launched.
The research helps explain why dual-frequency measurements need physical models and supporting observations. Comparing signals can supply information about snow and ice, but interpreting the difference requires accounting for the surfaces and materials that produced the reflections.
Continuing the Polar Observation Record
CRISTAL is designed to continue measurements used to track changes in polar ice. Sea-ice thickness and snow depth support assessments of the amount and seasonal condition of floating ice. Repeated measurements of ice-sheet elevation help researchers investigate changes in land ice and its contribution to sea level.
The mission includes successive CRISTAL-A and CRISTAL-B spacecraft to support continuity of observations. The spacecraft now assembled is progressing through the hardware verification required before launch.
The next campaign will expose the satellite to conditions representative of its journey to orbit and operation in space. That environmental testing will follow the completed assembly, solar-array deployment and launch-interface checks.
