On 13 July 2026 ESA informed us that the Preliminary Requirements Review of the Alticube+ phase-A study was succesfully completed. They “look forward to the next steps of this ambitious project”.
The project was kicked off on 7 February 2025. The phase-A study followed up on an elaboration session in ESA’s Concurrent Design Facility with the Alticube+ proposal that was a winner in the ESA SysNova Challenge back in 2023.
The phase-A project consortium consisted of TU Delft, ISISpace and Robin radar in the Netherlands and Comet Aerospace in Spain. Jian Guo (TU Delft, Aerospace faculty) was the project manager. The radar payload was drafted by Peter Hoogeboom (TU Delft, CEG faculty, Geoscience and Remote Sensing).
After slightly more than one year of hard work most of the uncertainties and possible showstoppers in this innovative and risky proposal had been solved. While there are still some matters that need further investigation before starting to build an In Orbit Demonstration in phase B, both the consortium and the ESA team were very happy with the results that have been achieved.
In short, Alticube+’ primary goal is an oceanographic mission to measure Sea Surface Heights with high relative precision (<2.5cm) and high geometric resolution (2x2km cells). The measurement principle is based on near nadir radar interferometry, which poses extremely challenging requirements on the radarsystem, its aggregated configuration and the orientation/ attitude/ position of the complete system in space.
The successful SWOT mission exploits the same measurement principle, but is placed on a single large, highly stable but costly satellite. In our proposal 5 cubesat based radar nodes are foreseen, that dock autonomously in space and extend connecting booms and parabolic reflector antennas to set up Ku-band interferometers with baselines up to nearly 9 meter. This way it is hoped to provide vital ocean measurements at reduced cost.
More information in previous posts on this website and in the Ruimtevaart (2024/4) article “MiniSWOT –an innovative cubesat based sidelooking interferometer”,
or contact: Jian Guo, Faculty of Aerospace Engineering, TU Delft.
Peter Hoogeboom, Faculty of Civil Engineering and Geoscience, TU Delft