The Polar-5 Aircraft (IMAGE) NASA/Goddard Space Flight Center Caption The Polar-5 aircraft, carrying the EM instrument that was used to validate Cryosat-2 sea ice thickness measurements, flying over the validation site. Credit Credit: NERC/UCL/Rosemary Willatt Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.