Isar Aerospace's Spectrum rocket launch scrubbed for fourth time in five months

Isar Aerospace, a leading European rocket startup based near Munich, Germany, continues to face obstacles in launching the second test flight of its Spectrum rocket. The latest attempt on Monday was scrubbed when teams detected 'off nominal behavior in the vehicle's fluid systems,' according to a social media post. This marks the fourth launch delay in five months, following earlier issues with a pressurization valve, rising propane fuel temperatures linked to an unauthorized boat in restricted waters, and a suspected composite pressure vessel leak. The Spectrum rocket—a two-stage, 28-meter launch vehicle—remains grounded at Andøya Spaceport in northern Norway, with the current launch window open through June 21.

The difficulties highlight broader tensions at Andøya, which serves as both a military testing range and a site for commercial launches. Local fishing interests have clashed with launch operations; in March, a fisherman refused to leave the hazard area to retrieve gear, contributing to a launch abort. Missile testing has also taken priority. Despite these setbacks, Isar CEO Daniel Metzler has emphasized that scrubs provide valuable data. The company's first Spectrum test flight in March 2025 lasted under a minute before crashing due to an unintentional vent valve opening. This time, Isar has five small CubeSats and a tech experiment onboard. The company remains at the forefront of Europe's new wave of small satellite launchers, competing with Rocket Factory Augsburg, MaiaSpace, and PLD Space.