Maritime safety notices indicate that a week-long launch window for Isar Aerospace’s second Spectrum flight will open on 4 September.
On 1 September, the Norwegian Coastal Administration issued a warning outlining that rocket launch operations were expected to be conducted daily between 16:00 and 21:35 UTC from 4 to 10 September. The warning establishes two maritime danger areas extending northwest from Andøya. While the notice doesn’t name Isar Aerospace, the coordinates match areas previously published by Norwegian authorities for the company’s previous launch attempt in June.
A separate notice published by Andøya Space on 27 August confirms planned launch activity from its orbital launch site between 4 and 10 September. The site’s only user is currently Isar Aerospace, which maintains a dedicated launchpad. This notice also does not identify the company by name.
The notices do not confirm that Isar Aerospace will attempt a launch between 4 and 10 September. They simply establish a seven-day period during which an attempt could be conducted. The company has not made any public announcement about the launch window and did not respond to a request for comment from European Spaceflight before publication.
Isar Aerospace has made several attempts to conduct Spectrum’s second flight. An initial attempt in January was scrubbed to address an issue with a pressurisation valve. An attempt in March was first postponed due to unfavourable weather and then scrubbed after a range violation caused by an unauthorised boat entering the danger area. An April attempt was then scrubbed due to a leak in a composite overwrapped pressure vessel. Finally, the company stood down from an attempt in June after detecting off-nominal behaviour in the rocket’s fluid systems.
The mission, which the company has called Onward and Upward, will serve as Spectrum’s qualification flight and will be the rocket’s first flight to carry payloads. The rocket will carry five CubeSats and one experiment selected by the German space agency DLR as part of its Microlauncher competition, which Isar Aerospace won in April 2021. The competition was supported by the European Space Agency through its Boost! programme.
