NASA reports its ACS3 solar sail deployed in orbit in August 2024
What was demonstrated
NASA reported on 29 August 2024 that the Advanced Composite Solar Sail System (ACS3), launched on 23 April 2024, was fully deployed in space after a successful test of its sail-hoisting boom system. NASA gives the unfurled sail as approximately 80 square metres (860 square feet), about 9 metres (30 feet) on a side. The NASA mission page describes two booms, each about 7 metres (23 feet) long, made from flexible polymer and carbon fibre materials. NASA says the primary objective is to deploy a new type of boom. A NASA update dated 5 September 2024 said the spacecraft was slowly tumbling, as expected, because its attitude control system was off, and that the team would re-engage that system after characterising the booms and sail.
Why it matters
A solar sail needs a lightweight structure that stays flat and stable in space. NASA says the ACS3 booms are stiffer and 75% lighter than earlier designs, so a flown deployment is a useful step towards larger sails. NASA's announcements do not yet show how the design performs over time.
Caveats
- The result is a deployment. NASA's announcements do not report measured thrust, orbit change or sail shape accuracy; NASA said the team would test the sail's manoeuvring capabilities over the following weeks.
- The 80 square metre area is given by NASA as approximate, and the sail and booms were still being characterised when the announcements were made.
- At the 5 September 2024 update the spacecraft was tumbling and attitude control had not yet been re-engaged, so the results describe a mission in progress rather than a completed demonstration.
Technology profiles
Sources
- other
NASA Composite Booms Deploy, Mission Sets Sail in Space
Arezu Sarvestani. NASA, 29 Aug 2024. - other
NASA Evaluates Deployed Advanced Composite Solar Sail System
NASA, 5 Sept 2024. - other
Advanced Composite Solar Sail System (ACS3) - NASA
NASA, 2024.
Last reviewed 22 Oct 2026.