Credit: CNES/Orbital Dreams
A 12 September call for proposals published by the French space agency CNES has revealed that the inaugural flight of the Callisto reusable rocket demonstrator has slipped from 2026 to 2027.
Conceived in 2015, the Cooperative Action Leading to Launcher Innovation in Stage Toss-back Operations (Callisto) project is a collaboration between CNES, DLR, and JAXA aimed at maturing reusable rocket technology for future European and Japanese launch systems. The Callisto demonstrator will stand 14 metres tall, with a width of 1.1 metres and a takeoff mass of 3,500 kilograms.
On Friday, CNES published a call seeking a partner to provide mechanical operations and procedures support ahead of the Callisto flight-test campaign, including contributions to operations user manuals, drafting mechanical operation procedures, and conducting detailed studies of mechanical interfaces between the vehicle and the ground segment. In the preamble to the scope of work, the notice states that the campaign will be carried out from the Guiana Space Centre in French Guiana in 2027. It will include an integration phase followed by eight test flights and two demonstration flights, all to be completed over a period of eight months.
This latest revision to the programme’s timeline comes less than a year after JAXA confirmed in October 2024 that the programme’s flight-test campaign had been pushed to 2026. The revision means that Europe’s other, more capable reusable rocket demonstrator, Themis, is likely to conduct its initial hop tests from Esrange in Sweden, currently scheduled for early 2026, before Callisto is even shipped to French Guiana. With a 2027 launch date, the project will also likely be beaten to the launch pad by MaiaSpace’s vehicle, which is not a demonstrator but a fully operational reusable rocket programme.