DLR has announced that, in conjunction with the French space agency CNES, it has begun acoustic testing on the Vehicle Equipment Bay of the Callisto reusable rocket demonstrator.
The Callisto project was initiated in 2015 to mature key technologies for the eventual development of a reusable launch system. The project is a joint effort between DLR, CNES, and the Japanese space agency JAXA. Once completed, the 13.5-metre-tall reusable booster demonstrator will conduct a series of ten test flights at the Guiana Space Centre in French Guiana.
On 4 March, the DLR Institute of Space Systems announced that the Callisto Vehicle Equipment Bay (VEB) had begun its journey from the institute’s facility in Bremen to CNES testing facilities in Toulouse on 12 February 2025. Along the way, the transport truck stopped at the DLR Institute of Structures and Design in Stuttgart to collect the Callisto fairing module.
Callisto consists of five main sections: the Aft Bay, which includes the engine and landing legs, the LH2 Tank, the LOx Tank, the VEB, and the Fairing. The VEB houses much of the demonstrator’s electronics, including its onboard computer, avionics, and a reaction control system that uses H2O2 propellant. Its distinctive features include a pair of control fins.
In addition to confirming that the VEB had been transported to the CNES facilities in Toulouse, the 4 March Institute of Space Systems update also revealed that the acoustic test campaign for the key Callisto module had commenced last week. The acoustic test campaign simulates the intense sound vibrations the demonstrator will experience during flight to ensure structural integrity and component reliability.
Launch site update
Callisto will launch from the old Diamant launch facility at the Guiana Space Centre. The site will also serve as a multi-user launch pad for commercial launch providers and for Themis reusable booster demonstrator flights after its initial hop tests at the Esrange Space Center in Sweden.
According to a 28 January CNES report, work will begin in the second half of 2025 to build the infrastructure needed to accommodate the Callisto demonstrator flight tests at the revamped facility. In late February, a public consultation period opened for the site’s environmental authorization and building permit request. The final session of the consultation period is expected to take place on 18 March.
