Callisto is a reusable vertical take-off and vertical landing demonstrator developed collaboratively by CNES (France), DLR (Germany) and JAXA (Japan). It aims to advance technologies for future reusable launch systems, including controlled descent and landing, refurbishment between flights and cost modelling for future reusable launchers.

There are a total of 10 test flights are planned, starting in 2026, with each flight reaching an altitude of about 20 km, then return to Earth for vertical landing.

Roles:

CNES - Provides launch infrastructure at the Guiana Space Centre in Kourou, where Callisto test flights are planned. Contributes to systems engineering and integration, particularly in coordination with ArianeGroup experience.

DLR - Leads development of the avionics bay and performs integration and dynamic testing in Bremen. Focuses on guidance, navigation and control (GNC), landing systems, and structural testing.

JAXA - Provides propulsion system expertise and contributes to thermal protection and reusability technologies.

Prerequisites:

• Institutional & political interest and support for access to space

• Technical and engineering capabilities for development of launchers

• Ground infrastructure (engine test stands, labs, propellant facilities, AIT facilities, clean rooms, etc.)

• Suitable space for launches, ideally a coastal or desert location with clear range over uninhabited areas and testing and range facilities (or agreements to use partner facilities)

• Clear regulatory framework for launch licensing, safety, and liability

• Export-control compliance, insurance, and mission assurance processes

• Partnerships with experienced launch providers 

• Cybersecurity, data protection, and continuity planning

Cost:

• Ballpark: USD 50k–250k (does not include cost for the fund)

• Includes: partnership setup, fund design and governance, technical assistance, monitoring & evaluation, administrative support.

Timeframe:

• Overall: 12-60 months

• Phase: fund design (6-12 months), funding round(s) (6 - 48 months), optional evaluation & scale-up (6 - 12 months)

The illustrated use case developed over multiple years.

2015: Project initiated internally by CNES, 2017: DLR and JAXA officially joined the collaboration, 2018–2019: Preliminary design and feasibility studies completed, 2020–: Development

Pros:

• R&D Cost Sharing – Shares the financial burden of research and development through international partnerships.

Considerations:

• Conflicting National Priorities – Reflects how divergent national interests and strategic goals may lead to friction and hinder collaboration.

• Challenging Timeline Coordination – Involves aligning project schedules across nations, which can be complex and time-consuming.