CALLISTO: Its Flight Envelope and Vehicle Design

Abstract

With the emergence of space launch systems featuring recoverable & reusable rocket stages, Europe and Japan are investigating their own way and merge their capabilities in developing CALLISTO Flight Demonstrator. As such, this original project relies on assets from JAXA in Japan on one hand, and DLR and CNES in Europe on the other hand. Intent of both parties is to collect direct knowledge and data in operating a space launch stage-like vehicle being recoverable (in vertical position) and then flown several times over a short period of time with minimized maintenance effort in between two flights from Space Center in French Guiana. One core contribution to this project is the rocket propulsion system from JAXA. It is a heavily reusable pump fed rocket engine mixing liquid oxygen and hydrogen and having a long heritage already. In addition, this robust engine offers a wide range of thrust setting capability and then gives design engineers flexibility in adapting flight paths in terms of range, altitude, speed and maneuvers to be (in flight) tested. The mission analysis is also enriched by CALLISTO advanced Flight Control System combining Thrust vectoring, Reaction Control and, last but not the least, a set of 4 aerosurfaces. In addition to airborne maneuvers, and thanks to systems sourced from DLR (Approach & Landing System, Hybrid Navigation System e.g.), accurate landing with various vertical touch down speeds is a primary objective as well. This paper provides a status of the CALLISTO project focusing on flight envelope and vehicle design matters and how they interrelate with each other.