A study of the spacecraft design is to be conducted at ESA's Concurrent Design Facility in September 2011. Current studies are based on the following broad characteristics:

The LOFT spacecraft depicted (left) inside the launcher fairing and (right) deployed in orbit. Credit: LOFT proposal team

The spacecraft will be composed of a payload module and a service module.

The payload module will host two instruments: the Large Area Detector (LAD) and the Wide Field Monitor (WFM).

The service module will consist of the subsystems necessary for normal operation of the spacecraft. This includes the Attitude & Orbit Control System, On-board Data Handling, Telemetry and Telecommunication, Electrical Power System, Structure (including secondary structure for payload), Thermal Control System, and Reaction Control Subsystem.

For the spacecraft subsystems, full redundancy is planned, while for the payload, the modular design of the LAD reduces the chances of single failures.

The spacecraft concept uses off-the-shelf equipment with an emphasis on reusing existing comparable platforms or subsystems.