The LDREX (Large-scale Deployable Reflector Experiment Model) is a small partial model
antenna built to validate the design of the ETS-8's Large
Deployable Antenna, and will conduct experiments to solve various technical problems that
the ETS-8 is facing. Since the result of LDREX experiments will
influence the design of ETS-8, an immediate launch of LDREX was
desired, which led the project team to switch a launch vehicle from the domestic H-II rocket to an European Ariane-5G rocket. The Large Deployable Reflector
Experiment (LDREX) was built by Toshiba for National Space Development Agency (NASDA). It
was mounted, along with cameras and support equipment, on an ASAP-5 platform. After the
deployment was complete, the antenna was to be ejected from the platform.
ETS-8 is designed to carry a large antenna for the purpose to
develop technologies to build the world's largest geostationary satellite, which will be
used for future mobile communications. Since deploying such a large antenna in orbit is
very difficult and requires lots of new technologies, a series of experiments prior to the
satellite's fabrication is necessary.
After launch, the deployment of the antenna failed, requiring a re-evaluation of the
mechanism. A reflight of the LDREX 2 took place in 2006, again on an ASAP-5 platform on
an Ariane-5ECA launch vehicle. It was successful.