Launch Configuration of FIRI
The launch configuration of the Far InfraRed Interferometer (FIRI) is with its two deployable booms in folded position and with two extra structural support beams providing support for the two telescopes and the hub during launch. Together the two booms and the structural beams transfer the inertia loads of FIRI's main parts to the Launch Vehicle Adapter (LVA) interface. After launch, the two support beams (in front of and behind the hub and two telescopes in this view) are disposed of upon ejection from the launcher.
The two deployable booms are connected to the Service Module of the hub by hinges, and consist of two parts. After deployment, they serve as support for the movable telescopes, making it possible for the two telescopes to reach a maximum separation of 30 m.
The main parts of the composite with a height of 8.4m and a maximum diameter of 3.8m, are shown in the above figure:
A dedicated cylindrical adapter is proposed for FIRI with a diameter of 2624 mm and a height of 900 mm. This height is required to distribute over the circumference the four concentrated loads of the structural support beams and the deployable booms, such that the over flux load at the interface with the launcher is within acceptable limits.