| AVS 65th International Symposium & Exhibition | |
| Vacuum Technology Division | Monday Sessions |
| Session VT-MoM |
| Session: | Vacuum Measurement |
| Presenter: | Freek Molkenboer, TNO, Netherlands |
| Authors: | F.T. Molkenboer, TNO, Netherlands R. Jansen, TNO, Netherlands R.G. Veraar, TNO, Netherlands G.C.J. Otter, TNO, Netherlands W.P. van Werkhoven, TNO, Netherlands N.B. Koster, TNO, Netherlands F.P.G. Driessen, TNO, Netherlands |
| Correspondent: | Click to Email |
TNO is investing in a new facility for calibration of optomechanical Space instruments. This facility, called Calibration Space Instruments (CSI) should be operational early 2021. To meet this deadline the conceptional design phase has started early 2018.
The facility has three major sub system; a Thermal Vacuum Chamber (TVC), an Optical Ground Support Equipment (OGSE) and a Mechanical Ground Support Equipment (MGSE).
The OGSE system will provide all the optical stimuli that are required to perform an optical calibration of a Space instrument.
During a calibration of a Space instrument many relative positions between the OGSE and the instrument must be tested. The MGSE is responsible for the high accuracy, and highly reproducible manipulation of both the OGSE and the instrument. It is expected that some of the manipulation is done in vacuum, leading to the corresponding challenges.
The calibration of the instrument must be performed at the temperature in which it will operate in orbit. The TVC needs to provide these conditions. Beside the operational temperature the instrument also needs to be tested at non-operational temperatures, which increases the temperature range. It can be expected that some parts of the instrument will require LN2 temperatures. The CSI facility will focus on calibration of mid-size instruments, this results in a chamber with a volume up to 15 cubic meter
The vacuum pressure during a calibration shall be below 10-5 mbar. The challenge is that the materials used in a Space instrument and the TVC absorb a lot of water when exposed to air, resulting in a high pumping speed needed to reach the required pressure.
Future Space instruments will have higher resolution, which will directly impact the calibration facility. To be able to perform a calibration, pointing accuracies of 0.0015° are needed, which might result in for instance active shielding of vibrations from the TVC system and the floor towards the instrument and the OGSE.
Space instruments represent a lot of money, therefore instrument safety is crucial in the design of the facility.
During the oral we will discuss challenges that come with the design of the TVC for Space instrument calibration, and the measures that are taken to ensure safe and successful calibration campaigns.