UCL Department of Space and Climate Physics


ISO class 6 Cleanroom

Assembly, test and integration of spacecraft components, instruments and structures, Moments of Inertia (MOI) and centre of gravity of flight hardware.

The ISO class 6 cleanroom houses the majority of MSSL vacuum test chambers and calibration facilities


These facilities are:

  • Low Energy Plasma Instrument Calibration (LEPIC) chamber
  • Optical calibration chamber
  • Twin materials screening (MSC) chambers
  • 20 Kelvin vacuum cryostat
  • Vacuum bakeout chamber

The ISO class 6 cleanroom is a vertical  flow particle filtration design. The LEPIC and Optical calibration chamber doors are positioned in such a manner that the cleanliness classification is ISO class 5. This ensures the cleanest possible environment when space flight hardware is prepared and installed into the facilities.


Dimensions: 12m (L) by 10m (W)

Filtration efficiency: HEPA, 99.997% for 0.3 micron diameter particles

Laminar flow benches: Yes, one ISO Class 5 laminar flow benches available

Network: Yes, 10/100 Mb

Gas supply: Yes, several nitrogen gas supply outlets for instrument purge. Zero grade nitrogen available

Temperature: 20oC +-2oC

Humidity: 50% RH +-10%

Max. occupants: 6

Cleanroom validation: Yes, by external independent contractors

Other services

The ISO class 6 cleanroom has a total of 7 liquid nitrogen outlet points mainly for use on the various vacuum test chambers and Optical calibration chamber. The liquid nitrogen supply lines are continous Super Insulated Vacuum Lines (SIVL) which minimises liquid nitrogen boil off. The SIVL supply lines are fitted with stay fulls to ensure that only liquid nitrogen is fed from the outlets no matter how many systems are demanding LN2.


Nominal, in use by Solar Orbiter EAS and LISA Pathfinder