Herschel instruments are 'good to go'

All three of Herschel's instruments, the Spectral and Photometric Imaging Receiver (SPIRE), the Photodetector Array Camera and Spectrometer (PACS) and the Heterodyne Instrument for the Far Infrared (HIFI), underwent short functional tests to verify the health of the instruments after transport to the launch site in Kourou.

All instruments performed flawlessly and passed their pre-launch test reviews.

The next time we hear from them will be a few days after launch when they will be switched on one-by-one as part of the payload check-out process.

Everything in its place

The instrument checks followed the completion of checks of the mechanical stability of the satellite. Engineers carried out alignment tests by measuring relative and absolute positions of a number of elements using reference cubes. The elements measured were mostly those which protrude from the body of the satellite for example, the cryostat nozzles, thrusters, sun acquisition sensor, attitude anomaly detector and the telescope mounting structure. The stability of all of these elements was verified during the tests.

Checks with the launcher adapter

After these alignment tests, engineers carried out a fit check of the Ariane 5 launcher adapter and verified that all mechanical and electrical connections between the adapter and the satellite worked perfectly. The launcher adapter is a lightweight metal cylinder, 0.32 m high and 2.624 m in diameter, that is used to fix the satellite to the launch vehicle.

Outer thermal protection completed

After completion of the mechanical checks, most of the final pieces of multi-layer insulation were placed on the satellite to complete the external thermal protection.

Credit: ESA/Thales/EADS

Herschel alignment measurements. Engineers measured relative and absolute positions of a number of elements using reference cubes to check the mechanical stability of the satellite.



Credit: ESA

Engineers have carried out a fit check of the Ariane 5 launcher adapter and verified that all mechanical and electrical connections between the adapter and the satellite worked perfectly. The launcher adapter is a lightweight metal cylinder, 32 cm high and 2.624 m in diameter, which is used to fix the satellite to the launch vehicle.


Credit: ESA

The Ariane 5 launcher adapter, a lightweight metal cylinder, 32 cm high and 2.624 m in diameter, that fixes Herschel to the launch vehicle.

Source: European Space Agency
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