High-Precision
Optical Metrology Study
(18 June 2007) Future missions
involving 'formation flying' will require very accurate measurements of the
distances between spacecraft.
An ESA-funded study of
high-precision optical metrology has developed prototype systems capable of
relative positional accuracies of the order of 0.1 millimetres over distances
of tens or hundreds of metres.
Optical interferometric head
A number of measuring technologies which are expected to be flown on the demonstrator mission were selected for prototyping and on-ground testing:
The second phase of the contract was
dedicated to the detailed design, manufacturing and testing of the metrology
prototypes. EADS Astrium SAS (France) was the Prime Contractor in charge of the
technical management of the study, of the prototype definition, and of the
Darwin and demonstrator optical metrology system configuration assessment and
trade-off.
A system using the lateral sensor combined with the
dual-wavelength interferometer has been selected for further development in a
follow-on contract (HPOM-2).
EADS Astrium GmbH (Germany) supported EADS
Astrium SAS in the laser metrology domain and in the coordination of
prototyping activities. EADS Astrium GmbH was responsible for the
dual-wavelength laser stabilisation and frequency control breadboard
development.
TPD/TNO (Netherlands) led the design and development of the
fine lateral sensor breadboard.
SIOS (Germany) specialises in the
manufacturing of laser distance measurement systems. They were responsible for
the design and the manufacturing of the dual-wavelength laser interferometer
breadboard and readout electronics based on the use of Nd-YAG
technology.
INETI-LAER (Portugal) was in charge of the design,
manufacturing and testing of the distance measurement breadboard based on
frequency scanning interferometer technology.
EADS CASA Espacio (Spain)
was tasked with the design and development of the test bench used to measure
the performance of the prototype systems. The testing was performed in their
vacuum optical test facility in Madrid.
(source: ESA)