Fine Lateral and Longitudinal Sensor (FLLS) on-board ESA’s PROBA-3 Mission

Paper number

IAC-17,A7,2,3,x38292

Author

Dr. Miranda Bradshaw, Neptec UK, United Kingdom

Year

2017

Abstract

PROBA-3 is a European Space Agency (ESA) mission to study the Sun’s corona, and is the world’s first precision formation flying mission.  The mission will comprise a pair of satellites separated by 150\,m, whose relative displacement must be monitored to within 300\,µm in order to produce an accurate coronagraph.  This measurement is provided by FLLS -- the Fine Lateral and Longitudinal Sensor -- being built by Neptec UK and Neptec Design Group Canada.

FLLS uses a retro-reflected laser beam to monitor the position of the occulter-disc satellite with respect to the coronagraph satellite.  Phase measurements of the reflected beam are used to determine the longitudinal displacement between the two satellites -- up to 250\,m -- while the motion of the returning beam on a CMOS sensor measures the lateral displacement.  This system is being designed in collaboration with Surrey Space Centre, and presents exciting challenges in performance testing and ground-based calibration over its full operating range.

The completed FLLS system will be suitable for any type of mission requiring accurate displacement measurements.  This could be between a constellation of satellites observing the Earth, or within a science mission monitoring instrumentation positions.  FLLS could allow large-scale structures to be deployed and maintained in space, monitoring structural distortion before, during, and after deployment, and providing in-flight corrections to data collection.  Examples of such future applications include in-orbit observatories, positioning of telecommunication satellite antennas, and deployable mechanisms on lunar or Martian missions.

The paper and presentation will provide a comprehensive overview of FLLS including technical designs, calibration and test plans, and the envisaged scope for future applications.

Abstract document

IAC-17,A7,2,3,x38292.brief.pdf

Manuscript document

IAC-17,A7,2,3,x38292.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.