NASA Logo, National Aeronautics and Space Administration
NASA Space Science Data Coordinated Archive Header

Faint-Object Camera (FOC)

NSSDCA ID: 1990-037B-08

Mission Name: HST
Principal Investigator:Dr. F. Duccio Macchetto


The faint-object camera (FOC), which operates at a high focal ratio, uses an imaging camera with a two-dimensional photon-event counting detector, and is able to detect objects that are 50 times fainter than those observable with the most powerful earthbased telescope. The FOC has a minimum format of 64 by 64 pixels. Based on a pixel size of 25 by 25 micrometers, a focal ratio of approximately f/96 is required to exploit the spatial resolving power of the HST. At that focal ratio, the pixel size is 0.022 by 0.022 arc-s. For imagery and photometry of very faint stars and extended sources, cumulative exposures are required to obtain a useful signal-to-noise ratio. The FOC wavelength range is 1200 to 7000 A. The observable range for point sources is from 21st to 28th visual magnitude, and for extended sources is the equivalent of from 15th to 22nd visual magnitude over an area of one sq arc-s.

Alternate Names

  • FOC
  • urn:nasa:pds:context:instrument:hst.foc

Facts in Brief

Mass: 320 kg
Power (avg): 150 W

Funding Agency

  • European Space Agency (International)


  • Astronomy: Visible
  • Astronomy: Ultraviolet

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. F. Duccio MacchettoPrincipal InvestigatorEuropean Space
Dr. A. BoksenbergTeam MemberRoyal Greenwich
Prof. Hendrik C. Van de HulstTeam MemberNetherlands Institute
Dr. T. M. KampermanTeam MemberAstronomical Institute
Prof. Ivan R. KingTeam MemberUniversity of California, Berkeley
Dr. Francesco ParesceTeam MemberSpace Telescope Science
Dr. Rudolf AlbrechtTeam MemberEuropean Space Telescope Coordinating Facility,
Prof. Cesare BarbieriTeam MemberInstituto di
Dr. Jean-Michel DeharvengTeam MemberCNRS, Laboratoire d'Astronomie Spatiale
Prof. M. J. DisneyTeam MemberUniversity College, Cardiff
Dr. C. D. MackayTeam MemberUniversity of Cambridge
Dr. R. N. WilsonTeam MemberEuropean Southern Observatory, Switzerland
Dr. Patrick C. CraneTeam MemberEuropean Southern Observatory,
Dr. Peter JakobsenTeam MemberESA-European Space Research and Technology
Mr. J. Chris BladesTeam MemberSpace Telescope Science
[] NASA Logo -