Galex – Orbital GALEX User Manual

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Orbital Sciences Corporation

45101 Warp Drive

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Dulles, Virginia 20166

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www.orbital.com

FS001_01_2998

GALEX

Mission Partners

California Institute of Technology

Principal Investigator: Dr. Chris Martin; science operations and
data analysis

Jet Propulsion Laboratory

Project management and instrument development

Orbital Sciences Corporation

Spacecraft development, satellite integration and test, launch
vehicle integration, ground data system, mission operations, and
Pegasus launch vehicle

University of California Berkeley

Science detectors

Laboratoire d’Astronmie Spatiale (Marseille, France)

Back focal assembly optics

Johns Hopkins University

Science data archive

Yonsei University (Seoul, South Korea)

Science operations and data analysis support

Universal Space Networks (Newport Beach, California)

Ground stations

Specifications

Spacecraft

Satellite Mass:

280 kg (617 lb.)

Redundancy:

Single-string with selected redundancy

Solar Arrays:

Fixed GaAs

Power:

290 W

Communications: Redundant S-band receivers, S-band and

X-band transmitters

Mission Life:

28 months (baseline mission)

Orbit:

690 km altitude Earth orbit @ 29

inclination

Status:

Baseline mission complete. Decommissioned
in 2013 after ten years of extended
operations.

Payload

Instrument:

50 cm Ultraviolet Telescope

Wavelength
Coverage:

135-300 nm, two bands large format
ultraviolet photon counting detectors

Inertial Pointer:

Slew rate 0-2,400 arcsec/sec, pointing
knowledge <0.15 arcsec

Launch

Launch Vehicle:

Pegasus

Site:

KSC, Cape Canaveral, Florida

Date:

April 28, 2003

The Space Segment

The GALEX satellite represented the space segment of the mission and comprised
the Orbital-supplied spacecraft bus and the JPL-supplied instrument. The
spacecraft bus provided all of the on-orbit support required for the instrument to
obtain mission science data and to transmit it to the ground for distribution and
processing. The instrument consisted of a 50 centimeter UV Telescope, its focal
plane detectors and supporting electronics.

The Ground Segment

The ground segment comprised Ground Stations, a Mission Operations Center
(MOC) and Science Operations and Data Analysis (SODA). The MOC, located at
Orbital’s Dulles, Virginia campus, was responsible for command and control of the
satellite. SODA, located at the California Institute of Technology, was responsible
for science data processing and science operations mission planning.

GALEX’s ultraviolet surveys produced an unprecedented
database of nearby and distant galaxies.