Wide Field and Planetary Camera 2

Wide Field and Planetary Camera 2
Name	Wide Field and Planetary Camera 2
Mission	Hubble Space Telescope
Operator	NASA, European Space Agency
Launch	1993-03-01
Launch vehicle	Space Shuttle Endeavour
Manufacturer	Jet Propulsion Laboratory, Ball Aerospace
Instruments	Charge-coupled devices
Wavelength	Ultraviolet, Optical, Near-infrared

Wide Field and Planetary Camera 2 was a third-generation imaging instrument installed on the Hubble Space Telescope that operated from 1993 to 2009. It replaced the original camera during STS-61 and provided a wide-field imaging capability together with a high-resolution planetary channel that transformed observations of Mars, Jupiter, Saturn, Andromeda Galaxy, and deep extragalactic fields. Developed by a collaboration including the Jet Propulsion Laboratory, Ball Aerospace, and the Space Telescope Science Institute, it addressed early optical aberrations and enabled prolific contributions to studies of Supernova 1993J, Comet Shoemaker–Levy 9, SN 1994D, and the Hubble Deep Field.

Design and Instrumentation

WFPC2 combined a wide-field camera and a planetary camera into a single boresighted assembly mounted on the Hubble Space Telescope focal plane. Its optical design included a set of pick-off mirrors, filter wheels, and a corrective optics package developed in response to the Hubble optical flaw discovered after launch; the corrective mirrors were built by teams at Ball Aerospace, Rochester Institute of Technology, and the Jet Propulsion Laboratory. The instrument used four 800×800 pixel charge-coupled device arrays manufactured by Ford Aerospace to provide three wide-field chips and one higher-resolution planetary chip; these detectors were arranged in an L-shaped pattern originally motivated by focal-plane engineering developed for the International Ultraviolet Explorer and the Wide Field Camera 3 concept studies. WFPC2 included a suite of broad, medium, and narrowband filters optimized for targets such as Orion Nebula, Crab Nebula, NGC 7252, and M51 (Whirlpool Galaxy), enabling observations across ultraviolet, visible, and near-infrared regimes used by teams from California Institute of Technology, Harvard–Smithsonian Center for Astrophysics, and the European Southern Observatory.

Operational History

Installed during STS-61 by astronauts from Space Shuttle Endeavour, WFPC2 began science operations following commissioning tests coordinated by the Space Telescope Science Institute and the Goddard Space Flight Center. Early operations included corrective calibration efforts tied to the Hubble optical flaw and joint observing programs with observatories such as the Keck Observatory, Arecibo Observatory, and the Very Large Array. The instrument functioned through multiple orbital cycles, responding to thermal and radiation environments characterized by studies performed with data from International Space Station payloads and the Hubble Space Telescope. WFPC2 remained the primary imager for many General Observer programs led by principal investigators at University of California, Berkeley, University of Washington, and University of Cambridge until it was removed during STS-125 in 2009.

Scientific Discoveries and Impact

WFPC2 produced images that led to fundamental advances in stellar, galactic, and cosmological astrophysics. Observations of SN 1994D and other Type Ia supernovae informed distance-ladder studies connected to work by researchers affiliated with Space Telescope Science Institute, Lawrence Berkeley National Laboratory, and the Supernova Cosmology Project, contributing to measurements of cosmic acceleration later associated with teams at Princeton University and Lawrence Berkeley National Laboratory. High-resolution imaging of star-forming regions such as the Orion Nebula and the Eagle Nebula provided iconic data for comparisons with infrared studies from Spitzer Space Telescope and submillimeter surveys by Atacama Large Millimeter/submillimeter Array. WFPC2 imagery of merging systems like Antennae Galaxies and NGC 4038/4039 informed galaxy interaction models used by groups at Max Planck Institute for Astronomy and California Institute of Technology. The instrument also played a central role in the production of the Hubble Deep Field, enabling population studies connected to work at Johns Hopkins University, University of Oxford, and University of Chicago.

Calibration and Data Processing

Calibration of WFPC2 combined pre-flight laboratory characterization by teams at Ball Aerospace with on-orbit programs executed by the Space Telescope Science Institute and the Goddard Space Flight Center. Photometric calibration tied to standard-star networks maintained by European Southern Observatory and Landolt standard stars allowed absolute flux measurements used in studies by researchers at Carnegie Institution for Science and University of Hawaii. Charge transfer efficiency degradation, cosmic-ray impacts, and hot pixels were mitigated through pipelines developed at the Space Telescope Science Institute and algorithms contributed by scientists from STScI and STScI affiliates; these pipelines interfaced with archival systems at the Mikulski Archive for Space Telescopes. Data products were used extensively in cross-calibration campaigns with instruments aboard Chandra X-ray Observatory, Spitzer Space Telescope, and ground-based facilities such as Keck Observatory.

Servicing Missions and Upgrades

WFPC2 itself was installed during STS-61 and later replaced during STS-125 by Wide Field Camera 3 and Advanced Camera for Surveys upgrades that reflected evolving instrument architectures conceived at NASA Goddard Space Flight Center and Jet Propulsion Laboratory. Servicing missions involving WFPC2 required coordinated extravehicular activity performed by astronauts trained at Johnson Space Center and complex payload operations orchestrated by Kennedy Space Center launch teams. Throughout its tenure, on-orbit maintenance was limited to module replacement and thermal control strategies developed by engineers from Ball Aerospace and the Jet Propulsion Laboratory.

Legacy and Successors

The scientific legacy of WFPC2 is preserved in archive holdings at the Mikulski Archive for Space Telescopes and in numerous citations in literature from institutions including Harvard University, Yale University, and Stanford University. Its role in shaping imaging requirements influenced the design of successors such as the Wide Field Camera 3, the Advanced Camera for Surveys, and concepts for space observatories pursued by European Space Agency and the James Webb Space Telescope project at Northrop Grumman. WFPC2 images remain cultural and educational touchstones exhibited by museums like the Smithsonian Institution and used in outreach by European Southern Observatory and the American Astronomical Society.

Category:Hubble Space Telescope instruments