Last Updated Jan 2001

Copyright © 2001 The Association of Universities for Research in Astronomy, Inc. All Rights Reserved.

1982: Two Perkin-Elmer PDS 2020G microdensitometers were delivered to Rowland Hall on the JHU campus, where the Space Telescope Science Institute spent its infancy.

1982: Plate vault specifications, designed for archival storage of photographic plates, and stable scanning conditions, are provided by Barry Lasker, GSSS project scientist; Jane Russell, GSSS astrometrist; and Jim Kinsey, PDS engineer.

1983: Muller building opens. The microdensitometers are delivered to the new building. The Perkin-Elmer engineer who rode down with them in the freight elevator is reported to have commented "That was a fast ride!!" upon his safe but rapid arrival.

1983: First plate shipments arrive from Palomar, ROE, and Siding Springs.

1984: Custom upgrades to the microdensitometers are completed by Barry Lasker, Jim Kinsey, Anatoly Evserov, Bob Denman, and Marc Damashek. These included the replacement of the Haidenhan encoder by a laser interferometer system for position measurement, an upgraded logarithmic amplifier, and the installation of a custom "cat's-eye" shaped aperture, to be used in conjunction with an electronic Bessel filter to blur the effective aperture into a Gaussian shape.

1985: Production scanning at 25 micron resolution for the GSC1 begins!

1988: The last plate is scanned for GSC1. Scanning activities continue with the digitization of the POSS-I E plates, which would later become part of the Digitized Sky Survey.

1990: The completed Guide Star Catalog is published, and the Hubble Space Telescope is launched.

1991: Work begins on redesigning and rebuilding the PDS microdensitometers into custom multi channel laser illuminated GAMMA scanning machines to support scanning of the second epoch surveys, PSS-II and SES.

1992: First plate shipments of original plates for the new surveys are received from Palomar and ROE, for scanning and return.

1992: 15 micron scanning begins!

1994: The Digitized Sky Survey, a 10x compressed version of the POSS E and SERC F plates, is published.

1994: Multi channel, laser illuminated scanning begins on one machine.

1995: The rebuilding of both scanning machines is completed by Barry Lasker, Gretchen Greene, Knute Ray, and Bruce Douglas.

2000: Scanning of the PSS-II J and F surveys are completed.

2001: Scanning of the SES F survey and the PSS-II infrared survey are completed.