NASA Space
Sensors and Instrument Technology
Telescope Technology Program
Quarterly Progress Report
Second Quarter, Fiscal Year 1995
January through March, 1995
Overview
The NASA OSAT Telescope Technology Program has a goal of developing and
demonstrating design, materials, processing, fabrication and test
technology to enable lightweight, low cost instrument and telescope
systems for future NASA missions and commercial applications. The
current research emphasis is on low mass, low temperature infrared and
submillimeter telescope systems.
Highlights (January - March, 1995)
- State-of-the-art Cryogenic Optical Test Facility established at JPL
providing interferometric test capability for up to 1.3 meter diameter
optics at temperatures down to 5 kelvins.
Ultra-lightweight, 14 kilogram, 85 centimeter diameter beryllium mirror
blank fabricated
and delivered to Hughes Danbury Optical Systems for figuring to achieve
cryogenic diffraction limited performance at 6.5 microns. This mirror
is the primary mirror for the Infrared Telescope Technology Testbed (ITTT).
- Flat 90 centimeter diameter cryogenic silicon carbide mirror development
effort
initiated at Lockheed Missiles and Space Company.
- Far Infrared and Submillimeter Space Telescope (FIRST) proposal
submitted by Caltech in response to the New Mission Concepts for
Astrophysics NRA selected for full funding and ranked number one by
the infrared/submillimeter/radio review panel. A key element of the
proposal was the 4 meter lightweight composite telescope based on
technology previously developed by OSAT and currently being pursed
under SBIR funding.
- Phase 1 and Phase 2 SBIR grants awarded to Composite Optics, Inc.
for further development of large stable composite mirrors for earth
observation and astrophysics applications.
- Phase B In-Space Technology Experiment Program (In-STEP) proposal
entitled "Adaptively Reconfigurable
Shaped Reflector Antenna" submitted to OSAT by JPL and Space
Systems Loral.
Accomplishments
Cryogenic Test Facility
In a remarkable example of faster, better, cheaper engineering, a
state-of-the-art Cryogenic Optical Test Facility (COTF) has been developed
at JPL. The COTF, shown in the accompanying photograph, advanced from
concept development to operation in 12 months and for a total cost of
$800K provided jointly by OSAT, OSS and JPL institutional funding.
Development costs were minimized by utilizing existing hardware
(interferometer, vibration isolation legs, crane, pumps, etc.)
from previous programs whenever possible. The large helium test
Dewar was developed by Janis Research.
- The optical axis of the COTF is oriented vertically and optics up to
1.3 meter in diameter can be tested via phase shifting interferometry in either
the "looking up" or "looking down" orientation. A 50 centimeter diameter
beryllium
test mirror developed by the Telescope Technology Program last year and
characterized at liquid helium temperature in the small test facility
at the Ames Research Center is being utilized to checkout and calibrate
and the COTF. In initial tests, the mirror cooled first to 80 kelvins and
subsequently to 4.9 kelvins (±0.5 kelvins). Interoferometric data was in
excellent
agreement with that obtained previously.
- Further checkout and calibration of the COTF is in progress. The
facility is expected to be fully calibrated and operational in time to
support cryogenic testing of the ITTT primary mirror assembly due to
arrive at JPL in June. Later this year, the COTF will be fitted with
the 90 centimeter diameter silicon carbide cryogenic test flat under
development at Lockheed to support autocollimation testing of the
full ITTT telescope assembly. The COTF is available to support the
cryogenic optical testing needs of NASA, other government, university
and commercial users. Inquiries regarding this facility should be
directed to Dan Coulter at (818) 354-3638 or via the Internet at
daniel.r.coulter@jpl.nasa.gov.
Infrared Telescope Technology Testbed
- Hughes Danbury Optical Systems is developing an ultralightweight,
85 centimeter clear aperture Infrared Telescope Technology Testbed (ITTT).
The ITTT is being fabricated from specially processed I-70-H beryllium via
the hot isostatic pressing process.
Industrial Collaborations
- Cryogenic optical test systems with Janis Research and Zygo Corporation.
- Silicon carbide optics with Lockheed Missiles and Space Company.
- Advanced beryllium optics with Brush-Wellman, Loral American Beryllium
and Hughes Danbury Optical Systems.
- Graphite Fiber Reinforced Composite Submillimeter Reflectors with Composite
Optics Inc.
Technical Contacts
Dan Coulter
818-354-3638
daniel.r.coulter@jpl.nasa.gov
Return to:
Quarterly report converted to HTML on May 10, 1995.
Last update: May 11, 1995. Maintained by
Gordon Johnston
Gordon.Johnston@hq.nasa.gov
Ultra-lightweight, 14 kilogram, 85 centimeter diameter beryllium mirror
blank fabricated
and delivered to Hughes Danbury Optical Systems for figuring to achieve
cryogenic diffraction limited performance at 6.5 microns. This mirror
is the primary mirror for the Infrared Telescope Technology Testbed (ITTT).
In a remarkable example of faster, better, cheaper engineering, a
state-of-the-art Cryogenic Optical Test Facility (COTF) has been developed
at JPL. The COTF, shown in the accompanying photograph, advanced from
concept development to operation in 12 months and for a total cost of
$800K provided jointly by OSAT, OSS and JPL institutional funding.
Development costs were minimized by utilizing existing hardware
(interferometer, vibration isolation legs, crane, pumps, etc.)
from previous programs whenever possible. The large helium test
Dewar was developed by Janis Research.
