Conference 7.286::space

Newsgroups: sci.space
Subject: TRW selected to develop Advanced X-ray Astrophysics Facility 
Posted: 23 Aug 88 22:16:05 GMT
Organization: NASA Ames Research Center, Moffett Field, CA
 
Charles Redmond                                August 22, 1988
Headquarters, Washington, D.C.                 4:00 p.m. EDT
 
Bob Lessels
Marshall Space Flight Center, Huntsville, Ala.
  
RELEASE:  88-118
 
    TRW SELECTED TO DEVELOP ADVANCED X-RAY ASTROPHYSICS FACILITY
  
    NASA announced today that TRW, Inc., has been selected for final
negotiations leading to the award of contracts for extended definition
and development of the space-based Advanced X-ray Astrophysics
Facility (AXAF). 
 
    The development contract will include a mirror development phase
and a priced-option for spacecraft development and completion of the
observatory.  Exercise of the option by NASA will require
congressional approval and will be based upon the successful
fabrication of the largest of six mirror pairs to the required
resolution.  The principal place of performance will be the TRW plant,
Redondo Beach, Calif., and that of the major subcontractor, Kodak
Federal Systems Division, Rochester, New York.  The proposed cost of
the contracts is approximately $508 million. 
 
    The facility will be the third in NASA's series of space-based
great observatories, following the Hubble Space Telescope and the
Gamma Ray Observatory, into orbit in the mid-1990s.  These
observatories, as well as the Space Infrared Telescope Facility, which
is to follow the X-ray observatory, will permit simultaneous,
complementary observations of astrophysical phenomena over different
wavelengths of the spectrum. 
 
    The objective of this project is to develop a high-quality, X-ray
telescope to be used by the international scientific community in
conjunction with NASA for an operational period of 15 years. 
 
    The observatory will be designed for on-orbit maintenance in order
to extend its life and to upgrade its scientific capability.  The
X-ray telescope will be used to gather data to expand our knowledge of
quasars, black holes, and the geometry and mass of the Universe. 
 
    The Marshall Space Flight Center, Huntsville, Ala., has management
responsibility for the telescope and will manage the contract.  The
AXAF program is under the direction of NASA's Office of Space Science
and Applications, Washington, D.C..  Also proposing was Lockheed
Missiles and Space, Co., Sunnyvale, Calif. 

Newsgroups: sci.space
Subject: NASA selects instrument for Advanced X-ray Astrophysics Facility
Date: 5 Jun 90 22:23:01 GMT
Reply-To: [email protected] (Peter E. Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
 
Paula Cleggett-Haleim                               June 5, 1990
Headquarters, Washington, D.C.
(Phone: 202/453-1548)
  
Allen Kenitzer
Marshall Space Flight Center, Huntsville, Ala.
(Phone: 205/544-0034)
  
    RELEASE:  C90-t
 
    NASA SELECTS INSTRUMENT FOR ADVANCED X-RAY ASTROPHYSICS FACILITY
  
     NASA has awarded a contract to the Smithsonian Astrophysics
Observatory, Cambridge, Mass., to provide a high resolution camera for
the space-based Advanced X-Ray Astrophysics Facility (AXAF).  This
cost-reimbursement-no-fee contract is for $26.7 million. 
 
     The contract will include development of the high resolution
camera, one of four candidate AXAF instruments, through launch and
2-1/2 half years of on-orbit operation.  Other instruments include a
charge-coupled device x-ray camera, which is in final negotiations
with Pennsylvania State University, State College, and an x-ray
spectrometer, being developed by NASA's Goddard Space Flight Center,
Greenbelt, Md.  In addition, NASA is continuing definition studies on
a Bragg Crystal Spectrometer at Massachusetts Institute of Technology,
Cambridge. 
 
      In Fiscal Year 1989, Congress approved the initiation of
technology development for AXAF's high-resolution mirror assembly.  In
Fiscal Year 1990, Congress provided initial instrument funding.  This
will be a 3-year program which, if successful, should lead to a
development start for the AXAF spacecraft in Fiscal Year 1992. 
 
     The AXAF is scheduled for launch in 1997 and will be the third in
NASA's series of space-based great observatories following the Hubble
Space Telescope, which was launched April 24, and the Gamma Ray
Observatory, which is currently scheduled for launch in November. 
 
     These observatories, as well as the proposed Space Infrared
Telescope Facility which would follow AXAF, will operate for the next
few decades above the haze of Earth's atmosphere.  This family of
telescopes will permit simultaneous, complementary observations of
astrophysical phenomena over different wavelengths of the spectrum. 
 
     NASA's Marshall Space Flight Center, Huntsville, Ala., has
management responsibility for the telescope and will manage the
contract.  The Advanced X-Ray Astrophysics Facility program is under
the direction of NASA's Office of Space Science and Applications,
Washington, D.C. 

    UPf 09/24/1990 1242 Ball gets NASA contract
 
   MUNCIE, Ind.  (UPI) -- Ball Corp.'s aerospace systems group has
been awarded a $24 million contract by NASA's Goddard Space Flight
Center to build a helium dewar to cool the X-Ray Spectrometer, the
company said Monday. 

   XRS is an instrument on the Advanced X-Ray Astrophysics Facility
that is scheduled to be launched aboard the shuttle in April, 1997. 

   The dewar, a thermally-insulated container, is expected to operate
for five years, making it the longest a stored cryogen cooler has ever
operated in space.  AXAF will be 100 times more sensitive than any
other X-ray telescope, over a broader energy range. 

   Data returned by AXAF will have a direct effect on several
scientific fields, including plasma physics, atomic and nuclear
physics, general relativity, and cosmology. 

   AXAF is being built by TRW Inc., based in Cleveland, for NASA's
Marshall Space Flight Center.  Ball also has a contract with TRW to
support spacecraft integration on AXAF. 

   Ball Corp.  manufactures and markets packaging, industrial and
consumer products, and provides aerospace systems and professional
services to the federal sector.  The company reported 1989 sales of
$1.2 billion. 
 

From: [email protected] (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: AXAF Contract (Forwarded)
Date: 22 Mar 91 07:38:06 GMT
Sender: [email protected]
Organization: Jet Propulsion Laboratory, Pasadena, CA.
 
Paula Cleggett-Haleim
Headquarters, Washington, D.C.                                 March 21, 1991
(Phone:  202/453-1547)                                                       
 
RELEASE:  91-46
 
    SMITHSONIAN ASTROPHYSICAL OBSERVATORY WINS AXAF CONTRACT
 
        NASA's Marshall Space Flight Center, Huntsville, Ala., has selected
the Smithsonian Astrophysical Observatory, Cambridge, Mass., for negotiations
leading to award of a contract to design, develop and operate a science support
center for the space-based Advanced X-ray Astrophysics Facility (AXAF).
Scheduled for launch in 1998, AXAF will be the third in NASA's series of
Earth-orbiting Great Observatories.
 
        The primary role of the science center will be to provide a service to
the international scientific community by developing and overseeing an
observation program for the X-ray telescope and by managing reception and
distribution of the data it collects.
 
        In addition, the facility will provide support during development of
the X-ray telescope and its complement of sensitive instruments, for testing
and verification of ground support systems, for calibration of the instruments
and for those orbital operations that relate to the science instrument data.
 
        The science center will serve as the primary focal point for the
observer community using the X-ray telescope.  Services it will provide for
users or potential users will include:
 
        o  Assistance in the preparation of observing proposals;
 
        o  Support for scientific observations, including planning the
           best observing strategy for study of specific objects;
 
        o  Processing and distribution of scientific data; and,
 
        o  Offering users appropriate software and computer resources,
           so they can most effectively and efficiently use the data.
 
        The  cost-reimbursement for the AXAF Science Center is at a proposed
cost of $86.7 million.  The contract is for a 10-year period of performance,
spanning the design, development and testing of the telescope as well as
support to its launch and early years of science mission operations.
 
        A major readiness milestone for the AXAF Science Center will be to
provide support for ground-based calibration tests in 1995.  The center must
be fully operational to support the telescope's launch in 1998.  Location of
the facility is to be determined by the Smithsonian Astrophysical Observatory
as part of this effort.
 
        The Marshall center, which manages the AXAF program for NASA, will
manage the contract.  The AXAF program is under the direction of NASA's Office
of Space Science and Applications, Washington, D.C.

      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [email protected]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | 
  ___| | | | |__) |/  | | |___   M/S 301-355        | Change is constant. 
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | 
 |_____|/  |_|/       |_____|/                      | 

RELEASE: 91-95  (6/24/91)


        The first mirror for NASA's Advanced X-ray Astrophysics
Facility (AXAF) space observatory was successfully completed at
Hughes Danbury Optical System, Danbury, Conn., and shipped on June
12 to Eastman Kodak, Rochester, N.Y., for assembly.  This mirror
will be paired with another already in its last polishing cycle
and shipped by June 30.

        The shipment of these two mirrors will mark the culmination
of a challenging 2 1/2-year period for the AXAF program.  The
emphasis during this initial phase of the program has been to
produce the first set of mirrors and then validate the
manufacturing process.  The most sophisticated aspect of this
activity is the highly complex measuring (metrology) stations,
used to characterize the mirrors and guide the polishing activity.
The AXAF observatory will be composed of six nested pairs of
mirrors to obtain high resolution x-ray images of the universe.

        Based on preliminary data, the first mirror pair has an
angular resolution of 0.37 arc second, better than the 0.5 arc
second resolution objective.  The expected on-orbit accuracy will
be significantly better, by a factor of 2, due to the
weightlessness of space flight.  The smaller the resolution the
more distinguishable are the distant x-ray sources.

        During the fabrication of the first two mirrors, numerous
technical challenges were surmounted including the elimination of
disturbances as small as 1 millionth the force of gravity.
Another challenge was the development of several cross checks to
validate the process.  These include comparative analysis across
metrology stations, self-consistency checks and end-to-end x-ray
testing.

        One such cross check detected a minute error of 0.03 arc
seconds in resolution, which was traced to a single sign reversal
within the more than 200,000 lines of computer code used for
metrology analysis.  This discrepancy already has been removed in
the second mirror.

        The AXAF team representing Hughes Danbury Optical System;
Marshall Space Flight Center, Huntsville, Ala.;  Smithsonian
Astrophysical Observatory, Cambridge, Mass.; and TRW, Redondo
Beach, Calif., is extremely pleased with the excellent quality of
this first mirror set and the demonstrated capability of the
metrology system.

        AXAF is the x-ray component of NASA's Great Observatories
program and is tentatively scheduled for launch in the late 1990s.
 

Article        35460
From: [email protected] (Ron Baalke)
Newsgroups: sci.space
Subject: AXAF Mirrors Tested Successfully (correction)
Date: 11 Sep 91 22:32:09 GMT
Sender: [email protected] (Usenet)
Organization: Jet Propulsion Laboratory
 
NOTE:  DUE TO INCORRECT NUMBER USED IN 3RD PARAGRAPH,
       USE THIS VERSION FOR RELEASE OF HQ 91-145.
 
Paula Cleggett-Haleim
NASA Headquarters, Washington, D.C.               September 11, 1991
(Phone:  202/453-1547)
 
Allen Kenitzer
Marshall Space Flight Center, Huntsville, Ala.
(Phone:  205/544-0034)
 
RELEASE:   91-145
 
AXAF MIRRORS SUCCESSFULLY TESTED AT X-RAY CALIBRATION FACILITY
 
     The two largest mirrors for NASA's Advanced X-ray Astrophysics
Facility (AXAF) have been successfully tested in the new X-ray
Calibration Facility at Marshall Space Flight Center (MSFC),
Huntsville, Ala. 
 
     "We're excited about the results," said Dr. Lennard Fisk,
Associate Administrator for the Office of Space Science and
Applications, NASA Headquarters, Washington, D.C.  "We've met our
goals, the mirrors were completed by June and tests were successfully
completed in September. The entire government and contractor team
should be congratulated on meeting this challenge." 
 
     The mirrors, at nearly 48 inches in diameter, are the largest
ever made to collect X-rays in space.  The angular resolution of the
mirrors is approximately 0.23 arcsecond after correcting for effects
of the test configuration, particularly gravity, which do not apply to
the space environment.  Even uncorrected, the results were consistent
with the specification of 0.5 arcsecond resolution. This angular
resolution is at least 10 times better than any other X-ray telescope
previously flown. 
 
     The mirror set is the outermost of six concentric mirror pairs
being manufactured for AXAF (12 mirrors total) that will become part
of the High Resolution Mirror Assembly of AXAF.  Later, the entire
assembly will return to MSFC for final calibration testing together
with the scientific instruments planned for AXAF. 
 
     The mirrors were manufactured at Hughes Danbury Optical Systems,
Danbury, Conn., and assembled in the test mount at Eastman Kodak,
Rochester, N.Y., both under contract to TRW, Redondo Beach, Calif.,
the AXAF prime contractor.  The optics were delivered to MSFC's X-ray
Calibration Facility, which was specifically designed to completely
test the AXAF optics and is the largest such facility in the world. 
At MSFC, tests were performed by scientists and engineers from MSFC,
TRW, Eastman Kodak, and the Smithsonian Astrophysical Observatory,
Cambrige, Mass. 
 
     AXAF will be the third of NASA's four proposed orbiting "Great
Observatories" and is scheduled to be launched in 1998.  It will be
used to study stellar structure and evolution, large scale galactic
phenomenon, active galaxies, clusters of galaxies, quasars and cosmology. 
 
      ___    _____     ___
     /_ /|  /____/ \  /_ /|     Ron Baalke         | [email protected]
     | | | |  __ \ /| | | |     Jet Propulsion Lab |
  ___| | | | |__) |/  | | |__   M/S 301-355 Telos  | Good judgement comes from
 /___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | experience.  Experience
 |_____|/  |_|/       |_____|/                     | comes from bad judgement.

    last week I submitted my resignation to DEC - I'm taking a job with the
    Smithsonian Astrophysical Observatory in Cambridge...
    
    I'll be working on AXAF. SAO is on INTERNET, so I would be able and
    quite willing to send over reports on the project. To whom shall I send
    them?

Post them to sci.space.news on USENET -- they we (and everyone else) can
follow AXAF!


Good Luck!


- dave

    Best of luck in your new line of work.  Keep in touch.
    
      John

    thanks!

    re .7
    
    You do realise they are a Sun shop? Best of luck anyway! (-:

    oh yes - I realize that. a smattering of PC's too.....
    
    but as it happens, my present group here at DEC has a few SUN's too -
    we are planning on porting our product over siome time in the near
    future....
    
    So.............

From:	US1RMC::"[email protected]" "Andrew Yee, Science North" 
        12-JUL-1993 04:27:00.03
To:	[email protected]
CC:	
Subj:	The Advanced X-ray Astrophysics Facility missions

[Extracted from Spacelink BBS.]

THE ADVANCED X-RAY ASTROPHYSICS FACILITY MISSIONS

May 1993

Jerry Berg
Marshall Space Flight Center

        In the late 1990s, NASA will launch two complementary orbiting
observatories being developed as the Advanced X-ray Astrophysics
Facility (AXAF).  The AXAF program will enable detailed, long-term
study of X-ray emissions from the universe and the phenomena that
produce them.  It is expected to yield data that will improve
knowledge and understanding in some of the most fundamental areas of
scientific investigation. 

        Astronomers know whenever they observe X-ray emissions, they are
viewing the most violent processes in the universe, since a tremendous amount
of energy is required to generate X-rays. Such X-ray sources include neutron
stars, suspected black holes, debris from supernova explosions, quasars, the
centers of active galaxies, and hot gas in individual galaxies and galaxy
clusters.  However, these phenomena and objects -- among the most interesting
and puzzling in the universe -- are usually hidden from human observation,
obscured by vast clouds of interstellar or intergalactic dust.

        While clouds of matter in space hinder such observations with optical,
or light-gathering telescopes, X-rays are able to penetrate dust-shrouded areas
of the universe.  But, X-rays and other types of high-energy radiation are
absorbed by the Earth's atmosphere.  Therefore, it was only in the 1970s, with
placement into Earth orbit of specialized X-ray instruments, that the first
significant surveys of space for X-ray sources were made.  One of these
instruments, the High- Energy Astronomy Observatory (HEAO-2, widely known as
the Einstein X-ray Observatory), provided such exceptional results that
astrophysicists, working with NASA, proposed development of a much more capable
X-ray project.  The result was the Advanced X-ray Astrophysics Facility or
AXAF.

        Originally planned to be accomplished as a single comprehensive
mission, AXAF was restructured in mid-1992 to consist of two smaller, more
specialized missions.  The program restructuring was necessary to stay within
budget constraints, while preserving a high percentage of the originally
planned AXAF scientific capabilities.

AXAF-I

        The AXAF-I mission will be especially suited for imaging
investigations.  It will develop and place into orbit a telescope for capturing
high resolution images and spectra of X-ray sources.  That is, its observations
will produce "picture-like" images analogous to those made in visible light
with an optical telescope.  However, it will use X-rays to create them, not
visible-energy wavelengths, so that the images will reveal otherwise-hidden
features, just as a medical X-ray does.  AXAF-I's capabilities in the area of
X-ray spectroscopy will complement its imaging function.  Spectra, or
spectrographs, reveal the "chemical fingerprint" of an object by separating the
radiation received from it according to wavelengths, much as a prism splits
visible light into constituent colors.  Again, AXAF performs these specialized
functions in the X-ray region rather than in visible wavelengths.

Key Features

        To provide these capabilities, AXAF-I will have a unique mirror
assembly.  In an X-ray instrument, the mirrors themselves are much different
from those used in optical telescopes.  With very short wavelengths and high
energy levels, X-rays are absorbed rather than reflected from the surface of a
conventional mirror.  Therefore, X-ray telescopes use "grazing-incidence"
mirrors -- finely polished cylinders of glass that look something like ordinary
drinking glasses with no bottom.  The walls of the cylinders are not straight,
however, but are very slightly angled so that X-rays graze off the surfaces,
like a stone skipping on a pond.  This configuration, coupled with a slight
curvature of the surfaces, funnels the rays toward a point of focus behind the
mirrors, in the focal plane.  AXAF-I's mirror assembly will consist of four
sets of these cylindrical mirrors, mounted concentrically in a nested array.
The use of more than one set of mirrors increases the area for collecting X-ray
energy, just as does increasing the mirror diameter in a visible-light
telescope.  The aperture diameter of the largest mirror set will be 47.2 in.
(1.2 m), making it the largest X-ray grazing incidence telescope to date.  The
focal length of the mirror assembly will be 32.8 ft. (10 m).

        The specialized types of scientific information to be collected by
AXAF-I require that its design incorporate several sophisticated data
collection elements: a charge-coupled device imaging spectrometer and a
high-resolution camera in the observatory's focal plane; and two grating
spectrometers behind the high-resolution mirror assembly.  During observation
periods, these data will be stored on-board and periodically transmitted to the
ground for analysis.

        Weighing roughly 11,500 pounds (5,200 kg), the observatory will be
approximately 39 feet (11.9 m) long by 14 feet (4.2 m) in diameter.  It is
planned to be launched in late 1998, into a high elliptical orbit of 5,400 by
54,000 nautical miles (10,000 by 100,000 km).  AXAF-I is designed to have an
operational life of five years.


Development

        Following a competitive procurement, TRW Inc. of Redondo Beach, Calif.,
was selected in August 1988 as the prime contractor to develop what was then
planned as the single-mission Advanced X-Ray Astrophysics Facility. TRW's major
subcontractors are Hughes Danbury Optical Systems of Danbury, Conn., and Kodak
Federal Systems Division of Rochester, N.Y. Following the 1992 restructuring
which created a two-mission AXAF program, the prime contractor's role was
modified to reflect those changes.  TRW's effort was specified as encompassing
development and initial operation of AXAF-I. The companion AXAF-S was
designated an in-house project to be accomplished by the Marshall Space Flight
Center in Huntsville, Ala.

        Management of the overall AXAF program, including supervision of
design, development, assembly and testing activities and the establishment of
the Operations Control Center is performed for NASA by the Marshall Center. The
Office of Space Science and Applications at NASA Headquarters in Washington,
D.C. is responsible for the overall direction of the program.

AXAF-S

        AXAF-S, the second mission, will concentrate on the area of high energy
X-ray spectroscopy, by which scientists study the chemical and physical
characteristics of celestial objects.  Different chemical elements emit or
absorb radiation at characteristic wavelengths or energies, producing spectral
lines which serve as "signatures" to uniquely identify the elements making up a
source.  In addition to providing insights regarding the chemistry of celestial
objects, such spectra can reveal their structural and dynamic features.

Key Features

        Just as the overall design and major components of the AXAF-I
observatory will be tailored toward its principal objective, X-ray imaging of
objects, those of AXAF-S will be specialized to best accomplish its primary
function of spectroscopy.

        As presently envisioned, the mirror assembly will consist of
approximately 40 formed metallic shells nested together, with a focal length of
15.7 ft. (4.8 m).  The largest mirror shell will be 17.7 in. (0.45 m) in
diameter.  As with the imaging observatory, the use of an array of concentric
mirrors allows intercepting a high percentage of the X-rays entering the
instrument's aperture.

        The X-ray spectrometer will be the heart of the AXAF-S instrument
package and is being provided for the mission by NASA's Goddard Space Flight
Center in Greenbelt, Md. Specifically, the spectrometer will provide unique
capabilities in high-resolution spectroscopy at energies above 4,000 electron
volts.  That is, it will be most sensitive in the portion of the energy
spectrum spanning the mid to upper, or shorter-wavelength, portion of the X-ray
band.  Its high resolution will enable distinguishing spectral lines which are
very close together in wavelength.  These characteristics will make the
instrument's spectroscopic capabilities complementary to those of AXAF-I.

        AXAF-S is expected to weigh approximately 7,000 pounds (3,150 kg), have
an overall length of 21.5 feet (6.55 m), and a diameter of 6.5 feet (2.0 m).

Development and Launch

        Plans to launch a separate observatory known as AXAF-S emerged from the
1992 AXAF program restructuring.  Along with the decision to develop two
specialized, complementary missions, it was decided that AXAF-S should be
undertaken by the Marshall Center as an "in-house" effort, as opposed to the
more traditional method of having the work performed by a contractor team.

        The in-house decision does not, however, mean all work on the 10-plus-
year-long AXAF-S program (seven in development and at least three years of
operations) will be performed by NASA employees at NASA facilities.  The
project team will obtain many elements for the observatory from suppliers
specializing in particular types of hardware, just as a prime contractor would.

        Completion of AXAF-S is planned for 1999, in preparation for a launch
near the end of that year.  To enable the highest efficiency in observation
time, the observatory will be launched into a polar, Sun-synchronous orbit.
That is, it will circle the Earth such that each orbit takes it above the north
and south poles, while maintaining the solar arrays exposed to the Sun for most
of the year.  This is possible by having the observatory's orbit plane progress
around the Earth at the same rate that the Earth progresses around the Sun,
thus maintaining a constant relationship to the Sun. Placing the observatory
into such an orbit requires a launch from the Vandenberg Air Force Base in
California. A Delta II expendable launch vehicle will loft AXAF-S to an
altitude of approximately 350 nautical miles (650 km).

        The launch will begin what is planned as at least a three-year
operational life for the observatory in which its specialized capabilities --
complementing those of AXAF-I -- will be used by scientists to pursue major
advances in our understanding of the most basic nature of the universe.

AXAF OPERATIONS CONTROL CENTER
AND SCIENCE CENTER

        Once each observatory is in orbit, the focal points for the two
missions will be the AXAF Operations Control Center at the Marshall Space
Flight Center and the AXAF Science Center at Cambridge, Mass. The two
facilities will be electronically linked for the most efficient interaction in
mission planning and data transfer.  The facilities will each serve specialized
functions:

o The AXAF Science Center will assist the international science community in
preparing for the AXAF missions, specifically in areas such as preparation of
research proposals, planning of science observations, and calibration of
instruments prior to their installation in the observatories.  The Science
Center will also manage the receipt, calibration, distribution and analysis of
data from observations.  In March 1991, a contract was awarded to the
Smithsonian Astrophysical Observatory for design, development, management and
operation of the Science Center. The contract is managed by the Marshall Space
Flight Center.

o The AXAF Operations Control Center will receive observation requests from the
Science Center and integrate them into a detailed schedule for transmission to
the two spacecraft.  In addition, the Control Center will provide capabilities
for mission planning and scheduling, processing of telemetry, command
processing and management, attitude determination and sensor calibration.  It
will interface with NASA's Deep Space Network and Space Network for spacecraft
communications.

* * *

        During their years of orbital operation, the two AXAF missions will
fill a major gap in the ability of astronomers to view the universe with the
widest possible scope.  AXAF will bridge the region of energy wavelengths
between those covered by the Hubble Space Telescope and by the Compton Gamma
Ray Observatory. The AXAF program represents a major stride toward advancing
the new age of astronomy and astrophysics.

Article: 920
Newsgroups: sci.space.policy
From: [email protected] (Gregg Germain)
Subject: Re: Cassini
Sender: [email protected]
Organization: Smithsonian Astrophysical Observatory, Cambridge, MA, USA
Date: Wed, 2 Mar 1994 18:04:52 GMT
 
AXAF could have been launched from either, and the latest decision was that
it will be launched on a shuttle.
 
Gregg
 

From:	US1RMC::"[email protected]" "HILL, DIANNE" 25-AUG-1994 21:28:01.08
To:	"[email protected]" <[email protected]>
CC:	
Subj:	94-139 NASA COMPLETES FIRST MIRROR FOR AXAF OBSERVATORY

Donald L. Savage
Headquarters, Washington, D.C. 

   August 24, 1994
(Phone:  202/358-1547)

Steve Roy
Marshall Space Flight Center, Huntsville, Ala.
(Phone:  205/544-0034)

RELEASE:  94-139

NASA Completes First Mirror FOR AXAF Observatory

     The first and largest of eight mirrors for the Advanced X-ray
Astrophysics Facility (AXAF) has been successfully completed, and is
superior in quality to any X-ray mirror ever destined for launch into
space. 

     The mirror, designated P1, is the first of eight mirrors which
will be assembled into the AXAF telescope, a large space-based
observatory scheduled for launch in 1998.  The prime contractor for
the telescope is TRW, Redondo Beach, Calif. 

     The P-1 mirror will form part of the high resolution mirror
assembly (HRMA), the central optical component in the AXAF 10-meter
telescope.  At 48 inches in diameter, the completed mirror will be the
largest ever made to collect X-rays in space.  The HRMA uses four
pairs of precision-shaped mirrors to focus X-rays from celestial
sources onto the spacecraft's imaging instruments. 

     Built by Hughes Danbury Optical Systems (HDOS), Danbury, Conn.,
the P1 mirror will be shipped to Eastman Kodak Company (EKC),
Rochester, N.Y., where it will initially be used in an engineering
test to verify telescope alignment processes.  The P1 mirror was X-ray
tested in 1991 at NASA's Marshall Space Flight Center, Huntsville,
Ala.  It was returned to HDOS, trimmed to final flight length, and
then polished to remove distortion resulting from stress relief after
trimming. 

     The P1 mirror's imaging quality for high energy X-rays is two
times better than what was originally specified resulting in a
significant improvement in its scientific capability. 

     Once in orbit, data from AXAF will be used to study X-ray
radiation and is expected to significantly improve scientific
understanding of some of the most energetic and violent processes in
the universe.  The observatory will produce "picture-like" images and
spectrograms which will yield information on temperature and chemical
composition of the objects it observes. 

     AXAF is designed to work in concert with NASA's Great
Observatories already in orbit -- the Hubble Space Telescope (HST) and
the Compton Gamma-Ray Observatory.  Each observatory makes
observations of stars, galaxies, and other astronomical objects in
distinct and separate wavelengths of energy, including visible light,
ultraviolet, gamma rays, and, in the case of AXAF, X-rays.  NASA
launched the HST in 1990 and in 1991 launched the TRW-built Compton
Gamma Ray Observatory. 

     The AXAF development team consists of NASA, the Smithsonian
Astrophysical Observatory, TRW, HDOS, EKC and Marshall Space Flight
Center, which manages the AXAF project for NASA's Office of Space
Science, Washington, D.C. 

 - end -

% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% From: "HILL, DIANNE" <[email protected]>
% To: "[email protected]" <[email protected]>
% Subject: 94-139 NASA COMPLETES FIRST MIRROR FOR AXAF OBSERVATORY
% Date: Thu, 25 Aug 94 12:22:00 PDT
% Sender: [email protected]