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The Interdisciplinary Evolution of the Hubble Space Telescope


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Title: The Interdisciplinary Evolution of the Hubble Space Telescope

The Interdisciplinary Evolution of the Hubble
Space Telescope
  • An Historical Examination of Key
    Interdisciplinary Interactions

Greg Carras, Jerry Cordaro, Andrew Daga, Sean
Decker, Jack Kennedy, Susan Raizer University of
North Dakota, Department of Space Studies 24
April 2006
The Hubble Space Telescope An Overview
  • An orbiting telescope that collects light from
    celestial objects in visible, ultraviolet, and
    near-infrared wavelengths
  • Launched 24 April 1990 aboard the Space Shuttle
  • Dimensions Cylindrical 24,500 lb (11,110-kg), 43
    ft long (13.1 m ) and 14.1 ft (4.3m) wide
  • Orbital period 96 minutes
  • Primarily powered by the sunlight collected by
    its two solar arrays
  • The telescopes primary mirror is 2.4 m (8 ft) in
  • Was created by NASA with substantial and
    continuing participation by ESA
  • Operated by the Space Telescope Science Institute
    (STSI) in Baltimore, MD
  • Named for Edwin Powell Hubble

"The Hubble Space Telescope is the most
productive telescope since Galileo's" - Robert
Kirshner, President of the American Astronomical
Reference Image and data STSI
The evolution of HST may be best approached by
understanding the interaction of four factors
The Social and Political Conditions
  • The Historical Context (and the post WWII trend
    toward Big Science)

The Technological Dimension
The Participants (People and Agencies)
Hubbles Historical Context
  • At the beginning of the 20th Century, scientists
    had a remarkably limited view of the physical
    universe many believed that our galaxy was the
    only galaxy.
  • Before WWII most astronomy was conducted by
    individuals or small groups, and astronomical
    observatories were funded by private
    philanthropists (example Carnegie) or by an
    individual astronomer (example Percival Lowell).
  • By the 1920s this view was being rapidly
    revised, in part due to the observations of Edwin
    Hubble and Milton Humason in the 20s and 30s
    who saw many other galaxies, and that these
    galaxies were moving away from each other (which
    leads to the concept of an expanding universe and
    the Hubble Constant).
  • During WWII, the federal government teamed up
    with industry and the scientific community to
    form working partnerships. People learned how to
    develop transformational projects quickly and
    Big Science is born.
  • Some scientists learn how to play the game and
    extend themselves to be activists for important
  • One of these, an astronomer, is Lyman Spitzer,

Hubbles Historical Context (continued)
  • In 1946 Spitzer publishes Astronomical
    Advantages of an Extra-Terrestrial Observatory,
    for RAND. It lays out in detail for the first
    time the enormous advantages of a space-based
    telescope. This report remains classified for
  • The US Army has been experimenting with captured
    V2 rockets, some of which have been equipped with
    scientific payloads.
  • In 1950, at a dinner party in his home, physicist
    James Van Allen and several scientists consider
    the idea for a third International Polar Year
    this will become the IGY. An increasing number
    of scientists are looking at the space
    environment and new space age technologies to
    further scientific exploration.
  • Other scientists and engineers are also
    speculating about the new realm of possibilities
    for science, including Wernher von Braun, who
    describes a manned orbital telescope in 1952.
  • 1955 In response to growing pressure from
    scientists, the US National Academy of Sciences
    and National Science Foundation jointly agree to
    seek approval to orbit a scientific satellite
    during the upcoming IGY (to be 1957-1958).
  • During this period, many scientists remain
    unconvinced of the idea to take science into
    space. Nevertheless a scientific advocacy
    emerges, and it learns to become politically
  • The paradigm has shifted to Big Science.

Hubbles Historical Context (continued)
  • In 1958 (and following Sputnik), the Space
    Science Board of National Academy of Sciences
    calls for and receives hundreds of suggestions
    for follow-on projects to IGY.
  • These are forwarded to NASA's Space Science
    Working Group on "Orbital Astronomical
    Observatories (OAOs)" President Eisenhower
    enthusiastically supports.
  • In the Cold War climate, NASA is interested in
    demonstrating what it can do. In 1960-61 it
    issues first RFPs for OAO series.
  • The contentious relationship between NASA and the
    science community takes form with the OAO
    project. Scientists who have been used to taking
    complete charge of their science projects will
    now have to contend with a loss of control to
  • On the positive side With OAO, the idea of a
    Guest Observer is introduced breaking from the
    idea of strict control by a single Principal
  • This will have later implications as key
    scientists will insist that the new Large
    Telescope be a National Facility (open to all)
  • On the negative side 2 of 4 OAO missions fail
    in large part because NASA did not communicate
    well with the scientists and the technology was
    too complicated.

Reference Smith, Robert W, et al. The Space
Telescope A Study of NASA, Science, Technology,
and Politics. New York Cambridge Univ. Press,
Social and Political Conditions
  • As NASA begins to seriously contemplate a Large
    Space Telescope, the financial and budgetary
    condition of the nation weighs heavily. This
    factor, and how the various participants perceive
    it, will prove to be critical in defining
    Hubbles scientific potential, management,
    ultimate cost, and schedule.
  • By the mid-1970s the federal budget has been
    overstressed by the expenses of war and the Great
    Society programs, and the economy is stagnating.
  • NASA senior management is concentrating on the
    new Space Shuttle and the political climate for
    new expensive projects is hostile.
  • NASA continues to pursue an LST by using
    available funds (not needing congressional
    approval) to fund Phase A studies, forcing
    Marshall Space Flight Center to compete with
    Goddard Space Flight Center to become the lead
  • NASA Administrator Fletcher finds the Phase A
    cost estimates politically untenable and orders
    MSFC to limit the program cost to 300M.
  • Finally, throughout the 1960s and 70s, the DoD
    has been building a series of increasingly
    sophisticated reconnaissance satellites, and it
    forces controls on NASA that severely limit
    NASAs access to the technology to protect
  • Ironically, the same companies that know how to
    build the recon satellites are ultimately
    selected to build Hubble.

Reference Smith, Robert W, et al. The Space
Telescope A Study of NASA, Science, Technology,
and Politics. New York Cambridge Univ. Press,
Hubbles Participants Key People and Agencies
  • The four key participants in the development
    lifecycle of Hubble
  • Space Agencies
  • NASA Headquarters the Office of Space Science
    believes the LST is a major priority, but senior
    management were reluctant to propose any new
  • MSFC it had no astronomy expertise and was
    threatened with closure at the time of the LST
    Phase A competition it wanted the LST badly and
    said so.
  • GSFC it had the experienced people and know-how
    to build astronomical sats (it was lead for OAO),
    but was overburdened with project work its
    Director was ambivalent about the project.
  • JSC, KSC and JPL would play important roles in
    the program too. JSCs astronauts would prove
    essential. JPL designed and built the WF/PC (and
    the 60M spare).
  • Astronomers and other scientists within NASA
    would play a pivotal role in coordinating with
    the science community, of these Dr Robert ODell
    (Chief Project Scientist at MSFC) and Dr Nancy
    Roman of NASA HQ were crucial.
  • ESA It wanted a substantial space science
    program but could not do it on its own, and NASA
    needed to satisfy Congress while reassuring
    domestic scientists that they would not sacrifice
    control as a price for ESAs involvement
  • Executive and Legislative Branches of Government
  • Executive Branch despite budget constraints
    imposed by the Ford administration, the OMB and
    President Ford were generally supportive, as were
    officials in the Carter and Reagan
  • Congress Hubble will face stiff opposition from
    key congressional committees forcing major delays
    and economic limits. Congress will ultimately
    mandate international cooperation. The most
    prominent opponents of Hubble were Representative
    Edward P. Boland (D-MA) and Senator William
    Proxmire (D-WI).

Reference Smith, Robert W, et al. The Space
Telescope A Study of NASA, Science, Technology,
and Politics. New York Cambridge Univ. Press,
Key People and Agencies (continued)
  • Scientists and Advocates
  • Individual scientists will come to save the
    telescope by rallying their community and
    aggressively lobbying congress.
  • Of these, the most influential will be Lyman
    Spitzer and John Bahcall, both of Princeton.
    Their collaboration with Robert ODell (at MSFC)
    in lobbying Congress will come to be called the
    Princeton-Huntsville Axis. ODell actively
    promotes the project in scientific journals and
  • Industry
  • Many companies contributed to LST/HST, including
    all major aerospace firms, most in subcontractor
    roles to Lockheed Missiles and Space Company (CA)
    for the SSM, and to Perkin-Elmer (CT) for the
  • Lockheed and P-E had substantial experience
    working on highly classified PHOTOINT satellites.
  • Other firms were contracted by the universities
    to build elements of the Scientific Instruments.
  • At various times, corporate competitors worked
    together and with NASA and outside scientists to
    lobby congress at critical junctures.
  • Importantly, since both Lockheed and P-E were
    operating as associate contractors no company
    was fully charged with systems engineering
    authority, and NASA was unable to perform this
    role adequately.

Reference Smith, Robert W, et al. The Space
Telescope A Study of NASA, Science, Technology,
and Politics. New York Cambridge Univ. Press,
Hubbles Evolution Consolidated Summary
  • In the context of big science and Cold War
    tensions and technology advancements, NASA and
    the scientific community find common purpose in
    proposing a large (3m) reflecting telescope in
    Earth orbit. Astronomers know it will be
    revolutionary NASA and several presidents agree.
  • As Apollo concludes, NASA is under fire and
    fighting to keep field centers open. It develops
    an LST program but forces GSFC to compete with
    MSFC to lead the program. The compromise sets up
    antagonism between the centers.
  • With Marshall in the lead, the program is
    believed to be untenable politically an
    artificial limit of 300M is imposed, and the DoD
    demands limits on contractor penetration of the
    two key defense contractors.
  • With constant cost overages, NASA management
    demands reductions, forcing trade-off studies of
    capability versus cost. In this process the 3m
    primary mirror will be reduced to 2.4m. The
    scientists are always pushing back.
  • When the program is proposed to Congress, the
    House appropriations subcommittee rejects it,
    forcing NASA to appeal to the Senate in hopes of
    effectuating a resolution, and NASA considers
    holding off on the program.
  • It is at this point that university scientists,
    key NASA staffers and scientists, and
    contractors, begin to collaborate to lobby
  • From this emerges a partial victory, leading to
    the restoration of some funding and the mandate
    that NASA collaborate with ESA. NASA begins
    talks with ESA.

Hubbles Evolution Consolidated Summary
  1. As the program moves into the design and
    development phase (C/D), a manpower cap and the
    limited budget restrain Marshalls ability to
    manage the program. NASA depends on two
    associate contractors to do their own systems
    engineering. MSFC saw itself in this role, but
    was not able to do it.
  2. During this period the relationship between MSFC
    and GSFC is antagonistic and even hostile.
    Goddard is charged with developing the scientific
    instruments and eventually operating the
    telescope, but only reluctantly takes direction
    from MSFC. Marshall objects to Goddards
    interference, and Marshalls project scientist
    (ODell) takes the initiative away from GSFC.
  3. As the project moves ahead, even with ESAs 15
    contribution, the LST runs out of money. Faced
    with the prospect of severely reducing the
    scientific capability and delaying the launch,
    NASA management concedes to extend the launch
    date and returns to congress for more money.
  4. Status 1980 From its inception, LST has been
    underfunded and consequently, its capabilities
    were oversold (Smith, 1989). In 1980, the program
    is in crisis but still at a design stage where
    NASA considers cutting back on certain
    technologies to save money.
  5. During this time, scientists are working to
    create the methodologies that will be needed to
    operate HST at the STSI. A entire new star
    reference system is created to help guide the
  6. In 1983, the program hits another crisis NASA
    finally recognizes that changes need to be made,
    the launch date extended, and NASA HQ demands new
    managers and appoints its own project manager.
    NASA works with OMB and Congress begins to infuse
    much more money. Things begin to change.

Hubbles Evolution Consolidated Summary
  1. Between 1983 and 1986, the program is disciplined
    and turned around. New managers at NASA do not
    feel tied to the unrealistic promises that the
    program has made. Launch is scheduled for 1986.
  2. In 1986, just as the program is being readied for
    its final round of thermal-vacuum chamber
    testing, the Shuttle fleet is grounded with the
    Challenger disaster. NASA is afraid to lose the
    technical skills it needs to finish the program,
    so work continues to fix lingering problems and
    complete the thermal-vacuum testing. HST goes
    into protected storage.
  3. In 1990, HST is launched and very quickly put
    into service. Soon, it will be discovered that
    there is a flaw in the optics, which will be
    traced to a manufacturing error at P-E (which P-E
    knew about for 10 years).
  4. In 1993, in a dramatic series of EVAs during the
    first servicing mission (SM), HSTs optics are
    corrected and a new era of space astronomy
    finally begins.
  5. Since 1993, there have been 3 additional SMs,
    each one replacing and upgrading HST to
    state-of-the-art technology. Hubble has
    generated data of unprecedented quality in vast
    quantities since and continues to do so. With
    more demand for observing time than can be
    filled, and the ability to be extended
    indefinitely, Hubble has turned out to be
    everything and more than its supporters ever

References Smith, Robert W, et al. The Space
Telescope A Study of NASA, Science, Technology,
and Politics. New York Cambridge Univ. Press,
1989, and personal interview, Dr David Leckrone,
Goddard Space Flight Center, 10 April 2006.
Hubbles Technological Dimension
  • The Hubble Space Telescope was designed with many
    constraints both technical and cost.
  • This technology section will cover the technology
    components of Hubble and the rationale that drove
    decisions on its design.

Index to Technology Slides Hubble Components
- Overall Components - Power Systems
- Spacecraft Systems - Mirrors and
Baffles Mirror Problem - Sensors -
Actuators - Scientific Instruments Most
Difficult Technical Challenge Pointing Control
System Get the Cost Down Initial Deployment
Components and Servicing Missions
Hubble Technology
Overall Components Exploded View
Hubble Technology
Power Systems
Batteries- 6 nickel-hydrogen (NiH) batteries-
Power storage capacity is equal to 20 car
batteries- Power usage 2,800 watts
Solar Arrays (2) 40-foot (12-meter) panels that
convert sunlight into 2400 watts of electricity
in order to power the telescope.
Hubble Technology
Power Systems
Hubble Technology
Spacecraft Systems
Communications antennae (2) Transmit Hubble's
information to communications satellites called
the Tracking Data Relay Satellite System
(TDRSS) for relay to ground controllers at the
Space Telescope Operations Control Center
(STOCC) in Greenbelt, Maryland. Computer support
systems modules Contains devices and systems
needed to operate the Hubble Telescope. Serves as
the master control system for
communications, navigation, power management,
etc. Electronic boxes Houses much of the
electronics including computer equipment and
rechargeable batteries. Aperture door Protects
Hubble's optics in the same way a camera's lens
cap shields the lens. It closes when Hubble
is not in operation to prevent bright light from
hitting the mirrors and instruments. Light
shield Light passes through this shaft before
entering the optics system. It blocks surrounding
light from entering Hubble. Pointing control
system This system aligns the spacecraft to
point to and remain locked on any target. The
telescope is able to lock onto a target without
deviating more than 7/1000th of an arcsecond,
or about the width of a human hair seen at a
distance of 1 mile.
Hubble Technology
Spacecraft Systems
Hubble Technology
Spacecraft Systems
Hubble Technology
Spacecraft Systems
Hubble Technology
Spacecraft Systems
Hubbles Spacecraft Systems the OTA

Hubble Technology
Hubble data path to the Goddard Space Flight
Hubble Technology
Pointing Control System
The Pointing Control System (PCS) aligns Hubble
so that the telescope points to and remains
locked on a target. The PCS is designed for
pointing to within .01 arcsec and is capable of
holding a target for up to 24 hours while Hubble
continues to orbit the Earth at 17,500 mph. If
the telescope were in Los Angeles, it could hold
a beam of light on a dime in San Francisco
without the beam straying from the coin's
Hubble Technology
Mirror and Baffles
  • Primary Mirror
  • Primary Mirror Diameter 94.5 in (2.4 m), Weight
    1,825 lb (828 kg).
  • Hubble's two mirrors were ground so that they do
    not deviate from a perfect curve by more than
    1/800,000ths of an inch. If Hubbles primary
    mirror were scaled up to the diameter of the
    Earth, the biggest bump would be only six inches
  • Secondary Mirror
  • Secondary Mirror Diameter 12 in (0.3 m), Weight
    27.4 lb (12.3 kg).
  • Focal Plane
  • Mirrors focus starlight on the Focal Plane.
  • Baffles
  • Keep out stray light.
  • Main baffle
  • Central baffle
  • Secondary mirror baffle

The telescope's primary mirror (2.4 m diameter)
being hoisted up
Hubble Technology
Mirror and Baffles
Hubble Main Mirror
Workers study Hubbles main, eight-foot (2.4 m)
mirror. Hubble, like all telescopes, plays a kind
of pinball game with light to force it to go
where scientists need it to go. When light enters
Hubble, it reflects off the main mirror and
strikes a second, smaller mirror. The light
bounces back again, this time through a two-foot
(0.6 m) hole in the center of the main mirror,
beyond which Hubbles science instruments wait to
capture it. In this photo, the hole is covered up.
Hubble Technology
Mirror and Baffles
Hubble Technology
Mirror and Baffles
Hubble Technology
Mirror and Baffles
Hubble Technology
Mirror and Baffles
Mirror Problem
The mission controllers made progress and by 21
May began receiving the first optical images from
the telescope. These views of a double star in
the Carina system, scientists believed, were much
clearer than those from ground-based telescopes.
Such success left project officials surprised on
the weekend of 2324 June when the telescope
failed a focus test. The controllers had moved
the telescopes secondary mirror to focus the
light, but a hazy ring or halo encircled the
best images. Subsequent tests determined that
the blurry images resulted from the spherical
aberration of the primary mirror spherical
aberration reflected light to several focal
points rather than to one. It occurred because
Perkin-Elmer had removed too much glass,
polishing it too flat by 1/50th of the width of a
human hair. This seemingly slight mistake,
however, prevented the telescope from making
sharp images.
Hubble Technology
Mirror and Baffles
COSTAR Corrective Optics Space Telescope Axial
Although the primary mirror was not one of the
replaceable units, its aberration could be
corrected, much like the way an eye doctor
corrects poor vision with spectacles, by
modifications to second generation scientific
instruments. COSTAR, the corrective optics Space
Telescope axial replacement, would replace the
high speed photometer and use relay mirrors
mounted on movable arms to focus the scattered
Hubble Technology
Optical Camera Channel and Baffles
Four Optical Camera Channel and Baffle assemblies
from the Wide Field and Planetary Camera (WF/PC)
1 recovered from the Hubble Space Telescope
during HST Service Mission
Hubble Technology
Optical Camera Channel and Baffles
Faint Object Camera (FOC) M1 Field Mirror
Mechanism that was ultimately installed as part
of the COSTAR (Corrective Optics Space Telescope
Axial Replacement) payload during Space Shuttle
Mission STS-61 (Hubble Service Mission 1) to
correct errors in the primary mirror onboard the
Hubble Space Telescope. The error was the
result of a residual aberration polished into the
primary due to a mis-assembled nulling apparatus
the error resulted in the Hubble's primary mirror
being ground about 2 micrometers too flat (1/40
the thickness of a human hair). Scientists and
engineers devised COSTAR with four small mirrors,
about the size of dimes and quarters. The small
mirrors were intentionally produced with a flaw
identical to and opposite the flaw on the primary
Hubble mirror.
Hubble Technology
Fine Guidance Sensors (3) These sensors are
locked onto two guide stars to keep Hubble in the
same relative position of these stars. Coarse
Sun Sensors (2) Measure Hubble's orientation to
the sun. Also assist in deciding when to open and
close the aperture door. Magnetic Sensing
System Measure Hubble position relative to
Earth's magnetic field. Rate Sensor Unit Two
rate sensing gyroscopes measure the attitude rate
motion about its sensitive axis. Fixed Head Star
trackers An electro-optical detector that locates
and tracks a specific star within its field of
Hubble Technology
Reaction Wheel Actuators (4) The reaction wheels
work by rotating a large flywheel up to 3000 rpm
or braking it to exchange momentum with the
spacecraft which will make Hubble turn. Magnetic
Torquers (4) The torquers are used primarily to
manage reaction wheel speed. Reacting against
Earth's magnetic field, the torquers reduce the
reaction wheel speed, thus managing angular
Hubble Technology
Hubble Technology
Scientific Instruments
Axial bays (4) Four instruments are aligned with
the main optical axis and are mounted just behind
the primary mirror. As of the year 2000 they
consisted of
ACS (Advanced Camera for Surveys) The newest
camera (2002) with a wider field of view, and
better light sensitivity. It effectively
increases Hubble's discovery power by 10x.
NICMOS (Near Infrared Camera and Multi-Object
Spectrometer) Infrared instrument that is able to
see through interstellar gas and dust. STIS
(Space Telescope Imaging Spectrograph) Separates
light into component wavelengths, much like a
prism. COSTAR Contains corrective optics for
spherical aberration in the primary
mirror. Radial bay (1) Wide Field/Planetary
Camera 2 (WFPC2) is housed here. Taking images
that most resemble human visual information,
WFPC2 is responsible for taking nearly all of
Hubble's famous pictures. Fine guidance sensors
(3) The sensors lock onto guide stars and measure
relative positions, providing data to the
spacecraft's targeting system and gathering
knowledge on the distance and motions of stars.
Hubble Technology
Scientific Instruments
Hubble Technology
Scientific Instruments
Space Telescope Imaging Spectrograph (STIS)
Engineers in a clean room at Ball Aerospace in
Boulder, Colo., work on one of Hubbles
instruments, the Space Telescope Imaging
Spectrograph (STIS), in 1996. The instrument,
installed in Hubble in 1997, breaks light into
colors, giving scientists an important analytical
tool for studying the cosmos. STIS has been used
to study such objects as black holes, new stars,
and massive planets forming outside our solar
Hubble Technology
The Most Difficult Technical Challenge Pointing
Control System The Problem
A major problem for NASA and its contractors was
the means to guide and stabilize the telescope.
If the completed telescope was to perform to the
negotiated requirements, it would have to be
capable of being aimed at an astronomical target
with a pointing stability of 0.005 seconds of
arc, an angle on the sky about 360,000 times
smaller than the angle that is subtended by the
diameter of the full moon. So taxing was this
requirement that it was widely viewed in NASA and
outside as the most difficult technical challenge
the designers and builders had to overcome. The
telescope not only had to be pointed extremely
accurately, means also had to be devised to keep
it locked on its astronomical targets. This task
was crucial because there would inevitably be
tiny disturbances that would act to move the
spacecraft away from its targets, disturbances
known as "jitter". Jitter might arise from the
motions of the gyroscopes in pointing, for
example. Should the entire spacecraft be moved
if small corrections in its position were needed
(a method known as body pointing)? Or should the
secondary mirror of the Large Space Telescope be
shifted to compensate for the spacecraft's minor
motions (a method known as image motion
Hubble Technology
The Most Difficult Technical Challenge Pointing
Control System The Answer
During Phase A, Bendix had performed studies for
Marshall that argued that body pointing alone was
sufficient. Marshall, however, was not
convinced. Hence the center's Phase A design
concept also incorporated a movable secondary
mirror. But more studies persuaded Marshall that
control moment gyroscopes could point and
stabilize the telescope. If so, a moving
secondary would not be essential, even though
Perkin-Elmer argued that it promised to give the
best performance. Marshall's basic engineering
approach was to use the simplest available
systems where possible, and for pointing and
control that would mean using either control
moment gyroscopes or reaction wheels alone, but
preferably not the two in combination.
Hubble Technology
Get the Cost Down The Problem
Financial pressure pushed the Centers design
activities and often forced it to relinquish
conservative engineering principles. The Centers
March 1972 project plan called for three
telescopes, an engineering model, a precursor
flight unit, and the final LST. Design and
development would cost between 570 and 715
million. Headquarters believed this was too
expensive. In a December 1972 meeting, NASA
Administrator Fletcher emphasized that the
current NASA fiscal climate was not conducive to
initiation of large projects and suggested 300
million as a cost target.
Hubble Technology
Get the Cost Down
A proto-flight approach would eliminate the
engineering and precursor units a single
spacecraft would serve as test model and flight
unit. The proto-flight approach had been
successfully tried for Department of Defense
projects, and the Center expected it to reduce
costswhich would please Congressand speed
progress to operationswhich would please the
astronomers. The telescope maintenance strategy
also changed. Rather than designing for extensive
repair in orbit inside a pressurized cabin,
Marshall suggested a design that would eliminate
the cabin and minimize repairs in orbit. The new
design assumed the Space Shuttle could return the
telescope to Earth for major repairs. These
changes simplified the overall LST design and
development scheme.
Hubble Technology
Get the Cost Down
By December 1974 the Program Development task
team had downsized the telescope. As before the
team had to balance cost and performance and
devise a design pleasing to Congress and the
astronomers. Team leader Downey said the Agency
wanted to procure the lowest cost system that
will provide acceptable performance and would
be willing to trade performance for cost.
Working with the LST science groups and
contractors, the team reduced the telescopes
primary mirror from a 3-meter aperture to 2.4
meters. This major change mainly resulted from
new NASA estimates of the Space Shuttles payload
delivery capability the Shuttle could not lift a
3-meter telescope to the required orbit. In
addition, changing to a 2.4-meter mirror would
lessen fabrication costs by using manufacturing
technologies developed for military spy
satellites. The smaller mirror would also
abbreviate polishing time from 3.5 years to 2.5
years. The redesign also reduced the mass of
the support systems module from 24,000 pounds to
17,000 pounds the SSM moved from the aft of the
spacecraft to one-third of the way forward and
became a doughnut around the primary mirror.
These changes diminished inertia and facilitated
steering of the spacecraft, thus permitting a
smaller pointing control system. The astronomers
chose to reduce the number of scientific
instruments from seven to four. Finally, the
Marshall team believed that designing for repair
would allow for lower quality standards.
Hubble Technology
Initial Deployment Components and Servicing
1990 Initial Complement at Deployment WFPC (1)
- Wide Field/Planetary Camera - First-generation
imaging camera. WFPC (1) operated in either Wide
Field mode, capturing the largest images, or
Planetary mode with higher resolution. GHRS -
Goddard High Resolution Spectrograph -
First-generation spectrograph. GHRS was used to
obtain high resolution spectra of bright targets.
FOS - Faint Object Spectrometer -
First-generation spectrometer. FOS was used to
obtain spectra of very faint or faraway sources.
FOS also had a polarimeter for the study of the
polarized light from these sources. FOC - Faint
Object Camera - First-generation imaging camera.
FOC is used to image very small field of view,
very faint targets. This is the final,
first-generation instrument still on Hubble.
HSP - High Speed Photometer - First-generation
photometer. This instrument was used to measure
very fast brightness changes in diverse objects,
such as pulsars. FGS - Fine Guidance Sensors -
Science/guidance instruments. The FGS's are used
in a "dual-purpose" mode serving to lock on to
"guide stars" which help the telescope obtain the
exceedingly accurate pointing necessary for
observation of astronomical targets. These
instruments can also be used to obtain highly
accurate measurements of stellar positions.
Hubble Technology
Initial Deployment Components and Servicing
  • 1993 Servicing Mission 1
  • WFPC2 - Wide Field Planetary Camera 2 -
    Second-generation imaging camera. WFPC2 is an
    upgraded version of WF/PC (1) which includes
    corrective optics and improved detectors.
  • COSTAR - Corrective Optics Space Telescope Axial
    Replacement - Second-generation corrective
    optics. COSTAR is not an actual instrument. It
    consists of mirrors which refocus the abbreviated
    light from Hubble's optical system for
    first-generation instruments. Only FOC utilizes
    its services today.
  • Restoring Hubble's Vision
  • As the first in a series of planned visits to the
    orbiting Hubble Space Telescope, the First
    Servicing Mission (STS-61) in December 1993 had a
    lot to prove and a lot to do. The mission's most
    important objective was to install two devices to
    fix Hubble's vision problem. Because Hubble's
    primary mirror was incorrectly shaped, the
    telescope could not focus all the light from an
    object to a single sharp point. Instead, it saw a
    fuzzy halo around objects it observed.
  • Once astronauts from the space shuttle Endeavour
    caught up with the orbiting telescope, they
    hauled it into the shuttle's cargo bay and spent
    five days tuning it up. They installed two new
    devicesthe Wide Field and Planetary Camera 2
    (WFPC2) and the Corrective Optics Space Telescope
    Axial Replacement (COSTAR). Both WFPC2 and the
    COSTAR apparatus were designed to compensate for
    the primary mirror's incorrect shape.
  • Also installed during the First Servicing Mission
  • New solar arrays to reduce the "jitter" caused by
    excessive flexing of the solar panels during the
    telescope's orbital transition from cold darkness
    into warm daylight
  • New gyroscopes to help point and track the
    telescope, along with fuse plugs and electronic
  • This successful mission not only improved
    Hubble's vision which led to a string of
    remarkable discoveries in a very short time but
    it also validated the effectiveness of on-orbit

Hubble Technology
Initial Deployment Components and Servicing
Servicing Mission 2 STIS - Space Telescope
Imaging Spectrograph - Second-generation
imager/spectrograph. STIS is used to obtain high
resolution spectra of resolved objects. STIS has
the special ability to simultaneously obtain
spectra from many different points along a
target. NICMOS - Near Infrared Camera/Multi-Object
Spectrometer - Second-generation
imager/spectrograph. NICMOS is Hubble's only
near-infrared (NIR) instrument. To be sensitive
in the NIR, NICMOS must operate at a very low
temperature, requiring sophisticated coolers.
Problems with the solid nitrogen refrigerant have
necessitated the installation of the NICMOS
Cryocooler (NCC) on SM3B to continue its
operation. The light from the most distant
galaxies is shifted to infrared wavelengths by
the expanding universe. To see these galaxies,
Hubble needed to be fitted with an instrument
that could observe infrared light. During the
10-day Second Servicing Mission (STS-82) in
February 1997, the seven astronauts aboard the
space shuttle Discovery installed two
technologically advanced instruments. The Near
Infrared Camera and Multi-Object Spectrometer
(NICMOS) would be able to observe the universe in
the infrared wavelengths. The second
instrumentthe versatile Space Telescope Imaging
Spectrograph (STIS)would be used to take
detailed pictures of celestial objects and to
hunt for black holes. Both instruments had
optics that corrected for the flawed primary
mirror. In addition, they featured technology
that wasn't available when scientists designed
and built the original Hubble instruments in the
late 1970sand opened up a broader viewing window
for Hubble. The new instruments replaced the
Goddard High Resolution Spectrograph and the
Faint Object Spectrograph. Also installed during
the Second Servicing Mission were A
refurbished Fine Guidance Sensorone of three
essential instruments used to provide pointing
information for the spacecraft, to keep it
pointing on target, and to calculate celestial
distances A Solid State Recorder (SSR) to
replace one of Hubble's data recorders (An SSR is
more flexible and can store 10 times more data)
A refurbished, spare Reaction Wheel Assemblypart
of the Pointing Control Subsystem.
Hubble Technology
Initial Deployment Components and Servicing
Servicing Mission 3a On December 19, 1999,
seven astronauts boarded the space shuttle
Discovery to pay the Hubble Space Telescope a
special holiday visit. After a successful launch
and several trips around Earth, the crew caught
up with Hubble and hauled it into the shuttle's
cargo bay. Six days and three 6-hour spacewalks
later, the crew had successfully completed Part A
of the two-part Third Servicing Mission, which
had them replacing worn or outdated equipment and
performing several critical maintenance upgrades.
Servicing Mission 3A (STS-103) was a busy one.
The most pressing task was the replacement of
gyroscopes, which accurately point the telescope
at celestial targets. The crew, two of whom were
Hubble repair veterans, replaced all six
gyroscopes-as well as one of Hubble's three fine
guidance sensors (which allow fine pointing and
keep Hubble stable during observations) and a
transmitter. The astronauts also installed an
advanced central computer, a digital data
recorder, an electronics enhancement kit, battery
improvement kits, and new outer layers of thermal
protection. Hubble was as good as new.
Hubble Technology
Initial Deployment Components and Servicing
Servicing Mission 3b On March 1, 2002, NASA
launched the space shuttle Columbia into an orbit
360 miles above Earth, where its seven-member
crew met with the Hubble Space Telescope to
perform a series of upgrades. Servicing Mission
3B, also known as STS-109, was the fourth visit
to Hubble. NASA split the original Servicing
Mission 3 into two parts and conducted the first
part Servicing Mission 3A in December
1999. The highly-trained astronauts performed
five spacewalks. Their principal task was to
install a new science instrument called the
Advanced Camera for Surveys, or ACS. The first
new instrument to be installed in Hubble since
1997, ACS brought the nearly 12-year-old
telescope into the 21st century. With its wide
field of view, sharp image quality, and enhanced
sensitivity, ACS doubled Hubbles field of view
and collects data ten times faster than the Wide
Field and Planetary Camera 2, the telescopes
earlier surveying instrument. Hubble gets its
power from four large flexible solar array
panels. The 8-year-old panels were replaced with
smaller rigid ones that produce 30 percent more
power. Astronauts also replaced the outdated
Power Control Unit, which distributes electricity
from the solar arrays and batteries to other
parts of the telescope. Replacing the original
unit, which has been on the job for nearly 12
years, required the telescope to be completely
powered down for the first time since its launch
in 1990. Reaction Wheel Assembly Four
Reaction Wheel Assemblies like this one are
needed to point the telescope. Astronauts will
replace one of them. During the last spacewalk
astronauts installed a new cooling system for the
Near Infrared Camera and Multi-Object
Spectrometer, or NICMOS, which became inactive in
1999 when it depleted the 230-pound block of
nitrogen ice that had cooled it since 1997. The
new refrigeration system, which works much like a
household refrigerator, chills NICMOSs infrared
detectors to below 315 F (193 C). NICMOS
Cooling System An experimental refrigeration
technology will make it possible to restore
Hubble's infrared vision. New Steering
Equipment Astronauts replaced one of the four
reaction wheel assemblies that make up Hubble's
pointing control system. Flight software commands
the reaction wheels to steer the telescope by
spinning in one direction, which causes Hubble to
spin in the other direction.
The Science of HubbleIt is not even remotely
possible to cover all the science that Hubble has
done in a single presentation. Tens of thousands
of papers and hundreds of books have been written
based on HST data, and every day generates 20 GB
of data. Astronomers will be mining this resource
for generations to come.
Exceeding Expectations
  • It should be emphasized, however, that the chief
    contribution of such a radically new and more
    powerful instrument would be, not to supplement
    our present ideas of the universe we live in, but
    rather to uncover new phenomena not yet imagined,
    and perhaps modify profoundly our basic concepts
    of space and time. - Lyman Spitzer, Jr.
  • This mechanism has succeeded in opening the
    universe to us in ways never dreamed possible.

Petersen, Carolyn C. and Brandt, John C. Hubble
Vision Further Adventures with the Hubble Space
Telescope, 2nd ed., Cambridge University Press,
Cambridge UK
The Science of Hubble
  • Even before Hubble was launched, it had changed
    the science of astronomy. Because of its exacting
    pointing requirements, the Guide Star Catalog had
    to be created to allow its fine guidance sensors
    to be used to their full capacity. The GSC now
    contains almost a billion objects and is a
    valuable resource for astronomers worldwide.

First Light
  • First light images from Hubble showed that,
    even with the spherical aberration of the main
    mirror, good science could still be done. The
    image on the left is from a ground-based
    telescope the right is from Hubble.

A Busy Ten Years
  • In its first decade of operation, Hubble refined
    and reshaped our knowledge of Mars, Jupiter, star
    formation, globular clusters, black holes, and
    the age of the universe.
  • After only five years of 20/20 vision, Hubble
    had studied the atmosphere of Mars, imaged Venus,
    studied the weather of Jupiter, discovered new
    moons, studied comets and asteroids, mapped
    Pluto, and forever changed our picture of the
    Solar System.

Livio M. et al, eds, A Decade of Hubble Space
Telescope Science, Cambridge University Press,
Cambridge UK 2003. Petersen, Carolyn C. and
Brandt, John C. Hubble Vision Further Adventures
with the Hubble Space Telescope, 2nd ed.,
Cambridge University Press, Cambridge UK
Hubbles Top 10 Scientific Discoveries
  • Hubbles studies of supernovas helped to show the
    existence of dark energy
  • Determining the age of the universe
  • Snapshots of the early universe via the Hubble
    Deep Field Surveys (image seen here)
  • First direct measurement of an extrasolar
    planets atmosphere (further work is halted due
    to STIS failure)
  • Discovering black holes in the hearts of galaxies
  • Sources of gamma ray bursts the collapse of
    massive stars in distant galaxies
  • Showing that quasars are the hearts of distant
  • Showing that protoplanetary disks are common
  • The 1994 impacts of comet Shoemaker-Levy 9 on
  • Studies of planetary nebulae yielded more
    information on how stars die.

Handwerk, Brian, Hubble Space Telescope Turns
15, National Geographic, April 25, 2005, viewed
at http//
/0425_050425_hubble.html Interview with Dr. David
Leckrone, Goddard Space Flight Center, April
The Future?
  • HST Service Mission 4 is currently being studied
    if carried out, it will install batteries, gyros,
    one fine guidance sensor, and two new science
    instruments, repair STIS, and extend the
    telescopes lifespan by at least five years. One
    instrument, WFC3, would allow astronomers to
    measure the universes rate of expansion over
    time with unprecedented accuracy.
  • If SM4 is not carried out, Hubble is expected to
    shut down by 2008.
  • James Webb Space Telescope (JWST) is slated for
    launch in 2013. It is expected to have finer
    resolution and concentrate more on IR than HST.
    Hubble can detect faint IR smudges at the very
    edge of resolution JWST should be able to reveal
    what those smudges are (probably some of the very
    first stars and proto-galaxies to form.)

Interview with Dr. David Leckrone, Goddard Space
Flight Center, April 10, 2006
Funding and Economics
  • Hubble Large Space Telescope, Astronomical Price

Overview of an Overrun
  • Original budget 475 million
  • OTA 69.4 million
  • Actual cost In 1986, when it was first assembled
    for launch, it cost 1.6 billion, and had several
    technical problems. Four years of tinkering and
    improvements later, it is finally launched at
    2.2 billion (not counting the 0.5 billion for
    the launch!)
  • Percentage overrun 463

NASA MSFC engineering and construction GSFC scientific instruments and mission operations JSC launch and astronaut training Science Interests -STScI created to oversee the interests of the outside scientific community -AURA international group of 31 educational and nonprofit entities Contractors Lockheed SSM Perkin-Elmer OTA Secondary contractors almost two dozen companies throughout the aerospace industry
Costs Plus
  • Mirror discovered to have spherical aberration
    only seeing about 21 of the light it is supposed
  • SM-1 repaired faulty optics, replaced gyros,
    solar panels, and memory banks.
  • SM-2, SM3A, SM3B 0.5 billion plus
  • Proposed fifth mission 1.7-2.4 million (not
    counting 2.2 billion for Shuttle rehab)

Hubbles Policy, Legal, and International
RamificationsLessons Learned
Political incrementalism is reflected in studies
on congressional decision-making as it relates to
Big Science (large-scale) NASA programs like the
Hubble Space Telescope.
Astronomers in the mid-to-late 1970s were very
effective in using the growing pluralistic
political interest group, single-issue oriented
politics, to advance the development of the Space
Civil space officials formulate international
agreements with foreign officials, in part to
expand their base of support. An international
agreement with a foreign government provides a
layer of extra protection not afforded a pure
domestic program.
Some of the technology of the Hubble Space
Telescope was developed initially for satellite
reconnaissance programs of the DoD. It has been
suggested that the initial telescope problems
could have been mitigated had the DoD been more
forthcoming with NASA Marshall.
Today International Traffic in Arms Regulation
(ITAR) limits international cooperation through
exclusion or added burden of bureaucratic waiver
paperwork upon scientists working with
international space telescope projects.
Technology transfer issues remain a vexing
political and legal issue.
The Hubble Space Telescope
  • Management Operations

Early Years of the Program
  • After Apollo, NASA considered both MSFC GSFC to
    manage its proposed Large Telescope program.
  • GSFC had the scientific expertise MSFC more
    experience in managing a large program and had a
    large idle staff.
  • In 1971, NASA divides the program between the two
    centers causing rivalry and animosity that lasted
    for most of the program
  • NASA gave lead to Marshall in 1972, as well as
    too many responsibilities, making it, in effect a
    prime contractor (without the experience to be
    one), that led to serious management and
    technical problems.
  • By 1976, this rivalry threatened program, with
    Goddards role viewed as that of a
  • Rivalry abated when NASA threatened to give
    entire program to Marshall.

Marshall and the Associate Contractors
  • In 1977, Marshall chose Lockheed Martin to build
    the support craft and Lockheed in turn chose
    Perkin-Elmer for the mirror.
  • Marshall was wary of Perkin-Elmer because their
    low bid did not include proper testing of the
    mirror polishing computer program. This concern
    proved to be prophetic.
  • European Space Agency becomes partner in program
    to provide camera a solar panels in exchange for
    15 of observation time.
  • MSFC also prevented from sufficient staff and
    management penetration at PE due to its DoD work.
  • Once NASA removed personnel cap in 1979, Marshall
    took more active role at PE, it was too late to
    make changes.
  • Marshall had to step in to help finish the
    mirrors shaping as PE was over budget behind
    schedule. MSFC felt that PE was good at testing
    but nothing else.
  • By 1982, Marshall was increasingly dissatisfied
    with PE had to increase its own staff in
    Danbury because Perkin-Elmer lacked competent
    management and inadequate operating procedures.

More Problems and New Solution
  • Marshall fully managing at PE, better progress
    was made.
  • Management, scheduling and cost problems at
    Lockheed that Marshall had to rectify
  • Marshall finally informed NASA of the worsening
    situation at PE and NASA reports it to Congress.
  • Communications breakdown caused by NASAs lack of
    experience at managing multiple centers for same
    project and Marshalls naiveté in hoping problems
    would correct themselves.
  • Science community had lobbied for independent
    institute to operate telescope finally got their
    wish in 1981, with the establishment of the Space
    Telescope Science Institute, located on the
    campus of Johns Hopkins University.

Program Management Prior to Launch
Management and Operations Today
  • Hubble is operated on behalf of NASA by AURA (the
    Association of Universities for Research in
    Astronomy, Inc.), Goddard Space Flight Center and
    the European Space Agency.
  • Operations are monitored by staffers (including
    15 from the ESA) at both GSFC and STSI
  • STSI operates 24/7 it is manned in rotating
    shifts (3-4 at a time)
  • Operations are divided into Engineering and
    Science foci
  • Engineering responsibility is spacecraft
    performance. By communicating in real time,
    engineers are able to tell HST what to do and how
    to focus.
  • Science Operations encompass observation
    scheduling, science hardware, interpreting the
    raw data, as well as maintaining the data and
    disseminate the data to end users.
  • Dr. David Leckrone (lead STSI Hubble scientist)
    explained that there is an oversubscription of
    proposals (51 at present 81 before STIS
    failed) with no sign of lessening. To date HST
    viewings have generated over 5,000 science

Operations (continued)
  • Once images are taken, the data (more than
    several million bits daily are taken by HSTs
    high gain antennas) is returned to Earth several
    times a day.
  • The data is then sent as digital signal to White
    Sands, NM, the HST ground station via a TDRSS
  • The data then goes to GSFC for accuracy
    determinations either immediately or are stored
    on tapes for later review.
  • STSI gets the data next for processing and
    distribution to the requesting astronomer who has
    exclusive rights to the data for one year.
  • Each orbit lasts about 95 minutes, with scheduled
    downtime to allow for maintenance, repositioning,
    target acquisition, etc.

  • Conclusions and Lessons Learned
  • What does this investigation of Hubbles
    integrated evolution teach us?

Conclusions and Lessons Learned
  • Hubble has been a stunning scientific and
    technological success.
  • The LST/HST history can be described as an
    example of how not to conduct a large national
    science program. The contributing detrimental
    factors in its development can be summarized as
  • The sources of trouble were multiple, but the
    overarching problem was money. The promise of
    the program was great, but NASA did not believe
    it could ask Congress for the money MSFC had
    estimated the project would cost.
  • Competition was misplaced. In the case of NASAs
    management, the forced competition between two
    co-equal NASA centers was detrimental.
  • NASA was faced with the threat of having one or
    more centers closed this was one factor in the
    selection of MSFC as the lead.
  • The decision to use two associate contractors
    (not a prime with real authority to do systems
    management) was a critical error since MSFC did
    not have the resources to perform this function.
  • NASA HQ had too few people to watch over the
    program and left it to the field centers to
    manage until 1983. By then, the program was
    faced with intractable problems.
  • Congress was opposed to the project and key
    legislators fought it. We can learn from this
    that efforts to unrealistically limit a programs
    budget by forcing limits can, over time, force a
    program to cost more, not less.
  • An overestimation of the Space Shuttles
    capabilities was a factor.
  • The influence of the DoD in limiting NASA
    penetration of key contractors was a major factor
    which exacerbated the problem.
  • Perkin-Elmer was unqualified to handle the OTA.
  • NASA did a poor job of communicating not just
    within the program, but in effectively
    describing the potential value of the project.

Conclusions and Lessons Learned
  • On the positive side, we have also learned the
  • Large national space science programs do work,
    and can lead to enormous gains for the nation.
    More should be done to explain the
    accomplishments effectively.
  • Hubble demonstrated the idea of a National
    Facility, breaking from the paradigm of a single
    Principal Investigator.
  • The scientific community was a hero in the story
    of the HST
  • HST demonstrated that multiple countries can
    cooperate effectively on a major science program
    in space.
  • The role of astronaut servicing on orbit was
    validated by Hubble without it, we would not
    have this program. With it, we hav
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