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A Telescope in Space?
In 1923, German scientist Hermann Oberth, one of the three fathers
of modern rocketry (Oberth, Robert Goddard and Konstantin Tsiolkovsky),
published "Die Rakete zu den Planetenraumen" ("The
Rocket into Planetary Space"), which mentioned how a telescope
could be propelled into Earth orbit by a rocket. In 1946, Princeton
astrophysicist Lyman Spitzer (see image on left)
wrote about the scientific benefits of a telescope in space, above
Earth's turbulent atmosphere.
Following the launch of the Soviet satellite Sputnik in 1957, the
fledgling National Aeronautics and Space Administration (NASA) successfully
launched two Orbital Astronomical Observatories (OAOs) into orbit.
They made a number of ultraviolet observations and provided learning
experiences for the manufacture and launch of future space observatories.
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The LST - Large Space Telescope
Meanwhile, scientific, governmental, and industrial groups planned
the next step beyond the OAO program. Spitzer gathered the support
of other astronomers for a "large orbital telescope" and addressed
the concerns of its critics. In 1969, the National Academy of Sciences
gave its approval for the Large Space Telescope (LST) project, and
the hearings and feasibility studies continued.
After Armstrong's "giant leap for mankind" on the moon in 1969, funding
for NASA space programs began to dwindle, putting the LST program
in jeopardy. LST planners had to design the telescope under budget
constraints. A number of downsizing measures were weighed and considered:
decrease the size of the primary mirror, the number of scientific
instruments, the diameter of the Systems Support Module and the number
of spare parts created and tests performed. In 1974, the LST Science
Working Group recommended the space telescope carry a large complement
of interchangeable instruments. They would have specifications to
resolve at least one-tenth of an arcsecond, and have a wavelength
range from ultraviolet through visible to infrared light.
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The Space Shuttle
NASA and its industrial partners—called contractors—brought
up the option of developing a vehicle that could achieve orbit and
return to earth intact and be reused repeatedly; the concept of the
Space Shuttle was born. The Space Shuttle could deploy the LST into
space and reel it back for return to Earth. The shuttle could, and
would, be used for a myriad of other operations for the space program
as well.
NASA suggested that the lifetime of the space telescope be fifteen
years, which implied that the instruments needed the ability to be
replaced on the ground or even serviced in orbit—an ability
not afforded to any satellite before or since. Scientists also had
to balance the size and quantity of scientific instruments versus
their cost. Too many instruments meant financial support was less
likely; conversely, instruments of minimal capability would result
in the loss of scientific support for the telescope. The European
Space Agency (ESA) joined the project in 1975 and provided fifteen
percent of the funding of the LST via contribution of the Faint Object
Camera (FOC) and the solar arrays. In return, NASA guaranteed at least
fifteen percent of telescope time—the amount of time astronomers
use the telescope for space observations—to European astronomers.
In 1977, Congress approved funding to build one of the most sophisticated
satellites ever constructed.
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