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light, doing much to raise
awareness of the advantages
of space-based astronomy.
Spitzer’s LST aimed to achieve
more dramatic results than the
OAO-2, observing near and far
objects with the visible light
spectrum. His team settled on a
10-ft 5-in (3-m) reflecting telescope
and a launch was scheduled for
- However, the project became
too expensive for its budget. The
aperture was reduced to a less
costly 100 in (2.4 m), and LST was
postponed to 1983. As that year
came and went, no launch occurred,
but Spitzer persisted and the project
continued. In the meantime, LST
was renamed the Hubble Space
Telescope (HST) after Edwin Hubble,
who had first grasped the true scale
of the universe (pp.172–77). By now,
the telescope’s mirrors had been
constructed. To help reduce weight,
a top layer of low-expansion glass
sat on a honeycomb support. The
shape of the mirrors was crucial.
During construction, they were
held on a support that emulated
weightlessness to ensure they
did not warp in space. The glass
had to be polished into a curve
with an accuracy of 10 nanometers.
This would make it possible for
HST to view everything from
UV light to the upper end of the
infrared spectrum.
Further delays pushed the
launch of HST to 1986, but then
tragedy struck with the explosionATOMS, STARS, AND GALAXIES
of Space Shuttle Challenger on
January 28, 1986, with the result
that NASA’s shuttle fleet was
grounded for two years.
Finally, on April 24, 1990,
Space Shuttle Discovery hauled
the 11-ton HST to its orbit
335 miles (540 km) above Earth.
Spitzer had finally realized the
dream of his career—a telescope
in space unencumbered by the
problems of poor seeing and an
atmosphere partly opaque to
ultraviolet and infrared rays.Hubble trouble
The problems that had beset the
mission on the ground, however,
continued in space. The first
images sent back by HST were
so badly distorted that they were
almost worthless. Was HST going
to be a worse observational tool
than a ground-based telescope? ❯❯The Hubble Space Telescope is
the realization of Spitzer’s vision. It
remains one of the finest scientific
instruments ever made.
A machine polishes the Hubble’s
mirror. Its 100-in (2.4-m) aperture may
seem small today, yet it is the same
size as the Hooker Telescope, which was
the world’s largest telescope until 1948.