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Elegant Connections in Physics
it will never forget. . . .
We watched the clock throughout that
Sunday, determined to be in front of a
television set at the time announced for the
astronauts to emerge from the LM. That
afternoon, watching in the basement of
my house with friends, and by extension,
watching with a fifth of the world’s population,
we beheld the ghostly black-andwhite
image of Neil Armstrong descending
the ladder in the shadow of the LM. He
paused on the spacecraft’s pod and said
“I’m going to step off the LM now. . . .”
As Neil Armstrong took the step that
no one had ever taken before, his words
were elegant in their simplicity: “That’s
one small step for a man, one giant leap
for mankind.” Eight years had elapsed
since President Kennedy’s challenge. It
took over 20 billion 1960s dollars spread
over that decade, and, as Armstrong
reminded everyone later, a “third of a
million people” to “manage it.”[11] But
the accomplishments in space during
those years will be remembered long after
their costs and the Cold War motives
that accelerated them have been buried
and forgotten.
Twenty-four Apollo astronauts
orbited the moon, and twelve walked
on its surface. So far they are the only
human beings to leave low-Earth orbit
and see with their own eyes the moon up
close and Earth from afar. The ten astronauts
who walked on the moon after
Apollo 11 stayed longer and went farther
and collected more data than Armstrong
and Aldrin, but even during the flight
of Apollo 12, many people from the
country who sent them did not even
bother to look up. We had been there,
done that. Apollo 13 captured much
interest because it came so close to ending
in tragedy. The remaining Apollo
flights were enormously successful.
The last moon mission was Apollo 17
in December 1972. By then the Nixon
administration had decided to cancel
Apollos 18, 19, and 20 to save money,
given the diminished public interest.
I suppose it is a property of human
nature that the amazing, when repeated,
becomes ordinary. Gus Grissom, before
his Mercury flight of July 21, 1961, said
after Alan Shepard’s flight, “There won’t
be this much fuss the next time. Once
you’ve seen one, you’ve seen ‘em all.”[12]
The moon landings presented NASA
with a hard act to follow. One wondered
what NASA would do next. Using
leftover Apollo hardware, we soon had
Skylab (1973–1979), where a Saturn
IVB stage was modified into an orbiting
laboratory. Then came Apollo-Soyuz
(July 1975), an encouraging gesture of
US/USSR cooperation that offered some
kind of benediction to the Cold War
Space Race, while showing what might
have been, and can be, for international
cooperation. Meanwhile, of course,
NASA engineers and managers had been
looking ahead.
The cost of expendable boosters and
modules makes unsustainable the practice
of depending on them for routine
access to space. For commuting to work
in orbit, a reusable vehicle would be essential.
Toward that end, the next longterm
program was the Space Shuttle.
The Space Shuttle
The shuttle program started in the late
1960s. Overshadowed by the anticipated
lunar landings, it received little attention
until the mid-1970s. As the Apollo
missions became routinely successful
and the public’s enthusiasm cooled for
watching astronauts pick up rocks, by
the early 1970s the public’s gaze shifted
to concerns closer to home. With an
unpopular war dragging on in Vietnam,
amid the push for civil rights and
concerns about poverty, pollution, and
a looming energy crisis, the American
public began asking what they were
getting for their money with yet another
visit to the moon. Even though NASA’s
budget was a small fraction of the
federal budget, should the expenditure
of NASA’s billions be directed to solving
problems here on Earth? Unlike the
Mercury, Gemini, and Apollo spacecraft,
each shuttle could be reused,
which looked like a better sale to a skeptical
public. The construction of the first
orbiter, the Columbia, began in 1974.
In September 1976 the public got a first
look at it. The Columbia and all other
shuttles had their origins in the X-1,
X-15, and X-20 rocket planes that were
developed from the late 1940s through
the 1960s.
Before the X-15 made its first flight
in 1959, the X-20 spaceplane was already
in the works. Also called the Dyna-Soar
for “dynamic soaring,” the X-20 was
the focus of an Air Force program to
develop a piloted delta-wing spaceplane
that could travel as high and as fast as
an intercontinental ballistic missile,
going into suborbital flight if necessary,
extending its range by skipping off the
upper atmosphere. It would return to
a landing strip in an unpowered glide.
Due to its high cost and questionable
usefulness, the X-20 program was
canceled in December 1963 before a first
prototype was built. However, in the
early 1970s NASA gave the X-20 drawings
new life as the Space Shuttle. Both
craft were delta-winged vehicles boosted
into orbit by large rockets, would glide
back to Earth and land on a runway like
an airplane, and do it all over again.
The shuttle program was formally
initiated on January 5, 1972, with an
announcement from President Nixon.
NASA originally envisioned a launch
schedule that would approach one
launch per week. Compromises were
eventually made from a fully reusable
design to one that featured reusable
orbiters and solid rocket boosters but an
expendable liquid fuel tank. Columbia’s
first flight occurred on April 12, 1981,
the 20th anniversary of Yuri Gagarin’s
first orbital flight.
The shuttle’s utility in putting
satellites and probes into orbit, such
as the Galileo mission to Jupiter and
the Hubble Space Telescope, are matters
of record and pride. Shuttles flew 135
missions. The tragedies on two of them,
with the losses of the crews aboard Challenger
and Columbia, sadly reminded
us yet again of how the high velocities,
extreme temperatures and pressures, and
the firepower on which one sits make
the exploration of space so dangerous an
adventure.
The shuttles made possible the
American contribution to the construction
of the International Space Station
Fall 2011 Radiations 23