The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

descent module to hold three spacesuited cosmonauts.
It also carried solar panels—a feature of early
Soyuz spacecraft that had been dispensed with after
Soyuz 11 to save weight—enabling the vehicle to function
independently of Salyut for up to four days.
Soyuz TM
A modernized version of the T with improved power
supplies, new parachutes, and extra space for equip-
space cannon
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than rocket fuel. Cannon projectiles are accurate, thanks
to the fixed geometry of the gun barrel, and are much
simpler and cheaper than rockets. However, there are also
serious drawbacks. The payload must be slender enough
to fit into a gun barrel and sturdy enough to withstand
the huge accelerations of launch, which can easily exceed
10,000g.
Long before the first test flights of the V-2 (see “V”
weapons), the Paris Gun of World War I set impressive
altitude and speed records for artificial objects. In the
1950s, as the rocket became established as the primary
means of reaching space, the Canadian engineer Gerald
Bull began a lifelong struggle to use guns for cheap access
to the high atmosphere and Earth orbit. His HARP
(High Altitude Research Project) in the 1960s showed
that a suborbital cannon can be cost-effective for studying
the upper atmosphere, between 50 km and 130 km,
and has the potential to launch vast numbers of satellites
each year in all kinds of weather. A further development
of this concept was Lawrence Livermore Lab’s SHARP
(Super High Altitude Research Project).
Even if shot out of an extremely powerful cannon, a
projectile would need to include a rocket in order to
enter a stable orbit. This is for two reasons. First, reaching
orbital velocity (with an extra margin for air resistance) is
difficult using a cannon alone. Second, by Kepler’s first
law, any orbit is an ellipse with one focus at the Earth’s
center. If the payload is launched from a point A on the
Earth’s surface, its orbit necessarily would intersect the
surface again at a symmetrically placed point B. An
orbital adjustment is therefore essential.
Plans also exist for accelerating a payload by magnetic
forces on a “rail gun” consisting of parallel conductors,
into which a very large electric current is directed. The
same problems apply here, plus the added one of storing
and then suddenly releasing a great amount of electrical
space colony 389
ment. It can carry an extra 200 kg into orbit and return
up to 150 kg to Earth—100 kg more than Soyuz T. First
used with Mir, it remains in service ferrying cosmonauts,
astronauts, and freight to and from the ISS.
Soyuz TMA
A version of the Soyuz spacecraft specially adapted to
serve as a lifeboat for crew return to Earth in the event
of an emergency aboard the ISS. See ACRV.
energy. This kind of technology might be appropriate for
future use on the Moon but is at an even earlier stage
than the space cannon. See Valier-Oberth Moon gun.
space colony
A large, self-contained, artificial environment in space,
also known as a space habitat, which is the permanent
home of an entire community. The first fictional account
of a space colony appears in 1869, in Edward Everett
Hale’s novel The Brick Moon. 140 Other early portrayals of
the idea are to be found in novels by Jules Verne in 1878
and Kurd Lasswitz in 1897. In the 1920s, J. D. Bernal
described spherical colonies that have come to be known
as Bernal spheres. 25 The companion idea of mobile
colonies, or generation starships, that could carry large
numbers of people relatively slowly to other stars was
envisioned in 1918 by Robert Goddard. 114 A vastly more
ambitious scheme for completely encircling a star with
artificial habitats was described by Freeman Dyson 83 in
the 1960s. Indeed, the development of concepts about
space colonies is deeply entwined with evolving notions
about the colonization of other worlds, terraforming,
and space stations. When does a space station become a
space colony? In his 1952 novel, Islands in the Sky, 53
Arthur C. Clarke depicts structures that are somewhere
between the two, while by 1961, in A Fall of Moondust, 54
he has moved on to even larger structures placed at the
stable Lagrangian points in Earth’s orbit where they
would remain fixed relative to both Earth and the Moon.
In 1956, Darrell Romick advanced a yet more ambitious
proposal for a rotating cylinder 1 km long and 300 m in
diameter that would be home to 20,000 people. In 1963,
Dandridge Cole suggested hollowing out an ellipsoidal
asteroid about 30 km long, rotating it about the major
axis to simulate gravity, reflecting sunlight inside with
mirrors, and creating on the inner shell a pastoral setting
as a permanent habitat for a colony. Related ideas, about
the use of extraterrestrial resources to manufacture