of its four folded arms did not swing
out properly and Kerwin expressed
dismay when he saw it had only
deployed to cover two-thirds of its
required area. “It’s not laid out the
way it’s supposed to be,” a dejected Conrad told Mission Control, as it
became clear that the parasol was
askew and somewhat crinkled.
Nevertheless, the ground team in
Houston assured the astronauts that
the wrinkles had probably set in during the coldness of the lengthy deployment, which took place during
orbital ‘night-time’, and, as the material heated up in sunlight, it would
spread out fully.
“I think the ground noticed the
temperatures coming down,” Weitz
recalled. “Within an hour, they
could tell.” Indeed, overnight on
26/27 May, the temperature on the
exterior of the workshop dropped
by 55°C and its interior by 11°C.
Eventually, the interior temperature
stabilised at around 30°C. However,
for the mission to survive and succeed, it was necessary to release
the jammed array, and soon, and
plans were set in motion for an EVA
on 7 June.
Since the airlock was right in the
middle of the Skylab cluster, with the
hatch to the workshop at its aft end
and a hatch to the station’s multiple docking adaptor and the command module at its forward end,
a fully-suited Weitz had to make
sure that Conrad and Kerwin had
all of their tools and tethers before
he depressurised them. Weitz then
retreated into the multiple docking
adaptor.
The hatch was opened at 10:23
a.m., just before the workshop entered the dark portion of its orbit.
Conrad assembled the tools – six 1.5
m rods were screwed together, the
cable cutter was fitted and several
metres of rope from the backup
SEVA sail were tied to the cutter’s
pull rope – and then he and Kerwin
moved into position alongside the
antenna boom. The unlikely contraption thus enabled them to operate the cutter from 8-9 m away…
just far enough from the airlock to
the jammed array.
As Kerwin tried to close the cut-
www.RocketSTEM.org
ters against the debris, it became
apparent that he was ‘slipping’,
because he was unable to establish a secure position for himself.
For half an hour or more, with one
hand steadying himself and the
other trying to close the cutters,
he struggled fruitlessly to complete
the work. As his pulse rate began
to climb, he decided on an alternative course of action and shortened his own tether, in an effort to
steady himself against the edge of
the workshop. It worked and after
ten minutes or so he was able to tell
ground controllers in Houston that
the cutters were now securely fastened to the debris. Next, he pulled
on the lanyard to operate them…
and nothing happened.
Conrad made his way, handover-hand, along the length of the
beam to see what was amiss, and
precisely as he reached the cutter
‘end’, the jaws snapped shut, freeing some of the metal strap at 2:01
p.m. and hurling the commander
into space. Fortunately, his tether
restrained him from moving far from
Skylab, and the jammed array now
stood at 20-degrees-open.
The frozen damper, however, still
resisted normal deployment and
the holes on the solar array were
smaller than on the ground model.
The two men heaved, without success, until Conrad placed his feet
on the frozen hinge, stooped to fit
the tether over his shoulder and
‘stood up’. Kerwin pulled on the
tether and, this time, the solar array
suddenly released and sprang into
its full, 90-degrees-open position.
Both astronauts were flung outwards by the catapult-like effect
and arrested by their tethers.
Inside Skylab, the needles of
the electricity meters dramatically
jumped, signalling success. By the
next day, 8 June, solar heating had
fully extended the array and it was
generating no less than 7 kW of
much-needed power. From just 40
percent power, the station’s output
suddenly increased to around 70
percent. Against all the odds, Skylab’s fortunes had been snatched
from the gaping jaws of defeat. The
mission was underway.
MISSIONS
continued from page 37
to the point of exhaustion,
the mission was enormously
successful, performing observations of Comet Kohoutek and
several spacewalks.
Skylab 5
At one stage, it was possible
that a fourth crew of Vance
Brand (Commander), Bill Lenoir
(Science Pilot) and Don Lind
(Pilot) may have flown a short,
21-day mission to finish up some
final experiments aboard Skylab.
However, when Skylab 4 was
extended from 56 to 84 days, this
mission became unnecessary.
STS-3
One of the early plans for the
Shuttle was to visit and re-boost
Skylab into a higher orbit. On the
third Shuttle mission, astronauts
Fred Haise (Commander) and
Jack Lousma (Pilot) would have
transported a system to dock
with Skylab and save it from a
fiery re-entry. It was hoped that
the Shuttle might enable a new
series of Skylab missions in the
1980s. However, solar activity
caused Skylab to descend to
Earth faster than expected, the
Shuttle was delayed and the
mission was cancelled. Skylab
burned up in the atmosphere in
July 1979.
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