Marshall's Role
in SKYLAB
Skylab's 3 different three-man crews spent up to 84 days in
Earth orbit and performed a variety of more than 100 experiments.
In addition to providing the four Saturn launch vehicles, the Marshall
Center was also responsible for directing many of the experiments.
The idea of an orbiting space station had occupied
the minds of science fiction writers and space flight enthusiasts
for years. Dr. Von Braun envisioned a laboratory in space in a
series of articles in Collier's Magazine in the early 1950s.
By 1962 NASA was seriously considering various space station concepts
for long-duration Earth-orbital missions, and by August 1965 the
agency created the Apollo Applications Office, moving America
closer to plans for a space station like Skylab. MSFC focused
on designs for a S-IVB orbital workshop where the astronauts could
live and conduct scientific experiments. On December 1, 1965,
George E. Mueller, Associate Administrator for Manned Space Flight,
met with Dr. Von Braun to discuss the Center's concept for
the orbital workshop. Mueller asked him to formulate a program
development plan for the Manned Space Flight Management Council.
In effect, historians later wrote, Mueller gave Marshall the "green
light" to begin the orbital workshop program, later called
Skylab.
In the years that followed, the Marshall Center worked
closely with McDonnell Douglas, the prime contractor for the workshop
unit, to convert a Saturn IB stage into a habitable module containing
living quarters and support systems as well as experiment areas.
Skylab Progress at MSFC
An underwater test program at MSFC's Neutral
Buoyancy Simulator provided essential information that Skylab designers
needed. Astronauts, technicians, design engineers, and professional
divers in spacesuits and scuba gear conducted tasks similar to those
necessary to activate the space orbiting workshop. The tasks were
performed in the 1.4 million gallon water tank containing mockups
of the Skylab cluster elements. In 1969 Astronauts Edward Gibson,
Joseph Kerwin, and Paul Weitz worked inside the NBS at MSFC, maneuvering
inside and around a full-scale replica of an Apollo Telescope Mount
and Saturn workshop. The Center also supported the Skylab hardware
development effort by creating a one-g "shirtsleeve" mockup
in building 4619 for detailed engineering simulations and analysis.
Marshall engineers tackled the problems of zero-gravity showers,
toilets, sleeping bags, exercise equipment and kitchen facilities.
They were also involved in developing and selecting materials used
in the crew quarters and as protective thermal coating.
Skylab Components
An airlock module attached to the forward end of the workshop would
enable crew members to make excursions outside the Skylab. McDonnell
Douglas fabricated the module with close Marshall involvement in
design, development, and test activities.
A docking adapter, attached to the forward end of the airlock module,
would provide the docking port for the Apollo command and service
module. Marshall designed and built the structure for this unit.
The Apollo Telescope Mount would be the first manned astronomical
observatory designed for solar research from earth orbit. Marshall
built some of the parts for the mount in-house and worked closely with
several contractors to develop a very precise attitude control and
pointing system that served the telescope and the entire Skylab
cluster. The Center provided a simulation facility for tests of the
attitude pointing control system hardware and software for real-time
mission support. Marshall also supervised systems integration of the
observatory and its instruments.
On November 2, 1971, as Skylab flight hardware manufacturing was
nearing completion, NASA Administrator Dr. James C. Fletcher approved
the Skylab Student Project, a joint effort between NASA and the
National Science Teachers Association. MSFC would be the NASA
interface with the students. The student experiments would be added to
the list of MSFC Skylab investigations in materials processing in
space and solar physics. MSFC also designed and built a series of
Skylab biomedical experiments. These included the metabolic analyzer,
the bicycle ergometer, the lower body negative pressure device, and
the experiment support system.
As the Skylab launch date approached, MSFC personnel moved into the
Huntsville Operations Support Center (HOSC) for real-time flight
support. Mission task centers were set up in Marshall's
laboratories to assist the HOSC team in resolving any problems that
might occur in flight. During the three manned periods, these support
groups were fully staffed for around-the-clock operations; in the
unmanned intervals, a skeleton staff maintained watch.
Repairing Skylab
The Skylab Workshop/Apollo Telescope Mount combination was launched
by a Saturn V on May 14, 1973. NASA had planned to launch the first
of three Skylab crews the following day. Unfortunately, trouble
began approximately 63 seconds after the May 14 launch. A huge panel
protecting the orbital workshop from micrometeorites and solar radiation
ripped off. Adding to the trouble, one of the solar arrays for the
workshop was torn away and a second array was only partially deployed.
The solar arrays were designed to provide electrical power to the
orbital workshop. The solar arrays for the Apollo Telescope Mount
remained intact.
After the micrometeoroid panel ripped off, the air temperature inside
the workshop soon began approaching 130 degrees F. Engineers from
Marshall and throughout NASA were concerned about the condition
of food, film, and other equipment inside Skylab. They were also
worried about plastic insulation material inside the workshop and
possible toxic gases if the temperatures rose too high.
Skylab -- seriously overheating -- was maneuvered through varying
nose-up attitudes that would best maintain an acceptable "holding
condition." During that 10-day period and for some time
thereafter, the space station operated on less than half of its
designed electrical system which, in the partially nose-up attitudes,
was generating power at reduced efficiency. All this meant one
thing---the first manned Skylab launch scheduled for May 15 would be
delayed until methods could be devised to repair and salvage the
workshop. Teams at Marshall and other NASA centers that had put years
of planning into Skylab began work quickly to save it. A
trouble-shooting team was formed in the Huntsville Operations Support
Center from existing support teams. Other space center and industry
personnel joined those already in Huntsville where some personnel did
not leave their posts from dawn Monday through Wednesday night. The
assembled group ranged from design, materials, manufacturing, and
simulation specialists from Marshall to procedures and stowage
personnel from JSC. Also present were sail-making seamstresses with
their stitching machines from New Jersey and the astronauts with a
command module simulator flown in from Houston.
Over the next several days, Marshall considered a variety of repair
options. Eventually three methods were developed, tested, rehearsed,
and approved. Marshall was intensely involved in all three, a parasol
sunshade, a twin-pole sunshade, and a set of metal cutting tools for
freeing the jammed solar array. MSFC, however, had the lead role in
developing the twin pole sunshade and the tools. Skylab 2 astronauts
Charles Conrad and Joe Kerwin arrived at the Marshall Center from
Kennedy Space Center to test solutions as they were developed and to
practice in Marshall's Neutral Buoyancy Simulator. At the Kennedy
Space Center, the astronauts' Saturn IB was kept on immediate
standby to carry the rescuers and their equipment to the Skylab space
station.
The First Manned Mission
At 8:00 a.m. on May 25, Skylab 2 was launched from the Kennedy Space
Center with Astronauts Conrad, Kerwin and Paul Weitz headed toward the
Skylab I Workshop that they hoped to repair in orbit. The rendezvous
occurred at 3:30 that afternoon. On the following day, May 26, the
crew began to deploy the solar parasol -- a mylar shade folded against
a telescopic pole -- through the solar airlock.
Temperatures began to drop and the crew began to activate the new
space station which was safe and contamination free. On June 7 the
astronauts, working outside of Skylab, used a technique developed at
Marshall to successfully cut the strap that had prevented deployment
of the remaining solar array.
As a result of the repair efforts, the mission continued. The
astronauts gathered data on some 80 percent of the planned solar
experiments. They also achieved a major scientific accomplishment,
monitoring a solar flare. They completed 11 of 14 planned Earth
resources data runs and conducted a total of 16 medical experiments.
The astronauts gathered data from five student investigations while
two others were rescheduled for the second mission. The first manned
Skylab crew splashed down June 22, 1973.
The Second Manned Mission
The second manned Skylab crew was launched on July 28, 1973. In
addition to continuing the Skylab science program, the crew had to
replace the parasol sunshade with the Marshall sail when the
temperature inside the workshop started rising again. On August 6,
with Astronaut Alan Bean standing by inside the workshop, Astronauts
Owen Garriott, and Jack Lousma exited the Skylab space station and
successfully erected the Marshall twin-pole solar shield.
By the tenth day of the mission, the crew was putting in about 19 man
hours a day on scientific experiments, but a week to 10 days later
they were doing 27 to 30 man hours of experiments each day. Although
26 Earth resources experiment passes had been planned, 39 were
actually accomplished. In addition, some 206 hours of solar viewing
had been planned while 305 were logged. The medical experiments had
included 327 planned runs while 333 were accomplished. The mission
also included the first orbital demonstration of astronaut maneuvering
equipment and orbited a pair of common spiders, Arabella and Anita, to
determine their ability to spin a web without the influence of
gravity, one of the Skylab student experiments coordinated by the
Marshall Center.
The Third Manned Mission
The second manned Skylab mission ended September 25, 1973, after 59
days in space. A Saturn IB carrying the third Skylab crew lifted off
November 16, 1973. Astronauts Gerald P. Carr, Edward G. Gibson and
William R. Pogue continued the Skylab in-flight experiment program,
including four EVAs and the observation and documentation of the newly
discovered Comet Kohoutek. The third crew also served as the source
for important new medical data on how man reacts to weightlessness in
space. Their mission ended February 8, 1974, setting a new endurance
record and reflecting man's ability to live and work in space for
extended periods of time.
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