“Get your ticket to that wheel in space.”
Lyrics from I.G.Y. by Donald Fagen
Background
In popular Science Fiction space stations were a common theme. Arthur C. Clarke and other early advocates of manned space flight believed that a station orbiting the earth would be required for communications, weather forecasting and military observations. In six vignettes written by Clarke in the 1950’s, he envisioned along with Werner Von Braun a large, circular station 250 feet (75m) in diameter that would rotate to generate artificial gravity. The crew aboard the station would include astronomers, meteorologists, broadcasters and soldiers to conduct surveillance. It was expected that future expeditions to the solar system would leave from the station.
What was not anticipated during the mid ‘50s was the development of the transistor, the solar cell, and telemetry, that led to satellites that could take photographs of weather patterns or enemy weapons. A large station was no longer necessary for such purposes, as small unmanned satellites would perform these missions. Additionally, the Apollo moon mission would not require in-orbit assembly. A smaller station that a single rocket could launch retained value, however, for scientific purposes.
Meanwhile, The U.S. Air Force decided that it wanted its own crewed facility. In December 1963 it announced the Manned Orbital Laboratory (MOL), a small space station primarily intended for photo reconnaissance using large telescopes directed by a two-person crew. The station was the same diameter as a Titan II upper stage, and would be launched with the crew riding atop in a modified Gemini capsule with a hatch cut into the heat shield on the bottom of the capsule. MOL was eventually cancelled in favor of a NASA program.
Apollo Applications Program
Way before the first lunar landing mission, NASA was concerned as to what would happen to the 400,000 program employees dedicated to the moon program. Von Braun, head of NASA’s Marshall Space Flight Center advocated for a small space station that he wished to provide his employees with work beyond developing the Saturn rockets. NASA set up the Apollo Logistic Support System Office, originally intended to study various ways to modify the Apollo hardware for scientific missions. The office initially proposed a number of projects for direct scientific study, including an extended-stay lunar mission and a large crewed solar telescope. Although it did not look at the space station specifically, over the next two years the office would become increasingly dedicated to this role. In August 1965, the office was renamed, becoming the Apollo Applications Program (AAP).
As part of their general work, in August 1964 the Manned Spacecraft Center (MSC) presented studies on an expendable lab known as Apollo “X”, short for Apollo Extension System. “Apollo X” would have replaced the LEM carried on the top of the S-IVB stage with a small space station slightly larger than the Command Service Module’s (CSM) service area. It would contain supplies and experiments for missions between 15 and 45 days’ duration. Using this study as a baseline, a number of different mission profiles were looked at over the next six months.
Completion and Launch
On August 8, 1969, the McDonnell Douglas Corporation received a contract for the conversion of two existing S-IVB stages to the Orbital Workshop configuration. The Orbital Workshop was renamed “Skylab” in February 1970. A Saturn V originally produced for the Apollo program was repurposed and redesigned to launch Skylab which replaced the third stage. The Orbital Workshop was large, it weighed about 91 thousand kilograms with the Apollo CSM docked and had 350 cubic meters volume. This is in contrast to the Soviet Salyut, which launched in April of 1971 and was a third of the volume of the Skylab and about 20% of its weight. Two Skylab’s were built with Skylab-B on display at the Smithsonian.
Problems at Launch, Solutions in Orbit
America’s first space station launched on May 14, 1973, with severe damage sustained during launch and deployment. This damage included the loss of the station’s micrometeoroid shield/sun shade and one of its main solar panels. Debris from the lost shield became tangled in the remaining solar panel, preventing its full deployment and thus leaving the station with a huge power deficit.
NASA delayed the launch SL-2 and the first crew, Commander Charles “Pete” Conrad, Pilot Paul J. Weitz, and Science Pilot Joseph P. Kerwin, by 10 days to allow managers and engineers to develop plans to save the station. Repair procedures were tested on the ground and tools were loaded into the Command Module shortly before the crew’s launch. After a successful launch on May 25 and rendezvous with Skylab the crew deployed a parasol that brought internal temperatures down to comfortable levels and they began their science experiments. But the lack of power from the missing and jammed solar arrays curtailed their activities.
Attention turned to freeing the jammed solar array. In the Neutral Buoyancy Simulator at Marshall Space Flight Center, techniques were developed that would be used during a spacewalk. On June 7, 1973, the SL-2 astronauts including Pete Conrad and Joe Kerwin floated out of Skylab’s Airlock Module. They set up a 25-foot pole with a cable cutter tool at the end that closed partway over the aluminum strap from the micrometeoroid shield that was holding down the solar array. Conrad used the pole as a handhold and attached a rope to its structure. Kerwin closed the jaws on the cutter tool slicing through the metal strap. The solar wing partially opened, but its hinge had frozen preventing it from fully opening. Conrad and Kerwin then both pulled on the rope to overcome the frozen hinge and the wing sprung fully open. Once the wing opened, the individual solar panels deployed and Mission Control notified the crew that they were generating power.
Mission Goals
Skylab was considered successful because it completed experiments in the following areas – advanced space science applications in medicine, technology, space operations including extended stays, earth resources and general science. Research in x-ray stellar observation eventually led to a Nobel in Physics being awarded in 2002 to Riccardo Giacconi, whose research was based on initial Skylab findings. The birth of the field of x-ray astronomy can be traced back to these studies conducted onboard Skylab.
The Problems with NASA
The space station known as Skylab was designed as an orbiting workshop for research on scientific matters and represented the next step toward wider space exploration. Unfortunately, Skylab was made to go up but not to come back down. Even though Skylab was devised for a nine-year lifespan, NASA failed to build in any control or navigation mechanisms to manage its orbit as well as to safely guide the orbiter to a safe reentry area. NASA administrator Robert Frosch said at the time providing this capability would have “cost too much”. This lack of preparation presented a problem in late 1978, when NASA engineers discovered the station’s orbit was decaying rapidly.
Station De-Orbit
The plan NASA relied on to stabilize the stations orbit was the Shuttle. However, bureaucratic in-fighting, lack of funding and quality problems continually pushed the launch of the Shuttle Orbiter beyond any date with the hope of stabilizing Skylab’s orbit. The best NASA could do was on July 11, 1979, when a burn was executed using the the station’s booster rockets, sending it into a tumble which NASA hoped would bring it down in the Indian Ocean. They were close. While large chunks did go into the ocean, parts of the space station also littered populated areas of western Australia. Fortunately, no one was injured.
Lessons Learned From The Program
Skylab was built with a 9 year mission life, so why was it abandoned and allowed to reenter after only six years of operation?
Over reliance on a technology not yet completed, the Space Shuttle. The Shuttle was supposed to fly new crews to the Workshop as well as provide stabilization to Skylab’s orbit. As noted above, the mismanagement of the Shuttle program led to Skylab’s demise. More importantly, NASA did not have a plan “B” which could have been implemented to save the Station.
Lack of onboard navigation or other control systems to manage the space craft’s orbit.
Body of knowledge on the effects of the solar cycle on earth’s atmosphere were still being developed and understood. Solar cycle #21 minimum began in 1976, with the max beginning 1979. During that time, additional solar activity could have affected the atmosphere, causing it to expand and increase drag on Skylab, leading to an unexpected orbit degradation.
NASA had to find a mission after Apollo, especially after cancellation of the final three moon flights. Skylab was one that used hardware already built, utilized an infrastructure and personnel experienced in managing space flight. It appeared to be a win for everyone, except that NASA failed to include the biggest risk, the Space Shuttle not being delivered on-time.
Summary
Skylab was the first United States space station, launched by NASA and occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate crews, the first SL-2 spending 28 days in orbit. SL-3 spent 59 days, with the crew of SL-4 shattering all duration records staying on board Skylab for 84 days. SL-4 was the last crew leaving in February 1974.
Major operations included an orbital workshop, a solar observatory, Earth observation, and hundreds of experiments.
Unable to be boosted by the Space Shuttle, which was not ready until the early 1980s, Skylab’s orbit decayed and it burned up in the atmosphere on July 11, 1979, over the Indian Ocean.
The International Space Station has replaced both the now Russian and United States space station programs and is expected to remain operational until 2024 when NASA is currently planning to end its support. With or without NASA, the 20-year-old station is approaching the end of its lifetime. The good news is, rather than abandoning the aging laboratory, NASA is transitioning the station’s operations to the private sector to stimulate the development of a low-Earth-orbit economy.
About The Author
Carl Rossi
Contributing author to http://WestEastSpace.com
The author is a retired Supply Chain/Logistics expert currently living in central Texas, USA. His passions include space exploration and fast sports cars. While his passion for fast sports cars has been satisfied, space exploration remains a burning ambition.
Carl Rossi holds an MBA in International Business and has been certified in Supply Chain Management, Logistics and Transportation by world wide industry organizations. He has been responsible for managing operations globally and has travelled extensively throughout Europe and Asia.
Retirement has allowed the author the opportunity to follow space extensively while also producing programs for community radio stations in Georgetown and Killeen, Texas. These shows can be heard online as well – Freeform on http://radiogeorgetown.org, Wednesdays at 6:00 PM central US time or 2300 hrs UTC; The Softer Side can be heard on http://knct.org anytime on demand.
