October 2016 - Skylab: Science in Space
Members of the Horndean & District U3A met for their regular monthly meeting on Friday 7th October at Merchistoun Hall where they learnt about the world’s first successful space station from Professor Mike Whittle who had supervised six experiments carried out on the station from the ground in Houston, Texas in his talk titled "Skylab (1973-4) Science & Medicine in Space."
Skylab was the United States' first space station following Russia’s unsuccessful attempt to put a laboratory in Space. It was launched into orbit in May 1973 by the modified Saturn V rocket following which the astronauts were transported to the space station by three manned expeditions by the Saturn 1B rocket between May 1973 and February 1974. Disaster hit the launch of Skylab when a heat shield and solar panel were torn away by the wind speed and the other main solar panel was jammed so that it could not unfold. This meant Skylab lost most of its electrical power as well protection from the intense solar heat. Fortunately, the first crew was able to deploy a replacement heat shade and release the jammed solar panel by cutting a metal strut using a bone saw from the medical kit and then pulling the panel free using rope and the heat of the sun to melt the ice. This was the first time a major repair had been carried out in space.
Skylab did not have the same weight restrictions as previous missions, which meant that it could have a freezer so that more varied food was available, and instead of having to wash with a flannel as in the past, astronauts could take a shower, although they were limited to one litre of water. A centrifuge and vacuum system enabled the shower to work in zero gravity and the whole process took about an hour, as everything had to be dried thoroughly to prevent it from going mouldy. Vacuum systems were also used with electric razors and the toilet which also included a dehydration process.
The astronauts were test pilots and they allegedly believed that the best way to counter space sickness was to do a lot of aerobatics before the mission. This was questioned by many people who thought that the pilots were simply using it as an excuse to put aircraft through their paces! A number of superstitions also determine what astronauts do in preparation for the launch, including being transported to the launch rocket in an old white van.
Weightlessness created a number of challenges for the astronauts on Skylab, which needed to be addressed by space craft engineering. To do anything you need to be fixed to the floor, as simply pressing a pencil against paper would send you across the room. A manoeuvring unit enabled the astronauts to move around the craft although the nitrogen jet that propelled it was difficult to use with any precision. An unplanned benefit of the air circulation system was that it was impossible to lose anything, as it would be blown toward the extraction vent where it would be found on the grill.
The astronauts carried out more experiments than originally planned. Major experiments included solar astronomy, which produced virtually everything we know about the sun. Cardiovascular function looked at the distribution of fluid in the body, and vestibular and cardiopulmonary experiments looked at space sickness and developed a device to measure blood pressure. Tests on mineral balance compared what the astronauts ate with the waste they produced. It also measured how much calcium they lost from different parts of their anatomy because of the way the body gets rid of it in a weightless environment as it thinks that strong bones are less important. It has been concluded that nine months is the maximum time someone should be in zero gravity because of the damage calcium loss causes to the skeleton, particularly the heel bone which is normally under stress but less so the wrist which is not.
High School experiments suggested by schools included finding out if a spider could spin a web in space, which it could although it took it time for it to perfect the initially chaotic structure of the web. Unexpectedly, it is possible to establish the weight of something in space, by bouncing it on a spring. This meant that uneaten food could be weighed to measure how much astronauts have eaten.
Mission Control had fifty people involved in a flight at any time, which had its benefits and its problems. The positive aspect was that all of these people were available to find a solution to a major problem, but they were underused when things ran smoothly so that a minor issue that required a quick answer was over-analysed and the solution was delayed as a result.
Skylab came down in 1979 landing mainly in the ocean although some debris came down in Australian desert southeast of Perth. Mike Whittle went on three recovery ships to the splash down sites to pick up the crew. As the modules can float either way up, they use balloons to turn them over as necessary. One conflict when the astronauts returned to earth was between Mission Control’s wish for them to be tested for the effects of weightlessness at once and NASA’s wish for them to walk around and wave to the public.
At the end of this fascinating and well-illustrated Talk, Geoff Smith struggled to pick out just a few of the numerous pieces of information about the mission and all that it achieved to include in his vote of thanks.
Andy Forbes