Jason's Space Anniversaries Thread
Following the positive reactions to my earlier threads, I'm making a new thread for space-related anniversaries, which I will update with what I think are interesting events in space. If I did every launch and milestone there'll be a post every day, and you'll all get bored, so I'll restrict myself to significant events. Which brings me to....
On May 14th 1973 the Skylab space station was launched from Cape Canaveral. This was NASA's first orbital workshop, and would go on to provide some very useful data on the Earth and the Sun before a combination of delays in the shuttle program and unusually high solar activity resulted in a premature re-entry in July 1979 which saw parts of Australia showered with debris.
Skylab itself was a modified S-IVB rocket stage. The S-IVB had been used as the second stage on Saturn IB launch vehicles and the third stage of the Saturn V. It was the S-IVB, burning liquid hydrogen and liquid oxygen, that had provided the thrust needed to get the Apollo spacecraft to the Moon. For some years, the idea of draining a rocket stage and making use of the space inside had been kicking around in NASA, and for Skylab they did just that. The S-IVB is nearly seven metres in diameter and about eighteen metres long, offering quite a substantial volume for equipment and crew as a space station. Initial plans had been for the S-IVB to be used as a rocket stage, then purged of remaining fuel while in orbit, prior to later missions arriving to kit it out with equipment and crew facilities. The cancellation of Apollo missions 18-20, however, freed up a Saturn V launch vehicle, and the first two stages of that would be able to put the entire equipped station into orbit directly.
The launch took place on May 14th 1973, and trouble started almost immediately. During launch a solar panel and micrometeoroid shield section tore away, and once in orbit debris from these parts snagged the remaining main solar array and prevented it from deploying. Skylab was in orbit, but had only a fraction of its power available. Mission controllers were able to perform a delaicate balancing act to keep the equipment operating at minimal power, but they had another problem. The micrometeoroid shield layer was also a thermal shield, and without it the temperatures in the station began to soar. Mission controllers had to use the manoeuvring system to keep Skylab at attitudes that would allow the solar panels that had deployed to receive sunlight, but keep the station from overheating. Meanwhile, the first crew for Skylab had ten days before their scheduled launch to develop ways to rescue the station and make it habitable....
Skyklab was the final launch of a Saturn V, the remaining few vehicles becoming very expensive lawn ornaments that are still on display today. With the planned space shuttle in the making, NASA was forced to cancel production of the Saturn V in order to prevent it being competition for the shuttle. No contractor would want to take on a project like the shuttle knowing that there was another highly reliable vehicle available for heavy payload launches. The Saturn V was the most powerful launch vehicle ever made operational (the Russian N-1 booster was significantly more powerful, generating 10 million lb thrust compared to the Saturn V's 7.5 million lb at takeoff, but it never managed to launch successfully), as well as one of the most successul. It made 13 launches, and all 13 were complete successes. Its loss as an operational vehicle remains a technologically sad thing.