Skylab reboost concept art

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After the Skylab 4 crew returned to Earth in February 1974, NASA had no further plans for the space station and shut down its systems. Prior to undocking, the crew had used the engine of their Apollo spacecraft to nudge Skylab into a higher orbit, roughly 440 km above the Earth. However, even at this height, the Earth’s atmosphere is dense enough to exert significant drag on a satellite. A period of increased solar activity in the 1970s made this situation worse for Skylab. This activity caused the density of the atmosphere at Skylab’s altitude to increase, and therefore the drag on the station to increase in proportion.

Based on measurements taken during the Skylab missions, NASA predicted that the station would remain in orbit another nine years, re-entering Earth’s atmosphere sometime in 1983.

Doomed if left where it was, the station still represented a valuable collection of resources in orbit: air, water, and shelter that NASA had already  paid to carry up there. By 1977, with the Space Shuttle program well underway, NASA planners recognised an opportunity to save the station for refurbishment and reuse. With orbital flights of the shuttle scheduled to begin in mid 1979, NASA contracted Martin Marietta Corporation (today, absorbed into Lockheed Martin) to develop a booster that could be carried to Skylab by a space shuttle and used to raise Skylab’s orbit out of imminent danger, as illustrated in this piece of concept art:

Here’s a close-up of the booster module itself, designated the Teleoperator Retrieval System (TRS):

It’s docked to the main port of Skylab’s Multiple Docking Adapter (MDA). The square plate visible at the centre of the cluster of engines carries an attachment point to allow the shuttle’s robot arm (Remote Manipulator System — RMS) to grasp the module and manœuver it into position. Note also that Skylab’s main solar array has been re-folded into its launch position (it’s the long, flat, rectangular structure along the side of the station with the words “United States” barely legible along it). I presume this was to keep the station’s centre of mass as close as possible to the TRS’s line of thrust during the boost, as well as to minimise stresses on the array—although the solar panels on the Apollo Telescope Mount (ATM) are still fully deployed.

Safe in its new orbit, Skylab would then be ready for renovations and expansions to keep it in useful service perhaps as far as 1989. Alternatively, NASA also considered the possibility of using the TRS to de-orbit Skylab in a safe, controlled manner, far away from human populations (Skylab’s orbit carried it over around 90% of the world’s people).

However, none of this was to be. Solar activity through the 1970s remained higher than predicted, and by April 1979, it was clear that Skylab would not last longer than a few more months. It was also clear that the Space Shuttle was nowhere near ready: ongoing problems and delays with its revolutionary new heat shield and engines postponed the first orbital flight past the end of the year.

On 11 July 1979, Skylab’s orbit decayed and brought the station down in an uncontrolled¹ re-entry over the Indian Ocean and Western Australia.

On 12 April 1981, the first space shuttle flew.

Incidentally, I’d love to know the name of the artist who did the original painting. If you know, please leave me a note!

Footnote:
¹ Well, almost uncontrolled. As the station crossed the east coast of North America, headed  south-east on what was almost certainly to be its final orbit, ground controllers fired the station’s thrusters to set it tumbling in its orbit. This tumble was intended to maximise the atmospheric drag and bring Skylab down as quickly as possible, hopefully somewhere in the South Atlantic or Indian Ocean and before it re-appeared over the Pacific North-West of the United States.

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Copyright information: The print in my collection was formerly held by a newspaper archive. It is a black-and-white version of NASA image S78-23631. As a work of the US federal government, this image is in the public domain.

Skylab 4 certificate from NASA MFA Office

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I work for a large organisation that regularly hands out awards of various kinds to recognise excellence or to celebrate particular milestones. I therefore feel some kind of camaraderie with the recipient of this award, although I never knew them personally.

These certificates were printed for employees of NASA and its contractors to commemorate the success of Skylab 4 — the third and final mission to take a crew to the space station.

Printed on US letter-size paper, it displays the insignia of the Skylab program, plus mission insignias for all three Skylab crews (with Skylab 4’s the largest). The employee’s name is printed below (blurred out here for their privacy), together with a short message of appreciation, and facsimiles of the signatures of the three astronauts who flew the mission: Jerry Carr, Ed Gibson, and Bill Pogue.

This is an ordinary piece of paper made extraordinary by its association with an extraordinary achievement. Skylab 4 put a crew of three astronauts on a space station for 84 days of scientific research and returned them safely to Earth.

I sometimes wonder whether any of the ephemera from our office will one day be collectable to someone!

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Copyright information: this certificate was issued by NASA’s Manned Spaceflight Awareness Office. As a work of the US federal government, it is in the public domain.

Skylab 3 press kit from the US DoD

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This week’s artifact is a press kit issued by the United States Department of Defense to describe the contribution of the military to the Skylab 3 mission. Probably the most visible role was that of the recovery forces: prior to the Space Shuttle, American spacecraft landed (“splashed down”) in the ocean. The astronauts and their capsule were recovered by helicopter and brought aboard an aircraft carrier waiting nearby.

However, as the press kit points out, the military involvement went far beyond recovering the spacecraft. Throughout Skylab 3’s launch and return, 2,260 members of the United States Air Force and United States Navy provided tracking, communications, safety, rescue, and meteorological services. Three ships and 51 aircraft were assigned to these efforts: a sizeable undertaking.

To most people, perhaps the most interesting thing about the document is how incredibly crude its production appears by today’s standards. The document itself is sixty pages of heavy stock in the old government letter size of 8” × 10½” (203 mm × 267 mm). Black-and-white printing appears on one side of the page only.

In 2012, any crank who hands out flyers on a street corner has slicker-looking material than the US Department of Defense was producing only forty years ago. Conversely, I’m struck by how closely some vintage sci-fi fanzines from the same era in my collection resemble this press kit: those amateurs were doing some impressive work.

One day, I’d like to scan the entire document for posterity, but the stapled binding on my copy is very tight, and getting good scans without damaging it will be a time-consuming challenge. For now, here are a few representative pages that deal with the recovery effort by USS New Orleans off the coast of California. New Orleans was flagship of Task Force 130, based at Pearl Harbor under Rear Admiral John L. Butts, Jr.

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Copyright information: The text and images in this press kit are the work of the United States federal government, and therefore in the public domain.

Skylab 2 parasol sample from NASA MFA office

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Here’s a tiny snippet of material used to solve a serious engineering problem in space. 

The Skylab 1 mission¹ was the launch of America’s first space station. It was carried into orbit—without a crew—by a Saturn V rocket that the cancellation of the last few Apollo moon missions had left surplus. Skylab 2 was to launch one day later and carry the first astronauts to the station for a 28-day visit.

However, during the launch of the station on 14 May 1973, it became apparent that something had gone badly wrong. Engineers deduced that during launch, Skylab had lost its meteroid shield—the tube-like structure that encircled the main body of the station to protect it from debris and from the Sun’s heat. Without this protection, the temperature inside Skylab soon reached 38° C and was expected to go as high as 77° C.

The launch of Skylab 2 was postponed while equipment and procedures were developed to repair the station. A key feature of these repair efforts was a “parasol” that the astronauts could deploy through one of Skylab's airlocks and which would provide the station with protection from the Sun. The parasol fabric was orange nylon laminated to aluminized Mylar, manufactured for NASA by the G. T. Schjeldahl Company² (today simply Sheldal) of Northfield, Minnesota.

The Skylab 2 crew launched on 25 May and successfully deployed the parasol the following day. Within a few days, the interior temperature stabilised at 26° C, making the station habitable and ensuring the safety of the supplies and experiments aboard.

To celebrate the success of the efforts, NASA’s Manned Flight Awareness Office issued laminated cards to employees that contained a small swatch of the parasol material (roughly 1 cm, or ½”, along each edge). The swatch was mounted on an image of Skylab taken by the Skylab 2 crew as they departed the station (NASA image 73-H-580), and clearly shows the parasol deployed. The card also bore the employee’s name (which I've blurred out here for their privacy), a message of congratulations, and facsimiles of the autographs of the nine Skylab astronauts.

The back of the card features another view of Skylab with the parasol in place (NASA image 73-H-578)—also taken by the departing Skylab 2 crew—overlaid with small portraits of all nine astronauts.

Footnotes:
¹ Skylab mission numbering is a little problematic. In this post, I’m following the scheme preferred by NASA headquarters—Skylab 1 was the launch of the station, followed by Skylab 2, 3, and 4, each of which took a crew of three astronauts up to it. Skylab Program management used a different scheme: they didn’t number the station launch, and used Skylab 1, 2, and 3 to refer to the three flights with a crew. Note that the front of this card uses this latter scheme.
² Wikipedia informs me that company founder Gilmore T. Schjeldahl (1 June 1912 – 10 March 2002) ‘may be best known for inventing the plastic-lined airsickness bag’.

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Copyright information: the Skylab photos, astronaut portraits, and card design and text are all works of NASA. As works of the US federal government, all are in the public domain.

Skylab 1 press release from Martin Marietta

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This week I wanted to post something from Skylab 1 — the mission that launched the space station itself.

This March 1973 press release from the Martin Marietta corporation (today, part of Lockheed Martin) shows the station’s multiple docking adapter (MDA) nearing completion. This component provided two ports at which an Apollo spacecraft could dock. Generally, the capsule would use the port located along the axis of the station—visible at the top of this image—and transfer crew and supplies. It would then remain docked there to provide the crew with a vehicle for their return to earth at the end of the mission. The second port, projecting out from the side of the module, provided a place to dock a rescue craft if necessary (thankfully, it never was).

The MDA was 5.1 metres (17 ft) long, 3 metres (10 ft) in diameter, and weighed 6,210 kg (13,800 lb). The press release also points out that it contained 7,000 electrical connections and 6 miles (9.6 km) of wiring!

Massive though it was, the MDA was a relatively small piece of Skylab, and an even tinier part of the launch vehicle that carried the station to orbit. It’s the third item from the top of the stack in this diagram released by NASA’s Marshall Space Flight Center in connection with the launch:

Note that in addition to building the MDA, Martin Marietta  was responsible for the overall integration of the station components produced by other contractors.

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Image copyrights:  Although issued by Martin Marietta, I believe the photo in the press release is actually a cropped version of a NASA image (72-H-1393). As a work of the US federal government, that would place it in the public domain. The diagram of the launch vehicle is from a NASA publication and therefore also in the public domain.

Skylab program brochure from McDonnell Douglas

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Today I’m sharing a brochure from 1972 put out by McDonnell Douglas about Skylab— America’s first space station. The company (today, absorbed into Boeing) was one of the major contractors for its construction.

It’s a lovely piece, printed on glossy, thick stock, 30 cm × 22.5 cm, and it shows up every smudge and bit of dirt on my scanner.

Skylab is perhaps best remembered today for its uncontrolled re-entry over Western Australia in 1979. In retrospect, this makes the timeline on page 7 look incredibly short-sighted: a 110-ton space station in orbit with no evidence of any plan for its future further than eight months.

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Copyright information: There’s no copyright notice on the brochure, so as a work first published in the United States before 1989 without any such notice, it seems to be in the public domain.