Skylab Spider Experiment

The SL-3 mission (the second manned Skylab mission; sometimes called "Skylab 2") performed a number of life sciences experiments, including one studying the effects of weightlessness on spiderweb formation. Two spiders, Arabella (displayed here at the USSRC) and Anita (displayed at the Udvar-Hazy Center) were launched with the crew, who studied their adaptation to weightlessness (I was amused to find that Arabella was designated as the "prime spider" and Anita the "backup spider").

For a scientific overview of the spider experiment (named "ED52"), see the Life Sciences Data Archive. For more general descriptions of how the experiment was carried out, see Skylab, Our First Space Station or Skylab, Classroom in Space; a formal description of the results of the experiment is presented starting at page 38 (page 43 in the PDF) of MSFC Skylab Student Project Report. Here's a link to a photo of Arabella spinning a web in zero-G.