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Web Formation (ED52)
Principal Investigator
Research Area:
Species Studied
Scientific Name: Araneus diadematus Species: Spider
Scientific Name: Fundulus heteroclitus Species: Fish, Killi Strain: Mummichog


A spider is not an insect, although it is commonly mistaken to be an insect. Spiders, along with ticks, mites, and scorpions, belong to the class arachnida. A spider has eight legs with no visible antennae and a two-piece body. A spider has silk-spinning organs, called spinnerets, at the back end of its abdomen, and usually eight eyes of various sizes and shapes. In addition, a spider's mouth parts are different from an insect's. Instead of mandibles capable of chewing, spiders have fang-tipped jaws called chelicerae used to inject digestive enzymes into it’s prey.

Araneus diadematus, the garden spider, is a very common resident of homes and gardens. It has a distinctive white "cross" mark on the abdomen which has given rise to the alternative aliases “cross spider” and “diadem spider.” It produces the traditional orb web, characterized by a pattern of concentric circles of silk threads that are small in the center of the web and get larger towards the outer area of the web. Since the spider senses its own weight when constructing the web to determine the required amount of silk to make the web, gravity plays an important role in the construction of the web. Therefore, the objectives of this experiment were to observe how microgravity affects the weight sensing mechanism for web construction in the common cross spider.

A bag with two "brackish water" minnows known as "Mummichog Minnows" was added to the flight at the request of Scientist-Astronaut Dr. Owen K. Garriott. The objective of this experiment was to show what disorientation the fish experienced when exposed to weightlessness. The fish were flown to obtain a better understanding of the vestibular or otolith organ, which enables an animal to maintain its balance or normal orientation to the gravity force of its natural environment.

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Anonymous. MSFC Skylab student project report. NASA Marshall Space Flight Center; Huntsville, AL, United States. August 01, 1974. NASA-TM-X-64866. [NTRS]

Newkirk RW, Ertel ID, and Brooks CG. Skylab: A Chronology. January 01, 1977. NASA SP-4011. [NTRS]

Skylab Student Project Summary Description. MSFC-SL-73-3, 1973.

Summerlin LB, ed. Skylab, Classroom in Space. NASA Marshall Space Flight Center; Huntsville, AL, United States. January 01, 1977. NASA SP-401. [NTRS]


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Data Information
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Web formation

Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Skylab 3 07/28/1973 09/25/1973 59.5 days

Additional Information
Other Key People
Managing NASA Center
NASA Marshall Space Flight Center
Responsible NASA Representative
Institutional Support
National Aeronautics and Space Administration (NASA)
Protocol / Approach
Not applicable
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