http://spaceflight.nasa.gov/ has been crawled 839 times going all the way back to January 17, 1999.

A crawl can be a duplicate of the last one. It happens about 25% of the time across 420,000,000 websites. FAQ

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January 10, 2011

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January 31, 2011

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February 8, 2011

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February 11, 2011

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February 27, 2011

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March 9, 2011

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March 15, 2011

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March 16, 2011

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March 30, 2011

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April 15, 2011

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April 16, 2011

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April 22, 2011

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April 29, 2011

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May
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May 11, 2011

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May 14, 2011

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May 18, 2011

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Jun
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June 8, 2011

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June 15, 2011

2 snapshots

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June 30, 2011

2 snapshots

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July 9, 2011

1 snapshot

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July 11, 2011

1 snapshot

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July 21, 2011

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Aug
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Sep
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Oct
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Nov
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Note

This calendar view maps the number of times http://spaceflight.nasa.gov/ was crawled by the Wayback Machine, not how many times the site was actually updated. More info in the FAQ.