[/caption] An historic milestone will be reached during the STS-127 space shuttle mission to the International Space Station, which will hopefully launch on Wednesday. The crew will include the 500th person ever to fly in space. Since there are four rookie astronauts on the mission, it's a bit of a coin toss as to who is actually the 500th, but seemingly the crew has agreed that former naval commander Chris Cassidy, 39, who has led combat missions in Afghanistan, will take the honor.

A few notables of the 499 who have gone before, below, and a quick report that things look good so far for Endeavour's second launch attempt. NASA is shooting for 5:40:52 a.m. Wednesday (9:40 GMT) on Wednesday June 17.

[caption id="attachment_32547" align="aligncenter" width="580" caption="Workers on Kennedy Space Center's Launch Pad 39A prepare to remove the 7-inch quick disconnect and flight seal from the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. Teams are removing the hardware to change out seals in the internal connection points. The GUCP is the overboard vent to the pad and the flare stack where the vented hydrogen is burned off. Credit: NASA"]

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On Tuesday, engineers pulled a protective gantry away from the shuttle Endeavour and restarted the orbiter's countdown Tuesday, setting the stage for launch. There are no technical problems of any significance and forecasters are predicting an 80 percent chance of good weather at launch time. You can watch

NASA TV

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Nancy

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Back to the list of space travelers – check out

Robert Perlman's complete list at collectSpace

, but here are a few notables:

1 on the list, of course is Russian Yuri Gagarin, with his flight in 1961.

12 was the first woman in space, another Russian, Valentina Tereshkova, in 1963.

First US woman was Sally Ride, but she is pretty far down the list at #122.

200 is newly named NASA administrator Charles Bolden.

Source:

collectSpace,