Mallory Jennings left and Heather Paul aerospace engineers with Johnson Space Center's Spacesuit Life Support.

At NASA's Kennedy Space Center in Florida, Mallory Jennings, left, and Heather Paul, aerospace engineers with Johnson Space Center's Spacesuit Life Support, perform a spacesuit demonstration during the STS-134 Tweetup event. About 150 people from 43 states, Washington, D.C., and half a dozen countries are participating in the event. A Tweetup gives followers of @NASA on the social messaging medium Twitter the opportunity to tour the center, view a shuttle launch and speak with NASA managers, astronauts, shuttle technicians and engineers. During the STS-134 mission, space shuttle Endeavour will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the International Space Station. Endeavour was scheduled to launch at 3:47 p.m. on April 29, but that attempt was scrubbed for at least 72 hours while engineers assess an issue associated with the shuttle's Auxiliary Power Unit 1. STS-134 will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller