NASA Delays Final Launch of Shuttle Endeavour to Avoid Space Traffic Jam

NASA has delayed the last launch of the shuttle Endeavour toward the International Space Station by at least 10 days, to April 29, in order to avoid a space traffic jam with an unmanned Russian cargo ship, also headed for the orbiting laboratory later this month. Endeavour is now targeted to blast off on its STS-134 flight on Friday, April 29 at 3:47 p.m. EDT, NASA officials said. The decision to postpone the launch removes a scheduling conflict with a Russian Progress cargo ship, which is currently scheduled to launch April 27. The robotic Progress vehicle will arrive at the station on April 29.

Discussions between NASA and its international partners have been ongoing for weeks, Beutel said, and the decision to delay Endeavour's flight was made after several other options, including moving the Progress' launch date, were deemed impractical. "Apparently there is a biological experiment onboard the Progress that has a very short shelf life onboard that spacecraft," Beutel said. "We even looked at the possibility of putting that experiment on Endeavour, but logistically that didn't work out as well." Balancing traffic at the space station and on the ground has proved challenging for the various space station partners, but is especially crucial for NASA, in order to capitalize on the unrivaled cargo-carrying capabilities of the space shuttles. The main objective of the remaining shuttle flights is to ferry supplies to the station so that the orbiting laboratory is in a good position for the years ahead, following the retirement of the agency's shuttle fleet later this year.