Space shuttle Endeavour’s tanking test officially began at 6:52 a.m. EDT at NASA’s Kennedy Space Center in Florida. No abnormal gaseous hydrogen leaks were detected during the test, which involved filling Endeavour’s external fuel tank with liquid hydrogen and liquid oxygen just as it is on launch day.
At about 9 a.m., the liquid hydrogen tank was 98 percent full and the “topping” mode began. A vent valve at the top of the hydrogen tank began cycling, as planned, to disperse excess gaseous Hydrogen through a vent system that carries it safely away from the launch pad. At that point during two June launch attempts, a gaseous hydrogen leak was detected outside the Ground Umbilical Carrier Plate, or GUCP, where the vent line is attached.
STS-127 Mission Overview
Endeavour is targeted to launch July 11 at 7:39 p.m. EDT.
The 16-day mission will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency’s Kibo laboratory. Astronauts will attach a platform to the outside of the Japanese module that will allow experiments to be exposed to space.
The STS-127 crew members are Commander Mark Polansky, Pilot Doug Hurley and Mission Specialists Dave Wolf, Christopher Cassidy, Tom Marshburn, Tim Kopra and Canadian Space Agency astronaut Julie Payette. Kopra will join the space station crew and replace Japanese astronaut Koichi Wakata. Wakata will return to Earth on Endeavour to conclude a three-month stay at the station.