Progress Docks With ISS, Removing Potential Endeavour Launch Obstacle

Progress Docks With ISS, Removing Potential Endeavour Launch Obstacle: "

Russia's Progress 42 closes within 70 meters of the International Space Station as the two spacecraft sail 220 miles above Kazakhstan. Photo Credit/NASA TV

Russia's Progress 42 successfully docked with the International Space Station on April 29, within six hours of the shuttle Endeavour's scheduled lift off from the Kennedy Space Center on a mission to equip the orbiting science laboratory with the $2 billion Alpha Magnetic Spectrometer and an external spare parts platform.

The Progress carried out a flawless automated linkup with the Pirs docking compartment on the station's Russian segment at 10:28 a.m., EDT, removing a potential obstacle to the shuttle's lift off.

The freighter was launched from the Baikonur Cosmodrome in Kazakhstan on April 27 with nearly three tons of propellant, crew equipment, research gear and other supplies. NASA postponed plans to launch Endeavour's 14 to 16-day mission on April 19 to accommodate the Russian supply mission.

Endeavour emerged early Friday (April 28-29) from a night of stormy weather in Florida still 'go' for a planned lift off at 3:47 p.m., EDT.

The three hour shuttle fueling operation was completed shortly before 9:30 a.m, EDT.

As the operation neared completion, the launch control team corrected a slight over pressure in the fuel tank of Endeavour's right orbiter maneuvering system pod. After the pressure rose above the 288 psi flight rule limit, it was lowered by opening a cross feed line with the left OMS pod fuel tank.

Pete Nickolenko, NASA's deputy lanch director, pointed to a problem with a balky regulator valve in the right OMS pod as the apparent source of the rise.

'The bottom line is we are good to go,' said Nickolenko. 'We had a temporary excursion.'

The two OMS pod engines mounted in the tail section are ignited for major rendezvous maneuvers as well as the shuttle's descent to Earth.

Shuttle commander Mark Kelly, pilot Greg. H. Johnson and mission specialists Mike Fincke, Greg Chamitoff, Drew Feustel and Roberto Vittori of the European Space Agency were to begin boarding their spacecraft at 12:30 p.m., EDT.

Forecasters offered a 70 percent change of favorable weather conditions for the several hundred thousand spectators expected to gather on the beaches and roadways of Central Florida to witness the launching.

President Obama and the first family were among those expected to watch from KSC.

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