HOUSTON — Shuttle Endeavour’s final flight — the STS-134 mission to equip the International Space Station with the $2 billion Alpha Magnetic Spectrometer (AMS) and stage external spare parts — is now formally set for an April 29 liftoff following a Flight Readiness Review at Kennedy Space Center on April 19.

Endeavour’s launch from Kennedy’s Launch Pad 39A is set for 3:47 p.m. EDT. The demanding mission, which will include four spacewalks, is set for a baseline duration of 14 days, but the shuttle’s Mission Management Team will consider a pair of one-day extensions once Endeavour’s six astronauts are docked to the station. At 14 days, Endeavour would touch down at Kennedy’s Shuttle Landing Facility on May 13 at 9:28 a.m. EDT, completing her 25th mission since 1992.

Plans for a complex photo shoot of the winged orbiter while it is docked to the station have been taken off the STS-134 flight plan. The space station portrait, initially planned for Discovery’s STS-133 mission in March, could be rescheduled for the final shuttle mission, STS-135. The photography would be carried out by three camera-toting cosmonauts and astronauts seated in a Soyuz during a brief undocking, fly around and redocking with the station.

STS-135, a 12-day station supply flight aboard Atlantis that will be the last space shuttle mission, is tentatively set for a June 28 launch.

Veteran shuttle commander Mark Kelly leads Endeavour’s six-member U.S. and European crew. Italian astronaut Roberto Vittori is the final European Space Agency shuttle crewmember. In all, European astronauts have participated in 26 flights aboard the winged orbiters, dating back to 1981.

Endeavour’s primary payload is the 15,200-lb. AMS, a particle detector under development for 16 years by the U.S. Energy Department and experts from 15 other nations. The detector will be mounted on the third segment of the station’s starboard solar power truss for studies of cosmic rays, dark matter and primordial antimatter. Scientists expect their observations over the next decade will better characterize the sub-atomic nature of the cosmic fabric.

Endeavour also will deliver the Express Logistics Module-3, an external platform with spare communications antennas, thermal control system coolant and replacement parts for Canada’s Dextre robotic hand.

Four spacewalks

The shuttle astronauts plan four spacewalks to retrieve and install external science experiments, route backup electrical power from the U.S. to the Russian segment of the outpost, and lubricate the station’s port-side Solar Alpha Rotary Joint.

Endeavour’s crew also plans to demonstrate the autonomous rendezvous and docking sensors developed by the NASA/Lockheed Martin-led Orion team in an exercise called the Sensor Test for Orion Relative Navigation Risk Mitigation (Storrm). The flash lidar and high-definition camera sensors will shadow Endeavour’s initial station rendezvous activities to permit the first inflight calibrations.

After undocking, Endeavour’s crew will carry out a traditional fly-around of the station before activating the Storrm sensors. The shuttle astronauts will separate to a distance of 28,000 ft. and initiate a second rendezvous that will bring Endeavour to a distance of just more than 1,000 ft. below the orbiting laboratory and 300 ft. behind.

Kelly’s wife, U.S. Rep. Gabrielle Giffords (D-Ariz.), who was gravely wounded during a shooting spree at a Tucson political event in early January, is recovering at the Texas Medical Center in Houston. Giffords’ staff is making plans for the lawmaker to attend Endeavour’s launch.