Spaceflight Now

Discovery perched atop launch pad for April flight

Posted: March 3, 2010

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Shuttle Discovery journeyed to the launch pad overnight at barely a walking pace, but the spacecraft will soar to orbital speeds next month to haul a load of science equipment and supplies to the International Space Station.

Credit: Justin Ray/Spaceflight Now
See our rollout photo gallery

An Apollo-era transporter carried the shuttle stack along Kennedy Space Center's rock-covered crawlerway between the Vehicle Assembly Building and the oceanfront launch pad 39A.

Bolted to a giant external fuel tank and twin solid rocket boosters atop a mobile launching platform, Discovery embarked on the three-and-a-half-mile trip at 11:58 p.m. EST.

Powerful hydraulics jacked up the platform, keeping it level as the crawler ascended the pad's concrete incline before dawn. A laser alignment system helped technicians precisely position the platform, then the crawler lowered it onto the pad's pedestals to complete the rollout at 6:48 a.m. EST.

The move was delayed 24 hours due to the threat of lightning from a passing cold front. That weather moved out, yet brisk winds buffeted the spacecraft during this morning's trek.

Weather hasn't been kind to Discovery's schedule planners. The shuttle stayed parked inside its Kennedy Space Center hangar an extra 10 days in late February due to unusually cold weather that gripped the Florida spaceport nightly. The orbiter finally rolled to the unheated Vehicle Assembly Building last Monday.

A metal "sling" grabbed ahold of Discovery later that day, lifting the shuttle from the 76-wheel transporter that brought it from the hangar. A heavy-duty crane rotated the spacecraft vertically, then began the methodical process of hoisting the ship high into the rafters, over to the assembly bay and carefully lowering Discovery into position next to the awaiting fuel tank for attachment last Tuesday morning.

Once the completed vehicle was fully mated together, a comprehensive Shuttle Interface Test to check the electrical and mechanical connections between the orbiter, tank and boosters was conducted.

Access platforms were folded up and the crawler was positioned underneath the launcher platform last night during final preparations for rollout of Discovery's next-to-last space mission.

Discovery's astronauts -- commander Alan Poindexter, pilot Jim Dutton, spacewalkers Rick Mastracchio and Clay Anderson, and mission specialists Dotty Metcalf-Lindenburger, Stephanie Wilson and Naoko Yamazaki of the Japan Aerospace Exploration Agency -- will climb aboard the shuttle on Friday morning for a countdown dress rehearsal with the launch team.

They are spending the week at KSC going through emergency training drills and participating in the mock countdown.

Liftoff is targeted for Monday, April 5 at 6:21 a.m. EDT (1021 GMT) for a two-week flight featuring the reusable Leonardo cargo-delivery module. The Italian-built container is packed with items large and small for the International Space Station, including a new crew sleeping compartment, a supercold laboratory freezer, an exercise machine, a window observation device, assorted experiment equipment and racks of supplies.

Leonardo rides to space anchored in Discovery's payload bay, then gets unberthed by the robotic arm and attached to the station for unloading by the astronauts. Late in the mission, the module will be returned to the shuttle bay for the trip back to Earth.

The Leonardo module, along with a tank of ammonia coolant for the station that the spacewalkers will install, are scheduled to be trucked to the launch pad the night of March 15 for insertion into Discovery's cargo hold.

STS-131 marks the 131st mission overall for the shuttle program that began in April 1981, Discovery's 38th spaceflight since its maiden voyage in August 1984 and the 33rd space shuttle flight to the International Space Station dating back to December 1998.

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