Space Shuttle Discovery Lights Skies With Nighttime Launch
First Checks Show No Damage
Space Shuttle Discovery executed a blazing liftoff at 8:47 p.m. ET Saturday to light the skies over Florida, in the first nighttime shuttle launch since the 2003 disaster of Space Shuttle Columbia, NASA reported.
Liftoff of the shuttle on mission STS-116 from Kennedy Space Center Launch Pad 39B came after weather problems delayed launch plans on Thursday and Friday.
Until now, fears that foam insulation might rip loose from the external fuel tank to damage an orbiter vehicle — similar to the disaster that led to loss of the Columbia ship and crew – had compelled NASA to confine the three ensuing shuttle launches to daylight hours.
But with the weekend launch of Discovery, NASA – backed by assessments of experts – decided that it could chance a nighttime launch.
The bet paid off.
As best could be determined in initial checks of the Discovery orbiter vehicle wing leading edges and nose cap, there was no damage, according to NASA briefers.
Further, the blinding light of the 5,000-degree exhaust from the shuttle plume showed the few pieces of foam that flecked off during the Discovery ascent were small objects, and they ripped loose well after the point in flight where they would cause concern.
They were seen after the shuttle had risen above most of the atmosphere that can accelerate foam pieces to lethal speeds, according to NASA briefers speaking to space journalists.
Further, sensors detected only minor hits on the orbiter vehicle, not strikes capable of harming it.
The sensor readings, which might not have been caused by impacts of foam or ice strikes, were negligible, about a tenth of what would be capable of inflicting “discernable damage” on the spacecraft, according to John Shannon, deputy manager of the space shuttle program.
“I don’t know they were strikes,” Shannon said of the readings. What is known is that there were registered readings on the accelerometer sensors about 110 to 120 seconds into the launch, “fairly late” in the ascent to cause any harm, he added.
Those sensor data readings came about the time that small bits of “popcorn” foam were seen flying loose from the tank, he said.
Discovery, moving at about 17,500 miles an hour, now is closing in on the International Space Station (ISS) at a rate of about 100 miles per orbit of the Earth. Discovery will catch the space station at 5:05 p.m. ET today.
Checking for damage with robotic arms swinging out of the shuttle orbiter vehicle payload bay, Discovery thus far has been given a clean bill of health.
Further checks of heat tiles on the underside of the spacecraft are scheduled, and the orbiter also will receive a careful 360-degrees scan once it arrives at the space station.
Crew members used the robotic arm to grapple a boom extension sensor system to check the heat shield. After completion of the inspections of the heat shield, the crew returned the boom to the payload bay. Later the crew used the arm’s cameras to check out the shuttle’s upper surfaces.
Preparations for docking with the ISS include the checkout of rendezvous tools and the installation of equipment for use when Discovery links up with the station.
ISS Construction Job
Discovery went aloft so that its crew could continue the years-long job of building the space station, under a demanding schedule of shuttle flights over the next four years before the huge spacecraft are slated to be retired.
This STS-116 mission will be very complex, involving tricky moves to switch vital electrical power lines that the space station requires to function.
To prepare for this arduous task, astronauts’ activities also included a checkout of spacesuits they will use during three scheduled spacewalks to install the P5 integrated truss structure on the space station and rewire its electrical system. During the 12-day mission, a new structural component will be added to the station. Shuttle and station crews will work with ground teams to install the P5 truss. This latest addition to the station’s backbone weighs 4,000 pounds and will extend the left side of the truss to allow future solar panels to rotate.
The mission includes extensive work to reconfigure the ISS electrical and cooling systems from temporary to permanent mode. During the mission, ground control will shut down and reroute the station’s power in stages so that the astronauts can reconfigure the power system and make the P4 solar arrays delivered during the last mission fully operational.
This complex operation has never been done before. Part of an existing solar panel after years of being extended hopefully will be retracted to allow the P4 arrays to track the sun for a full 360 degrees and provide power to the rest of the station.
As part of these operations, the station’s temporary cooling system will be deactivated and a permanent system will become operational.
The station’s newest resident will also be traveling aboard Discovery. Astronaut Sunita Williams joins the ISS Expedition 14 crew, NASA noted. Thomas Reiter, a European Space Agency astronaut who has been aboard the station since July, will return to Earth with the Discovery crew. Williams is scheduled to spend six months on the station.
Discovery’s crew is Polansky, Pilot Bill Oefelein and mission specialists Bob Curbeam, Joan Higginbotham, Nicholas Patrick, Williams and Christer Fuglesang, a European Space Agency astronaut.