Only Problem Is Shutdown In Backup Electronic Unit For Second Left Orbital Maneuvering System; Primary Unit Works, So No Loss Of Capability Faces Mission

Space Shuttle Discovery docked this afternoon with the International Space Station (ISS) in an STS-124 Mission that has been one of the smoothest ever, from its easy countdown to its blazing on-time liftoff from Kennedy Space Center (KSC) Launch Pad 39A, and from the perfection of its orbit to its arrival at the ISS.

This mission, when it concludes, will mark the halfway point from the Space Shuttle Columbia disaster to the end of shuttle missions and the end of NASA transportation capability for half a decade beginning in 2010.

The payload bay doors on Discovery are open to show the world below the gigantic, tour-bus-sized, 36-foot-long Japanese Kibo pressurized laboratory module, the largest habitable section to be attached to the space station.

It was "a huge day" for NASA, and for the Japanese Aerospace Exploration Agency (JAXA), NASA Administrator Michael Griffin told reporters in a post-launch news conference at KSC Saturday evening.

He was joined at the briefing room dais by JAXA President Keiji Tachikawa, and by top leaders of the NASA shuttle and launch team who pronounced the countdown and liftoff "really smooth … flawless …gorgeous … outstanding," in part because it was unmarred by the famously fickle Florida weather.

Because the Kibo module is so huge, a robotic boom arm had to be left on the space station in a prior shuttle mission, so Discovery would have sufficient room in its cargo bay for Kibo.

Also, an arm that is on Discovery won’t have sufficient dexterity and movement range for the usual minute inspection of the shuttle orbiter vehicle upon arrival in orbit, to see if it was damaged during launch and ascent. However, a less thorough examination will be possible, and a more detailed inspection of Discovery will be conducted later on Flight Day 12, prior to reentry, after Discovery delivers Kibo to the space station. And the shuttle will perform the now-routine back-flip (rendezvous pitch maneuver) close to the space station, so that the station crew can examine its underside and other areas for possible damage.

As always, a key concern for NASA leaders is the possibility that a large chunk of foam insulation could rip loose from the external fuel tank and damage the orbiter vehicle as it streaks toward space, such as the damage that led to the loss of Space Shuttle Columbia and its crew in 2003.

This was the first shuttle liftoff where the full complement of safety alterations was in place on the external tank.

Perhaps five pieces of foam ripped off from the Discovery external tank during the launch Saturday, which was conducted at 5:02 p.m. ET in late-afternoon sunlight so that any objects were visible clearly on live video streaming down from the external fuel tank.

Those foam chunks likely weren’t a danger for two reasons, according to Bill Gerstenmaier, associate NASA administrator for space operations: the pieces were fairly thin and therefore light, and they tore loose fairly late in the ascent to orbit so that the atmosphere wasn’t thick enough to accelerate the insulation chunks to harmful velocities.

"They were all late" in the climb to orbit, Gerstenmaier said. And "they looked thin." Even if a foam piece touched the orbiter, it was such a gentle impact that the foam piece didn’t break apart, he said.

He said he doubts there ever will be a shuttle mission where there is not even one piece of foam tearing loose. In any event, the foam loss seen on the weekend launch was "not an issue."

"This tank performance looked very good," said LeRoy Cain, deputy shuttle manager and leader of a key shuttle panel.

Further, there was little problem of ice forming and then ripping off the tank. Use of titanium components that reduce ice formation contributed to the improvement, Gerstenmaier said.

The Discovery countdown and flight preparation tied the all-time record for fewest problems, with only 74 issues raised, according to Mike Leinbach, NASA shuttle launch director. The lack of problems allowed him to sit back and watch the KSC teams do their jobs well, he said.

Tachikawa said the Japanese laboratory soon will be filled with scientific experiments that will benefit mankind, and thanked NASA for transporting Kibo (Hope) to orbit.

It also is key to being able to double the space station permanent crew from three to six, a "huge step" that will increase, greatly, the amount of scientific experimentation work that can be performed aloft, Griffin noted.

Backup Electronics Failure

Amidst the smooth performance, one small glitch occurred that didn’t cause any loss of capabilities. A backup electronics software for gimbal operation on one of the orbital maneuvering engines failed, meaning there is no redundant system there for safety. But since the primary system continued functioning well, there was no problem for the shuttle.

A team of experts "has some work to do" to figure out why the anomaly occurred, Cain said. He declined to speculate on what might occur if the primary system also fails.

When Kibo is attached to the space station during the two-week Discovery mission, it will be the second of three Kibo components to be hooked up with the station.

Also expanding the space station are the European Space Agency laboratory, Columbus, and a U.S. laboratory Destiny, along with a Russian lab.

All of those lab modules require extensive electrical power.

But movement of space station solar arrays to capture the most sunlight for generating electricity has been limited because of a problem in the solar array rotary joint (SARJ) permitting movement of the arrays.

There won’t be any problem ensuring adequate electrical power for the fast-growing space station into next year, Gerstenmaier indicated. And there may be steps that can help the SARJ to gain more freedom of movement, such as cleaning and lubricating the joint.

"We have plenty of power to operate the [lab] modules," he said.

Soyuz Problem Still Puzzling

Russian experts still haven’t resolved why their Soyuz spacecraft has developed a chilling and dangerous problem. On the last two Soyuz missions to return to Earth, the craft each time has entered a terrifyingly steep descent — "ballistic reentry" — and rough landing far from its intended landing site.

In the last mission, the jarring landing left Russian and South Korean crew members with back injuries.

A key point here is that a Soyuz vehicle always is docked to the space station, to act as a life raft and an emergency ride back to Earth if serious trouble erupts on the station. Some have questioned whether it is safe to have U.S. astronauts on the station when the Soyuz is their only means of escape (except for times when a space shuttle is docked there.)

Nonetheless, NASA sent astronaut Gregory Chamitoff up on Discovery to replace astronaut Garrett Reisman as a member of the space station Expedition 17 crew, a half-year-long assignment for Chamitoff.

While NASA would have preferred having a final verdict on what’s wrong with Soyuz, and a plan to fix it, before Discovery blasted off for the space station, it likely will be July or August before a final word is delivered about why Soyuz — a decades-old spacecraft design that was a model of dependability — suddenly developed the glitch.

Tests are scheduled in Russia this month that may shed light on the problem, Gerstenmaier said.

Meanwhile, the Soyuz woes will "have no impact on this [two-week-long Discovery] mission," he said.

The mission is led by Commander Mark Kelly, who is married to Rep. Gabrielle Giffords (D-Ariz.).

As he prepared for Discovery to thunder off the launch pad, Kelly said he would provide "the greatest show on Earth."

Aside from Kelly and Chamitoff, the Discovery crew includes Pilot Kenneth T. Ham and mission specialists Michael E. Fossum, Karen L. Nyberg, Ronald J. Garan and Akihiko Hoshide of JAXA.

Hubble And Hurricanes

Looking past the current Discovery mission, the remaining 10 shuttle flights must be flown by October 2010, under an existing mandate.

Griffin was asked whether that is possible, or whether it is likely some disruption could make reaching that date impossible. For example, NASA shut down shuttle flights for years after the Columbia disaster in 2003, and for years after the Space Shuttle Challenger tragedy in 1986. But there now is little more than two years before the deadline to terminate shuttle flights.

In response, Griffin again said NASA will be able to complete the shuttle manifest, with all flights flown before the 2010 shutdown. He noted that on average, NASA has flown four-and-a-half flights a year, and continuing that average pace will see the shuttle flights program complete scheduled missions.

One interesting challenge will be for NASA to perform the Hubble Space Telescope mission later this year, which will involve having two shuttles on KSC launch pads simultaneously: Atlantis will fly to Hubble to repair it and extend its life, while Space Shuttle Endeavour will be poised to launch a rescue mission if Atlantis encounters problems. That’s because Atlantis won’t be anywhere near the space station, which can act as a life raft if a shuttle is damaged or encounters severe problems.

While Atlantis is readied to launch, both it and Endeavour will be sitting on launch pads during the infamous Florida hurricane season, Leinbach observed.

But, he said, preparations on Atlantis and Endeavour are well underway and proceeding smoothly, and "we’re going to be well ready for both of those missions," if needed.