by Playfuls Staff |
8th July 2006
A report sent to the crew Thursday indicated two pieces of foam may have harmlessly struck Discovery during launch. One impact came 19 seconds after liftoff. The other occurred about four minutes and 45 seconds after launch.[more]
Mission Specialists Piers Sellers and Mike Fossum will take a stroll in space today. They will conduct a spacewalk to repair the International Space Station’s mobile transporter and to test astronaut movement on the end of the robotic arm boom extension for possible heat shield repairs during future flights.
The excursion is scheduled to begin at 9:13 a.m. EDT and end at 3:43 p.m. Assisting the spacewalkers will be Mission Specialists Lisa Nowak and Stephanie Wilson by operating the robot arm. Shuttle Pilot Mark Kelly will serve to coordinate the spacewalk’s activities.
The STS-121 crew will conduct two more spacewalks during its stay at the station.
The Mission Management Team added the third spacewalk and an extra day to the STS-121 mission on Friday.
Of course, the concern about the safety and integrity of Discovery space shuttle could not have missed the press releases and the declarations that flight officials gave.
The foam is the “Achilles’ heel” that triggered the disastrous atmosphere re-entry of Columbia space shuttle back in 2003.
There are only four spots that need attention and none of them were a big deal, said deputy shuttle program manager John Shannon. The arm used by the two astronauts mentioned earlier will look at the shuttle's left side for the two tile fillers, the nosecap area that eluded earlier photography and the fabric behind the nose.
The robotic arm and boom were used two days ago to examine the shuttle's nosecap and wings for damage. Before docking Thursday, Discovery commander Steve Lindsey maneuvered the shuttle into a back flip so that the space station's crew could photograph the shuttle's belly and transmit to the images to engineers in Houston.
NASA chief safety officer Bryan O'Connor and chief engineer Christopher Scolese had called for a delay to the Discovery launch to redesign the foam on the fuel tank, but Michael Griffin defended his controversial positive decision and told The Washington Post that any further delay would have led to a tighter launch schedule for the ISS program. NASA plans to fly 16 missions involving the three remaining shuttles to the ISS and one mission to repair the Hubble orbital telescope by 2010.
The report mentioned at the beginning of this article stated that both events (the pieces of foam falling and hitting Discovery) happened outside the critical time "of concern that spans from 35 seconds to 140 seconds."
The flight controllers also told the shuttle crew that the shuttle, while docked to the station, wouldn't be able to use a thruster whose heater malfunctioned since its temperature likely was to drop to 60 degrees, about 30 degrees below the use limit.
Despite all these worrying NASA officials mentioned that Discovery seems to be in surprisingly good shape after the harsh ascent, with a remarkably clean fuselage.
The space shuttle orbiter projects manager, Steve Poulos, told in a news briefing on Friday that analysts were still examining two blemishes on the hard panels that line the leading edge of the right wing.
Mr. Poulos added that teams were continuing to work through questions about a piece of stiff cloth known as a gap filler, which sits between tiles so they do not rub against each other as the shuttle flexes. The filler is poking out from the underside of the craft, toward the rear; a similar piece near the nose was removed by a spacewalking astronaut during the Discovery's mission last summer.
Technical staff is also trying to determine whether a blemish on the nose of the vehicle was a weakened spot, Mr. Poulos said, or something as harmless as bird droppings.
Neither Mr. Poulos nor John Shannon, the deputy shuttle chief and leader of the mission management team, appeared to be worried about any of the three issues, though they said they were withholding judgment until the analysis was complete.
"We don't rule out anything until the analysts come out and say it's not a problem," Mr. Shannon said.
