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A busy mission to repair and service the station BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: June 29, 2006 The seemingly endless debate about the external tank foam insulation has shifted attention away from the actual goals of Discovery's mission. But STS-121 is an exceedingly complex flight as such missions go, with three major objectives: space station resupply; repair of the stalled mobile crane transporter; and delivery of Reiter as a third full-time crew member. Even if no obvious signs of foam shedding or damage show up in the ascent video, one of the recommendations of the Columbia Accident Investigation Board requires NASA to "provide a capability to obtain and downlink high-resolution images of the underside of the orbiter wing leading edge and forward section of both wings' thermal protection system." The Discovery astronauts are going to spend their second day in space carefully inspecting the leading edges of both wings, along with the reinforced carbon carbon nose cap of the shuttle, using the orbiter boom sensor system, or OBSS. First, the shuttle's 50-foot-long robot arm will lock onto the OBSS, which is stowed on the right side of the cargo bay. Nowak and Wilson then will spend the entire day maneuvering the boom back and forth along the leading edges of both wings, using an OBSS television camera and the new laser sensor to inspect every square inch of the RCC panels. The astronauts also will use the boom to inspect the nose cap. Maximum speed of the boom survey: 2 inches per second. The shuttle's nose cap and wing leading edge panels, all made of heat-resistant reinforced carbon carbon - RCC - endure temperatures of more than 3,000 degrees during re-entry. It was a breach in an RCC leading edge panel that triggered Columbia's destruction in 2003 and it is concern about the integrity of the system that has prompted the flight day two inspections. And it doesn't take a major, Columbia-class hole to threaten disaster. Ground tests show impacts that wear away the outer coating of an RCC panel, coupled with internal delamination of the carbon composite layers making up the material, could lead to catastrophic damage. But the laser sensor on the end of the OBSS should be able to detect any potentially dangerous damage. "The first couple of flights we'll do a lot of inspections to make sure that we really understand the changes that have been made to the external tank, and that the sensing system that we're adding to the leading edge of the wing are really working properly and telling us what we need to know," Fossum said in a NASA interview. "After we get more comfortable with that, with the tank, with the modifications that we've made, my understanding is that we'll be backing off on some of these inspection requirements. But a lot of them are here to stay because we understand how important it is." DAY.ET.........DD...HH...MM...EVENT 07/01/06 Sat 03:49 PM...00...00...00...STS-121 Launch Sat 03:58 PM...00...00...09...Main engine cutoff Sat 04:26 PM...00...00...37...OMS-2 rocket firing Sat 07:24 PM...00...03...35...Shuttle arm (SRMS) powerup Sat 07:49 PM...00...04...00...Umbilical camera download Sat 08:16 PM...00...04...27...NC1 rendezvous rocket firing Sat 08:34 PM...00...04...45...Group B computer powerdown Sat 09:49 PM...00...06...00...Crew sleep begins 07/02/06 Sun 05:49 AM...00...14...00...Crew wakeup Sun 07:35 AM...00...15...46...NC2 rendezvous rocket firing Sun 08:14 AM...00...16...25...SRMS checkout Sun 08:29 AM...00...16...40...Centerline camera installation Sun 08:59 AM...00...17...10...Middeck transfer preparations Sun 08:59 AM...00...17...10...OBSS unberthing Sun 09:49 AM...00...18...00...OBSS starboard wing leading edge survey Sun 10:59 AM...00...19...10...OMS pod survey from flight deck Sun 11:19 AM...00...19...30...Ergometer setup Sun 11:19 AM...00...19...30...OBSS nose cap survey Sun 11:49 AM...00...20...00...Crew meals begin Sun 01:04 PM...00...21...15...Docking ring extension Sun 01:44 PM...00...21...55...NPC rendezvous rocket firing Sun 02:04 PM...00...22...15...Spacesuit checkout Sun 02:04 PM...00...22...15...OBSS port wing leading edge survey Sun 03:34 PM...00...23...45...OBSS berthing Sun 04:39 PM...01...00...50...SRMS survey Sun 06:04 PM...01...02...15...NC3 rendezvous rocket firing Sun 06:09 PM...01...02...20...Rendezvous tools checkout Sun 08:49 PM...01...05...00...Crew sleep beginsDocking is targeted for flight day three. Lindsey will guide Discovery through a standard rendezvous profile, approaching the lab complex from behind and below. The terminal phase of the rendezvous procedure begins about three hours before docking with the shuttle trailing the station by about 9.2 miles. On final approach, at a distance of about 600 feet directly below the station, with Discovery's nose facing forward and its open payload bay facing the station, Lindsey will carry out the slow 360-degree rotational pitch maneuver, or RPM, that will point the belly of the shuttle at the station. As the shuttle's underside rotates into view, Expedition 13 commander Vinogradov and flight engineer Williams, shooting through windows in the Zvezda service module, will photograph Discovery's belly with handheld digital cameras equipped with 400mm and 800mm lenses. "The 800 millimeter gives them one-inch resolution, which is what we're looking for around (landing gear) door seals," Hill said. "400 millimeters gives three inches, which is what they're looking for everywhere else." Imagery from the station will be downlinked to Houston for detailed analysis. After completing the RPM maneuver, Lindsey will position Discovery about 400 feet directly ahead of the space station with the shuttle's nose facing deep space and its cargo bay facing the lab complex. He then will guide the spacecraft to a docking with a pressurized mating adaptor attached to the Destiny laboratory module. Assuming an on-time launch, docking is expected around 11:25 a.m. on July 3. After leak checks, Vinogradov and Williams will welcome the shuttle crew aboard the station and provide a safety briefing before all nine astronauts get down to work. DAY.ET.........DD...HH...MM...EVENT 07/03/06 Mon 04:19 AM...01...12...30...ISS crew wakeup Mon 04:49 AM...01...13...00...STS crew wakeup Mon 06:04 AM...01...14...15...Group B computer powerup Mon 06:13 AM...01...14...24...NH rendezvous rocket firing Mon 06:19 AM...01...14...30...Rendezvous timeline begins Mon 06:58 AM...01...15...09...NC4 rendezvos rocket firing Mon 08:34 AM...01...16...45...RPM photo setup verification Mon 08:30 AM...01...16...41...TI rendezvous rocket firing Mon 09:54 AM...01...18...05...Approach timeline begins Mon 10:19 AM...01...18...30...RPM photo documentation Mon 11:25 AM...01...19...36...ISS docking Mon 11:49 AM...01...20...00...Leak checks Mon 12:19 PM...01...20...30...Group B computer powerdown Mon 12:19 PM...01...20...30...Orbiter docking system preps for ingress Mon 12:39 PM...01...20...50...Hatches open; welcome aboard! Mon 01:39 PM...01...21...50...Safety briefing Mon 02:04 PM...01...22...15...Russian seat liner installation Mon 02:04 PM...01...22...15...SSRMS: OBSS grapple Mon 02:24 PM...01...22...35...SSRMS: OBSS unberthing Mon 02:59 PM...01...23...10...SSRMS: move to OBSS handoff position Mon 03:19 PM...01...23...30...ROOBA leak check Mon 04:09 PM...02...00...20...OBSS handoff from SSRMS Mon 04:34 PM...02...00...45...Reiter officially joins ISS crew Mon 04:39 PM...02...00...50...Spacewalk tools transfer Mon 04:39 PM...02...00...50...SRMS positioned to support MPLM install Mon 08:19 PM...02...04...30...STS/ISS crew sleep beginsOne of the first items on the agenda is to transfer a Soyuz seat liner from Discovery to the station and to check out Reiter's re-entry pressure suit. Once those tasks are accomplished, about four hours after docking, the European astronaut will become an official member of the Expedition 13 crew. He is scheduled to remain aboard the outpost until late December, returning to Earth with the crew of the year's third shuttle mission. While Reiter's equipment is being transferred, Wilson and Nowak will use the station and shuttle robot arms to redeploy the OBSS boom for additional inspection work and photo support of the upcoming spacewalks. Because of clearance issues after the shuttle is docked, Discovery's robot arm cannot unberth the OBSS on its own. Instead, the space station's arm - the SSRMS - will pluck the sensor boom from the shuttle's cargo bay and hand it off to Discovery's arm about five hours after docking. The astronauts also will begin moving station equipment stowed in the shuttle's middeck area over to the space station, along with tools that will be used in the upcoming spacewalks. Flight day four - the July Fourth holiday in the United States - will be devoted to attaching a 21,000-pound cargo module to the Unity module's downward-facing, or nadir, port. Known as Leonardo, the Italian built multi-purpose logistics module is loaded with about 5,100 pounds of supplies and equipment, including a high-tech laboratory freezer, a European plant biology experiment rack and a U.S.-built oxygen generator that ultimately will help support a crew of six. In addition, more than 1,000 pounds of fresh water, a by-product of the shuttle's electricity producing fuel cells, will be transferred to the station while Discovery is docked. DAY.ET.........DD...HH...MM...EVENT 07/04/06 Tue 04:19 AM...02...12...30...STS crew wakeup Tue 04:49 AM...02...13...00...ISS crew wakeup Tue 06:29 AM...02...14...40...SSRMS grapples MPLM Tue 06:59 AM...02...15...10...MPLM unberthing Tue 07:49 AM...02...16...00...MPLM installation Tue 08:59 AM...02...17...10...MPLM bolt torquing; crew meals begin Tue 10:09 AM...02...18...20...SSRMS ungrapples MPLM Tue 10:24 AM...02...18...35...SSRMS grapples mobile transporter Tue 11:04 AM...02...19...15...MPLM vestibule pressurization Tue 11:09 AM...02...19...20...SSRMS ungrapples lab module Tue 11:39 AM...02...19...50...SSRMS moves to survey support position Tue 11:59 AM...02...20...10...SRMS/OBSS heat-shield survey Tue 01:19 PM...02...21...30...MPLM activation Tue 02:49 PM...02...23...00...MPLM vestibule ingress Tue 03:34 PM...02...23...45...MPLM ingress Tue 04:50 PM...03...01...01...EVA-1: Procedures review Tue 08:19 PM...03...04...30...STS/ISS crew sleep begins"We're re-supplying them with some rack experiments, a lot of food, clothing, things like that, hardware replacements - there's a whole laundry list of things that we're supplying to the space station," Lindsey said in a NASA interview. "The other purpose, of course, of the MPLM is to bring things down. And so, we're going to bring back a whole bunch of stuff that they don't need anymore. That includes experiment samples, used articles they're not using anymore, and trash - you name it. "One of the issues with space station since we've lost Columbia is we've been putting things on board, but we haven't been able to get very many things off. So, one of the goals will be to help them with their stowage issues and logistics issues by bringing a bunch of things off the space station as well." Once Leonardo has been robotically bolted in place, the astronauts will perform leak checks to make sure the MPLM is firmly mated to Unity and pressurize the vestibule between Unity and the supply module. Then they'll open the module, float inside and begin the process of moving supplies into the space station. At roughly the same time, yet another shuttle tile survey will begin using the RMS-OBSS boom, with additional TV views provided by the SSRMS. The tools that will be used for the upcoming spacewalks will be configured for use and the crew will spend an hour reviewing the procedures that will be used in the first spacewalk.
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