Spaceflight Now



The Mission




Orbiter: Discovery
Mission: STS-120
Payload: Harmony module
Launch: Oct. 23, 2007
Time: 11:38 a.m. EDT
Site: Pad 39A, Kennedy Space Center, Florida
Landing: Nov. 7 @ 1:01 p.m. EST
Site: Shuttle Landing Facility, KSC

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STS-120 Quick-Look

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The Crew




Meet the astronauts flying aboard Discovery's STS-120 mission.

Meet the Astronauts

CDR: Pam Melroy

PLT: George Zamka

MS 1: Scott Parazynski

MS 2: Stephanie Wilson

MS 3: Doug Wheelock

MS 4: Paolo Nespoli

Up: Dan Tani

Down: Clay Anderson

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Video archive

STS-120 day 5 highlights

Highlights from Flight Day 5 see the astronauts enter into the newly-installed Harmony module.

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STS-120 day 4 highlights

The Flight Day 4 highlights movie shows Harmony's attachment to the station and the Discovery mission's first spacewalk.

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STS-120 day 3 highlights

This movie shows the highlights from Flight Day 3 as Discovery docked to the space station.

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STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.

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STS-120 launch videos

Check out all angles of space shuttle Discovery's launch with our extensive video collection.

 Full coverage

STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.

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STS-120: Crew arrival

The space shuttle Discovery astronauts arrive at the Kennedy Space Center for their countdown to launch.

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STS-120: The programs

In advance of shuttle Discovery's STS-120 mission to the station, managers from both programs discuss the flight.

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STS-120: The mission

Discovery's trip to the station will install the Harmony module and move the P6 solar wing truss. The flight directors present a detailed overview of STS-120.

 Part 1 | Part 2

STS-120: Spacewalks

Five spacewalks are planned during Discovery's STS-120 assembly mission to the station. Lead spacewalk officer Dina Contella previews the EVAs.

 Full briefing
 EVA 1 summary
 EVA 2 summary
 EVA 3 summary
 EVA 4 summary
 EVA 5 summary

The Discovery crew

The Discovery astronauts, led by commander Pam Melroy, meet the press in the traditional pre-flight news conference.

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Metal shavings seen in solar array rotary joint
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: October 28, 2007

Spacewalker Dan Tani, inspecting a massive solar array rotary joint that has been experiencing high vibration and power usage, reported a large number of metal shavings inside the mechanism after removing a thermal cover and to get a glimpse at the joint's inner workings.

"Great discovery, Dan," spacewalker Scott Parazynski radioed. "I didn't think you'd be able to see anything, but..."

"It's quite clear," Tani said. "There's metal-to-metal scraping, or something, and it's widespread."

"Wow."

Engineers had speculated a thermal blanket or perhaps a misaligned bolt was causing unusual friction in the rotating mechanism of the right-side solar alpha rotary joint, or SARJ. The space station is equipped with two SARJ units, one on each side of the main power truss, to turn outboard solar arrays and keep them face-on to the sun. The port, or left-side, SARJ is operating normally and while the starboard unit still functions, engineers have been monitoring high vibration and current use in recent weeks.

It was not immediately clear what might be producing the metal shavings Tani reported. He did not immediately see what might be causing the problem.

Tani initially simply floated around the perimeter of the joint and inspected its outward appearance, checking each of 22 thermal blankets and making sure no bolts were out of position.

"I see you've done everything from 1 to 22," Italian astronaut Paolo Nespoli said. "You don't see any missing bolts, the gap looks more or less constant everywhere.

"All the swing arms are locked, the gap looks very constant, yes," Tani reported. "And nothing obvious, no scratching. The only thing I could see maybe is these big SLR, the outboard, the SLR parts that rotate, the corner braces at the corners? They might rub up against the MLI (multi-layer insulation), but I don't see any marks on the MLI. So I don't know if that's happened. And it looks like it's designed for the MLI to stay out of there."

"OK, Paolo, is there anything you or the ground want me to do while I'm out here? I guess, unfortunately, I have nothing to report in terms of anomalous conditions."

Tani then was asked to peel back one of the insulation blankets to look inside the joint. That's when he saw the shavings.

"There are lots of very fine metal shavings, and I can see that because the motor that is the, what is that, that's a trunnion bearing, has a lot of those iron shavings. It's like the (result) that you get with the metal, iron filings and you put a magnet under it and they stand straight up."

Footage from Tani's helmet camera showed the large gear inside the starboard solar alpha rotary joint, but the filings he reported were not obvious.

The shavings, he said, could be seen "on this big motor, it looks like a big magnet that is this upper roller, I don't know why there'd be a magnet here but there's a magnet. I see microswitches, there's two microswitches on it and a metal squarish 2- by 2-inch by 2-inch cube that I believe holds the roller and it looks like it's magnetic because it looks like there are these iron filings, or shavings, on it.

"There's quite a bit and then the outer race, the flat part, is discolored, if you can see that, from the teeth, the angled portion that are between the teeth and the thin part of the race is all sort of discolored. I would almost say corroded in some way. And there are even some filings... I'm going to look up, there's a connector here that says J-15 outboard, looks like there are some filings there. There must be something magnetic to hold those on."

In a worst-case scenario, the starboard SARJ could be locked in a position to maximize solar energy production while engineers assess various options for future troubleshooting. Lead station flight director Derek Hassmann said Friday the station could operate with one stationary set of solar arrays without any major problems.

"One of the concerns we have about the way the SARJ is behaving is the potential it might stall in a position that's not optimal for power," he said. "So one of the things we have been talking about ... is to find a current (power) value at which we're going to stop rotating the SARJ and put it in a position that's good for power consumption. We've basically got constraints to find that will allow us to park the SARJ in a good power producing attitude before it would stall.

"As long as we can get it into an attitude that's reasonably good for power generation, combined with what the other SARJ can produce, we wouldn't have any significant power impacts that we couldn't deal with."

Tani was asked to collect samples of the shavings to help engineers troubleshoot the problem. His camera, meanwhile, malfunction and prevented him from immediately completing the desired photo documentation.

Spaceflight Now Plus
Additional coverage for subscribers:
VIDEO: PREVIEW OF SUNDAY'S SPACEWALK PLAY
VIDEO: BIOGRAPHY MOVIE ON DISCOVERY'S ASTRONAUTS PLAY
VIDEO: BIOGRAPHY MOVIE ON EXPEDITION 16 CREW PLAY
VIDEO: BIOGRAPHY ON NEW EXPEDITION 16 MEMBER DAN TANI PLAY

VIDEO: THE FLIGHT DAY 5 HIGHLIGHTS MOVIE PLAY
VIDEO: CREW INTERVIEWED BY CBS NEWS PLAY
VIDEO: CREW INTERVIEWED BY FOX NEWS PLAY
VIDEO: CREW INTERVIEWED BY WHAM-TV PLAY
VIDEO: SATURDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: ASTRONAUTS ENTER HARMONY FOR FIRST TIME PLAY
VIDEO: CREW COMMENTS FROM INSIDE HARMONY PLAY

VIDEO: THE FLIGHT DAY 4 HIGHLIGHTS MOVIE PLAY
VIDEO: POST-EVA MISSION STATUS BRIEFING PLAY
VIDEO: FIRST STS-120 SPACEWALK CONCLUDES PLAY
VIDEO: ROBOT ARM INSTALLS HARMONY ON THE STATION PLAY
VIDEO: HARMONY MODULE LIFTED OUT OF PAYLOAD BAY PLAY
VIDEO: S-BAND ANTENNA STOWED IN DISCOVERY'S BAY PLAY
VIDEO: WHEELOCK RIDES STATION ARM WITH ANTENNA PLAY
VIDEO: MISSION STS-120'S SPACEWALK NO. 1 BEGINS PLAY

VIDEO: ANIMATED PREVIEW OF HARMONY INSTALLATION PLAY
VIDEO: NARRATED ANIMATION OF SHUTTLE PAYLOAD BAY PLAY
VIDEO: HARMONY'S PRE-LAUNCH PREPS AT THE CAPE PLAY
VIDEO: BACKGROUND INFO ON HARMONY MODULE PLAY
VIDEO: PREVIEW OF FRIDAY'S SPACEWALK PLAY

VIDEO: THURSDAY MANAGEMENT TEAM NEWS BRIEFING PLAY
VIDEO: POST-DOCKING MISSION STATUS BRIEFING PLAY
VIDEO: INSPECTION BOOM HANDED BETWEEN ROBOT ARMS PLAY
VIDEO: SHUTTLE CREW WELCOMED ABOARD THE STATION PLAY
VIDEO: RING BETWEEN THE DOCKING PORTS RETRACTED PLAY
VIDEO: REPLAY OF DOCKING FROM PAYLOAD BAY CAMERAS PLAY
VIDEO: SHUTTLE DISCOVERY DOCKS TO THE STATION PLAY
VIDEO: DISCOVERY PERFORMS 360-DEGREE BACKFLIP PLAY
VIDEO: SHUTTLE APPROACHES STATION FROM BELOW PLAY
VIDEO: NARRATED PREVIEW OF THE DOCKING PLAY

VIDEO: THE FLIGHT DAY 2 HIGHLIGHTS MOVIE PLAY
VIDEO: BRIEFING ON LAUNCH IMAGERY AND TANK'S PERFORMANCE PLAY
VIDEO: WEDNESDAY'S MISSION STATUS BRIEFING PLAY
VIDEO: HEAT SHIELD INSPECTIONS EXPLAINED PLAY
VIDEO: THE FLIGHT DAY 1 HIGHLIGHTS MOVIE PLAY
VIDEO: INSIDE MISSION CONTROL DURING LAUNCH PLAY

VIDEO: DISCOVERY'S LAUNCH AS SEEN LIVE PLAY
VIDEO: EXTERNAL TANK CAMERA FROM LIFTOFF TO ORBIT PLAY
VIDEO: LAUNCH REPLAY: VAB ROOF PLAY
VIDEO: LAUNCH REPLAY: KSC RUNWAY PLAY
VIDEO: LAUNCH REPLAY: BEACH TRACKER PLAY
VIDEO: LAUNCH REPLAY: UCS-23 WIDESCREEN PLAY
VIDEO: LAUNCH REPLAY: PLAYALINDA WIDESCREEN PLAY
VIDEO: LAUNCH REPLAY: WEST TOWER PLAY
VIDEO: LAUNCH REPLAY: PRESS SITE PLAY
VIDEO: LAUNCH REPLAY: CAMERA 009 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 041 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 049 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 050 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 051 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 054 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 060 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 061 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 063 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 070 PLAY
VIDEO: LAUNCH REPLAY: CAMERA 071 PLAY
VIDEO: LAUNCH REPLAY: CAMERA UCS-12 PLAY
VIDEO: LAUNCH REPLAY: CAMERA UCS-15 PLAY
VIDEO: LAUNCH REPLAY: CAMERA CS-1 PLAY
VIDEO: LAUNCH REPLAY: CAMERA CS-2 PLAY
VIDEO: LAUNCH REPLAY: CAMERA CS-6 PLAY

VIDEO: THE CREW DEPARTS QUARTERS FOR THE PAD PLAY
VIDEO: ASTRONAUTS SUITS UP ON LAUNCH MORNING PLAY
VIDEO: A LOOK BACK AT SHUTTLE DISCOVERY'S HISTORY PLAY
VIDEO: PAD 39A'S ROTATING GANTRY MOVED BACK PLAY
VIDEO: INTERVIEW CLIPS WITH THE ASTRONAUTS PLAY
VIDEO: MONDAY MORNING'S STATUS BRIEFING PLAY
VIDEO: PRE-LAUNCH NEWS CONFERENCE PLAY
VIDEO: SUNDAY COUNTDOWN STATUS BRIEFING PLAY
VIDEO: SATURDAY COUNTDOWN STATUS BRIEFING PLAY
VIDEO: WATCH THE CREW'S ARRIVAL FOR LAUNCH PLAY
VIDEO: NEWS CONFERENCE AFTER FLIGHT READINESS REVIEW PLAY
VIDEO: SHUTTLE DISCOVERY ROLLS TO LAUNCH PAD 39A PLAY
VIDEO: CRANE HOISTS DISCOVERY FOR MATING TO TANK PLAY
VIDEO: DISCOVERY MOVED TO THE VEHICLE ASSEMBLY BUILDING PLAY
VIDEO: HYDRAULIC SEALS REPLACED ON LANDING GEAR STRUT PLAY
VIDEO: FUEL TANK ATTACHED TO SOLID ROCKET BOOSTERS PLAY
VIDEO: FOAM REMOVED FROM FUEL TANK FEEDLINE BRACKETS PLAY

VIDEO: STS-120 MISSION OVERVIEW BRIEFING PART 1 | PART 2
VIDEO: PREVIEW OF THE MISSION'S FIVE SPACEWALKS PLAY
VIDEO: DISCOVERY'S ASTRONAUTS MEET THE PRESS PLAY
VIDEO: BRIEFING ON SHUTTLE AND ISS PROGRAMS PLAY
MORE: STS-120 VIDEO COVERAGE
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