The Discovery astronauts are preparing for a lengthy inspection of the shuttle's nose cap and wing leading edge panels to make sure the critical heat shield components came through launch without any major problems.

Credit: NASA TV

Because of trouble with the shuttle's Ku-band antenna system, the astronauts will be unable to immediately downlink video to mission control. As a result, they will record laser scans and imagery for downlink to analysts using the Ku-band communications system aboard the International Space Station after Discovery docks with the outpost Wednesday.

The antenna problem will delay the heat shield assessment and could force the astronauts to conduct a final heat shield inspection while the shuttle is docked to the station instead of immediately after undocking, which is the usual practice.

"We're still going to press ... with the flight-day-two inspection of the reinforced carbon carbon on the port and starboard (wing leading edge panels) and nose cap areas on Discovery," Flight Director Mike Sarafin said earlier Monday. "The crew's going to record all that information and then we'll transmit that over to station and downlink it from the station's Ku-band assets after we get docked.

"Other information that goes up, like the timeline modifications we have every morning as part of the mission, those are going to have to be verbalized up to the crew. It'll take a little bit longer in the morning to get the plan rolling as we've modified it overnight."

The heat shield inspection will be carried out by shuttle pilot James Dutton, Naoko Yamazaki and Dorothy Metcalf-Lindenburger using a 50-foot-long extension attached to the end of the shuttle's robot arm. The extension is called the Orbiter Boom Sensor System, or OBSS.

"We've got several sensors on the end of a long boom that we now carry up on the starboard side of the shuttle," Dutton said in a NASA interview. "We'll take the shuttle arm over and grab that boom and unberth (it), then use those sensors to essentially scan the leading edge and the underside of each of the wings, as well as around the nose of the shuttle to make sure we don't have any damage and, if we do have damage, to assess how big that damage is.

"It's a long day so we actually rotate through. There's three of us, Dottie, Naoko and myself, who will be the primary ones for operating the arm that day, and then (commander Alan Poindexter and Stephanie Wilson) will be sort of the backups where they will be standing back, using a couple of software programs we have to help watch clearances of the arm and the boom to the shuttle, and also to watch the configuration of the arm and make sure it's safe.

"So we essentially go through a very scripted set of maneuvers and collect the data that the ground needs ... so that they can then do the analysis to clear our thermal protection system for entry."

While the heat shield inspection is going on, astronauts Rick Mastracchio and Clay Anderson plan to check out the spacesuits they will use during three excursions when docked at the space station to swap out an ammonia coolant tank.

Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision A of the NASA television schedule):

EDT........DD...HH...MM...EVENT

04/05
08:21 PM...00...14...00...Crew wakeup
09:56 PM...00...15...35...NC-2 rendezvous rocket firing
10:51 PM...00...16...30...Robot arm (SRMS) powerup
11:06 PM...00...16...45...SRMS checkout
11:21 PM...00...17...00...Ergometer setup
11:51 PM...00...17...30...SRMS unberths OBSS
11:51 PM...00...17...30...Spacesuit checkout preps

04/06
12:21 AM...00...18...00...Spacesuit checkout
01:06 AM...00...18...45...OBSS starboard wing survey
01:51 AM...00...19...30...Spacesuit prepped for transfer to station
03:01 AM...00...20...40...Crew meals begin
03:11 AM...00...20...50...OBSS nose cap survey
04:01 AM...00...21...40...OBSS port wing survey
05:01 AM...00...22...40...Middeck transfer preps
06:00 AM...00...23...39...Mission status briefing on NTV
06:16 AM...00...23...55...SRMS berths OBSS
07:21 AM...01...01...00...Centerline camera setup
07:26 AM...01...01...05...Rendezvous tools checkout
08:21 AM...01...02...00...OMS pod survey
09:32 AM...01...03...10...NC-3 rendezvous rocket firing
09:36 AM...01...03...15...Orbiter docking system ring extension
12:21 PM...01...06...00...Crew sleep begins
01:00 PM...01...08...39...Daily highlights reel on NTV
05:00 PM...01...10...39...Post-MMT briefing on NTV
08:21 PM...01...14...00...Crew wakeup

Additional coverage for subscribers:
VIDEO: DESCRIPTION OF KU-BAND ANTENNA PROBLEM PLAY

VIDEO: PREVIEW OF FLIGHT DAY 2 ACTIVITIES PLAY
VIDEO: NARRATED TOUR OF DISCOVERY'S PAYLOAD BAY PLAY

VIDEO: FLIGHT DAY 1 HIGHLIGHTS MOVIE PLAY
VIDEO: SHUTTLE DISCOVERY BLASTS OFF! PLAY | HI-DEF
VIDEO: GO INSIDE MISSION CONTROL DURING LAUNCH PLAY
VIDEO: POST-LAUNCH NEWS CONFERENCE PLAY

VIDEO: LAUNCH REPLAY: VAB ROOF PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PRESS SITE PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PATRICK AFB PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PAD PERIMETER PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: BEACH TRACKER PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PAD CAMERA 070 PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PAD CAMERA 071 PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PLAYALINDA BEACH PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: PAD FRONT CAMERA PLAY | HI-DEF
VIDEO: LAUNCH REPLAY: KSC WEST TOWER PLAY | HI-DEF

VIDEO: ASTRONAUTS LEAVE CREW QUARTERS PLAY | HI-DEF
VIDEO: CREW FINISHES GETTING SUITED UP PLAY | HI-DEF

VIDEO: NARRATED REVIEW OF SHUTTLE'S PREPARATIONS PLAY | HI-DEF
VIDEO: NARRATED REVIEW OF PAYLOADS' PREPARATIONS PLAY | HI-DEF
VIDEO: PREPARING AN EXTERNAL TANK FOR LAUNCH PLAY | HI-DEF

VIDEO: TIME-LAPSE OF GANTRY ROLLING BACK FOR LAUNCH PLAY
VIDEO: LAUNCH PAD'S SERVICE TOWER RETRACTED PLAY | HI-DEF
VIDEO: PAYLOAD BAY DOORS CLOSED FOR LAUNCH PLAY | HI-DEF
VIDEO: ASTRONAUTS INSPECT THE PAYLOAD BAY PLAY | HI-DEF

VIDEO: STS-131 MISSION PREVIEW MOVIE PLAY | HI-DEF
VIDEO: PRE-LAUNCH INTERVIEW WITH COMMANDER POINDEXTER PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH PILOT JIM DUTTON PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH RICK MASTRACCHIOPLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH METCALF-LINDENBURGER PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH STEPHANIE WILSON PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH NAOKO YAMAZAKI PLAY
VIDEO: PRE-LAUNCH INTERVIEW WITH CLAY ANDERSON PLAY

VIDEO: PRE-LAUNCH NEWS CONFERENCE PLAY
VIDEO: COUNTDOWN STATUS AND WEATHER OUTLOOK PLAY
VIDEO: PREVIEW OF DISCOVERY'S LAUNCH COUNTDOWN PLAY
VIDEO: ASTRONAUTS ARRIVE FOR LAUNCH PLAY | HI-DEF

VIDEO: FULL FLIGHT READINESS REVIEW NEWS BRIEFING PLAY
VIDEO: RECAP OF THE FLIGHT READINESS REVIEW PLAY | HI-DEF
VIDEO: HELIUM VALVE NO CONSTRAINT TO LAUNCH PLAY | HI-DEF
VIDEO: MANAGERS ASSESS ISSUES BEFORE FLIGHT PLAY | HI-DEF
VIDEO: UPDATE ON PRE-LAUNCH PREPS AT PAD 39A PLAY | HI-DEF

VIDEO: SPACEWALKING SUITS LOADED ABOARD PLAY | HI-DEF
VIDEO: INTERVIEW WITH STS-131 PAYLOAD MANAGER PLAY | HI-DEF
VIDEO: INTERVIEW WITH BOEING PAYLOAD MANAGER PLAY | HI-DEF
VIDEO: PAYLOADS DELIVERED TO LAUNCH PAD 39A PLAY | HI-DEF
VIDEO: TRANSPORT CANISTER ROTATED VERTICALLY PLAY | HI-DEF
VIDEO: LEONARDO PLACED INTO THE TRANSPORTER PLAY | HI-DEF
VIDEO: STATION'S NEW AMMONIA COOLANT TANK PLAY | HI-DEF
VIDEO: LEONARDO HATCH CLOSED FOR FLIGHT PLAY | HI-DEF
VIDEO: FILLING UP ONE OF THE SUPPLY RACKS PLAY | HI-DEF

VIDEO: CAN THE SHUTTLE PROGRAM AVOID LOOMING RETIREMENT? PLAY
VIDEO: WHAT ABOUT ADDING ONE MORE SHUTTLE MISSION? PLAY
VIDEO: FULL BRIEFING BY SHUTTLE AND STATION OFFICIALS PLAY
VIDEO: THE STS-131 MISSION OVERVIEW PRESENTATIONS PLAY
VIDEO: PREVIEW BRIEFING ON MISSION'S SPACEWALKS PLAY
VIDEO: THE ASTRONAUTS' PRE-FLIGHT NEWS BRIEFING PLAY

VIDEO: SHUTTLE EVACUATION PRACTICE PLAY | HI-DEF
VIDEO: CREW MODULE HATCH IS CLOSED PLAY | HI-DEF
VIDEO: ASTRONAUTS BOARD DISCOVERY PLAY | HI-DEF
VIDEO: CREW BRIEFED ON EMERGENCY PROCEDURES PLAY | HI-DEF
VIDEO: TEST-DRIVING AN EMERGENCY ARMORED TANK PLAY | HI-DEF
VIDEO: NIGHTTIME APPROACHES IN TRAINING AIRCRAFT PLAY | HI-DEF
VIDEO: ASTRONAUTS CHAT WITH REPORTERS AT PAD 39A PLAY
VIDEO: CREW ARRIVES FOR PRACTICE COUNTDOWN PLAY | HI-DEF

VIDEO: GANTRY PLACED AROUND DISCOVERY PLAY | HI-DEF
VIDEO: DISCOVERY REACHES PAD 39A PLAY | HI-DEF
VIDEO: OVERNIGHT ROLLOUT BEGINS PLAY | HI-DEF
VIDEO: SHUTTLE HOISTED FOR ATTACHMENT TO TANK PLAY | HI-DEF
VIDEO: CRANE ROTATES THE ORBITER VERTICALLY PLAY | HI-DEF
VIDEO: DISCOVERY MOVES TO ASSEMBLY BUILDING PLAY | HI-DEF

VIDEO: ASTRONAUTS VISIT THEIR SPACECRAFT PLAY | HI-DEF
VIDEO: CREW GOES INSIDE LEONARDO MODULE PLAY | HI-DEF

VIDEO: EXTERNAL TANK ATTACHED TO BOOSTERS PLAY | HI-DEF
VIDEO: FUEL TANK LIFTED INTO CHECKOUT CELL PLAY | HI-DEF
VIDEO: EXTERNAL TANK ARRIVES AT SPACEPORT PLAY | HI-DEF

VIDEO: DISCOVERY'S NOSE POD ATTACHED PLAY | HI-DEF
VIDEO: INSTALLING DISCOVERY'S MAIN ENGINES PLAY | HI-DEF
VIDEO: KSC'S SHUTTLE MAIN ENGINE SHOP PLAY | HI-DEF
VIDEO: GASEOUS NITROGEN TANK REMOVED PLAY | HI-DEF
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