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Mission: STS-121/ULF1.1
Orbiter: Discovery

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NASA's Launch Blog - Mission STS-121


The NASA Launch Blog was activated at 8:30 a.m. EDT.

The NASA Launch Blog was deactivated at 3:00 p.m. EDT.

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NOTE: Refresh/Reload your browser every few minutes to view blog updates. All times are in EDT unless otherwise stated.

2:50 p.m. - The crew of Discovery and mission control have confirmed that the orbiter's external tank camera captured images of the tank. The pictures will be analyzed by the mission management and imagery analysis teams over the next few hours.
+ Watch On-Orbit Footage of Tank and Ice

2:46 p.m. - MECO: Discovery's main engines have "cut off" and separation of the external fuel tank was successful.

2:45 p.m. - Discovery is currently traveling at more than 4 miles per second, 14,000 mph.

2:44 p.m. - Discovery has rolled to a heads up position. All three engines continue to function normally. Two minutes of powered flight remaining for Discovery.

2:42 p.m. - Discovery is now at the point of negative return and four minutes, eight seconds into the flight

VIDEO: Rocketing From Earth
The onboard camera provides an excellent view of the Space Shuttle Discovery's external tank as the Kennedy Space Center below quickly disappears from sight after liftoff of mission STS-121.
+ Watch Discovery's Climb into Space

2:41 p.m. - Discovery is now 53 miles in altitude, speeding along at more than 4,000 mph.

VIDEO: Boosters Jettisoned
The solid rocket boosters successfully separate from the Space Shuttle Discovery as it continues toward space on mission STS-121 to the International Space Station. The boosters will be retrieved from the ocean by NASA's recovery ships, Liberty Star and Freedom Star, and reused for future missions.
+ Watch Solid Rocket Booster Separation

2:40 p.m. - Discovery's solid rocket boosters have cleanly separated from the shuttle.

VIDEO: Discovery Lifts Off!
On the Nation's birthday, Space Shuttle Discovery pierced the clear blue Florida sky, carrying its crew of seven on mission STS-121 to the International Space Station. This is the first shuttle to ever liftoff on the July 4 holiday, providing a view more spectacular that any fireworks display.
+ Watch Discovery's Launch
+ Watch WB-57 Chase Plane Footage

2:38 p.m. - 10...9...8...We have a "go" for main engine start...5...4...3....2....1...Booster ignition...and...LIFTOFF OF THE SPACE SHUTTLE DISCOVERY - Returning to the Space Station...while paving the way for future missions beyond....

2:37 p.m. - The launch pad's water sound suppression system will begin flooding the mobile launcher platform with 300,000 gallons of water. The system protects the shuttle and its payloads from any damage caused by energy generated by the rocket engines during launch.

2:36 p.m. - T-2 minutes and counting.

2:35 p.m. - The vent hood or "beanie cap" over Discovery has been raised to clear the external tank. The crew has been told to close and lock their visors.

2:32 p.m. - APU prestart is complete and the units are ready for activation. The orbiters "black boxes" to record flight data are now in the recording mode and will continue to collect data of the shuttle systems performance during the flight.

2:30 p.m. - The orbiter access arm is being retracted from Space Shuttle Discovery. In an emergency, it could be returned to its extended position in just 28 seconds. The White Room, which only hours ago provided access to Discovery's crew module, is at the tip of the arm.

2:28 p.m. - T-9 minutes and counting down to the liftoff of Space Shuttle Discovery on this glorious July day.

VIDEO: "Good luck and Godspeed, Discovery"
The launch team pronounces Discovery is ready to fly and Commander Lindsey extends his thanks to the team and promises the Florida coast a look at, "the rockets' red glare."
+ Watch Discovery's Cleared to Launch

2:25 p.m. - After the NASA Test Director and Launch Director's poll, Mike Leinbach advises Commander Lindsey that Discovery is go for launch and he wished the crew well. Lindsey said he hoped that soon the east coast would see "the rocket's red glare."

2:16 p.m. - The Mission Management team has been polled and they are ready to proceed with the countdown.

2:14 p.m. - According to mission control in Houston, there are no longer any wind issues at the Shuttle Landing Facility in the event a landing would be required. No other weather issues are in work and it is looking good for Discovery to launch this afternoon.

2:04 p.m. - There will probably be an unscheduled hold at T-31 seconds while we wait for the liquid oxygen (LOX) inlet temperatures on Discovery's main propulsion system to come back down to within limits. At this time, the team is not sure if this temperature will be exceeded or not. The main propulsion system LOX temperature is slightly higher than during the last few days and must be at a specific temperature to ensure that the propellant is in a precise state for engine startup. The hold could last for up to three minutes and 44 seconds without delaying the launch.

1:55 p.m. - Just before this hold is released there will be a number of polls. Mission Management Team Chairman John Shannon will poll the Mission Management Team to proceed with the count. NASA Test Director Jeff Spaulding will complete his poll of the various test conductors, including those responsible for the vehicle, the spacecraft, the launch range, the tracking stations and mission control. Mike Leinbach, launch director, will poll the shuttle engineering director, the Cape weather officer and the director of safety to verify that everyone is ready to pick up the countdown to launch.

1:43 p.m. - The countdown is at T-9 and holding. When the count resumes, the GLS will be in control of all critical space shuttle launch operations. This master computer program will issue all of the commands necessary to perform final critical tasks required to put the vehicle in the final launch configuration.

This is the last of our built-in holds and will last for about 45 minutes.

1:36 p.m. - Pilot Mark Kelly is performing the main propulsion system helium reconfiguration. This procedure will open the helium isolation valves to permit in-flight purges of the three engines, as well as provide an emergency source of pressure for pneumatic shutdown of the engines.

1:32 p.m. - The clock has started again at T-20 minutes and counting. The latest weather report states that crosswinds at the runway are gusting in and out of the 15-knot limit. This will continue to be monitored and an average wind speed will be calculated as we get closer to launch time. Offshore rain showers are dissipating as they approach 20 nautical miles from the pad.

1:22 p.m. - The countdown is at T-20 minutes and holding. The booster recovery ships have reported that they are on station in the Atlantic and ready for launch.

1:12 p.m. - Commander Lindsey is prepping the gaseous nitrogen system for Discovery's orbital maneuvering system (OMS) engines while Pilot Kelly is activating the gaseous nitrogen supply for the orbiter's auxiliary power units.

1:03 p.m. - The Ground Launch Sequencer (GLS) computer has been activated in the firing room. The GLS is a master computer program which controls the final nine minutes of the countdown. The GLS will monitor approximately one thousand different measurements to ensure the system operates within predetermined limits.

The crew inside Discovery continues to perform their preflight checklists.

Did you know?
The Shuttle Discovery and STS-121 crew are scheduled to land at Kennedy Space Center’s Shuttle Landing Facility on flight day 13.

12:54 p.m. - The preflight calibration of the inertial measurement units (IMU) will be completed shortly. The IMU system controls the guidance and navigation of the shuttle during ascent and while on orbit. The system tells the orbiter where in space it is in relation to Earth.

12:48 p.m. - The STA being piloted by Astronaut Mike Bloomfield has just taken off from the Shuttle Landing Facility at Kennedy. Bloomfield will remain airborne through the rest of the countdown monitoring weather around the pad and runway.

12:29 p.m. - The hatch has been closed and locked for flight. Technicians are now performing cabin leak checks to make sure Discovery is maintaining pressure.

12:21 p.m. - The time remaining to the launch of Discovery is now T-1 hour, 20 minutes and counting. The go was given by launch control to close and seal the orbiter's hatch. The closeout crew leader is making final preparations to shut the hatch. Once sealed, the leader will ensure that the hatch is properly pressurized for flight.

12:15 p.m. - The clock is at T-1 hour, 33 minutes and counting. At launch time, the ISS will be located 763 km. (474 miles) south of Tazmania at 50:36:10 S latitude and 148:13:26 E longitude tracking southeast.

Did you know?
Discovery is named for two famous sailing ships; one sailed by Henry Hudson in 1610-11 to search for a northwest passage between the Atlantic and Pacific Oceans, and the other by James Cook on a voyage during which he discovered the Hawaiian Islands.

11:42 a.m. - Mission Specialist Lisa Nowak will be the last crew member to enter the orbiter. She will be sitting on the flight deck between Steven Lindsey and Mark Kelly. Like Wilson, Nowak will also operate the robotic arm during the mission's spacewalks. Nowak's official responsibilities aren't just limited to on-orbit events. During launch and landing, she serves as a second set of eyes for Commander Lindsey and Pilot Kelly.

As the astronauts are seated and "buckled" into place, they are conducting air-to-ground communications checks with the launch team and mission control in Houston.

11:32 a.m. - Once all of the astronauts are in their seats, they will spend three hours on their backs completing their preflight checklists. Their work will culminate at T-0 when Discovery is scheduled to liftoff at 2:38 p.m.

Piers Sellers and Mike Fossum are the next two crew members to enter the orbiter. The two astronauts will be the space walkers for this mission, conducting either two or three "EVAs."

VIDEO: In the White Room
In the White Room at Launch Pad 39B, the closeout crew assists the astronauts as they take their positions inside the orbiter and are strapped in for launch. Once all crew members are in place, the White Room team then closes and seals Discovery's hatch.
+ Watch White Room

11:28 a.m. - Mission specialist and first time astronaut Stephanie Wilson is the next crew member to get ready to enter the orbiter as she follows Pilot Mark Kelly. Wilson will be the robotic arm operator for the mission's spacewalks. This is the third time in four days that the astronauts are being seated inside Discovery for launch.

11:25 a.m. - Commander Steve Lindsey is participating in communications checks with launch control at Kennedy and mission control in Houston. He has wished the teams Happy 4th of July!

11:16 a.m. - European Space Agency (ESA) astronaut Thomas Reiter is the next crew member to be seated in Discovery. Reiter will be sitting below the flight deck on the mid-deck. He will be remaining on the International Space Station (ISS) and is the first ESA astronaut to live on the outpost for a long duration. Pilot Mark Kelly follows Reiter into the orbiter and will be seated on the flight deck next to Commander Lindsey.

11:11 a.m. - The astronauts have specific seating designations for each launch. Often the seating arrangement is changed for descent. There is room for up to four seats on the mid-deck. Shuttle commander Steve Lindsey will be the first astronaut to board the shuttle. He will have the forward-left seat on the flight deck.

As each crew member is suited for launch, orange glow sticks are tucked into the shoulder pockets on their upper arms. Like the orange suits themselves, the glow sticks are intended to give the astronauts a means of identifying one another in the unlikely event of an emergency landing in darkness.

Earlier, the crew module was configured by the Astronaut Support Personnel. Known as the "Cape Crusaders," they have helped prepare the orbiter for launch today. The team supporting today's launch is led by astronaut Douglas (Chunky) Hurley as the Prime for this mission with Michael (Bueno) Good as back-up Prime and Alan (Dex) Poindexter, Jose Hernandez, Kathryn (Kay) Hire and Barry (Butch) Wilmore.

11:07 a.m. - The STS-121 crew is now at Launch Pad 39B where they will take the elevator in the Fixed Service Structure Tower to the 195-foot level to begin boarding the shuttle.

Did you know?
Two 6 1/2 hour spacewalks are scheduled for crewmembers Piers Sellers and Michael Fossum on the fifth and seventh days of the mission.

VIDEO: Astronauts Leave For Launch Pad
The seven STS-121 crew members, who hope to celebrate July 4th by launching aboard Discovery, suited up before leaving the Operations and Checkout Building at NASA's Kennedy Space Center in Florida. From there they travel in a convoy aboard a special van to Launch Pad 39B -- a 25-minute drive accompanied by a helicopter escort.
+ Watch Crew Departure

10:47 a.m. - The STS-121 astronauts have departed the crew quarters and entered the elevator to descend to the main floor of the Operations and Checkout Building, where they will be walking outside and entering the Astrovan. The astronauts are waving American flags on this July 4, Independence Day. Traffic is stopped along the route that the Astrovan takes to the pad and employees who are at work today will come out and wave as the crew drives by.

10:42 a.m. - The countdown clock has resumed at T-3 hours. The next scheduled hold will be at T-20 minutes for a duration of 10 minutes. After that, there will be one final hold at T-9 minutes, which will last for 46 minutes in this countdown.

Did you know?
Three of the astronauts on STS-121 are taking their first flight. + Read More

10:24 a.m. - All seven astronauts are donning their pumpkin-orange launch and entry spacesuits. After final adjustments of the suits are completed, the crew will depart for the launch control center to drop off launch managers who will receive a briefing on what was seen on the vehicle and pad structures during the inspections earlier this morning.

Did you know?
NASA has two ships called Freedom Star and Liberty Star that head to sea the day before launch to be in position to retrieve the solid rocket boosters that power the shuttle's ascent. + Read More

9:57 a.m. - The countdown to launch STS-121 and Discovery is at T-3 hours and holding. There are approximately 45 minutes left in the hold. There are no technical or weather issues being addressed at this time. The Final Inspection Team is ready to leave the pad, leaving only the Closeout Crew in the White Room who await the arrival of the astronauts in about an hour. Forecasters are watching some showers in the Atlantic, but with the sea breezes and temperatures as they are now, weather is not an issue and considered "green" at this time.

One thing to watch: the crosswinds at the Shuttle Landing Facility are almost at the limit for a safe return-to-launch-site abort landing. Astronaut Mike Bloomfield will be flying the Shuttle Training Aircraft (STA) today to monitor landing weather during the launch countdown.

9:42 a.m. - The launch team and astronaut support personnel are working together to preconfigure the controls and switches inside Discovery's cockpit for the arrival of the crew. Also, the cabin air temperature has been adjusted to comfortable levels.

9:38 a.m. - The Final Inspection team is now conducting the final survey for any foreign object debris or ice around the shuttle. After the team finishes its inspection, the members will return to Firing Room 4 to report their findings to Launch Director Mike Leinbach.

Also, the launch team has decided that the Red Team will not go out to the launch pad to replace the back-up circuit breaker on the mobile launcher platform. We are fine to fly with the booster heaters in their current working condition.

Did you know?
Discovery was the third space shuttle orbiter to join the fleet, arriving at Kennedy Space Center in November 1983.

8:59 a.m. - At this time the STS-121 crew is seated in the crew dining area for their traditional preflight meal. All crew members are in their red crew polo shirts and are smiling as they look forward to their mission. The mission's insignia is proudly displayed on the front of the table. After they finish their meal, the crew will have a photo opportunity, suit up for flight and receive the latest weather briefing.

8:35 a.m. - One issue has just come up that is being addressed at this time. The back-up circuit breaker that controls the primary heaters on the segment joints of both solid rocket boosters has failed. The "Red Team" will be going out to the mobile launcher platform to quickly replace the circuit breaker and then leave. We could fly with only the main circuit breaker functioning, but since there is the time to replace the failed unit, the team will do so.

8:30 a.m. - The countdown is at T-3 hours and holding. Happy Independence Day and welcome to NASA's Launch Blog. The sun is shining brightly through blue sky dotted with puffy clouds. Space Shuttle Discovery is waiting on launch pad 39B and the countdown is continuing toward a liftoff time of 2:38 p.m. this afternoon. There are no technical issues with the vehicle in work at this time.

VIDEO: Commentator Bruce Buckingham Opens Launch Coverage
From NASA's Kennedy Space Center in Florida, Launch Commentator Bruce Buckingham opens live coverage of the third attempt to launch STS-121, Discovery's mission to the International Space Station. Buckingham describes the progress of the countdown so far, and one technical issue that the mission team is working.
+ Watch Opening Moments of Launch Coverage

The following events took place before the start of live coverage:

Fueling operations began at 4:33 a.m. with the chilldown thermal conditioning of the propellant lines and Discovery's plumbing. The chilldown prepares the systems for over 500,000 gallons super-cold cryogenic liquid oxygen and liquid hydrogen fuels that will be pumped into the shuttle's external tank. Tanking was completed at 7:28 a.m. for a total time of 2 hours and 55 minutes. Word was then received that we had gone into stable liquid oxygen and hydrogen replenish mode to keep the tank topped off through the rest of the countdown. The engine cut-off (ECO) sensors in the external tank, which caused an issue during the launch of STS-114 last year, have been tested and are performing as expected.

Shuttle Weather Officer Kathy Winters has given the latest weather briefing to Launch Director Mike Leinbach. Weather has improved for today's launch to only a 20-percent chance that weather could be an issue, primarily due to afternoon thunderstorms. The temperature at liftoff is expected to be 82 degrees. There have been some showers off shore that have been wandering into the area, but are not a serious problem this early into the countdown. + View Weather Forecast

The Final Inspection Team and the Closeout Crew were given the all clear to head out through the roadblock and arrived at the pad at about 7:40 a.m. The Final Inspection Team, known as the "Ice Team," will begin the inspection of the shuttle for ice and debris once they arrive at the pad. The Ice Team arrived at Pad 39B at 7:49 a.m. and began their inspections from the 135-foot level. They will go on to inspect the entire shuttle, working their way down to the base of the vehicle at the Mobile Launcher Platform (MLP) level. This inspection usually takes approximately two hours of the three hour built-in hold which began at T-3 hours.

The Ice Team is composed of seven NASA and contractor members who carry binoculars and a telescope to get a better look at the hard-to-see areas. The team objective is to assess the integrity of the thermal insulation on the external tank. They also look for ice and frost formations on the tank, measure temperatures on various parts of the vehicle, as well as assess debris concerns on the shuttle and pad that could impact launch or flight safety.

NASA Commentator George Diller has just stated that the Ice Team has observed no ice or frost on the liquid oxygen feedline support bracket that the foam broke away from on Sunday.

The Orbiter Closeout Crew arrived at the White Room and was given a go to enter the crew compartment at 7:55 a.m. The White Room sits on the end of the Orbiter Access Arm catwalk that extends to Discovery's crew module. They will make the final preparations for the astronaut's arrival at the pad schedule for a few hours from now.

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