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The Mission




Rocket: Delta 2 (7925)
Payload: THEMIS
Date: Feb. 17, 2007
Window: 6:01-6:19 p.m. EST (2301-2319 GMT)
Site: SLC-17B, Cape Canaveral, Florida

Video Coverage

Mission Status Center

Launch events timeline

Ground track map

Restricted hazard area

THEMIS overview

Delta 2 fact sheet

Pre-launch flow

Launch Complex 17

Archived Delta coverage



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BY JUSTIN RAY

Follow the countdown and launch of the ULA Delta 2 rocket with NASA's THEMIS spacecraft. Reload this page for the very latest on the mission.

Spaceflight Now Plus
Additional coverage for subscribers:
VIDEO: DELTA ROCKET LAUNCHES THEMIS PLAY
VIDEO: WIDE-SCREEN LAUNCH MOVIE FROM PRESS SITE PLAY
VIDEO: WIDE-SCREEN LAUNCH MOVIE FROM PATRICK AFB PLAY
VIDEO: WIDE-SCREEN LAUNCH MOVIE FROM PLAYALINDA BEACH PLAY
VIDEO: SPACECRAFT SEPARATION CONFIRMED PLAY
VIDEO: POST-LAUNCH COMMENTS PLAY

VIDEO: FRIDAY'S LAUNCH ATTEMPT SCRUBBED PLAY
VIDEO: PAD SERVICE GANTRY ROLLED BACK PLAY
VIDEO: THEMIS MISSION SCIENCE PREVIEW PLAY
VIDEO: WATCH THE PRE-LAUNCH NEWS CONFERENCE PLAY
VIDEO: ROCKET NOSE CONE INSTALLED AROUND THEMIS PLAY
VIDEO: SPACECRAFT MOUNTED ATOP DELTA ROCKET PLAY
VIDEO: THEMIS DELIVERED TO THE LAUNCH PAD PLAY
VIDEO: SECOND STAGE ATTACHED PLAY
VIDEO: FIRST STAGE ERECTED PLAY
MORE: THEMIS LAUNCH COVERAGE
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SUNDAY, FEBRUARY 18, 2007

Aiming to uncover the physics that power the auroras that crown Earth's poles, five tiny probes have been launched into space for a synchronized orbital dance to locate where the trigger is pulled to create the eerily magnificent displays.

Read our full story.

   IMAGES: AERIAL VIEWS OF ROCKET
   IMAGES: FRIDAY'S GANTRY ROLLBACK
   IMAGES: SATURDAY'S GANTRY ROLLBACK
   IMAGES: LAUNCH PHOTO GALLERY
   IMAGES: MORE LAUNCH PHOTOS

0245 GMT (9:45 p.m. EST Sat.)

"The United Launch Alliance team is proud to support the science and robotic mission of NASA's space exploration program by successfully completing our first east coast launch," said Michael C. Gass, president and chief executive officer of ULA. "While it's the first east coast ULA Delta 2 mission, it's the 103rd successful Cape Delta 2 launch in the program's proud history since its first flight in 1989. We are committed to providing assured access to space for all our customers and it continues with our next launch, an Atlas 5 with the DOD's Space Test Program payload in early March at the Cape."

"This is the first of a total of 21 launches we have manifested in 2007 consisting of a dozen Delta 2s, six Atlas 5s and three Delta 4s from the east and west coasts," said Dan Collins, ULA chief operating officer. "As our team proved today, they are up to the task. By focusing on safe practices, customer needs and mission success, I believe 2007 will be a banner inaugural year for ULA."

0210 GMT (9:10 p.m. EST Sat.)

Spacecraft ground controllers at the University of California, Berkeley, have received signals from all five THEMIS probes, NASA says.

0019 GMT (7:19 p.m. EST Sat.)

This marks the 72nd consecutive successful flight by a Delta 2 rocket since 1997 and the 125th success overall in the 127-flight history of the workhorse booster dating back to 1989.

It was the first Delta 2 launch of the year. The next is targeted for May 24 from Vandenberg Air Force Base in California carrying the Italian COSMO-SkyMed radar Earth-imaging satellite. The X-Band Synthetic Aperture Radar payload on the spacecraft will be used for civil and military applications.

The next NASA flight aboard a Delta 2 rocket will be the Dawn spacecraft bound to explore the asteroids Vesta and Ceres. That launch from Cape Canaveral is targeted for June 20.

0014 GMT (7:14 p.m. EST Sat.)

T+plus 73 minutes, 42 seconds. SPACECRAFT SEPARATION! All five of the THEMIS probes have separated from their specially-designed carrier mounted on the third stage, completing today's flight of the United Launch Alliance Delta 2 rocket.

The top spacecraft, known as Probe A, separated first. The four other craft -- Probes B, C, D and E -- were released a few moments later.

The probes will fly in highly elliptical orbits around Earth to find the origin of explosive events, called substorms, that trigger auroral sky shows in the form of the Northern and Southern Lights.

"For over 30 years, the source location of these explosive energy releases has been sought after with great fervor. It is a question almost as old as space physics itself," said THEMIS principal investigator Vassilis Angelopoulos. "A substorm starts from a single point in space and progresses past the moon's orbit within minutes, so a single satellite cannot identify the substorm origin. The five-satellite constellation of THEMIS will finally identify the trigger location and the physics involved in substorms."

"Substorms are what make the aurorae interesting," said John Bonnell, a plasma physicist and aurora specialist with THEMIS. "Without them, the greenish white sheets are static, like a cloud. Substorms make the sheets ripple and create different colors, such as red borders and colorful edge effects."

"THEMIS is so important because the same fundamental physical process is seen around all planets, it happens on the sun in solar flares, and in astrophysical systems such as black holes," Angelopoulos said. "It's amazing that being so close to us, here at Earth, it is not understood yet."

0012 GMT (7:12 p.m. EST Sat.)

T+plus 71 minutes. Separation of the payload is about two minutes away.

0010 GMT (7:10 p.m. EST Sat.)

T+plus 69 minutes. Solid data is being received at the Cape via the U.S. Army's Reagan Test Site located in the Kwajalein Atoll of the Marshall Islands.

0009 GMT (7:09 p.m. EST Sat.)

T+plus 68 minutes, 18 seconds. The Thiokol Star 48B third stage has burned out of its solid fuel, ending the Delta 2 rocket's powered flight for the launch of THEMIS.

0008 GMT (7:08 p.m. EST Sat.)

T+plus 67 minutes, 45 seconds. Third stage ignition has been verified by the Big Crew aircraft.

0007 GMT (7:07 p.m. EST Sat.)

T+plus 66 minutes, 50 seconds. The stage separation and ignition of the third stage should have occurred by now. Live telemetry relay to the Cape isn't available at the moment to confirm.

0006 GMT (7:06 p.m. EST Sat.)

T+plus 65 minutes, 20 seconds. The second stage has completed its second burn of this launch. In the next minute, tiny thrusters on the side of the rocket will be fired to spin up the vehicle in preparation for jettison of the second stage.

0005 GMT (7:05 p.m. EST Sat.)

T+plus 64 minutes, 45 seconds. Good chamber pressure reported from the Aerojet powerplant.

0005 GMT (7:05 p.m. EST Sat.)

T+plus 64 minutes, 24 seconds. The Delta 2 rocket's second stage engine is firing again to boost the vehicle into a higher orbit. The "Big Crow" tracking aircraft is providing the live telemetry relay from the rocket back to Cape Canaveral.

0001 GMT (7:01 p.m. EST Sat.)

T+plus 60 minutes. THEMIS and the Delta launch vehicle continue their trek high over Australia. About four minutes remain until second stage engine restart.

SATURDAY, FEBRUARY 17, 2007
2356 GMT (6:56 p.m. EST)


T+plus 55 minutes. The "Big Crow" tracking plane is expected to acquire the rocket's signal about 8 minutes from now. The mobile telemetry aircraft will follow the vehicle during the second stage burn, stage separation and ignition of the third stage. The U.S. Army's Reagan Test Site located in the Kwajalein Atoll of the Marshall Islands will acquire the third stage telemetry stream during deployment of the five THEMIS spacecraft.

2351 GMT (6:51 p.m. EST)

T+plus 50 minutes. The ground track will take the Delta rocket with THEMIS over Australia during the next 15 minutes.

2341 GMT (6:41 p.m. EST)

T+plus 40 minutes. The rocket is crossing the Indian Ocean now.

2336 GMT (6:36 p.m. EST)

T+plus 35 minutes. The vehicle is placed in a slow rolling motion during the parking orbit coast period. This is designed to keep the thermal conditions even across the rocket. The roll begins at T+plus 14 minutes and should end at about T+plus 56 minutes, 30 seconds.

2331 GMT (6:31 p.m. EST)

T+plus 30 minutes. As this quiet coast phase of the launch continues, you can see a map of the rocket's planned track here.

2326 GMT (6:26 p.m. EST)

T+plus 25 minutes. The official Range liftoff time was 6:01:00.384 p.m. EST.

2321 GMT (6:21 p.m. EST)

T+plus 20 minutes. Restart of second stage engine is expected at about T+plus 64 minutes, 19 seconds. The stage will fire for approximately 56 seconds to raise the orbit higher. That will be followed by separation between the second and third stages. The solid-fuel upper stage then burns to inject THEMIS into the intended orbit. Deployment of the payload to complete the launch is expected at T+plus 73 minutes.

2315 GMT (6:15 p.m. EST)

T+plus 14 minutes. The rocket has flown out of range from the Antigua tracking station. An airborne tracking plane northeast of Australia will provide live data relay during the second stage engine re-start at T+plus 64 minutes. No telemetry from the rocket is expected until then.

2312 GMT (6:12 p.m. EST)

T+plus 11 minutes. The rocket has successfully achieved a parking orbit with an apogee of 303.78 miles, perigee of 100.0 miles and inclination of 28.5 degrees. That is right on the pre-planned orbit parameters.

2310 GMT (6:10 p.m. EST)

T+plus 9 minutes, 59 seconds. SECO 1. The second stage engine cutoff has occurred right on time, completing the motor's first firing of the day. The Delta 2 rocket with THEMIS has arrived in a preliminary orbit around Earth following launch today from Cape Canaveral. The vehicle will coast for about 54 minutes before the second stage is re-ignited.

2310 GMT (6:10 p.m. EST)

T+plus 9 minutes, 30 seconds. The rocket is traveling at 16,660 mph.

2310 GMT (6:10 p.m. EST)

T+plus 9 minutes. About a minute left in this initial firing of the second stage.

2309 GMT (6:09 p.m. EST)

T+plus 8 minutes, 15 seconds. The second stage engine is still firing normally, consuming a hydrazine propellant mixture and nitrogen tetroxide oxidizer. This burn is needed to achieve a parking orbit around Earth.

2308 GMT (6:08 p.m. EST)

T+plus 7 minutes, 55 seconds. Altitude now 100 miles, downrange distance 990 miles and speed 15,200 mph.

2308 GMT (6:08 p.m. EST)

T+plus 7 minutes, 10 seconds. Altitude now 97.5 miles.

2308 GMT (6:08 p.m. EST)

T+plus 7 minutes. Thrust chamber pressure remains stable.

2307 GMT (6:07 p.m. EST)

T+plus 6 minutes, 35 seconds. The Air Force's downrange tracking station on Antigua Island has acquired the rocket's signal.

2307 GMT (6:07 p.m. EST)

T+plus 6 minutes, 20 seconds. The rocket is 91 miles in altitude, 660 miles downrange from the launch pad and traveling over 14,000 mph.

2307 GMT (6:07 p.m. EST)

T+plus 6 minutes. Good chamber pressure reported on the second stage engine.

2306 GMT (6:06 p.m. EST)

T+plus 5 minutes, 30 seconds. The rocket is 80 miles in altitude, 485 miles downrange from the launch pad and traveling over 13,500 mph.

2305 GMT (6:05 p.m. EST)

T+plus 4 minutes, 58 seconds. The rocket's nose cone enclosing the spacecraft has been shed.

2305 GMT (6:05 p.m. EST)

T+plus 4 minutes, 42 seconds. The Delta's second stage engine has ignited following jettison of the spent first stage.

2305 GMT (6:05 p.m. EST)

T+plus 4 minutes, 28 seconds. MECO. Main engine cutoff is confirmed. The first stage has completed its firing.

2304 GMT (6:04 p.m. EST)

T+plus 3 minutes, 55 seconds. THEMIS is 56 miles in altitude, 217 miles downrange from the launch pad and traveling at nearly 10,000 mph.

2304 GMT (6:04 p.m. EST)

T+plus 3 minutes, 30 seconds. The main engine and the twin vernier steering thrusters are still firing normally.

2304 GMT (6:04 p.m. EST)

T+plus 3 minutes, 5 seconds. The vehicle is 45 miles in altitude, 130 miles downrange from the launch pad and traveling at 6,900 mph.

2303 GMT (6:03 p.m. EST)

T+plus 2 minutes, 14 seconds. The three air-ignited solid rocket boosters have burned out and separated. The rocket is now flying solely on the power generated by the liquid-fueled first stage main engine.

2302 GMT (6:02 p.m. EST)

T+plus 1 minute, 45 seconds. The air-lit boosters continue to burn along with the main engine. The vehicle is 16 miles in altitude, 36 miles downrange from the launch pad and traveling at 3,400 mph.

2302 GMT (6:02 p.m. EST)

T+plus 1 minute, 12 seconds. All six ground-start solid rocket boosters have burned out of propellant and separated from the Delta 2's first stage. A moment before the jettison occurred, the three remaining motors strapped to rocket ignited to continue assisting the rocket's RS-27A main engine on the push to space.

2301 GMT (6:01 p.m. EST)

T+plus 56 seconds. The Delta 2 rocket has passed through the region of maximum aerodynamic pressure during its atmospheric ascent.

2301 GMT (6:01 p.m. EST)

T+plus 45 seconds. The six solid rocket motors ignited on the launch pad have surpassed their period of maximum thrust. Each of the Alliant Techsystems-made boosters generate roughly 100,000 pounds of thrust.

2301 GMT (6:01 p.m. EST)

T+plus 35 seconds. Speed has hit Mach 1.

2301 GMT (6:01 p.m. EST)

T+plus 20 seconds. The main engine and all six ground-lit solid boosters are burning to boost the 12-story rocket into the Florida sky.

2301 GMT (6:01 p.m. EST)

LIFTOFF! Liftoff of the ULA Delta 2 rocket launching NASA's THEMIS mission to probe the physics of Earth's auroras. And the vehicle has cleared the tower.

2300 GMT (6:00 p.m. EST)

T-minus 30 seconds. SRB ignitors will be armed at T-minus 11 seconds.

The launch ignition sequence will begin in the final two seconds of the countdown when a ULA engineer pushes the engine start switch. The process begins with ignition of the two vernier engines and first stage main engine start. The six ground-lit solid rocket motors then light at T-0 for liftoff.

2300 GMT (6:00 p.m. EST)

T-minus 1 minute. Sixty seconds from launch. The vehicle's second stage hydraulic pump has gone to internal power after its pressures were verified acceptable.

2259 GMT (5:59 p.m. EST)

T-minus 75 seconds. The Air Force's Eastern Range has given the all-clear to launch.

2259 GMT (5:59 p.m. EST)

T-minus 100 seconds. First stage LOX topping to 100 percent is underway.

2259 GMT (5:59 p.m. EST)

T-minus 2 minutes. Pressurization of the first stage liquid oxygen is now beginning. Puffs of vapor from a relief valve on the rocket will be seen in the remainder of the countdown as the tank pressure stabilizes.

2258 GMT (5:58 p.m. EST)

T-minus 2 minutes, 30 seconds. The THEMIS spacecraft have been declared "go" for launch.

2258 GMT (5:58 p.m. EST)

T-minus 3 minutes and counting. The rocket's third stage safe and arm devices are being armed. The third stage will boost the THEMIS spacecraft from a low-Earth orbit to a highly elliptical orbit with a high point of 49,500 nautical miles.

2257 GMT (5:55 p.m. EST)

T-minus 3 minutes, 45 seconds. The Delta 2 rocket's systems are now transferring to internal power for launch.

2257 GMT (5:55 p.m. EST)

T-minus 4 minutes and counting! The Delta 2 rocket is ready to launch the five THEMIS spacecraft at 6:01 p.m. EST from pad 17B at Cape Canaveral Air Force Station in Florida.

The THEMIS probes will fly in highly elliptical orbits around Earth to find the origin of explosive events, called substorms, that trigger auroral sky shows in the form of the Northern and Southern Lights.

2256 GMT (5:56 p.m. EST)

The technical issue has been put to rest. The count will resume in one minute.

2254 GMT (5:54 p.m. EST)

Three minutes remain in the built-in hold. Liftoff is still targeted for 6:01 p.m., pending the third stage issue and a "go" from the launch director to resume the count.

2252 GMT (5:52 p.m. EST)

The launch team has been polled to give a "go" for liftoff. Officials are awaiting resolution of the third stage issue.

2251 GMT (5:51 p.m. EST)

NASA launch manager Chuck Dovale says a third stage issue is being discussed.

2251 GMT (5:51 p.m. EST)

The THEMIS spacecraft cargo atop the Delta 2 rocket are switching to internal power for launch.

2247 GMT (5:47 p.m. EST)

T-minus 4 minutes and holding. The countdown has entered the final planned built-in hold. This is a scheduled 10-minute pause leading to today's liftoff at 6:01 p.m. for the Delta 2 rocket and THEMIS spacecraft.

During the hold, officials will poll the various team members in the "soft blockhouse," Range Operations Control Center and Mission Directors Center.

2245 GMT (5:45 p.m. EST)

Weather conditions remain "go" for launch.

2244 GMT (5:44 p.m. EST)

Liquid oxygen topping to the tank's 100 percent level is underway.

2241 GMT (5:41 p.m. EST)

Now 20 minutes from liftoff. The first stage kerosene fuel tank is being pressurized for flight.

2236 GMT (5:36 p.m. EST)

T-minus 15 minutes and counting. The countdown has resumed following the planned hold. Clocks will tick down to T-minus 4 minutes where the final hold is scheduled. Liftoff of the Delta rocket from Cape Canaveral is slated to occur at 6:01 p.m. EST.

2232 GMT (5:32 p.m. EST)

A launch team readiness poll for a "ready" status to resume the countdown found no constraints to pressing ahead as scheduled.

2231 GMT (5:31 p.m. EST)

Now 30 minutes to launch. There are no issues being reported by NASA.

2228 GMT (5:28 p.m. EST)

A poll by NASA launch manager Chuck Dovale concluded with the space agency team giving a "go" to proceed with the count.

2225 GMT (5:25 p.m. EST)

Launch team and management polls will be coming up shortly. Once the countdown resumes, clocks will tick down to the T-minus 4 minute mark where a 10-minute hold is planned.

2216 GMT (5:16 p.m. EST)

T-minus 15 minutes and holding. The countdown has entered a planned 20-minute built-in hold. The pause is designed to give the launch team a chance to work any problems or catch up on activities that might be running behind schedule. Engineers will also have time to examine all the data from the just-completed steering tests.

Upper level winds continue to be "go" for launch.

2211 GMT (5:11 p.m. EST)

The first stage steering checks just finished, completing this slew tests for today's countdown.

2207 GMT (5:07 p.m. EST)

Slews of the second stage engine are complete.

2206 GMT (5:06 p.m. EST)

Technicians are starting the "slew" or steering checks of the first and second stage engines. These are gimbal tests of the nozzles on the first stage main engine and twin vernier engines and second stage engine to ensure the rocket will be able to steer itself during launch.

2201 GMT (5:01 p.m. EST)

Sixty minutes and counting. Range Safety just completed inhibited checks of the command destruct receivers. The CRDs would be used in destroying the Delta rocket should the vehicle veer off course or malfunction during the launch.

Meanwhile, data from the most recent weather balloon indicates conditions aloft are still "go" for launch today.

2145 GMT (4:45 p.m. EST)

Loading of the Delta 2 rocket's first stage liquid oxygen tank has concluded. The operation took 27 minutes and 2 seconds today. The tank will be replenished through the countdown to replace the supercold liquid oxygen that naturally boils away.

The rocket is now fully fueled for liftoff at 6:01 p.m. EST. The vehicle's first stage was successfully loaded with RP-1 kerosene fuel along with the liquid oxygen over the past hour-and-a-half. The second stage was filled with its storable nitrogen tetroxide and Aerozine 50 fuels earlier this week. The nine strap-on booster rockets and third stage use solid propellants.

At this time, everything remains "go" for launch.

2142 GMT (4:42 p.m. EST)

The first stage liquid oxygen tank just reached the 95 percent full level. The "rapid load" valve was closed, with the slower "fine load" phase continuing to fill the tank.

2131 GMT (4:31 p.m. EST)

Now 90 minutes to launch. The upper level winds remain "go" and there are no technical issues being worked in the countdown.

2127 GMT (4:27 p.m. EST)

Now 10 minutes into liquid oxygen loading. The process should take about 25 minutes in total.

2117 GMT (4:17 p.m. EST)

Cryogenic liquid oxygen, chilled to Minus-298 degrees F, has started flowing from the storage reservoir at Complex 17, through plumbing and into the bottom of the ULA Delta 2 rocket. The LOX will be consumed by the first stage main engine during the first four-and-a-half minutes of flight along with the 10,000 gallons of RP-1 kerosene already loaded aboard the vehicle.

2114 GMT (4:14 p.m. EST)

The official "go" has been given to start filling the rocket's first stage with liquid oxygen. Activities to prepare for the operation have started.

2105 GMT (4:05 p.m. EST)

NASA launch manager Chuck Dovale just polled the NASA management team to verify there are no constraints with proceeding into liquid oxygen loading. No technical issues with rocket systems, the THEMIS spacecraft or Range are being worked. And upper level winds are favorable thus far today.

2059 GMT (3:59 p.m. EST)

A weather briefing just concluded for launch management in advance of the decision to begin liquid oxygen loading into the first stage.

"Looking at a real good day today," launch weather officer Joel Tumbiolo says.

Ground winds are well within limits and skies are clear.

The upper level wind shear in the 10,000 to 20,000 foot range that was the problem yesterday has eased. The largest shear is around 25,000 feet. But the conditions are "go" for launch so far.

2053 GMT (3:53 p.m. EST)

The launch team has completed work to turn on and configure the Delta's onboard guidance computer.

2048 GMT (3:48 p.m. EST)

Upper level winds are considered "go" for launch based on the weather balloons dispatched thus far in the countdown, a NASA spokeswoman says. Further balloons will be released to continue monitoring the winds aloft for today's launch.

2045 GMT (3:45 p.m. EST)

The first stage fuel tank of the Delta 2 rocket has been fully loaded for today's planned 6:01 p.m. launch. The tank was filled with a highly refined kerosene, called RP-1, during a 19-minute, 30-second process that concluded at 3:45 p.m. EST.

The next major task in the count will be loading super-cold cryogenic liquid oxygen into the first stage starting in about 30 minutes.

The kerosene and liquid oxygen will be consumed by the stage's Pratt & Whitney Rocketdyne RS-27A main engine and twin vernier steering thrusters during the initial four-and-a-half minutes of flight.

2041 GMT (3:41 p.m. EST)

Rapid-loading of the RP-1 tank has concluded with 9,800 gallons already aboard the rocket. Fine load is continuing to finish filling the tank.

2039 GMT (3:39 p.m. EST)

The launch team has computed that today's full load for the first stage fuel tank is 10,074 gallons.

Once the tank is filled to 98 percent or 9,800 gallons, the "rapid load" valve will be closed and the slower "fine load" phase will continue to top off the tank.

2033 GMT (3:33 p.m. EST)

The first stage tank is now half full.

2025 GMT (3:25 p.m. EST)

Fueling is now underway. About 10,000 gallons of the kerosene propellant are pumping into the base of the rocket from storage tanks at pad 17B as fueling of the Delta 2's first stage begins for today's launch.

2021 GMT (3:21 p.m. EST)

First stage fueling preparations are starting. After verifying valves, sensors, flow meters and equipment are ready, a highly-refined kerosene fuel will begin flowing into the vehicle a few minutes from now.

2019 GMT (3:19 p.m. EST)

First stage helium and nitrogen pressurization is complete. Next up will be loading the Delta rocket's first stage with RP-1 fuel.

2005 GMT (3:05 p.m. EST)

Workers have cleared the Complex 17 area in advance of the hazardous portion in today's launch operation. The pad clear status will allow the start of activities such as pressurizing the helium and nitrogen storage tanks inside the rocket's first and second stages, along with the second stage fuel and oxidizer tanks.

2001 GMT (3:01 p.m. EST)

T-minus 150 minutes and counting. The Terminal Countdown has started for today's attempt to launch the Delta 2 rocket carrying NASA's THEMIS mission.

The next three hours will be spent fueling the rocket, activating systems and performing final testing before liftoff at 6:01 p.m. EST (2301 GMT) from pad 17B at Cape Canaveral Air Force Station in Florida.

The countdown clocks currently stand at T-minus 150 minutes. Two holds -- totaling 30 minutes in duration -- are planned at T-minus 15 minutes and T-minus 4 minutes that will lead toward a T-0 and liftoff at the opening of today's 18-minute launch window.

1901 GMT (2:01 p.m. EST)

T-minus 150 minutes and holding. Clocks are entering a planned 60-minute built-in hold prior to the start of the Terminal Countdown.

1615 GMT (11:15 a.m. EST)

The gantry has wheeled back and the Delta rocket stands poised under bright blue skies. Liftoff time is 6:01 p.m. EST today.

Upper level winds will be the main concern this afternoon. Analysts using weather balloon data on the wind speeds and directions will determine late in the countdown whether the conditions pose a structural concern for the rocket as well as threaten the vehicle's ability to remain under control while ascending through the winds.

1544 GMT (10:44 a.m. EST)

The mobile service tower is in motion right now. The massive structure on wheels is rolling away from the Delta 2 rocket for today's countdown.

The gantry had been returned to its position around the rocket after the scrub.

FRIDAY, FEBRUARY 16, 2007

Unfavorable upper level winds between 10,000 and 20,000 feet forced launch of the ULA Delta 2 rocket to be scrubbed Friday evening. The final weather balloon data indicated the conditions aloft weren't safe for the rocket's flight. The information came just as the launch team was about to resume the countdown from the T-minus 4 minute hold point.

"We do have some red winds. We're going to have to stand by. Do not come out of the hold," the launch team was instructed at 6:00 p.m.

A moment later the launch was postponed for the day.

"We've run out of our upper air balloon options. We will scrub for tonight," the team was told.

A 24-hour turnaround plan was put in place to prepare for another countdown and launch attempt on Saturday. The launch window will be 6:01 to 6:19 p.m. EST.

2310 GMT (6:10 p.m. EST)

Saturday's weather forecast predicts scattered clouds at 3,000 feet, westerly winds of 10 gusting to 18 knots and a temperature of 54 to 56 degrees for the 6:01 to 6:19 p.m. launch window.

The upper level winds are expected to remain strong.

2308 GMT (6:08 p.m. EST)

Draining of the first stage liquid oxygen tank is about to begin. The launch crew is moving forward with a 24-hour delay plan to prepare for another countdown tomorrow.

2302 GMT (6:02 p.m. EST)

The launch team is beginning the procedures to safe the rocket and spacecraft following today's launch postponement.

2300 GMT (6:00 p.m. EST)

SCRUB! The upper level winds have now been deemed "no go" for tonight. The latest weather balloon that officials had hoped would show acceptable conditions found unfavorable winds aloft.

Another countdown will be performed Saturday, with a planned liftoff time of 6:01 p.m. EST. The day's launch window extends to 6:19 p.m. EST.

Read our earlier status center coverage.

Copyright 2007 SpaceflightNow.com, all rights reserved.



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