BY JUSTIN RAY

Follow the countdown and first launch of Boeing's Delta 4 rocket and the DMSP F17 weather satellite. Reload this page for the very latest on the mission.

SATURDAY, NOVEMBER 4, 2006

A globe-spanning weather observatory successfully launched into space Saturday aboard a Boeing Delta 4 rocket, giving the U.S. military a new set of orbiting eyes to help plan air, sea and land operations around the world. Read our launch story.

A launch photo gallery is available here.

1548 GMT (10:48 a.m. EST)

The spent second stage of the Delta 4 rocket has just completed its propellant depletion firing. This is a normal event after payload deployment in which a rocket stage ignites its engine to burn away the remaining fuel reserves. The purpose of the maneuver is safing the stage from exploding in orbit and creating hazardous space debris.

But the lengthy three-minute depletion firing today actually resulted in a deorbit burn for the motor. The stage is now plunging back into the atmosphere over the Pacific Ocean. Any surviving pieces will impact the water a short time from now.

This concludes our live coverage of today's launch. Check back later for launch photos and a wrapup story on the liftoff of DMSP F17.

1450 GMT (9:50 a.m. EST)

"I'm extremely proud of the precision with which the base and the Vandenberg Launch Team planned and executed this Delta 4 mission," said Col. Terry Djuric, the 30th Space Wing vice commander at Vandenberg Air Force Base and the spacelift commander for today's launch. "This West Coast launch helped kick off the Air Force's year-long 60th anniversary celebration."

Vandenberg's 4th Space Launch Squadron oversees the Evolved Expendable Launch Vehicle programs -- Delta 4 and Atlas 5 -- at the base. Lt. Col. David Goldstein, the squadron commander, served as the Air Force launch director for this mission.

"From an operational perspective, this was another perfectly executed mission by the entire team," Goldstein said. "Vandenberg worked extremely well with our launch partners to bring everything together for that one perfect shot."

1411 GMT (9:11 a.m. EST)

T+plus 18 minutes, 27 seconds. SPACECRAFT SEPARATION! The Defense Meteorological Satellite Program F17 spacecraft has been released from the Boeing Delta 4 rocket, completing today's ascent from Vandenberg Air Force Base in California.

The Lockheed Martin-built craft carries a sophisticated suite of weather instruments to observe virtually the entire planet twice daily. Data from DMSP satellites is used to create global weather forecasts that military commanders and strategic planners rely upon.

The satellites can track weather systems by visible and infrared cloud-cover imagery, day or night, plus monitor ice and snow coverage, pollution and fires.

The new DMSP F17 craft will replace a remarkably long-lasting satellite launched in March 1995 with a three-year design life.

1411 GMT (9:11 a.m. EST)

T+plus 18 minutes, 10 seconds. The vehicle is now confirmed to be in the payload deploy orientation.

1410 GMT (9:10 a.m. EST)

T+plus 17 minutes, 30 seconds. About a minute from completing this seventh flight of Boeing's Delta 4 rocket.

1409 GMT (9:09 a.m. EST)

T+plus 16 minutes. The rocket stage will be reorienting itself into the proper position for releasing the payload. Separation is expected less than three minutes from now.

1408 GMT (9:08 a.m. EST)

T+plus 15 minutes, 5 seconds. Engine cutoff. The powered phase of this morning's Delta 4 mission to loft the DMSP F17 payload has been concluded. The vehicle has reached polar orbit.

1406 GMT (9:06 a.m. EST)

T+plus 13 minutes. To see the track the rocket is following this morning, click here.

1405 GMT (9:05 a.m. EST)

T+plus 12 minutes, 45 seconds. The rocket is 442 miles in altitude with a velocity of 19,740 feet per second.

1404 GMT (9:04 a.m. EST)

T+plus 11 minutes, 15 seconds. Delta is passing an altitude of 416 miles with a speed of more than 17,600 feet per second.

1403 GMT (9:03 a.m. EST)

Now 10 minutes since liftoff. About five minutes remain in this burn by the second stage.

1402 GMT (9:02 a.m. EST)

T+plus 9 minutes, 40 seconds. The rocket is 372 miles in altitude with a velocity of 15,867 feet per second.

1402 GMT (9:02 a.m. EST)

T+plus 9 minutes. The RL10 engine is burning a mixture of liquid oxygen and liquid hydrogen cryogenic propellants.

1401 GMT (9:01 a.m. EST)

T+plus 8 minutes. The RL10 burn continuing to go well.

1400 GMT (9:00 a.m. EST)

T+plus 7 minutes, 30 seconds. The second stage engine continues to fire. This burn will place the vehicle into polar orbit for deployment of the DMSP weather satellite.

1359 GMT (8:59 a.m. EST)

T+plus 6 minutes, 35 seconds. The rocket is 243 miles in altitude with a velocity of 13,888 feet per second.

1359 GMT (8:59 a.m. EST)

T+plus 6 minutes. Good chamber pressure being reported from the RL10 engine as it thrusts to reach orbit.

1358 GMT (8:58 a.m. EST)

T+plus 5 minutes, 8 seconds. The two-piece protective payload fairing enclosing the DMSP spacecraft atop the rocket has separated.

1357 GMT (8:57 a.m. EST)

T+plus 4 minutes, 34 seconds. The cryogenic RL10B-2 upper stage engine has ignited!

1357 GMT (8:57 a.m. EST)

T+plus 4 minutes, 25 seconds. The Common Booster Core first stage and the attached interstage have been separated in one piece from the Delta 4's upper stage. The upper stage engine's extendible nozzle is dropping into position.

1357 GMT (8:57 a.m. EST)

T+plus 4 minutes, 20 seconds. MECO! Main engine cutoff confirmed as the RS-68 powerplant shuts down.

1356 GMT (8:56 a.m. EST)

T+plus 4 minutes. The RS-68 powerplant is throttling down to about 57 percent as planned in preparation for shutdown.

1356 GMT (8:56 a.m. EST)

T+plus 3 minutes. The RS-68 is consuming nearly a ton of propellants per second as the powerplant pushes the Delta 4 rocket closer to the edge of space.

1355 GMT (8:55 a.m. EST)

T+plus 2 minutes, 30 seconds. The rocket now weighs half of what it did at liftoff. The main engine burning well.

1355 GMT (8:55 a.m. EST)

T+plus 2 minutes. A smooth flight for the Delta 4 rocket.

1354 GMT (8:54 a.m. EST)

T+plus 95 seconds. Altitude 9 miles.

1354 GMT (8:54 a.m. EST)

T+plus 85 seconds. The vehicle is now traveling at Mach 1 and passing through the region of maximum aerodynamic pressure.

1354 GMT (8:54 a.m. EST)

T+plus 60 seconds. The rocket is 2 miles in altitude. The main engine is firing at full throttle as the vehicle slowly climbs away from Vandenberg Air Force Base.

1353 GMT (8:53 a.m. EST)

T+plus 30 seconds. The Delta 4 rocket is steering to the proper trajectory for its southerly flight downrange over the Pacific Ocean.

1353 GMT (8:53 a.m. EST)

LIFTOFF! Liftoff of the Boeing Delta 4 launching a globe-spanning weather observatory for the U.S. military. And the vehicle has cleared the tower!

1352 GMT (8:52 a.m. EST)

T-minus 12 seconds. Residual hydrogen burnoff ignitors have been fired beneath the main engine.

1352 GMT (8:52 a.m. EST)

T-minus 30 seconds. Green board. All systems remain "go" for launch.

1352 GMT (8:52 a.m. EST)

T-minus 35 seconds. Second stage liquid hydrogen tank is at flight level.

1352 GMT (8:52 a.m. EST)

T-minus 1 minute and counting. The ignition conditions for the RS-68 main engine are "go." The terminal countdown sequencer will take control at T-minus 8.5 seconds. Ignition of the RS-68 powerplant will follow at T-minus 5.5 seconds. The engine powers up to the 102 percent level of thrust for a computer-controlled checkout before liftoff.

1351 GMT (8:51 a.m. EST)

T-minus 65 seconds. The Air Force-controlled Range has given its "go" for launch.

1351 GMT (8:51 a.m. EST)

T-minus 70 seconds. Second stage liquid oxygen tank has been secured at flight level.

1351 GMT (8:51 a.m. EST)

T-minus 75 seconds. The liquid hydrogen fuel tank on the second stage is being secured for launch.

1351 GMT (8:51 a.m. EST)

T-minus 2 minutes. Securing of the second stage liquid oxygen tank is starting.

1350 GMT (8:50 a.m. EST)

T-minus 2 minutes, 12 seconds. First stage cryogenic tanks are reported at flight levels and pressures.

1350 GMT (8:50 a.m. EST)

T-minus 3 minutes and counting. The first stage liquid hydrogen and liquid oxygen systems are being secured.

1349 GMT (8:49 a.m. EST)

T-minus 4 minutes and counting. Vehicle ordnance is being armed.

1348 GMT (8:48 a.m. EST)

T-minus 4 minutes, 20 seconds. The systems of the first and second stages of the Delta 4 rocket have switched from ground-fed power to internal batteries for launch.

1348 GMT (8:48 a.m. EST)

T-minus 5 minutes and counting! Clocks are ticking down the final minutes of today's countdown for launch of Boeing's Delta 4 rocket carrying the DMSP F17 military weather satellite. Liftoff is set to occur at 5:53 a.m. local time from Space Launch Complex 6 at Vandenberg Air Force Base, California.

1347 GMT (8:47 a.m. EST)

Approval has been given to resume the countdown for liftoff at 1353 GMT.

1345 GMT (8:45 a.m. EST)

The launch pad swing arm retraction system pins are being pulled. The two arms will be rotated away from the Delta 4 rocket at liftoff.

1344 GMT (8:44 a.m. EST)

All launch team stations reported a "ready" to proceed with Terminal Count for liftoff at 1353 GMT. Weather is "go" as well. Now, final instructions are being read to the team.

1343 GMT (8:43 a.m. EST)

Launch team readiness polling is beginning. Now 10 minutes from liftoff time.

1341 GMT (8:41 a.m. EST)

Boeing flight director Rich Murphy is performing his readiness poll for continuing the countdown.

1338 GMT (8:38 a.m. EST)

The DMSP spacecraft has switched from ground-fed power to internal batteries for launch.

1332 GMT (8:32 a.m. EST)

T-minus 5 minutes and holding. The countdown has entered a planned 16-minute hold. This pause is designed to give the launch team the opportunity to catch up on any work running behind schedule and verify all is in readiness for the final moments of the count. A series of management polls will be conducted during the hold to give approval to proceed with the launch.

1322 GMT (8:22 a.m. EST)

T-minus 15 minutes and counting. The countdown is headed to the T-minus 5 minute point where a 16-minute hold is planned. Liftoff is targeted for 1353 GMT, the revised opening of today's launch window.

1303 GMT (8:03 a.m. EST)

Pressurization of the RS-68 first stage main engine spin start system has been completed.

1301 GMT (8:01 a.m. EST)

The first stage Common Booster Core slews have been finished, wrapping up this pre-launch program.

1256 GMT (7:56 a.m. EST)

The second stage engine steering checks have been completed. The first stage tests are next.

1248 GMT (7:48 a.m. EST)

The team is now preparing to conduct the steering checks of the Delta 4 rocket's engines, starting with the second stage RL10 engine.

1239 GMT (7:39 a.m. EST)

The Air Force-controlled Western Range has performed the inhibited command destruct receiver checks. This ensures safety personnel can destroy the Delta 4 rocket if it veers off course.

1228 GMT (7:28 a.m. EST)

Health checks of the command receiver decoder devices on the rocket are starting. These units would hear the command from Range Safety and trigger the Delta 4's destruct system if a problem occurred during launch.

1225 GMT (7:25 a.m. EST)

We have posted some pictures of the Delta 4 rocket on the launch pad that were taken yesterday afternoon and last night during tower rollback. See the images here.

1218 GMT (7:18 a.m. EST)

The target liftoff time is expected to shift a minute later due to a Collision Avoidance, or COLA, blackout period that includes the first minute of today's launch window. COLAs are short periods of time in which a rocket cannot lift off, ensuring the vehicle's trajectory does not take it too close to another object already in space.

So liftoff is now anticipated at 5:53 a.m. local time, with a 9-minute launch window available.

1214 GMT (7:14 a.m. EST)

The RF link checks between the rocket and ground have been completed and verified acceptable.

1205 GMT (7:05 a.m. EST)

Today's launch will be the 320th for a Delta rocket since the program began in 1960 and the seventh of 2006. It is the seventh flight for Delta 4 since debuting in 2002 and the third time a Delta 4-Medium configuration has flown.

1152 GMT (6:52 a.m. EST)

Now two hours to go until liftoff time.

1135 GMT (6:35 a.m. EST)

Things are very quiet now that the rocket is fueled for launch. Ranfe Safety and engine steering tests will be coming up a little later in the count.

1112 GMT (6:12 a.m. EST)

Topping of the second stage liquid oxygen tank has commenced, putting all four fuel tanks aboard the Delta 4 rocket in stable replenish mode to replace the propellants that boil off given their supercold nature.

1048 GMT (5:48 a.m. EST)

Post-filling tests on the second stage liquid oxygen and liquid hydrogen systems are underway.

1032 GMT (5:32 a.m. EST)

Interrogation checks are starting on the rocket's C-band tracking beacon.

1012 GMT (5:12 a.m. EST)

The second stage fueling operations are continuing. The first stage liquid hydrogen tank is entering the topping phase.

0952 GMT (4:52 a.m. EST)

Four hours and counting down to launch of the Boeing Delta 4 rocket. Forecasters continue to predict a 40 percent chance of acceptable conditions at launch time this morning. Gusty winds at the pad are the main worry.

The forecast calls for a blanket of low stratus clouds shrouding the launch pad and only a mile of visibility, high cirrus clouds at 25,000 feet, a temperature between 52 and 57 degrees F and northerly winds at 15 to 20 knots.

Sunday's outlook for the backup launch day predicts high cirrus clouds, good visibility, temperatures in the mid-50s and northeasterly winds 15 to 20 knots. The wind limit varies on direction and the northeasterly forecast means there is only a 20 percent chance of acceptable conditions for liftoff tomorrow.

0941 GMT (4:41 a.m. EST)

The second stage conditioning on the liquid hydrogen side has finished. Loading of the tank is commencing. This is the last of the rocket's four cryogenic supplies to be loaded in today's countdown to launch.

Space Launch Complex 6 has giant sphere-shaped fuel tanks to store the cryogenic liquid oxygen and liquid hydrogen for the Delta 4 rocket.

The cryogenics flow from the storage tanks, through pipes to the base of the pad. For the first stage, the propellants are routed up to the launch table upon which the rocket sits. Tail service masts, the large box-like structures at the base of the vehicle, feed the oxygen and hydrogen to the stage in separate umbilicals. The second stage receives its cryos from a swing arm that extends from the Fixed Umbilical Tower to the front-side of the rocket.

0933 GMT (4:33 a.m. EST)

The chilldown of the second stage liquid oxygen system is being completed, clearing the way for loading the vehicle's tank.

0917 GMT (4:17 a.m. EST)

Chilldown conditioning of the upper stage liquid hydrogen system is about to begin.

0910 GMT (4:10 a.m. EST)

The first stage liquid oxygen loading has finished. The tank is loaded with its supercold oxidizer that is chilled to Minus-298 degrees F. Topping will be completed a little later, after the launch team performs vent and relief checks.

The liquid oxygen chilldown for the rocket's second stage is now beginning in advance of filling that tank.

0852 GMT (3:52 a.m. EST)

Now inside the final five hours of the launch countdown for the Delta 4 rocket and DMSP F17 spacecraft. Launch time remains set for 1352 GMT (5:52 a.m. local; 8:52 a.m. EST) from Vandenberg Air Force Base, California.

Fueling of the first stage with liquid oxygen and liquid hydrogen cryogenic fuel continues at the pad.

0839 GMT (3:39 a.m. EST)

First stage liquid hydrogen tanking operation is transitioning from "slow-fill" to "fast-fill" mode.

0827 GMT (3:27 a.m. EST)

Liquid hydrogen propellant is beginning to flow into the first stage. This "slow-fill" will be sped up to "fast-fill" after a small portion of the tank is loaded.

Chilled to Minus-423 degrees Fahrenheit, the liquid hydrogen will be consumed by the RS-68 main engine along with liquid oxygen during the first four minutes of the launch.

0758 GMT (2:58 a.m. EST)

The first stage liquid oxygen chilldown is complete. Fueling will begin in the "slow-fill" mode to load a small percentage of the tank. Then the process will speed up to the "fast-fill" mode until the tank is nearly full.

0748 GMT (2:48 a.m. EST)

The next step in preparing to fuel the Delta 4 rocket is the cold gas chilldown conditioning of the first stage liquid hydrogen system.

0744 GMT (2:44 a.m. EST)

Chilldown of the first stage liquid oxygen system is starting. This preps the tank and pumping to guard against shock with the supercold oxidizer begins flowing into the rocket a short time from now.

0722 GMT (2:22 a.m. EST)

T-minus 6 hours, 15 minutes and counting! The Terminal Countdown has begun for today's launch of the Boeing Delta 4 rocket with the DMSP F17 weather observatory. The countdown has one planned built-in hold at T-minus 5 minutes for 15 minutes, leading to liftoff at 1352 GMT (5:52 a.m. local; 8:52 a.m. EST) from Vandenberg Air Force Base, California.

The weather forecast still indicates a 40 percent chance of acceptable conditions during the 10-minute launch opportunity this morning. Northerly winds at 15 to 20 knots, gusting to 25 knots, and thick clouds are the two concerns.

0702 GMT (2:02 a.m. EST)

Man stations for Terminal Count. That announcement has been made for launch team members to take their seats in preparation to continue with today's countdown.

FRIDAY, NOVEMBER 3, 2006

While the launch pad stood nearly invisible from fog and low clouds, the 425-foot tall mobile service tower was rolled away from the Boeing Delta 4 rocket Friday night, leaving the 20-story booster exposed for liftoff Saturday morning.

Earlier on Friday, crews at Space Launch Complex 6 retracted the 27-story mobile assembly shelter. This structure, which moves along rails, was built in the 1980s when the pad was being prepared for space shuttle launches. It was designed to shield the shuttle from the weather during on-pad assembly of the vehicle's solid rocket boosters, external tank and mating of the orbiter.

Countdown clocks will enter an hour-long hold at the T-minus 6 hour, 15 minute mark at 0622 GMT. During this time, the entire launch team and mission managers will report for duty at their consoles and verify all systems are ready for proceeding with the Terminal Countdown.

Fueling of the Delta 4's first and second stages with supercold liquid oxygen and liquid hydrogen propellants will get underway in the final six hours prior to launch time. It takes roughly three hours to fully load all four tanks on the rocket.

Next, testing of communications links between the rocket and Air Force Western Range will occur. Steering checks of the first stage RS-68 engine and second stage RL10 powerplant are performed about an hour before liftoff.

A 15-minute build-in hold is slated for T-5 minutes, during which time teams will go through final polling for launch clearance. As the count resumes, rocket systems will transition to internal power, the ordnance armed and all four cryogenic fuel tanks secured for flight.

About 15 seconds before liftoff, sparklers are fired beneath the RS-68 main engine to burn away excess hydrogen before ignition.

The computer sequencer assumes control of the countdown at T-minus 8.5 seconds. Command to light the main engine comes at T-minus 5.5 seconds, creating a large fireball around the base of the rocket from the hydrogen-rich ignition of the powerplant. The engine begins to produce thrust at T-minus 3.3 seconds and should reach full power by T-minus 1 second to undergo the computer-run check of key parameters.

Four hold-down bolts pop apart at T-0 to release the Delta 4 rocket for its liftoff from Space Launch Complex 6 carrying the DMSP F17 satellite.

2100 GMT (4 p.m. EST)

Preparations remain on schedule for Saturday morning's launch of the Boeing Delta 4 rocket from Vandenberg Air Force Base, California.

The latest launch weather forecast, however, now predicts a 40 percent chance of acceptable conditions. The earlier forecast predicted a 70 percent chance. The bleaker outlook is due to the direction of gusty winds expected at launch time. The weather team says winds will be north-to-northeasterly at 15 to 20 knots.

Sunday's backup launch opportunity has just a 20 percent chance of allowable weather due to the windy conditions.

Thick clouds will be an issue to watch both days, too.

THURSDAY, NOVEMBER 2, 2006

A global weather observatory for the U.S. military is scheduled for launch early Saturday aboard a Boeing Delta 4 rocket.

Liftoff from California's Vandenberg Air Force Base is scheduled for 5:52 a.m. local time (8:52 a.m. EST; 1352 GMT). The available window to launch extends 10 minutes.

"Literally thousands of people have put tremendous effort into this," Col. Brad Smith, commander of the Defense Meteorological System Group, said in an interview this week. "We're all looking forward to the launching on Saturday. It's really a great moment. We've been very fortunate, the schedule has held amazingly well and the launch flow has gone amazingly well. I just really feel blessed to be associated with this whole team."

The two-stage Delta 4-Medium booster will haul the 2,700-pound Defense Meteorological Satellite Program F17 spacecraft into a polar orbit around Earth. Deployment of the satellite from the upper stage is expected 18 minutes and 18 seconds after liftoff.

The Lockheed Martin-built craft carries a sophisticated suite of weather instruments to observe virtually the entire planet twice daily. Data from DMSP satellites is used to create global weather forecasts that military commanders and strategic planners rely upon.

The satellites can track weather systems by visible and infrared cloud-cover imagery, day or night, plus monitor ice and snow coverage, pollution and fires.

The new DMSP F17 craft will replace a remarkably long-lasting satellite launched in March 1995 with a three-year design life.

"After several years of building, integrating, upgrading and testing DMSP F17, our second Block 5D-3 spacecraft, we're eagerly anticipating this launch so that this satellite can carry out its vital mission of supporting our warfighters," said Michael O'Hara, Lockheed Martin DMSP program director. "Our partnership with the Air Force dates to the very beginning of the DMSP program with a common goal of ensuring that commanders have access to environmental data critical to the preparation and execution of military operations."

Saturday's launch -- valued at $445 million in combined rocket and satellite costs -- will be the second for the next-generation Delta 4 program from Vandenberg Air Force Base. The debut mission successfully flew in June with a classified spy satellite payload.

Delta 4's West Coast pad is Space Launch Complex 6 -- the site originally constructed in the 1960s for the Air Force's Manned Orbiting Laboratory space station project. But the program was cancelled. Then the complex was rebuilt in the 1980s for military space shuttle launches to polar orbit. Again, cancellation came before the first liftoff. The pad finally saw use by Lockheed Martin's Athena rockets in the 1990s.

Air Force weather forecasters predict a 70 percent chance of favorable conditions for Saturday morning's liftoff. Gusty winds and thick clouds are the two main worries.

"A weak shortwave ridge in the mid/upper levels is over central California. This feature is just down stream of a deep low pressure center off the Washington/Oregon coast. Through the period, the low center breaks down the weak ridge and moves eastward into the Pacific Northwest. As a result, the heavy precipitation and thick, mid-level cloudiness remains well north of the launch area," forecasters reported Thursday.

The launch time forecast predicts scattered stratus clouds at 500 feet and overcast cirrus clouds at 28,000 feet, visibility of 7 miles, a temperature between 52 and 57 degrees F and northerly winds of 15 to 20 knots.

Should the liftoff slip to Sunday for some reason, the outlook deteriorates considerably. Forecasters give only a 30 percent chance of acceptable conditions due to strong winds.