BY JUSTIN RAY

Follow the countdown and launch of the Boeing Delta 2 rocket with the U.S. Air Force's latest GPS navigation spacecraft. Reload this page for the very latest on the mission.

Video coverage for subscribers only:
VIDEO: DELTA ROCKET LIFTS OFF WITH GPS 2R-15 QT
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MONDAY, SEPTEMBER 25, 2006

One year to the day after the Global Positioning System constellation began a modernization effort to improve the accuracy of the navigation network, the next step in that upgrade blasted into space from Cape Canaveral, Florida.

Read our full story.

2047 GMT (4:47 p.m. EDT)

"I'm extremely pleased with today's launch, and thrilled to be part of this mission that enhances our nation's critical GPS capability. It culminates a tremendous team effort between our GPS customer, Boeing, the 45th Space Wing, the Aerospace Corporation, and the Launch and Range Systems Wing," said Col. James Planeaux, the director of the Delta Launch Systems Group and mission director for this launch.

"I am very proud of the team and its achievement, which extends the string of successful launches by the Space and Missile Systems Center to 46."

2021 GMT (4:21 p.m. EDT)

T+plus 91 minutes. Boeing is announcing a good deployment of the Air Force's Global Positioning System Block 2R-15 spacecraft by the Delta 2 rocket.

The $75 million GPS satellite is the second with modernized features that will transmit additional signals for military and civilian users, promising greater accuracy, added resistance to interference and enhanced performance.

The advancements will provide the military with a more robust jam-resistant signal and enable better targeting of GPS-guided weapons in hostile environments. The new civilian signal removes navigation errors caused by the Earth's ionosphere.

Lockheed Martin has built 21 of the GPS Block 2R satellites for the Air Force, with today marking the 15th launch. The first with added modernization updates was successfully deployed a year ago.

The spaceborne GPS network features 24 primary and several backup satellites flying in six orbital groupings. The Air Force began launching the fleet in 1989 and continues to send up new satellites to keep the navigation system in good health. There are 29 operational GPS satellites, not including the just-launched 2R-15.

GPS 2R-15 will assume the Plane A, Slot 2 position, taking over for the GPS 2-12 craft launched in February 1992. The aging satellite, which has long surpassed its expected life span, is showing symptoms of failure in its internal clock system.

To get the last bit of usefulness out of the old satellite, controllers plan to relocate it to the A4 slot within the GPS constellation to act as a backup for another craft.

2014 GMT (4:14 p.m. EDT)

T+plus 84 minutes. A playback of the recorded third stage telemetry from Guam to Cape Canaveral is being planned to confirm good performance by the motor.

2012 GMT (4:12 p.m. EDT)

T+plus 82 minutes. Communications with the GPS spacecraft have been established through its own tracking assets. It appears the third stage burned as planned and then deployed the payload.

2003 GMT (4:03 p.m. EDT)

T+plus 73 minutes. To recap, live data from the third stage was not available at Cape Canaveral. So confirmation of the motor's firing and deployment of the GPS payload was not possible in real-time. We're awaiting word from the satellite team that the craft's signal has been detected via its own tracking assets.

Meanwhile, the orbit reached by the rocket at the conclusion of the second burn of the second stage was normal with a high point of 672 miles, low point of 104 miles and inclination of 37.95 degrees.

1959 GMT (3:59 p.m. EDT)

T+plus 69 minutes. The team is awaiting word from the satellite controllers to verify the GPS spacecraft is flying on its own.

1958 GMT (3:58 p.m. EDT)

T+plus 68 minutes. Real-time confirmation of spacecraft separation from the launch vehicle isn't possible right now due to the lack of telemetry back at Cape Canaveral.

1956 GMT (3:56 p.m. EDT)

T+plus 66 minutes, 10 seconds. The third stage -- a Thiokol Star 48B motor -- should have completed its burn by now. However, live data is not available at the Cape telemetry station to verify this event.

1954 GMT (3:54 p.m. EDT)

T+plus 64 minutes, 30 seconds. Live data from the third stage is not being received back at Cape Canaveral. So real-time confirmation of spinup, separation and ignition of the third stage is not possible at the moment.

1953 GMT (3:53 p.m. EDT)

T+plus 63 minutes, 25 seconds. SECO 2. 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.

1953 GMT (3:53 p.m. EDT)

T+plus 63 minutes. Confirmation is now being received indicating that the Delta 2 rocket's second stage engine is firing.

1952 GMT (3:52 p.m. EDT)

T+plus 62 minutes, 40 seconds. Guam has acquired the rocket's signal. The station will cover the second stage burn, stage separation, the third stage burn and deployment of the payload.

1951 GMT (3:51 p.m. EDT)

T+plus 61 minutes. Second stage engine restart is about 90 seconds away.

1950 GMT (3:50 p.m. EDT)

T+plus 60 minutes. The Delta 2 rocket should be soaring within range of the Guam tracking station in the next two minutes.

1935 GMT (3:35 p.m. EDT)

T+plus 45 minutes. The thermal conditioning roll of the rocket will end in about 11 minutes. Ignition of the second stage is up coming in 17 minutes.

1920 GMT (3:20 p.m. EDT)

T+plus 30 minutes. The vehicle just passed out of range from the Ascension Island tracking site in the central Atlantic Ocean. The next station to acquire the rocket's signal will be Guam a half-hour from now.

As this coast phase of the launch continues, you can see a map of the rocket's planned track here.

1916 GMT (3:16 p.m. EDT)

T+plus 26 minutes. We are receiving sighting reports of today's launch from as far away as Fort Lauderdale.

1912 GMT (3:12 p.m. EDT)

T+plus 22 minutes. The rocket is in a one-degree per second rolling motion. This is a normal procedure to keep the thermal conditions even across the vehicle.

1906 GMT (3:06 p.m. EDT)

T+plus 16 minutes. Restart of second stage engine is expected at about T+plus 62 minutes, 29 seconds. The stage will fire for approximately 42 seconds to raise the orbit's high point, or apogee. That will be followed by separation between the second and third stages. The upper stage will burn to inject GPS into the intended transfer orbit. Deployment of the payload to complete the launch is expected at T+plus 68 minutes.

1905 GMT (3:05 p.m. EDT)

T+plus 15 minutes. The rocket has successfully achieved a parking orbit with an apogee of 110 miles, perigee of 94 miles and inclination of 37.5 degrees. That is right on the pre-planned orbit parameters.

1902 GMT (3:02 p.m. EDT)

The official launch time was 2:50:00.024 p.m. EDT.

1900 GMT (3:00 p.m. EDT)

T+plus 10 minutes, 58 seconds. SECO 1. The second stage engine cutoff has occurred, completing the motor's first firing of the day. The Delta 2 rocket with GPS 2R-15 has arrived in a preliminary orbit around Earth following launch today from Cape Canaveral. The vehicle will coast for about 52 minutes before the second stage is re-ignited.

1900 GMT (3:00 p.m. EDT)

T+plus 10 minutes, 20 seconds. The speed has increased to 16,100 mph.

1859 GMT (2:59 p.m. EDT)

T+plus 9 minutes, 30 seconds. The Delta 2 rocket is 97 miles in altitude, 1,260 miles downrange from the launch pad, traveling at 15,400 mph.

1858 GMT (2:58 p.m. EDT)

T+plus 8 minutes, 45 seconds. The second stage engine is still firing, consuming a hydrazine propellant mixture and nitrogen tetroxide oxidizer. This burn is needed to achieve a parking orbit around Earth.

1857 GMT (2:57 p.m. EDT)

T+plus 7 minutes, 45 seconds. This initial firing of the second stage should last another three minutes.

1856 GMT (2:56 p.m. EDT)

T+plus 6 minutes, 30 seconds. Good chamber pressure reported on the second stage engine. The vehicle is 90 miles in altitude, 800 miles downrange from the launch pad and traveling at 13,800 mph.

1855 GMT (2:55 p.m. EDT)

T+plus 5 minutes, 45 seconds. The vehicle is 77 miles in altitude, 530 miles downrange from the launch pad and traveling at 13,100 mph.

1855 GMT (2:55 p.m. EDT)

T+plus 5 minutes, 20 seconds. The rocket's nose cone enclosing the spacecraft has been jettisoned.

1854 GMT (2:54 p.m. EDT)

T+plus 4 minutes, 41 seconds. The spent first stage has been jettisoned and the Delta's second stage engine has ignited!

1854 GMT (2:54 p.m. EDT)

T+plus 4 minutes, 26 seconds. MECO. The first stage main engine cutoff is confirmed.

1854 GMT (2:54 p.m. EDT)

T+plus 4 minutes. Coming up on first stage engine cutoff.

1853 GMT (2:53 p.m. EDT)

T+plus 3 minutes, 30 seconds. The main engine is still firing normally. The rocket is 47 miles in altitude, 203 miles downrange from the launch pad and traveling at 9,100 mph.

1852 GMT (2:52 p.m. EDT)

T+plus 2 minutes, 30 seconds. The vehicle is 28 miles in altitude, 77 miles downrange from the launch pad and traveling at 5,300 mph.

1852 GMT (2:52 p.m. EDT)

T+plus 2 minutes, 12 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.

1851 GMT (2:51 p.m. EDT)

T+plus 1 minute, 45 seconds. The air-lit boosters are burning well.

1851 GMT (2:51 p.m. EDT)

T+plus 1 minute, 15 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.

1850 GMT (2:50 p.m. EDT)

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

1850 GMT (2:50 p.m. EDT)

T+plus 40 seconds. The vehicle has broken the sound barrier as it accelerates rapidly.

1850 GMT (2:50 p.m. EDT)

T+plus 30 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.

1850 GMT (2:50 p.m. EDT)

T+plus 20 seconds. The Boeing rocket is maneuvering to the proper heading. All six ground-lit SRBs and the main engine are firing.

1850 GMT (2:50 p.m. EDT)

LIFTOFF! Liftoff of the Delta 2 rocket and the next step in modernizing the Global Positioning System.

1849 GMT (2:49 p.m. EDT)

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 Boeing 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.

1849 GMT (2:49 p.m. EDT)

T-minus 1 minute. The Delta 2 rocket's second stage hydraulic pump has gone to internal power after its pressures were verified acceptable.

1848 GMT (2:48 p.m. EDT)

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

1848 GMT (2:48 p.m. EDT)

T-minus 95 seconds. First stage LOX topping to 100 percent is underway.

1848 GMT (2:48 p.m. EDT)

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.

1847 GMT (2:47 p.m. EDT)

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

1847 GMT (2:47 p.m. EDT)

T-minus 3 minutes and counting. The rocket's third stage safe and arm devices are being armed.

1846 GMT (2:46 p.m. EDT)

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

1846 GMT (2:46 p.m. EDT)

T-minus 4 minutes and counting! The Delta 2 rocket is ready to launch the GPS 2R-15 military navigation satellite at 2:50 p.m. EDT from pad 17A at Cape Canaveral Air Force Station in Florida.

1845 GMT (2:45 p.m. EDT)

Standing by to resume the countdown in one minute. There are no problems being reported in the countdown.

1844 GMT (2:44 p.m. EDT)

The Air Force launch management poll has been conducted.

1841 GMT (2:41 p.m. EDT)

The Boeing launch conductor has polled the team for a "go" to proceed with the countdown. No problems were reported. The team is now receiving final instructions on countdown procedures.

1841 GMT (2:41 p.m. EDT)

Launch team polling is underway.

1840 GMT (2:40 p.m. EDT)

Time to launch is 10 minutes.

1836 GMT (2:36 p.m. EDT)

T-minus 4 minutes and holding. The countdown has entered the final planned hold point for this afternoon's launch attempt. During this planned 10-minute hold, officials will poll the various team members in the soft blockhouse, Range Operations Control Center and Mission Directors Center. If all systems are "go," the countdown will resume for liftoff at 2:50 p.m. EDT (1850 GMT).

1834 GMT (2:34 p.m. EDT)

The Air Force launch weather officer says conditions are "go" for liftoff.

1832 GMT (2:32 p.m. EDT)

The first stage kerosene fuel tank is being pressurized for launch.

1831 GMT (2:31 p.m. EDT)

The spacecraft safe and arm devices are armed.

1829 GMT (2:29 p.m. EDT)

The Lockheed Martin-built GPS spacecraft payload is now confirmed to be on internal battery power for flight.

1825 GMT (2:25 p.m. EDT)

T-minus 15 minutes and counting. The planned hold in the countdown has been released. Clocks will now tick down to T-minus 4 minutes where the final hold is scheduled.

1824 GMT (2:24 p.m. EDT)

The GPS 2R-15 spacecraft cargo atop the Delta 2 rocket is now switching to internal power for launch.

1820 GMT (2:20 p.m. EDT)

The launch team is being polled for "ready" status to resume the countdown at the end of the hold as scheduled.

1815 GMT (2:15 p.m. EDT)

Now half-way through this built-in hold. 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.

1805 GMT (2:05 p.m. EDT)

T-minus 15 minutes and holding. The countdown has entered the 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.

This hold normally occurs at the T-minus 20 minute mark -- not quite sure why the change today. The press kit indicated the typical T-minus 20 hold as well.

1801 GMT (2:01 p.m. EDT)

The first stage steering checks are finished.

1756 GMT (1:56 p.m. EDT)

The second stage engine slews have been completed.

1754 GMT (1:54 p.m. EDT)

The launch team is beginning 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.

1750 GMT (1:50 p.m. EDT)

Sixty minutes from launch.

1745 GMT (1:45 p.m. EDT)

Inhibited checks are now beginning for the Range Safety command destruct receivers that would be used in destroying the Delta rocket should the vehicle veer off course and malfunction during the launch.

Coming up in about five minutes, engine steering tests will be conducted on the Delta 2 launch vehicle.

1731 GMT (1:31 p.m. EDT)

Loading of the Delta 2 rocket's first stage liquid oxygen tank has been completed. The operation took 25 minutes and 20 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 2:50 p.m. EDT. The vehicle's first stage was successfully loaded with RP-1 kerosene fuel along with the liquid oxygen over the past hour. The second stage was filled with its storable nitrogen tetroxide and Aerozine 50 fuels on Saturday. The nine strap-on booster rockets and third stage use solid propellants.

1726 GMT (1:26 p.m. EDT)

Now passing the 20-minute mark of this approximate 25-minute cryogenic tanking process for the Delta rocket's first stage.

Once the liquid oxygen tank reaches the 95 percent full level, the "rapid load" valve will be closed and the slower "fine load" phase will continue to fill the tank.

1720 GMT (1:20 p.m. EDT)

The countdown is entering the final 90 minutes to launch.

1716 GMT (1:16 p.m. EDT)

Now 10 minutes into liquid oxygen loading. The bottom of the Boeing Delta 2 rocket is icing over as the supercold liquid oxygen continues to flow into the first stage. And bright white vapor is streaming from a vent port on the side of the vehicle.

1706 GMT (1:06 p.m. EDT)

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 Boeing 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.

1700 GMT (1:00 p.m. EDT)

The launch team is beginning preps for loading the first stage liquid oxygen tank.

1657 GMT (12:57 p.m. EDT)

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

1635 GMT (12:35 p.m. EDT)

The first stage fuel tank of the Boeing Delta 2 rocket has been fully loaded for this afternoon's planned 2:50 p.m. launch. The tank was filled with a highly refined kerosene, called RP-1, during a 20-minute, 17-second process that concluded at 12:35:04 p.m. EDT.

The next major task in the count will be loading super-cold cryogenic liquid oxygen into the first stage starting at the top of the hour.

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.

1632 GMT (12:32 p.m. EDT)

Rapid-loading of the RP-1 tank has concluded as 9,800 gallons have been pumped into the rocket. Fine load is continuing.

1629 GMT (12:29 p.m. EDT)

Now 15 minutes through this 20-minute process to load the rocket's first stage with kerosene fuel. Some 8,000 gallons have been loaded to this point.

1624 GMT (12:24 p.m. EDT)

The launch team has computed that the full load for the first stage fuel tank is 10,017 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.

1620 GMT (12:20 p.m. EDT)

Two-and-a-half hours remain in the countdown to launch of the Delta 2 rocket. First stage propellant loading has passed the 3,000-gallon mark.

1614 GMT (12:14 p.m. EDT)

Fueling of the Delta 2 rocket's first stage has begun for today's launch. About 10,000 gallons of the kerosene propellant, called RP-1, are being pumped into the base of the rocket from storage tanks at pad 17A.

1610 GMT (12:10 p.m. EDT)

Preparations for loading the Delta 2 rocket's first stage RP-1 fuel tank are beginning. After verifying valves, sensors, flow meters and equipment are ready, the highly-refined kerosene fuel will start flowing into the vehicle a few minutes from now.

1609 GMT (12:09 p.m. EDT)

First stage helium and nitrogen pressurization is complete.

1553 GMT (11:53 a.m. EDT)

Activation of the rocket's Redundant Inertial Flight Control Assembly (RIFCA) guidance computer is beginning. Also, the launch team is starting pressurization steps for the first and second stage helium and nitrogen systems and second stage fuel tanks.

Read our earlier status center coverage.