Spaceflight Now Home

The Mission

Rocket: Delta 2 (7320)
Payload: Swift
Date: November 20, 2004
Window: 12:10 to 1:10 p.m. EST (1710-1810 GMT)
Site: SLC-17A, Cape Canaveral, Florida
Broadcast: AMC 6, Transponder 9, C-band, 72° West

Launch events timeline

Ground track map

Launch hazard area

The Payload

NASA's Swift spacecraft will detect gamma-ray bursts, the most powerful explosions in the universe, for asronomers to study.

The Launcher

Boeing's workhorse Delta 2 rocket has flown more than 100 times, launching military, scientific and commercial satellites.

Delta 2 fact sheet

The pre-launch process

Archived Delta coverage

The Venue

Cape Canaveral's Launch Complex 17 is the East Coast home of Delta 2.

Learn more


Sign up for our NewsAlert service and have the latest news in astronomy and space e-mailed direct to your desktop.

Enter your e-mail address:

Privacy note: your e-mail address will not be used for any other purpose.


Follow the countdown and launch of the Boeing Delta 2 rocket with NASA's Swift gamma-ray burst detection observatory. Reload this page for the very latest on the mission.

Spaceflight Now Plus
Additional coverage for subscribers:



NASA launched a $250 million quick-response satellite today to study enigmatic gamma ray flashes from brief-but-titanic deep space explosions that may be the "death cries" of massive stars imploding to form black holes. Read our full story.

1940 GMT (2:40 p.m. EST)

Swift has unfurled its two power-generating solar arrays, NASA confirms.

"It's a thrill that Swift is in orbit. We expect to detect and analyze more than 100 gamma-ray bursts a year. These are the most powerful explosions in the universe, and I can't wait to learn more about them," said Swift Principal Investigator Dr. Neil Gehrels.

Swift was released into space by Boeing's Delta 2 rocket at the conclusion of today's successful launch.

"Swift is an exciting science mission that will help bridge the connection between the mysterious explosions that occur in space and the black holes they leave behind," said Dan Collins, vice president, Boeing Expendable Launch Systems. "Our Delta team did an outstanding job in preparing for this mission, including overcoming challenges associated with the recent hurricanes in Florida. We're proud that NASA continues to place its confidence in the Delta 2 and our launch team in achieving its science goals."

1842 GMT (1:42 p.m. EST)

NASA launch manager Chuck Dovale confirms the successful delivery of Swift into a circular orbit at 324 nautical miles and inclined at about 20.5 degrees north and south of the equator.

This marks the 115th successful Delta 2 rocket launch out of 117 flights since 1989 and extends the string of consecutive successes to 62 dating back to 1997. It was the seventh Delta launch in 2004.

The next Delta 2 flight will occur from Cape Canaveral on December 30 to launch NASA's Deep Impact probe on its voyage to Comet Tempel 1. On-pad assembly of the rocket begins Monday when the first stage will be erected.

NASA expects to announce in about an hour the initial health of Swift, including confirmation of the solar array deployment.

This concludes our live play-by-play coverage of today's mission. Check back later for a wrap-up story, pictures and many movie clips of the launch.

1838 GMT (1:38 p.m. EST)

T+plus 82 minutes. The second stage is carrying out planned maneuvers to move away from Swift.

1836 GMT (1:36 p.m. EST)

T+plus 80 minutes, 10 seconds. SPACECRAFT SEPARATION! NASA's Swift spacecraft has been released from the Boeing Delta 2 rocket to complete today's launch from Cape Canaveral.

Swift is an agile gamma-ray observatory with a focus on the most intense explosions in the cosmos -- cataclysmic blasts occurring every day throughout the universe that seemingly foreshadow the creation of black holes.

While circling Earth, Swift will detect and study the brilliant bursts of gamma-rays, which erupt in random points across the sky without warning. Swift's scientific data will determine a burst's distance and brightness, plus provide insight into the blast's locale and surroundings to offer clues about what ignites these events.

1835 GMT (1:35 p.m. EST)

T+plus 79 minutes. The second stage has maneuvered to the spacecraft deployment orientation.

1834 GMT (1:34 p.m. EST)

T+plus 78 minutes. The deployment of Swift from the Delta rocket is a multi-step process. It begins with firing the separation bolts. A 30-second period passes to allow the shock to subside. Next, latches holding the satellite to the second stage are opened. Finally, the stage uses its helium system to gently back away from Swift.

1833 GMT (1:33 p.m. EST)

T+plus 77 minutes. Telemetry is being received through Hawaii now.

1831 GMT (1:31 p.m. EST)

T+plus 75 minutes. The Kwajalein data relay from the second stage didn't occur as planned. The next vehicle telemetry pass will come via the Hawaii tracking station.

1830 GMT (1:30 p.m. EST)

T+plus 74 minutes. Spacecraft separation is about six minutes away.

1829 GMT (1:29 p.m. EST)

T+plus 73 minutes. A television signal is now being received from the second stage video camera. However, there was no telemetry available during the engine firing to confirm that burn.

1828 GMT (1:28 p.m. EST)

T+plus 72 minutes. This data blackout does not imply a problem with the rocket.

1827 GMT (1:27 p.m. EST)

T+plus 71 minutes, 30 seconds. The second stage should have ignited. However, communications with the second stage have not been restored.

1816 GMT (1:16 p.m. EST)

T+plus 60 minutes. It has been a full hour since the Delta rocket blasted off from Florida. The rocket flew over the Atlantic, Africa and the Indian Ocean, and is skirting Australia as it nears the point the second stage will be restarted above the Pacific. Spacecraft separation to finish the launch is 20 minutes away.

1756 GMT (12:56 p.m. EST)

T+plus 40 minutes. As the rocket coasts in this parking orbit, the second stage performs a "BBQ roll" maneuver to keep the thermal conditions on the vehicle equal. This maneuver was scheduled to start at T+plus 31 minutes, 20 seconds and conclude at T+plus 61 minutes, 40 seconds. Since the Delta 2 rocket is not within range of any data relay station, this could not be confirmed in real-time.

At T+plus 61 minutes, 50 seconds, the rocket is programmed to begin orienting itself into the proper position for engine ignition. This maneuver will take about seven minutes.

Ignition is expected at T+plus 71 minutes, 17 seconds.

1746 GMT (12:46 p.m. EST)

T+plus 30 minutes. The vehicle will be out of telemetry range throughout this coast. The next data should be available just before engine ignition via the Army's Kwajalein station in the South Pacific. The Air Force tracking station in Hawaii will cover Swift deployment from the Delta second stage.

1743 GMT (12:43 p.m. EST)

T+plus 27 minutes, 30 seconds. The rocket has returned to the normal coast mode. The next engine start will happen around T+plus 71 minutes.

1742 GMT (12:42 p.m. EST)

T+plus 26 minutes, 50 seconds. SECO 2. The second stage has completed its second burn of this launch.

1742 GMT (12:42 p.m. EST)

T+plus 26 minutes, 18 seconds. Engine ignition! The Delta 2 rocket's second stage engine has restarted to boost the vehicle into an elliptical orbit with a higher apogee than the initial parking orbit achieved earlier.

1742 GMT (12:42 p.m. EST)

T+plus 26 minutes. Data is being received from the second stage again.

1737 GMT (12:37 p.m. EST)

T+plus 21 minutes. About five minutes remaining in this coast. The 30-second engine firing by the second stage will raise the orbit's apogee while decreasing the inclination. An extended coast period follows before the second stage fires for a third time at T+plus 71 minutes. Deployment of Swift to complete the launch is expected at T+plus 80 minutes.

1734 GMT (12:34 p.m. EST)

T+plus 18 minutes. The vehicle will ignite the second stage just south of the equator near the west-central coast of Africa. The Libreville telemetry station and Air Force's deployable tracking site at Sao Tome will be covering upcoming events.

1732 GMT (12:32 p.m. EST)

T+plus 16 minutes. As this coast phase of the launch continues, you can see a map of the rocket's planned track here.

1731 GMT (12:31 p.m. EST)

T+plus 15 minutes. The official launch time was 12:16:00.611 p.m. EST

1729 GMT (12:29 p.m. EST)

T+plus 13 minutes, 50 seconds. The rocket has successfully achieved a parking orbit with an apogee of 100.161 nautical miles, perigee of 99.88 miles and inclination of 28.47 degrees.

1729 GMT (12:28 p.m. EST)

T+plus 13 minutes, 20 seconds. The rocket has passed out of range from the Antigua tracking site. This begins an expected telemetry blackout while the vehicle coasts in the parking orbit.

1727 GMT (12:27 p.m. EST)

T+plus 11 minutes, 15 seconds. The vehicle will coast for the next 15 minutes before the second stage is re-ignited.

1726 GMT (12:26 p.m. EST)

T+plus 10 minutes, 20 seconds. SECO 1. The second stage engine cutoff has occurred, completing the motor's first firing of the day. The Delta 2 rocket with Swift has arrived in a preliminary orbit around Earth following launch today from Cape Canaveral.

1725 GMT (12:25 p.m. EST)

T+plus 9 minutes, 35 seconds. The rocket is now 103 miles in altitude, 1,198 miles downrange from the launch site, traveling at 15,900 mph.

1725 GMT (12:25 p.m. EST)

T+plus 9 minutes. The second stage systems reported normal.

1724 GMT (12:24 p.m. EST)

T+plus 8 minutes, 30 seconds. The rocket is now 101 miles in altitude, 950 miles downrange from the launch site, traveling over 14,000 mph.

1724 GMT (12:24 p.m. EST)

T+plus 8 minutes. Antigua ground tracking station is acquiring the rocket's signal as the vehicle flies downrange. The second stage engine continues to fire.

1723 GMT (12:23 p.m. EST)

T+plus 7 minutes. Just over three minutes remain in this second stage firing to reach a preliminary parking orbit around Earth.

1722 GMT (12:22 p.m. EST)

T+plus 6 minutes. Second stage engine is burning properly, consuming a hydrazine propellant mixture and nitrogen tetroxide oxidizer.

1721 GMT (12:21 p.m. EST)

T+plus 5 minutes. The 10-foot diameter protective payload fairing enclosing Swift atop the rocket has jettisoned in two halves.

1720 GMT (12:20 p.m. EST)

T+plus 4 minutes, 45 seconds. The Aerojet AJ10-118K engine of the Delta 2 rocket's second stage engine has ignited! This is the first of three critical firings that the second stage must perform to deliver Swift into the proper orbit.

1720 GMT (12:20 p.m. EST)

T+plus 4 minutes, 37 seconds. MECO! Main engine cutoff. The Rocketdyne RS-27A first stage main engine has shut down to complete its firing during today's launch. The twin vernier steering thrusters fired a few additional seconds before they cut off. Then the spent stage was jettisoned to fall into the Atlantic.

1720 GMT (12:20 p.m. EST)

T+plus 4 minutes, 5 seconds. Coming up on staging.

1719 GMT (12:19 p.m. EST)

T+plus 3 minutes, 15 seconds. The RS-27A main engine is firing normally along with the twin vernier steering jets.

1718 GMT (12:18 p.m. EST)

T+plus 2 minutes, 30 seconds. The rocket is flying solely on the power generated by the liquid-fueled first stage main engine.

1717 GMT (12:17 p.m. EST)

T+plus 1 minute, 40 seconds. Altitude is 13 miles, downrange distance 33 miles, speed 2,400 mph as the first stage engine continues to fire.

1717 GMT (12:17 p.m. EST)

T+plus 1 minute, 15 seconds. All three ground-start solid rocket boosters have burned out of propellant and separated from the Delta 2's first stage.

1717 GMT (12:17 p.m. EST)

T+plus 60 seconds. The Delta 2 rocket has passed through the region of maximum aerodynamic pressure during its atmospheric ascent.

1716 GMT (12:16 p.m. EST)

T+plus 40 seconds. The vehicle has broken the sound barrier.

1716 GMT (12:16 p.m. EST)

T+plus 30 seconds. The three 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.

1716 GMT (12:16 p.m. EST)

T+plus 20 seconds. The Boeing Delta 2 rocket is riding a half-million pounds of thrust as it soars away from Cape Canaveral's Complex 17A and heads eastward for the flight over the open waters of the Atlantic Ocean.

1716 GMT (12:16 p.m. EST)

LIFTOFF! Liftoff of NASA's Swift gamma-ray observatory seeking out the most powerful explosions in the universe!

1715 GMT (12:15 p.m. EST)

T-minus 30 seconds. Hydraulics and electronics status checks are reported "go."

The launch ignition sequence will begin at T-minus 2 seconds when a Boeing engineer triggers the engine start switch. The process begins with ignition of the two vernier engines and first stage main engine start. The three ground-lit solid rocket motors then light at T-0 for liftoff.

1715 GMT (12:15 p.m. EST)

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

1714 GMT (12:14 p.m. EST)

T-minus 75 seconds. The Range has given its final clear-to-launch.

1714 GMT (12:14 p.m. EST)

T-minus 1 minute, 45 seconds. The liquid oxygen tank topping off at 100 percent.

1714 GMT (12:14 p.m. EST)

T-minus 2 minutes. The first stage liquid oxygen vents are being closed so the LOX tank can be pressurized for launch. Puffs of vapor from a relief valve on the rocket will be seen in the remainder of the countdown as the tank pressure stabilizes.

1713 GMT (12:13 p.m. EST)

T-minus 2 minutes, 35 seconds. The Swift spacecraft has been declared "go" for launch.

1713 GMT (12:13 p.m. EST)

T-minus 3 minutes and counting.

1712 GMT (12:12 p.m. EST)

T-minus 3 minutes, 30 seconds. The vehicle is now being armed.

1712 GMT (12:12 p.m. EST)

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

1712 GMT (12:12 p.m. EST)

T-minus 4 minutes and counting! The final phase of the countdown is underway for launch of the Delta 2 rocket and the Swift spacecraft at 12:16 p.m. EST from pad 17A at Cape Canaveral Air Force Station in Florida.

1711 GMT (12:11 p.m. EST)

Standing by to resume the countdown in one minute.

1711 GMT (12:11 p.m. EST)

The Swift spacecraft atop the Delta 2 rocket has switched to internal power for launch.

1707 GMT (12:07 p.m. EST)

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

1706 GMT (12:06 p.m. EST)

NASA launch manager Chuck Dovale just performed a final readiness poll of the space agency team. No problems were reported.

1706 GMT (12:06 p.m. EST)

Time remaining to the new launch time is 10 minutes. Liftoff was delayed six minutes to give the team a bit more time to catch up on work that was behind schedule.

1705 GMT (12:05 p.m. EST)

Final launch configuring of Swift is starting.

1700 GMT (12:00 p.m. EST)

NEW LAUNCH TIME. Liftoff of the Delta 2 rocket has been reset to 12:16 p.m. EST (1716 GMT).

1657 GMT (11:57 a.m. EST)

Some countdown activities are still running a few minutes behind. Mission managers are looking at pushing back liftoff time to 12:16 p.m. EST.

1656 GMT (11:56 a.m. EST)

The Air Force launch weather officer has declared that conditions are "go" for liftoff today.

1656 GMT (11:56 a.m. EST)

T-minus 4 minutes and holding. The countdown has entered the final planned hold point for today'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 12:10 p.m. EDT (1710 GMT).

1655 GMT (11:55 a.m. EST)

The first stage fuel tank is being pressurized.

1654 GMT (11:54 a.m. EST)

Command receiver checks on the rocket's safety system are complete and acceptable for launch, the Range says.

1650 GMT (11:50 a.m. EST)

T-minus 10 minutes and counting. Clocks are heading to T-minus 4 minutes where a 10-minute hold is planned. Launch is still targeted for 12:10 p.m. EST.

1649 GMT (11:49 a.m. EST)

RF link checks have been completed successfully.

1646 GMT (11:46 a.m. EST)

Inhibited checks are 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.

1644 GMT (11:44 a.m. EST)

The steering checks are complete.

1640 GMT (11:40 a.m. EST)

With a half-hour remaining in the countdown, NASA launch manager Chuck Dovale reports that everything is still "go" for liftoff at 12:10 p.m. EST.

1638 GMT (11:38 a.m. EST)

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.

1630 GMT (11:30 a.m. EST)

Time to launch is 40 minutes.

Coming up shortly, engine steering tests will be conducted on the Delta 2 launch vehicle.

1620 GMT (11:20 a.m. EST)

The launch team reports the loading of the Delta 2 rocket's first stage liquid oxygen tank was completed at 11:20:48 a.m. EST. The operation took 27 minutes and 29 seconds today. The tank will be replenished through the countdown to replace the super-cold liquid oxygen that naturally boils away.

The rocket is now fully fueled for launch. 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 a few days ago. The three strap-on boosters are solid-propellant.

1612 GMT (11:12 a.m. EST)

Cryogenic tanking of the Delta rocket's first stage has reached the 19-minute mark of this approximate 25-minute process. 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.

1610 GMT (11:10 a.m. EST)

The countdown is entering the final 60 minutes to launch! Weather is great, the rocket and Swift spacecraft are "go" and the countdown is progressing to liftoff on time at 12:10 p.m. EST.

1603 GMT (11:03 a.m. EST)

The bottom of the Boeing Delta 2 rocket is icing over as the super-cold liquid oxygen continues to flow into the first stage.

1558 GMT (10:58 a.m. EST)

Now five minutes into liquid oxygen loading.

1553 GMT (10:53 a.m. EST)

Super-cold liquid oxygen is beginning to flow into the first stage of the Boeing Delta 2 rocket as the countdown continues for today's 12:10 p.m. EST launch.

The liquid oxygen, chilled to Minus-298 degrees F, is being pumped from a storage tank at pad 17A, through plumbing and into the bottom of the rocket. The LOX and the RP-1 kerosene fuel -- loaded aboard the vehicle in the past hour -- will be consumed by the first stage main engine.

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

The launch team has been given approval to begin preps for loading the liquid oxygen tank.

1547 GMT (10:47 a.m. EST)

NASA launch manager Chuck Dovale has just polled his management team to verify there are no constraints for liquid oxygen tanking. All systems are "go."

1541 GMT (10:41 a.m. EST)

The first stage fuel tank of the Boeing Delta 2 rocket has been fully loaded for today's planned 12:10 p.m. EST launch. The tank was filled with a highly refined kerosene, called RP-1, during a 18-minute, 48-second process that concluded at 10:41:50 a.m. EST.

The next major task in the count will be loading super-cold cryogenic liquid oxygen into the first stage starting in about 10 minutes.

There are no significant technical issues being worked by the launch team, the weather is favorable and upper level winds are acceptable. One minor arose a little earlier in the countdown when a crew was sent back into the pad to remove a loose cord in the lanyard umbilicals extending from the tower to the Delta rocket.

1539 GMT (10:39 a.m. EST)

Rapid-loading of the RP-1 tank has concluded. Fine load is continuing.

1534 GMT (10:34 a.m. EST)

The launch team has computed that the full load for the first stage fuel tank is 9,882 gallons.

Once the tank is filled to 98 percent or 9,650 gallons, the "rapid load" valve will be closed and the slower "fine load" phase will continue to top off the tank.

1533 GMT (10:33 a.m. EST)

Now 10 minutes, or half-way, through this 20-minute process to load the rocket's first stage with kerosene fuel.

The propellant will be used along with liquid oxygen -- to be pumped into the rocket a little later -- by the first stage Rocketdyne RS-27A main engine and twin vernier steering thrusters during the initial four-and-a-half minutes of flight.

1528 GMT (10:28 a.m. EST)

A weather briefing just concluded. All conditions remain "go" for launch and there is little worry about weather today.

1526 GMT (10:26 a.m. EST)

About 2,000 gallons have been loaded into the rocket so far.

1523 GMT (10:23 a.m. EST)

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

1519 GMT (10:19 a.m. EST)

Boeing technicians are starting preparations for loading the Delta 2 rocket's first stage RP-1 fuel tank. After verifying valves, sensors, flow meters and equipment are ready, the highly-refined kerosene fuel will start flowing into the vehicle.

1506 GMT (10:06 a.m. EST)

Pressurization of the first and second stage helium and nitrogen systems is getting underway. Also, the second stage propellant and oxidizer tanks, which were loaded with hypergolic fuels a few days ago, will be pressurized.

1458 GMT (9:58 a.m. EST)

The pad crew has completed its work and will be leaving the launch complex momentarily.

Although countdown activities have been delayed a bit, including fueling the first stage that was supposed to begin a few minutes ago, the timeline as margin to deal with these sorts of issues without impacting the target liftoff time.

1452 GMT (9:52 a.m. EST)

The launch team has completed work to turn on and configure the Delta's onboard guidance computer -- called the Redundant Inertial Flight Control Assembly, or RIFCA.

1442 GMT (9:42 a.m. EST)

The Delta 2 rocket has been safed and the workers are being permitted into the pad now.

1435 GMT (9:35 a.m. EST)

Workers will be going up the launch tower to secure a loose cord in the lanyards that extend outward and mount to the Delta vehicle. Once this is finished and the team clears the hazard area, the pressurization activities and fueling of the first stage can occur.

1433 GMT (9:33 a.m. EST)

Vehicle pressurization scheduled to be getting underway now will be delayed while a team is sent back into the launch pad to address an issue. It is not yet clear what problem the crew will be dealing with.

1430 GMT (9:30 a.m. EST)

T-minus 150 minutes and counting. The Terminal Countdown is now underway for today's launch of the Delta 2 rocket carrying NASA's Swift gamma-ray observatory. The next three hours will be spent fueling the rocket, activating systems and performing final testing before liftoff at 12:10 p.m. EST (1710 GMT) from pad 17A at Cape Canaveral Air Force Station in Florida.

The Complex 17A area is verified cleared of workers. A warning horn will be sounded three times at the seaside complex as a precaution to alert any remaining personnel in the vicinity that they should leave immediately.

The pad clear status will allow the start of hazardous operations such as the pressurization of helium and nitrogen storage tanks inside the rocket's first and second stages, along with the second stage fuel and oxidizer tanks.

The countdown currently stands at T-minus 150 minutes. However, there is one 10-minute hold built into the count at T-minus 4 minutes.

1422 GMT (9:22 a.m. EST)

The launch team members have been polled for a "ready" status to resume the countdown as planned at the end of this hold. No issues were reported. Clocks will start ticking again at 9:30 a.m. EST as the Terminal Countdown begins.

1415 GMT (9:15 a.m. EST)

Just 15 minutes remain in this planned hold. Coming up in about five minutes, the launch team will be polled to ensure all the consoles are staffed and everyone is ready to begin Terminal Count.

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

The mobile service tower was rolled away from the Delta rocket and into its launch position before dawn this morning. You can see a couple of pictures of the event here.

1335 GMT (8:35 a.m. EST)

Air Force meteorologists continue to predict near-perfect weather conditions for today's launch. There is less than a 10 percent chance that weather will prohibit liftoff. Read the latest forecast here.

1330 GMT (8:30 a.m. EST)

T-minus 150 minutes and holding. Clocks are entering a planned 60-minute built-in hold in the countdown. Holds are scheduled into the count to give workers a chance to catch up on any activities that may be running behind.

Over the next hour, all launch team members and management officials will be seated at their consoles. A series of polls will be conducted to verify everyone is ready to enter Terminal Count at end of the built-in hold.

Liftoff of the Delta 2 rocket remains scheduled for 12:10 p.m. EST from Cape Canaveral, Florida.

1245 GMT (7:45 a.m. EST)

The launch team is beginning work to activate the Delta rocket's guidance system for launch. Meanwhile, hold-fire checks were conducted in the last few minutes. This verifies the capability to halt the countdown if a safety problem arises.

1210 GMT (7:10 a.m. EST)

The countdown is entering the final five hours to launch. Launch remains set for 12:10 p.m. EST today.

1059 GMT (5:59 a.m. EST)

The mobile service tower is currently being retracted from around the Boeing Delta 2 rocket, exposing the 126-foot tall vehicle atop Cape Canaveral's pad 17A. The tower was used to assemble the rocket on the pad and provided access for workers during the booster's stay on the seaside complex.

Workers will get the tower locked into its launch position and put the final touches on rocket and ground equipment before evacuating the pad by about 9 a.m. EST (1400 GMT).

The Terminal Countdown commences at 9:30 a.m. EST (1430 GMT) for the final two hours and 40 minutes to launch. That is 20 minutes shorter than usual because officials have deleted the typical built-in hold at the T-minus 20 minute mark. Officials schedule hold periods to give engineers time to work problems or catch up on late-running activities. But with the hour-long launch window, it was decided the T-minus 20 minute hold wasn't necessary.

The launch team will start loading a highly refined kerosene propellant into the rocket's first stage at 9:50 a.m. EST (1450 GMT). Filling of the first stage liquid oxygen tank will follow beginning at 10:45 a.m. EST (1545 GMT).

The final hour of the countdown will be spent conducting engine steering tests, Range safety system checks and final arming. Swift switches to internal power for launch about six minutes before liftoff time, while the Delta rocket's systems transition to battery power inside the final four minutes.

The count will feature one built-in hold at T-minus 4 minutes lasting for 10 minutes. During that time, mission managers will conduct a series of readiness polls to ensure everyone is "go" to proceed with liftoff.

Launch will be possible during today's 60-minute window that extends from 12:10 to 1:10 p.m. EST (1710-1810 GMT).

2155 GMT (4:55 p.m. EST)

All systems are "go" for tomorrow's launch of Swift and the Delta 2 rocket. Seniors officials met a short time ago to give approval for liftoff. The Range safety system equipment replacement and subsequent testing has been a success, NASA says.

Watch this page for live coverage of the final countdown and launch.

1915 GMT (2:15 p.m. EST)

Mission managers will be meeting at 4 p.m. EST (2100 GMT) this afternoon to review the safety system fix performed at pad 17A over the past day. Assuming all systems are deemed "go" for launch, countdown activities will begin late night for liftoff at 12:10 p.m. EST (1710 GMT) Saturday.

1540 GMT (10:40 a.m. EST)

Launch of Swift atop the Delta 2 rocket remains scheduled for Saturday at 12:10 p.m. EST, pending completion of testing on the repaired Range safety system aboard the vehicle.

The weather forecast is excellent with better than a 90 percent chance of favorable conditions. You can read the full forecast here.

Read our earlier status center coverage.



© 2014 Spaceflight Now Inc.