BY JUSTIN RAY

Follow the countdown and launch of the Boeing Delta 2 rocket with the U.S. Air Force's GPS 2R-12 navigation spacecraft. Reload this page for the very latest on the mission.

MONDAY, JUNE 21, 2004
2114 GMT (5:14 p.m. EDT)

The third try was not the charm during today's attempt to launch Boeing's Delta 2 rocket carrying a Global Positioning System satellite. Weather has scrubbed the mission for the third straight day. Another try will come no sooner than Wednesday at approximately 6:54 p.m. EDT (2254 GMT).

Air Force weather forecasters say there is an 80 percent chance of bad weather on Wednesday.

Officials are skipping over Tuesday due to servicing requirements.

2111 GMT (5:11 p.m. EDT)

SCRUB! Today's attempt has been called off. The next launch attempt would be no sooner than Wednesday.

2108 GMT (5:08 p.m. EDT)

Activation of the rocket's guidance system has just finished.

2104 GMT (5:04 p.m. EDT)

Fueling of the first stage with 10,000 gallons of a highly refined kerosene, called RP-1, has just been completed.

2102 GMT (5:02 p.m. EDT)

The launch weather officer is providing a briefing to mission managers. He says there is no significant change to the forecast. There are storms to the north, west and southwest.

At the current time, the all the weather rules are "go" for launch. However, the approaching weather is likely to begin breaking the rules in about a half-hour.

The outlook for the rest of week is no better. The weather officer says this pattern of afternoon thunderstorms across Florida will continue for the next several days.

2054 GMT (4:54 p.m. EDT)

Now 10 minutes into this approximate 20-minute process to load the rocket's first stage with about 10,000 gallons of refined kerosene fuel. Some 6,000 gallons have been loaded to this point.

2049 GMT (4:49 p.m. EDT)

About 2,000 gallons of RP-1 have been loaded into the rocket over the past five minutes.

2044 GMT (4:44 p.m. EDT)

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 17B.

2040 GMT (4:40 p.m. EDT)

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.

2032 GMT (4:32 p.m. EDT)

The launch team is working through the pressurization steps. Liftoff is now two-and-a-half hours away.

2015 GMT (4:15 p.m. EDT)

Pad 17B is verified cleared of workers. A warning horn will be sounded three times at the 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.

2006 GMT (4:06 p.m. EDT)

A few technicians are still finishing chores at launch pad 17B. Once they clear the area, hazardous operations can begin including pressurization of the rocket's helium and nitrogen systems.

2002 GMT (4:02 p.m. EDT)

The Terminal Countdown has commenced for this third attempt to launch Boeing's Delta 2 rocket carrying the Global Positioning System 2R-12 spacecraft. Liftoff is targeted for 7:02 p.m. EDT (2302 GMT). Officials will have 27 minutes -- until 7:29 p.m. EDT (2329 GMT) -- to get the rocket airborne today.

The countdown currently stands at T-minus 150 minutes. However, there are a pair of holds -- totaling 30 minutes in duration -- planned at T-minus 20 minutes and T-minus 4 minutes.

The weather forecast continues to predict an 80 percent chance of unfavorable conditions during the launch opportunity this evening.

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

The launch team members have been polled for a "ready" status to pick up the countdown as planned at the end of this hold. Clocks will start ticking again at 4:02 p.m. EDT as the Terminal Countdown begins.

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

Final launch pad preps are being performed. Countdown clocks are scheduled to resume running in 10 minutes.

1925 GMT (3:25 p.m. EDT)

Satellite imagery shows storms developing to the southwest of Cape Canaveral and moving this way. They have fired up rapidly. Also, large storms are located across the northern parts of the state this afternoon.

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

The mobile service tower has moved away from the Delta 2 rocket. Workers will get the tower secured in the launch position and configure the pad deck and flame ducts in preparation for this evening's liftoff.

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

T-minus 150 minutes and holding. Countdown clocks have stopped for the pre-planned 60-minute built-in hold. Once the clocks resume ticking at 4:02 p.m. EDT, the Terminal Countdown will begin.

Launch is still scheduled for 7:02 p.m. EDT (2302 GMT) this evening -- weather permitting.

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

Countdown activities are continuing at the Cape. Workers at pad 17B are standing by for approval from management to roll back the mobile service tower from around the rocket. Following last night's scrub, the tower was returned to its position enclosing the vehicle.

There are storms over the northern parts of Florida this afternoon. For the moment, skies are relatively clear around the launch site.

1640 GMT (12:40 p.m. EDT)

Boeing and the Air Force are trying again today to launch the GPS 2R-12 military navigation satellite aboard a Delta 2 rocket. But like the past two days, the weather is troublesome.

The latest weather forecast issued this morning still indicates there is an 80 percent chance of lightning, anvil and cumulus clouds and rain in the rocket's flight path that would scrub the mission.

"No change in synoptic pattern from Sunday," the forecast says. "Weak shear line oriented east to west across Jacksonville aiding in early formation of thunderstorms to the north and pushing south along the east coast sea breeze through the afternoon and evening. The surface and upper level ridge remains to the south resulting in west-southwesterly flow at all levels. With this type of pattern expect formation of east coast sea breeze thunderstorms between 1:00-2:00 p.m. EDT. The Cape will see showers and thunderstorms forming overhead and west of the Indian river with the onset of the sea breeze, throughout the afternoon hours. The primary concern will be showers and thunderstorms over launch pad 17B through the launch countdown."

The launch time forecast calls for three levels of clouds, scattered at 1,500 feet, broken at 2,500 feet and broken at 25,000 feet, visibility of 5 miles, southeasterly winds from 140 degrees at 8 gusting to 12 knots and a temperature between 81 and 83 degrees F.

0018 GMT (8:18 p.m. EDT Sun.)

Mission officials just completed a post-scrub meeting and decided that a third attempt to launch this Delta 2 rocket and the GPS 2R-12 satellite will be made Monday evening. Liftoff is targeted for 7:02 p.m. EDT (2302 GMT) at the opening of a 27-minute launch window that extends to 7:29 p.m. EDT (2329 GMT).

SUNDAY, JUNE 20, 2004
2310 GMT (7:10 p.m. EDT)

There will be no launch tonight as stormy weather keeps the Boeing Delta 2 rocket and the Air Force's Global Positioning System 2R-12 spacecraft grounded on pad 17B at Cape Canaveral, Florida.

"There is severe weather to the north and to the west, and it is moving in on Cape Canaveral like a bull's-eye," Boeing spokesman Brian Nelson says.

"We have played cat and mouse with the weather for two days and...the Boeing launch team has not been able to be successful in this second attempt to launch the GPS 2R-12 satellite."

Another launch attempt could be made on Monday. But that is being assessed by management.

2257 GMT (6:57 p.m. EDT)

SCRUB! For the second straight day thunderstorms and lightning over Cape Canaveral have forced launch of Boeing's Delta 2 rocket with a Global Positioning System satellite to be postponed.

Boeing and the Air Force gave a valiant effort during the countdown, overcoming several hours of delay in rolling back the mobile service tower and shuffling pre-launch activities to make up the time. But in the end the weather simply would not cooperate today.

The weather forecast for tomorrow calls for the same stormy conditions and an 80 percent chance of violating the launch rules. The launch window would extend from roughly 7:02 to 7:29 p.m. EDT.

2257 GMT (6:57 p.m. EDT)

A Phase 2 lightning advisory has been issued. Safing of the vehicle is underway.

2253 GMT (6:53 p.m. EDT)

Rumbling thunder and flashes of lightning are being reported from the press site.

2252 GMT (6:52 p.m. EDT)

T-minus 4 minutes and holding. The countdown has entered the final planned hold point for today's launch attempt. This is a scheduled 10-minute hold leading to liftoff at 7:06 p.m. EDT. However, local weather conditions are still unacceptable for launch. Officials have until 7:33 p.m. EDT to launch the Delta 2 rocket with GPS 2R-12 or else scrub for the day.

2249 GMT (6:49 p.m. EDT)

The lightning, anvil and cumulus cloud rules are still "no go" at this time.

2248 GMT (6:48 p.m. EDT)

The spacecraft safe and arm devices have been armed.

2245 GMT (6:45 p.m. EDT)

The GPS 2R-12 spacecraft cargo atop the Delta 2 rocket has switched to internal power for launch.

2242 GMT (6:42 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.

2236 GMT (6:36 p.m. EDT)

T-minus 20 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 planned.

2228 GMT (6:28 p.m. EDT)

Boeing and Air Force officials have conducted readiness polls in preparation for continuing the countdown. No technical problems were reported.

2223 GMT (6:23 p.m. EDT)

The engine steering tests have been completed at launch pad 17B.

2217 GMT (6:17 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.

2216 GMT (6:16 p.m. EDT)

T-minus 20 minutes and holding. The countdown has entered the scheduled 20-minute built-in hold. This pause is designed to give the launch team a chance to catch up on activities running behind schedule.

2210 GMT (6:10 p.m. EDT)

The countdown is nearing the T-minus 20 minute mark where a planned 20-minute hold will occur.

2207 GMT (6:07 p.m. EDT)

The launch weather officer is giving another briefing to mission managers. He says the storms extend west to Orlando and north to Daytona. The forecast remains unchanged.

2204 GMT (6:04 p.m. EDT)

Now five minutes into this approximate 25-minute process to fill the first stage liquid oxygen tank.

Meanwhile, the lightning, anvil and cumulus cloud rules are still "no go" at this time.

2159 GMT (5:59 p.m. EDT)

Super-cold liquid oxygen, chilled to Minus-298 degrees F, is being pumped into the first stage of the Boeing Delta 2 rocket as the countdown continues for today's possible launch, weather permitting.

The liquid oxygen is flowing from a storage tank at pad 17B, through plumbing and into the bottom of the rocket. The LOX and the RP-1 kerosene fuel -- loaded aboard the vehicle earlier a little while ago -- will be consumed by the first stage main engine.

2156 GMT (5:56 p.m. EDT)

The launch team has been given approval to start loading liquid oxygen into the Delta 2 rocket's first stage.

2152 GMT (5:52 p.m. EDT)

The lightning rule is now being violated, too.

2148 GMT (5:48 p.m. EDT)

The launch weather officer says the anvil clouds that are over the Cape extend about 40-to-50 miles to the west. He foresees no break over the next two hours through the launch window. Also, the cumulus cloud rule has gone "no go" as well.

2140 GMT (5:40 p.m. EDT)

Launch complex 17 has been cleared of all workers. This will allow the launch team to begin hazardous activities in the countdown, which have been on hold while the crews were on the pad. Pressurization of the helium and nitrogen systems on the rocket and the second stage fuel and oxidizer tanks will be upcoming. Also, loading of the liquid oxygen tank of the first stage is scheduled.

2136 GMT (5:36 p.m. EDT)

The scheduled launch is now 90 minutes away. The Delta 2 rocket can launch between 7:06 and 7:33 p.m. EDT (2306-2333 GMT) this evening or else the mission would be scrubbed until Monday.

2127 GMT (5:27 p.m. EDT)

The anvil cloud rule is being broken again at Cape Canaveral. All other launch rules are currently "go." Of course, no rules can be violated at launch time.

2122 GMT (5:22 p.m. EDT)

Reporters and photographers have gathered at the Cape Canaveral Air Force Station gate to be escorted to the press viewing site. They report the skies look good overhead and to the east. But the view to the west is a wall of clouds as that approaching storm's leading edge nears the Cape.

2120 GMT (5:20 p.m. EDT)

Loading of the first stage liquid oxygen tank normally would begin at this point in the countdown. However, the delays earlier this afternoon of rolling back the mobile service tower and performing the final preps to the launch pad have caused the countdown script to be juggled a bit.

Once the pad configuration work is finished and crews clear the hazard area, the liquid oxygen loading could begin. Of course, that will be dependent on the weather and the approaching storm.

2106 GMT (5:06 p.m. EDT)

Workers continue their efforts at pad 17B to prepare the complex for launch as the countdown progresses.

2102 GMT (5:02 p.m. EDT)

While the weather is presently favorable at the Cape, another storm is roughly 20 miles due west of the launch site and slowly drifting toward the east. It is predicted to be overhead the pad area near launch time. The weather officer says there is still an 80 percent chance of violating the launch rules during this evening's available launch window that runs from 7:06 to 7:33 p.m. EDT.

2058 GMT (4:58 p.m. EDT)

The anvil cloud rule is no longer being broken. So at the moment all weather rules are currently "go" for launch. A briefing by the launch weather officer is upcoming in a few minutes.

2040 GMT (4:40 p.m. EDT)

While the situation is improving over the launch site, another storm is about 20-to-30 miles to the west and moving toward the Cape.

2038 GMT (4:38 p.m. EDT)

The lightning and cumulus cloud rules have just gone "green" as they are no longer being violated. The anvil cloud rule is the only rule still being violated.

2030 GMT (4:30 p.m. EDT)

With the mobile service tower rolled back, workers are configuring the pad and positioning equipment to support liftoff. Once the pad area is cleared of all personnel, then the hazardous phase of the countdown will begin, leading to loading the first stage liquid oxygen tank.

2027 GMT (4:27 p.m. EDT)

The disturbed weather and electrical charge rules are now "go" for launch.

The lightning, cumulus and anvil cloud rules are still be violated.

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

The launch team has been polled to verify all of the consoles are manned and systems are ready to continue the countdown.

2010 GMT (4:10 p.m. EDT)

The mobile service tower is currently being wheeled away from the Delta 2 rocket and into the launch position as the countdown continues for this evening's 7:06 p.m. EDT liftoff.

The metal cocoon-like service structure was used to assemble the rocket on the seaside pad, provide workers access to all areas and give protection from the weather.

2008 GMT (4:08 p.m. EDT)

Loading of the first stage fuel tank of the Boeing Delta 2 rocket was just completed.

2006 GMT (4:06 p.m. EDT)

The Terminal Countdown has started for launch of Boeing's Delta 2 rocket carrying the U.S. Air Force's Global Positioning System 2R-12 spacecraft.

The countdown currently stands at T-minus 150 minutes. However, there are a pair of holds -- totaling 30 minutes in duration -- planned at T-minus 20 minutes and T-minus 4 minutes.

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

The Air Force launch weather officer says the area of storms over the Cape remains in place and more storms are moving this way.

The lightning, cumulus and anvil cloud, and electrical charge rules are still being violated. Also, the disturbed weather rule has been added to the "no go" list.

The outlook for launch time is an 80 percent chance of unacceptable conditions.

The forecast for Monday is virtually the same. Tuesday's prediction calls for a 70 percent chance of bad weather.

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

Now passing the 10-minute mark in this approximate 20-minute process to load the rocket's first stage with about 10,000 gallons of refined kerosene.

A weather briefing is upcoming at 4 p.m. EDT.

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

RP-1 has been flowing for five minutes with no problems reported. About 3,000 gallons have been loaded into the rocket.

1948 GMT (3:48 p.m. EDT)

Fueling of the Delta 2 rocket's first stage has begun. 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 17B.

RP-1 loading is an activity that can occur out of sequence in the countdown. So officials are taking advantage of that fact as they watch the weather and keep alive the option of launching this evening if the storms and lightning over the Space Coast clear out.

1943 GMT (3:43 p.m. EDT)

The launch team is beginning work to load the first stage with its supply of kerosene fuel.

1942 GMT (3:42 p.m. EDT)

The lightning, cumulus and anvil cloud, and electrical charge rules are still being violated.

1930 GMT (3:30 p.m. EDT)

Launch team members are posturing themselves to quickly pick up with countdown operations if officials give approval. There is a Phase 2 lightning advisory covering Cape Canaveral this afternoon, which is complicating activities at pad 17B. If the lightning alert passes and the weather forecast shows any optimism, crews will get the mobile service tower rolled away from the Delta 2 rocket, configure the pad for liftoff and begin fueling the vehicle's first stage. But the weather remains the driving force.

Launch is possible today during a 27-minute window extending from 7:06 to 7:33 p.m. EDT (2306-2333 GMT).

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

The weather evaluations and predictions continue at Cape Canaveral Air Force Station. Officials have until around 4 p.m. EDT to make the call whether to press ahead with the countdown and retract the mobile service tower to the launch position or scrub for the day.

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

We are awaiting word from the management meeting. Launch is four hours away. The mobile service tower is still around the Delta 2 rocket at pad 17B, and clocks have entered the planned hold point at T-minus 150 minutes prior to the start of the Terminal Countdown at 4:06 p.m.

1835 GMT (2:35 p.m. EDT)

At the present time, the lightning, cumulus and anvil cloud rules are being violated. Also, the field mills are registering an electrical charge in the air that is out of limits for launch.

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

Mission managers are still watching the weather and the development of afternoon thunderstorms across Central Florida. At a 1 p.m. EDT meeting, officials decided to continue with launch preparations for now. They will meet again around 3 p.m. EDT to reassess the latest weather outlook.

1650 GMT (12:50 p.m. EDT)

The local radar is showing a cluster of showers and storms building to the north of Cape Canaveral. The mobile service tower has not yet been retracted to the launch position at pad 17B. A management meeting is scheduled to begin a short time from now to decide whether to roll back the tower and continue with today's countdown.

1520 GMT (11:20 a.m. EDT)

The Air Force weather team has released its launch day forecast update. The outlook is unchanged from the forecast issued last night. There is an 80 percent chance of unacceptable weather today at Cape Canaveral.

After last night's scrub, the mobile service tower was rolled back around the Delta 2 rocket. It currently remains in that position enclosing the launch vehicle at pad 17B.

0500 GMT (1:00 a.m. EDT)

The updated launch weather forecast issued following Saturday evening's scrub shows an 80 percent that stormy conditions will prohibit liftoff on Sunday, Monday and Tuesday.

What's more, the thunderstorms are predicted to fire up much earlier in the day on Sunday than was experienced on Saturday.

"The surface ridge and upper level ridge has pushed to the south resulting in west-southwesterly flow at all levels. With this type of pattern expect formation of storms between 1:00-2:00 p.m. EDT. The Cape will see showers and thunderstorms forming west of the Indian river with the onset of the sea breeze, throughout the afternoon hours," the official forecast says.

"The primary concern will be showers and thunderstorms building over launch pad 17B through the launch countdown."

The launch time forecast calls for three levels of clouds, scattered at 1,500 feet, broken at 2,500 feet and broken at 25,000 feet, visibility of 5 miles, southwesterly winds from 230 degrees at 8 gusting to 12 knots and a temperature between 81 and 83 degrees F.

The specific concerns that caused meteorologists to predict an 80 percent chance of violating the launch weather rules are lightning, anvil clouds, cumulus clouds and rain in the rocket's flight path.

The outlook for Monday and Tuesday shows the same concerns.

SATURDAY, JUNE 19, 2004
2345 GMT (7:45 p.m. EDT)

If Mother Nature cooperates, another attempt at launching the Global Positioning System 2R-12 satellite atop a Boeing Delta 2 rocket will be made Sunday evening at Cape Canaveral, Florida. Liftoff will be possible between 7:06 and 7:33 p.m. EDT (2306-2333 GMT).

Today's countdown was thwarted by thunderstorms drifting over the launch site, bringing rain, gusty winds and lightning. The dismal conditions meant officials had no choice but to suspend the activities prior to loading the rocket's first stage with liquid oxygen.

Scrub turnaround operations are underway to safe the vehicle and prepare for another countdown.

However, the weather predictions for the next couple of days are not overly optimistic. The launch weather officer said there is a 70-to-80 percent chance of storms preventing liftoff on both Sunday and Monday.

There is a deadline looming that would force this launch to be postponed significantly. Pad 17B where the Delta 2 rocket stands awaiting liftoff is needed to support the planned July 30 launch of a Delta 2-Heavy rocket with NASA's MESSENGER spacecraft to orbit the planet Mercury. That high-priority launch must occur during a 15-day period for planetary alignment reasons.

If this GPS mission does not fly soon, officials will be forced to disassemble this Delta 2 rocket and remove it from the pad. MESSENGER's rocket could then begin on-pad assembly. It takes over a month to prepare a Delta 2 for flight.

Prior to today's weather scrub, the GPS launch had been delayed 15 days by technical issues.

Once launched, the GPS satellite will replace an ailing craft in the U.S. military's navigation constellation that provides precision location and timing information to soldiers, ships, aircraft and even guided bombs.

2210 GMT (6:10 p.m. EDT)

The launch weather officer reports that conditions on Sunday and Monday will be similar to the stormy situation experienced today. The forecast calls for a 70-to-80 percent chance of violating the launch rules each day.

2204 GMT (6:04 p.m. EDT)

SCRUB! This evening's launch of the Boeing Delta 2 rocket carrying the Global Positioning System 2R-12 spacecraft has been postponed due to stormy weather over Cape Canaveral Air Force Station.

Another launch opportunity is possible tomorrow evening at roughly 7:06 p.m. EDT. However, meteorologists are again predicting iffy weather.

2201 GMT (6:01 p.m. EDT)

The launch weather officer just gave another briefing to management. There is not much hope of conditions approving in the next hour so that the pre-launch work could resume for liftoff. The lightning, anvil cloud, cumulus cloud, debris cloud, thick cloud, surface field mill and disturbed weather rules are still being violated at this time.

2155 GMT (5:55 p.m. EDT)

The countdown clocks continue to tick. However, pre-launch work is on hold due to storms in the Cape Canaveral area.

2147 GMT (5:47 p.m. EDT)

Reporters have arrived at the press viewing location just over a mile from launch pad 17B. However, the rain is keeping everyone huddled in their cars.

2144 GMT (5:44 p.m. EDT)

The weather team reports there has been a lightning strike about a half-mile from the launch pad. The Phase 2 lightning advisory for the Cape is expected to last at least another 40 minutes.

2140 GMT (5:40 p.m. EDT)

Reporters are driving through stiff winds and rain as they make their way to Cape Canaveral's press site.

2134 GMT (5:34 p.m. EDT)

While this weather-induced hold continues, the launch team just reported that activation of the rocket's guidance system has been completed.

2133 GMT (5:33 p.m. EDT)

The lightning, anvil cloud, cumulus cloud, debris cloud, thick cloud, surface field mill and disturbed weather rules are all being violated at this time.

The rules that are currently "go" are launch winds, flight through precipitation, cloud ceiling and the smoke plume rule.

2127 GMT (5:27 p.m. EDT)

The countdown is structured so that liquid oxygen loading can be delayed a little while without impacting the scheduled launch time. But the weather is the driving force at the Cape currently.

2125 GMT (5:25 p.m. EDT)

Air Force management has reported a "no go" for cryogenic tanking due to local weather conditions.

2123 GMT (5:23 p.m. EDT)

The launch team is awaiting approval from senior officials to load liquid oxygen in the Delta 2 rocket's first stage.

2116 GMT (5:16 p.m. EDT)

A Phase 2 lightning advisory is being posted the Cape. Meanwhile, officials are looking closely at the speed and direction that winds would be gusting if one of these storms moved over pad 17B with the Delta 2 rocket standing exposed.

2112 GMT (5:12 p.m. EDT)

The Air Force weather officer just gave the launch management team a briefing on the current and forecast conditions. The generally favorable outlook issued this morning calling for a 30 percent chance of violating the launch weather rules has worsened to 60 percent.

There is a wide-spread area of storms and clouds to the north and west, including rain some 5 to 10 miles due west of the pad. Another pocket of rain is located about 50 miles to the north and moving toward the Cape.

At the present time, the lightning, cumulus and anvil cloud rules are being violated.

Officials are deciding whether to proceed with loading liquid oxygen into the Delta's first stage as scheduled about 10 minutes from now.

2055 GMT (4:55 p.m. EDT)

The first stage fuel tank of the Boeing Delta 2 rocket has been fully loaded. The tank was filled with a highly refined kerosene, called RP-1, during a 20-minute, 32-second process that concluded at 4:55:29 p.m. EDT.

The next major task in the count, weather permitting, will be loading super-cold cryogenic liquid oxygen into the first stage.

Flashes of lightning can be seen around the Space Coast as the storms continue to drift through the area.

2051 GMT (4:51 p.m. EDT)

Skies are becoming quite dark over Cape Canaveral as storms approach from the north and west. Mission managers will be receiving a weather briefing a short time from now in advance of loading liquid oxygen into the first stage.

2049 GMT (4:49 p.m. EDT)

The launch team has computed that the full load for the first stage fuel tank today is 10,040 gallons.

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

2045 GMT (4:45 p.m. EDT)

Fueling is now passing the 10-minute mark in this approximate 20-minute process to load the rocket's first stage with about 10,000 gallons of refined kerosene. The vehicle has been filled with over 5,000 gallons to this point.

2040 GMT (4:40 p.m. EDT)

RP-1 has been flowing for five minutes with no problems reported. Over 2,000 gallons have been loaded into the rocket.

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

2035 GMT (4:35 p.m. EDT)

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 17B.

2030 GMT (4:30 p.m. EDT)

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

Launch remains scheduled for 7:10 p.m. EDT this evening. However, the weather is looking like a 50-50 situation at this point as clouds and storms form all around Cape Canaveral this afternoon.

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

Launch team members are beginning the work to activate the Delta's onboard guidance computer -- called the Redundant Inertial Flight Control Assembly, or RIFCA.

2010 GMT (4:10 p.m. EDT)

The Terminal Countdown has commenced for launch of Boeing's Delta 2 rocket carrying the U.S. Air Force's Global Positioning System 2R-12 spacecraft. Over the next three hours, the launch team will prep the rocket, payload and ground support systems for the planned 7:10 p.m. EDT (2310 GMT) liftoff from pad 17B at Cape Canaveral Air Force Station in Florida.

Today's available launch window extends 27 minutes to 7:37 p.m. EDT.

The countdown currently stands at T-minus 150 minutes. However, there are a pair of holds -- totaling 30 minutes in duration -- planned at T-minus 20 minutes and T-minus 4 minutes.

The Complex 17B 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.

2001 GMT (4:01 p.m. EDT)

The launch team has been polled to verify all of the consoles are manned and systems are ready to resume the countdown as planned at the end of this hold. Clocks will start ticking again at 4:10 p.m. EDT.

1940 GMT (3:40 p.m. EDT)

Terminal Count begins a half-hour from now. That three-hour sequence will see the Delta 2 rocket fully fueled, the guidance system turned on and final system testing conducted.

The loading of RP-1 kerosene fuel into the rocket's first stage is expected to start around 4:30 p.m. Liquid oxygen tanking will follow about an hour later. The second stage was loaded with storable propellant a few days ago and the third stage is solid-fueled.

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

We have posted a gallery of photos taken earlier this morning as the mobile service tower was rolled away from the Delta 2 rocket. The picture collection includes shots of a commemorative sign on the pad umbilical tower dedicating this launch to President Reagan.

See the gallery here.

1933 GMT (3:33 p.m. EDT)

A check of the local weather conditions shows that the Cumulus Cloud Rule is currently being violated. The clouds are within 5 miles of the launch pad. The forecast for launch time at 7:10 p.m. EDT calls for a 70 percent chance of good weather -- a 30 percent chance of clouds and/or rain scrubbing the liftoff today.

1910 GMT (3:10 p.m. EDT)

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, the entire launch team and management will be seated at their consoles. A series of polls will be conducted to verify all is in readiness for entering Terminal Count at end of the built-in hold.

Liftoff of the Delta 2 rocket remains scheduled for 7:10 p.m. EDT from Cape Canaveral, Florida.

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

The countdown continues at Cape Canaveral for today's launch of the Delta 2 rocket. Terminal Count is still scheduled to commence at 4:10 p.m. EDT, followed by fueling of the vehicle's first stage.

1550 GMT (11:50 a.m. EDT)

The weather forecast for today's launch attempt has degraded slightly. In the latest weather report issued this morning, meteorologists say there is a 30 percent chance that conditions will prohibit liftoff during today's 7:10 to 7:37 p.m. EDT launch window. Anvil and cumulus clouds and rain in the rocket's flight path are the chief concerns. Yesterday's forecast called for a 20 percent chance of bad weather.

The outlook for the backup launch opportunities on Sunday and Monday is significantly worse -- with 60 and 70 percent chances of unfavorable weather, respectively.

You can see the full forecast here.

1515 GMT (11:15 a.m. EDT)

After overcoming a handful of technical issues that delayed liftoff by 15 days, a Boeing Delta 2 rocket is ready to fly today on a GPS satellite deployment mission for the U.S. military.

The protective service tower at Cape Canaveral's launch pad 17B was rolled back a short time ago, revealing the white and blue-green rocket standing 126 feet tall.

Workers are putting the final touches on the vehicle and arranging ground support equipment in preparation for this afternoon's countdown. Clocks will enter the Terminal Countdown phase of the launch operation at 4:10 p.m. EDT.

Liftoff remains targeted for 7:10 p.m. EDT (2310 GMT) as the Delta 2 thunders away from Earth on a 25-minute flight to place the next Global Positioning System spacecraft into orbit.

FRIDAY, JUNE 18, 2004
1630 GMT (12:30 p.m. EDT)

The Launch Readiness Review was conducted by senior officials this morning to verify all systems are "go" for liftoff at 7:10 p.m. EDT (2310 GMT) Saturday. The meeting concluded with approval to proceed with the countdown to launch of the Air Force's GPS 2R-12 satellite atop the Boeing Delta 2 rocket.

Watch this page for live updates during Saturday's countdown and launch!

1500 GMT (11:00 a.m. EDT)

Air Force meteorologists have improved the probability of good weather for Saturday's launch attempt. The latest forecast now calls for just a 20 percent chance of conditions violating the launch weather rules. It had been 30 percent earlier. You can see the full forecast here.

0401 GMT (12:01 a.m. EDT)

A Boeing Delta 2 rocket is poised to launch a replacement satellite for the U.S. military's Global Positioning System navigation network on Saturday evening from Cape Canaveral, Florida.

Liftoff from pad 17B is scheduled for 7:10 p.m. EDT (2310 GMT). The available launch window extends 27 minutes to 7:37 p.m. EDT (2337 GMT).

Weather forecasters are calling for good conditions.

The three-stage rocket will deliver the $45 million GPS 2R-12 spacecraft into a temporary egg-shaped orbit stretching 11,000 miles from Earth at the highest point and just 100 miles at the closest point.

In the following days, the satellite will raise the low point and circularize the orbit using an onboard engine to reach the GPS constellation where it will replace an ailing satellite.

Controllers will maneuver the satellite into the Plane F, Slot 4 position of the constellation. That slot is currently held by the GPS 2A-16 satellite, which was launched on November 22, 1992 and has long surpassed its design life.

Air Force program officials say GPS 2A-16 "is aging and clock performance is degrading."

GPS 2A-16 is expected to be repositioned in the same orbital plane, making it a backup satellite for the remainder of its life, officials said.

The orbiting network currently has 28 working satellites that are relied upon by U.S. military forces to guide aircraft, ships, troops and precision bombs.

GPS satellites send continuous navigation signals that allow users around the world to find their position in latitude, longitude and altitude and determine time. The signals are so accurate that time can be figured to less than a millionth of a second, velocity to within a fraction of a mile per hour and location to within a few feet.

This will be the second of three routine GPS replacement launches scheduled in 2004. The GPS 2R-11 craft was successfully lofted into orbit on March 20, and the next mission is slated for flight from Cape Canaveral on September 22.

THURSDAY, JUNE 17, 2004
1730 GMT (1:30 p.m. EDT)

Preparations continue for Saturday's rescheduled launch of the Delta 2 rocket with GPS 2R-12. The weather forecast calls for a 70 percent chance of favorable conditions. You can see the full forecast here.

WEDNESDAY, JUNE 16, 2004
1625 GMT (12:25 p.m. EDT)

The NAVSTAR Global Positioning System 2R-12 satellite launch using the Boeing Delta 2 rocket has been postponed to Saturday. The launch window will extend from 7:10 to 7:37 p.m. EDT (2310-2337 GMT).

This additional 24-hour delay in the launch campaign was ordered after activities at pad 17B were temporarily halted Tuesday. A hazard alarm sounded at the Cape Canaveral launch complex, causing workers to evacuate. It turned out to be a false alarm, but the event delayed routine pre-launch chores, officials said.

The early weather forecast calls for a 70 percent chance of favorable conditions during Saturday's launch attempt. Cumulus clouds and rain in the rocket's flight path will be the two concerns that meteorologists keep a close eye on.

This mission to deliver a replacement GPS satellite into the U.S. military's orbiting navigation network has been postponed several times by technical concerns, including replacement of the rocket's first stage hydraulic pump for precautionary reasons, a review of wiring and swap out of an actuator on a vernier steering engine. The Air Force had to review and certify the work, which had slipped the launch date from Wednesday to Friday. The pad-clearing alarm forced the additional delay to Saturday.

MONDAY, JUNE 14, 2004
1700 GMT (1:00 p.m. EDT)

Officials are now looking at a potential Friday attempt to launch the Delta 2 rocket with the GPS 2R-12 spacecraft. The day's launch window would extend from 7:14 to 7:41 p.m. EDT (2314-2341 GMT).

Everything remains unsettled. We'll post more details as they become available.

FRIDAY, JUNE 11, 2004
1730 GMT (1:30 p.m. EDT)

Officials are targeting a Wednesday evening blastoff of the GPS 2R-12 satellite. Launch of the Delta 2 rocket will be possible during a 27-minute window extending from 7:22 to 7:49 p.m. EDT (2322-2349 GMT).

THURSDAY, JUNE 10, 2004
2315 GMT (7:15 p.m. EDT)

There has been another delay in the launch of Boeing's Delta 2 rocket with the Global Positioning System 2R-12 military navigation satellite from Cape Canaveral Air Force Station, Florida.

Technicians must replace a faulty yaw actuator on one of the rocket's first stage vernier engines. The verniers are small thrusters that help steer the vehicle during the initial four-and-a-half minutes of flight.

The work will delay the launch until next Tuesday or Wednesday at the earliest.

In the meantime, crews are facing a scheduling crunch at Cape Canaveral's pad 17B where the Delta rocket and GPS 2R-12 satellite await launch. Once the mission takes off, the pad will be quickly refurbished so another Delta 2 booster can be assembled for launch of NASA's MESSENGER space probe that will orbit the planet Mercury.

Ongoing delays in the launch the GPS 2R-12 mission have already begun to eat up slack in MESSENGER's pre-flight schedule. MESSENGER must blast off during a tight window extending from July 30 to August 13 or else remain grounded until another planetary alignment opportunity.

If the GPS flight is postponed much further, the tough decision will be made to disassemble that rocket and military satellite to vacate the pad for MESSENGER and its launcher.

Stacking of the rocket stages for MESSENGER's Delta 2 vehicle was originally slated to begin June 18. That work is now expected to start no sooner than June 23. However, officials remain hopeful that margin built into the launch campaign will still allow the craft to depart Earth on July 30 as scheduled for its long journey to the innermost planet.

The Delta 2 rocket's other Florida launch complex -- pad 17A -- is currently out of service while some maintenance and upgrade work is performed.

1405 GMT (10:05 a.m. EDT)

A Sunday launch attempt is no longer doable, pushing back liftoff of the GPS 2R-12 satellite aboard the Delta 2 rocket to no earlier than Monday evening at 7:31 p.m. EDT (2331 GMT).

WEDNESDAY, JUNE 9, 2004

Launch could be pushed back another day -- to Monday evening. Check back for more details Thursday.

TUESDAY, JUNE 8, 2004

A Boeing Delta 2 rocket is aiming for a Sunday evening liftoff from Cape Canaveral with the next replacement Global Positioning System satellite, if Air Force officials become satisfied with an examination of wiring used on the booster.

"The Air Force asked for a little more information relative to this wire harness investigation that we were doing," Boeing mission director Rich Murphy said in an interview Tuesday.

Launch of the GPS 2R-12 satellite atop a Delta 2 rocket from pad 17B had been scheduled for last Friday, June 4. But the mission was delayed to this week to swap out a hydraulic pump on the rocket after a similar unit on a different Delta 2 had a problem. Because the two pumps were built around the same time, it was decided to replace the device on the GPS rocket just to be safe.

"Although it didn't act up, it was in a questionable time period in terms of the build. So we decided to change it," Murphy said of the reasoning to replace the GPS rocket's pump.

"While we were doing that, we got into this wire harness investigation a little further," Murphy added.

The analysis of wiring has been underway for some time. The work has included dissecting some wiring harnesses.

"As a result of that, one of the wire harnesses came up with some damage. So the evaluation of that damage became a constraint for this launch. The investigation is still in process and that is why we are still answering some questions," Murphy explained.

"It is coming to a conclusion that the damage seen on this particular harness was done while we were taking it apart rather than in the build up. So it was a dissection problem rather than a build up problem."

The pump and wiring issues didn't begin with the GPS launcher, they've only impacted the launch campaign.

"Nothing on the (GPS) 2R-12 vehicle has indicated any problem. But the pump because of the proximity of its build to the one that was on Aura we changed it out. And then the wire harness dissection. Everything has checked out on 2R-12. It is just answering the questions associated with this harness that showed some damage. It was not on the vehicle," Murphy said.

"The up shot of all of this we hope to have an updated Flight Readiness Review on Thursday and try to go for a launch on Sunday. But that all predicated on finishing answering these questions that the Air Force came up with."

Sunday's launch window runs from 7:35 to 8:02 p.m. EDT (2335-0002 GMT).

The pump problem stems from the launch campaign at Vandenberg Air Force Base, California, where a Delta 2 will carry NASA's Aura environmental satellite into polar orbit. Coverage of that mission is available here.

1930 GMT (3:30 p.m. EDT)

Launch of the Delta 2 rocket has been pushed back two additional days to no earlier than Sunday. This further slip allows officials to complete a review of wiring harnesses used on the Delta rockets. Sunday's launch window would extend from 7:35 to 8:02 p.m. EDT (2335-0002 GMT). More details later today.

FRIDAY, JUNE 4, 2004

With the first stage hydraulic pump removed and replaced, officials are targeting liftoff of the Boeing Delta 2 rocket and GPS 2R-12 spacecraft for Friday, June 11 from Cape Canaveral Air Force Station, Florida.

The day's 27-minute launch window extends from 7:43 to 8:10 p.m. EDT (2343-0010 GMT).

The pump had to be swapped out after concerns with a similar unit arose during launch preparations in California for another Delta 2 rocket. The replacement work forced a one-week delay for the GPS 2R-12 military navigation satellite. Additional information and a preview of the launch is available in our earlier story.

MONDAY, MAY 31, 2004

This week's planned launch of the next Global Positioning System satellite aboard a Boeing Delta 2 rocket has been delayed a few days so workers can replace a suspect pump.

"Boeing has a flightworthiness concern with the Delta 2 first stage hydraulic pump," Air Force launch officials said.

"A new pump, with improved inspection and testing procedures, will be installed on the Delta 2/GPS 2R-12 launch vehicle."

The rocket and its $45 million GPS 2R-12 payload are assembled atop pad 17B at Cape Canaveral Air Force Station, Florida. Liftoff had been targeted for 8:11 p.m. EDT Friday, June 4.

A new date has not been established for liftoff, but launch could occur on or about Wednesday, June 9. The day's launch window would extend from 7:51 to 8:18 p.m. EDT.

Read our launch preview story.

SATURDAY, MARCH 20, 2004

As the 50th Global Positioning System satellite rose to space Saturday, it celebrated the man who championed the concept of orbiting spacecraft serving as "lighthouses in the sky" to guide mankind with precision navigation information. Read our full story.

Video coverage for subscribers only:
   VIDEO: DELTA 2 ROCKET BLASTS OFF WITH GPS 2R-11 QT
   VIDEO: LONGER LENGTH LAUNCH MOVIE QT
   VIDEO: SPACECRAFT SEPARATION ANNOUNCED QT
   VIDEO: FIRST COUNTDOWN HALTED BY ALARM QT
   SUBSCRIBE NOW