BY JUSTIN RAY

Follow the preparations and launch of the Lockheed Martin Titan 4B rocket carrying a classified cargo for the U.S. National Reconnaissance Office. Reload this page for the very latest on the mission.

WEDNESDAY, OCTOBER 3, 2001

The Lockheed Martin-built Titan 4B rocket and its National Reconnaissance Office payload won't fly until at least Friday because of a voltage problem that engineers are troubleshooting at the Vandenberg Air Force Base launch pad.

Officials said Wednesday evening that more time was needed to sort through this latest in a series of issues that have postponed the Titan 4 mission past its original Monday launch date. Earlier concerns involving the onboard guidance computer and a faulty solid rocket motor telemetry unit have since been resolved.

In a statement about the new problem, the Air Force said: "The team is evaluating stray voltage detected by the ground computer. Initial causes of the stray voltage included a possible faulty relay inside the Titan, which has now been exonerated. The team continues to troubleshoot the umbilical cable, which connects the rocket to the facility.

"A decision on proceeding with the countdown will be made late Thursday morning for a launch attempt Friday," the statement said.

Friday could be the last day to launch the rocket until next week. If not off the ground by Friday workers likely will have to service onboard batteries, delaying the liftoff by at least a few days.

If a slip to next week occurs, then officials will have to decide whether to keep the Titan their first priority or press ahead with the planned Wednesday evening blastoff of an Atlas rocket carrying a National Reconnaissance Office payload from Cape Canaveral Air Force Station in Florida. The NRO says members of its launch crew are working both the Titan and Atlas missions, so some spacing between the flights will be necessary.

2323 GMT (7:23 p.m. EDT)

DELAYED AGAIN. Officials meeting this afternoon have just decided that the launch will slip at least one more day to Friday, an NRO spokesman says. There is apparently another technical issue being worked beyond the two problems addressed earlier this week, but details are not yet confirmed. There is also a deadline approaching for some onboard batteries that could force the launch to be delayed until next week.

1810 GMT (2:10 p.m. EDT)

The weather forecast has been issued for a possible Thursday launch attempt of the Titan 4B rocket. Launch Weather Officer Capt. Andrew Goodnite says there will be a 90 percent chance of acceptable conditions with launch drift winds the only concern. Here is his summary:

"The low to our west has started a slow movement to the east but won't be affecting our area until Friday afternoon. Tropical Depression Juliette is dissipating over northern Baja. Current maximum wind speed is 20 kts. The latest model runs are showing dry conditions over Vandenberg above the marine layer on launch day. Expect marine layer clouds to remain over SLC-4E and along the coast throughout the day although the rest of the base will see mostly clear skies at launch time. Surface winds will be from the northwest at 10 to 14 knots with upper level winds from the northwest; expect maximum winds from 25 to 35 knots at 40,000 feet."

The launch time forecast calls for stratus clouds at 500 feet with tops at 1,000 feet and 5/8ths sky coverage, three to four miles visibility, fog in the area, northwesterly winds from 300 to 330 degrees at 10 gusting to 14 knots and a temperature of 60 to 64 degrees F.

TUESDAY, OCTOBER 2, 2001
2358 GMT (7:58 p.m. EDT)

DELAYED AGAIN. The Air Force has just announced another 24-hour delay for the launch of the Lockheed Martin Titan 4B rocket carrying a National Reconnaissance Office payload. Liftoff will now occur no sooner than Thursday afternoon from Vandenberg Air Force Base in California.

Reviews were underway this afternoon to determine when the launch could proceed after technical issues had arisen in the past several days. Word came minutes ago that officials had decided to push back the launch by at least one more day.

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

Officials are meeting this afternoon to determine when the Titan 4B rocket can be cleared for launch. A pair of technical issues have thus far delayed the launch 48 hours to no earlier than Wednesday.

First, there was a problem with a guidance computer similar to one used by Titan 4 that produced faulty data during testing back at the Honeywell factory. As a result, officials on Sunday evening called off Monday's launch attempt to give engineers more time to review records to ensure the Titan 4's computer was OK. The Titan 4's guidance system has since been deemed flight-worthy.

Meanwhile, a problem was uncovered with a telemetry unit on one of the solid rocket motors. The instrumentation was producing "noisy" data on some of the booster telemetry monitors when supplied by ground power, the Air Force said. The problem caused a potential Tuesday launch try to be scrapped, delaying the launch until at least Wednesday.

Launch pad workers successfully removed and replaced the telemetry unit overnight, and initial testing of the new unit today has gone well. That led to an engineering evaluation board meeting this afternoon to determine the readiness to reenter the countdown later today, the Air Force said in a statement.

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

UPDATE. The U.S. Air Force, which governs this Titan 4B rocket launch, released a statement this morning to officially say why the mission had been postponed originally:

"The Titan 4B launch was postponed to give experts time to assess anomalous data which arose during testing of an Atlas rocket inertial navigation unit at the factory over the weekend. The Atlas inertial navigation unit is similar in design to the Titan guidance control unit. The postponement allowed Titan and Atlas engineers to review the data and make sure we were not faced with an increased risk to mission success."

Col. John D. Wagner, commander of Detachment 9, Space and Missile Systems Center, Air Force Space Command, at Vandenberg AFB, Calif., said: "Since the Atlas box has similarities to the Titan Guidance Control Unit (GCU) we are flying on this mission, we just want to make sure our GCU is good to go."

However, a second issue involving noisy date from instrumentation for the Titan 4B's solid rocket boosters also caused the launch to be delayed. That problem is still being worked, and the launch date has been pushed back to no sooner than Wednesday.

MONDAY, OCTOBER 1, 2001

Engineers continue to troubleshoot a technical problem with the Titan 4B rocket at Vandenberg Air Force Base in California, delaying the launch until Wednesday at the earliest, officials announced Tuesday evening.

Liftoff would occur at approximately 2119 GMT (5:19 p.m. EDT; 2:19 p.m. PDT). The launch plans will be firmed up on Tuesday if the technical issue is resolved in time to support a Wednesday blastoff.

While the Air Force has still not given reporters any details on the nature of the problem, sources familiar with the situation say it involves the instrumentation for the Titan 4B's solid rocket boosters.

The sources said technicians saw unexpected noise in the data stream from the instrumentation. That prompted officials to delay the launch so the cause of the noise could be tracked down.

The twin solid-propellant boosters are ignited at liftoff, producing the three million pounds of thrust to propel the massive Titan 4 skyward. Built by Alliant Techsystems, the motors burn for nearly two-and-a-half minutes before separating to fall into the ocean below.

Wednesday's weather forecast calls for an 80 percent chance of favorable conditions. The only concern will be launch drift winds. Clear skies and unrestricted visibility are predicted for launch time.

2335 GMT (7:35 p.m. EDT)

ANOTHER DELAY. Although not yet announced by the Air Force, launch team sources say the Titan 4 liftoff will be delayed at least another 24 hours to Wednesday afternoon at approximately 2119 GMT (5:19 p.m. EDT; 2:19 p.m. PDT).

Now nearly a day after officials ordered the launch postponed, Air Force has still not explained why. A spokesperson said the answer wouldn't be ready until Tuesday.

1600 GMT (12:00 p.m. EDT)

Details of why today's Titan 4 launch had to be postponed remain sketchy and unconfirmed. In any event, the Air Force, which governs this launch, says liftoff has been rescheduled for Tuesday at 2119 GMT (5:19 p.m. EDT; 2:19 p.m. PDT).

We'll update this page as soon as more information becomes available.

0457 GMT (12:57 a.m. EDT)

Today's launch of a Lockheed Martin Titan 4B rocket carrying a top-secret spy satellite cargo was called off Sunday evening because of an unspecified technical concern. The liftoff was tentatively rescheduled for Tuesday.

More information is expected to be released by officials later today.

SUNDAY, SEPTEMBER 30, 2001

The countdown clocks at Vandenberg Air Force Base in California lit up today at T-minus 26 hours for Monday's launch of a Titan 4B rocket carrying a classified satellite cargo for the U.S. National Reconnaissance Office.

Liftoff remains scheduled for 2119 GMT (5:19 p.m. EDT; 2:19 p.m. PDT) from the SLC-4 East launch pad on Vandenberg's South Base. The duration of the launch window remains secret. However, the Air Force says the launch won't occur after 2300 GMT (7 p.m. EDT; 4 p.m. PDT).

The first 17 hours of the countdown are known as Phase One, with planned activities including initial pad preparation chores, running final pressurization checks on the rocket and making ordnance connections.

Phase Two of the countdown will begin at T-minus 9 hours when efforts start in earnest to roll the mobile service tower away from the Titan 4B rocket, such as disconnecting various water, electrical and other systems. The 30-minute tower retraction is currently targeted to occur at approximately 1649 GMT (12:49 p.m. EDT; 9:49 a.m. PDT).

Once the tower is secured in its launch position, workers will finish prepping the complex for rocket's thunderous blastoff and then clear the area.

Unlike some Cape Canaveral Titan 4 missions that carry a Centaur upper stage that has to be fueled during the final countdown, Monday's launch does not have such a kick motor for the payload. So the final couple of hours of the countdown will be fairly straightforward with the focus on status checks, switching the vehicle to internal power and arming onboard systems for flight.

The launch weather forecast remains generally favorable with an 80 percent chance of acceptable conditions. The two concerns are thick cloud layers and launch drift winds. Launch Weather Officer Capt. Andrew Goodnite issued this updated summary today:

"The large low-pressure area that is currently developing southwest of Alaska will remain well to the west of our area on launch day with an upper level high embedded over the central coast. Hurricane Juliette has been downgraded to a Tropical Depression and is weakening and slowly moving to the northwest. Current maximum wind speed is 35 knots.

"The latest models runs are showing some mid and upper level moisture moving into the area on launch day. We should see enough moisture to see scattered mid and high-level clouds move over Vandenberg. We will also see some cumulus cloud development over the mountains to our east but well over 10 nautical miles away from the launch facility on both launch day and scrub day. Surface winds will be from the southwest at 8 to 12 knots with mid level (5,000-18,000 ft) winds out the southeast at 15-25 knots and upper level winds from the northwest; expect maximum winds from 30 to 40 knots at 40,000 feet."

The launch time forecast now calls for cumulus clouds at 5,000 feet with tops at 8,000 feet and 2/8ths sky coverage, altocumulus clouds at 10,000 feet with tops at 12,000 feet and 2/8ths sky coverage, cirrus clouds at 25,000 feet with tops at 27,000 feet and 2/8ths sky coverage, 7 miles visibility, southwesterly winds from 210 to 240 degrees at 10 gusting to 14 knots and a temperature of 60 to 66 degrees F.

Should the launch be delayed to Tuesday, there is a 70 percent chance of good weather with thick clouds and launch drift winds the two threats.

For the 24-hour delay forecast, Goodnite says: "Expect increasing mid and upper level clouds on Tuesday with a broken altocumulus deck from 10,000 ft to 12,000 ft and an overcast cirrus deck at 25,000 ft. If these clouds are greater than 4,500 ft thick and are between the 0 degrees Celsius and -20 degrees Celsius levels, they would violate the Thick Cloud Layer Constraint -- only a slight concern at this time. Surface winds will be from the northwest from 10 to 14 knots. Maximum upper level winds will remain relatively light from 35 to 45 knots at 40,000 ft."

We will have complete live coverage of Monday's countdown and launch. Watch this page for the latest updates!

SATURDAY, SEPTEMBER 29, 2001

A Lockheed Martin Titan 4B rocket, America's most powerful unmanned launcher, will haul a top-secret spy satellite into orbit on Monday from Vandenberg Air Force Base in California. Experts believe the cargo is some sort of imaging spacecraft, possibly a powerful eye-in-the-sky KeyHole satellite. Read our full launch preview story.

Launch Weather Officer Capt. Andrew Goodnite says there is an 80 percent chance of favorable conditions for Monday's liftoff. The only concern is launch drift winds.

"The large low-pressure area that is currently developing southwest of Alaska will remain well to the west of our area on launch day with an upper level high embedded over the central coast," Goodnite said.

"Hurricane Juliette is currently located on the southern tip of Baja and has become stationary. Current maximum wind speed is 65 knots. It is forecasted to weaken and move very slowly to the north over the next couple of days. Therefore, most moisture and clouds associated with Juliette will remain well south of our area. We should see enough moisture however to see some high cirrus clouds move over Vandenberg.

"Surface winds will be from the northwest at 10 to 14 knots with mid level (5,000-18,000 ft) winds out the southeast at 15-25 knots and upper level winds from the northwest; expect maximum winds from 30 to 40 knots at 40,000 feet."

The launch time forecast calls for cirrus clouds at 25,000 feet with tops at 27,000 feet and 2/8ths sky coverage, 7 miles visibility, westerly winds from 270 to 300 degrees at 10 gusting to 14 knots and a temperature of 60 to 66 degrees F.

Should the launch be delayed to Tuesday, there is again an 80 percent chance of good weather. The two threats will be launch drift winds and cumulus clouds.

Goodnite reports: "Expect another nice weather day on Tuesday as the remnants of Hurricane Juliette remain well to the south of our area. We will see some cumulus cloud development over the mountains to our east but well over 10 nautical miles away from the launch facility.

"Surface winds will be from the northwest from 10 to 14 knots. Maximum upper level winds will remain relatively light from 25 to 35 knots at 40,000 ft."

Watch this page for play-by-play live coverage during Monday's countdown and launch!