BY JUSTIN RAY

December 12, 1999 -- Follow the launch of the DMSP F15 weather satellite aboard a U.S. Air Froce Titan 2 rocket. Reload this page for the very latest on the mission.

2046 GMT (3:46 p.m. EST)

A $250 million Defense Meteorological Satellite Program military weather spacecraft successfully arrived in near-polar orbit today. The DMSP F15 satellite was boosted into space aboard a U.S. Air Force Titan 2 rocket following an on-time liftoff at 1738 GMT (12:38 p.m. EST) from Vandenberg Air Force Base, California. Minutes later, the apogee kick motor attached to the satellite fired to place the craft into the proper orbit.

The Titan 2 rocket used was once an Intercontinental Ballistic Missile stationed at McConnell Air Force Base in Kansas. The booster was modified by Lockheed Martin to launch payloads into space after being decommissioned in 1987.

DMSP F15 will now undergo tests and checkouts over the next few weeks before it enters service in mid-January, replacing two older DMSP satellites that have suffered failures of onboard systems.

DMSP, operated by NOAA, is used for strategic and tactical planning by the U.S. military. But the satellites are also used by other parts of the government and universities for detecting forest fires, monitoring volcanic activity, hurricane forecasting and helping long-term climate change studies.

Today's launch was unique for the DMSP project because the satellite was placed into a different orbit than usual -- an orbit that will improve weather forecasting over the global hotspots that the U.S. military is interested in. The satellite will pass above Kosovo and the Korean Peninsula at a different time than current satellites in space, allowing better nighttime weather monitoring in those areas, said Col. Jeff Quirk, U.S. Air Force program director of DMSP. See more of Col. Quirks comments below.

The satellite is also the first of a new generation being built by Lockheed Martin Missiles & Space. The satellites feature advancements such as a new spacecraft structure, two additional panels on the solar array for more power, one additional battery, larger computer memory, improved software and two solid state recorders that replace the older reel-to-reel tape recorders on previous DMSPs.

The DMSP F15 satellite also carries an experimental payload called the Radar Calibration, or RADCAL. The experimented is designed to collect and transmit C-band data to monitor C-band tracking radar performance at the 30th Space Wing located at Vandenberg Air Force Base in California, the site of today's launch. A secondary objective of RADCAL is to transmit Doppler data for the Naval Research Laboratory's Coherent Electromagnetic Tomography, or CERTO experiment.

There are five more DMSP satellites awaiting launch over the next several years.

1905 GMT (2:05 p.m. EST)

Officials say the DMSP spacecraft has fired its kick motor and deployed its solar array. It will take several more tracking passes before they can confirm the spacecraft is in the correct orbit. The Air Force reports it is not working any problems. We will await further word on the progress of the mission and update this page later.

1749 GMT (12:49 p.m. EST)

T+plus 11 minutes. At this point, the DMSP spacecraft should have reoriented toward the proper attitude to ignite its onboard kick motor. Ignition will come at T+plus 13 minutes, 37 seconds, and the burn will last until T+plus 14 minutes, 28 seconds. A trim burn would then follow a few seconds later. The solar array on the satellite will deploy about 19 1/2 minutes after launch.

We will provide our final update on this launch later today once the U.S. Air Force confirms the satellite has completed its engine firing and successfully arrived into polar orbit.

1748 GMT (12:48 p.m. EST)

T+plus 10 minutes. SPACECRAFT SEPARATION CONFIRMED. The Defense Meteorological Satellite Program 5D-3-15 spacecraft has been released into space by the U.S. Air Force Titan 2 rocket. The satellite has achieved orbital altitude on one side of its orbit thanks to the Titan 2. However, its onboard rocket motor must fire in a short while to circularize the orbit or else the DMSP would reenter the atmosphere. This final boost to orbit is normally done by the launch vehicle's upper stage, but the satellite's kick motor serves as the upper stage, if you will.

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

T+plus 8 minutes. Release of the DMSP satellite from the Titan 2 rocket was expected at T+plus 6 minutes, 14 seconds. No word yet from the Air Force.

1745 GMT (12:45 p.m. EST)

T+plus 7 minutes. Awaiting confirmation of spacecraft separation from the U.S. Air Force.

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

T+plus 5 minutes, 40 seconds. The Titan 2 rocket's second stage has burned out as planned. The stage will now prepare to deploy the DMSP spacecraft in about a half-minute.

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

T+plus 5 minutes. Coming up on shutdown of the second stage of Titan 2 in about 25 seconds.

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

T+plus 4 minutes. The payload fairing enclosing the DMSP spacecraft has been jettisoned.

1741 GMT (12:41 p.m. EST)

T+plus 3 minutes. All systems reported nominal.

1740 GMT (12:40 p.m. EST)

T+plus 2 minutes, 45 seconds. The first stage has burned out and separated. The rocket's second stage has ignited to boost DMSP spacecraft.

1740 GMT (12:40 p.m. EST)

T+plus 2 minutes. Official liftoff time was 1738:01.822 GMT.

1739 GMT (12:39 p.m. EST)

T+plus 1 minute. The Titan 2 rocket continues it climb to orbit. No problems have been reported.

1738 GMT (12:38 p.m. EST)

T+plus 30 seconds. Rocket rolling to proper azimuth.

1738 GMT (12:38 p.m. EST)

LIFTOFF. Liftoff of the Titan 2 rocket with an advanced U.S. military weather satellite to improve forecasting over the global hotspots of the world.

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

T-minus 1 minute. The Titan 2 rocket will need just 6 minutes, 14 seconds to carry the DMSP F15 satellite into space. The spacecraft will then perform a burn of its kick motor to complete the journey to orbit.

1736 GMT (12:36 p.m. EST)

T-minus 90 seconds. The Western Range has reported its final go for launch.

1736 GMT (12:36 p.m. EST)

T-minus 2 minutes. The rocket's flight termination system has been checked. No problems reported.

1735 GMT (12:35 p.m. EST)

T-minus 3 minutes. A final clear to launch poll has been completed. Launch is go.

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

T-minus 4 minutes.

1733 GMT (12:33 p.m. EST)

T-minus 5 minutes and counting. Col. Jeff Quirk, U.S. Air Force program director of DMSP, says the satellite being launched today will be placed into a different orbit than previous DMSP weather satellites to improve forecasting over specific parts of the world:

"This is orbit is approximately a half-hour later than we have ever flown before. That was established to increase its utility to our deployed tactical users around the world. If I can take you back to the operations that we were conducting in Kosovo earlier in the year, one of things that we discovered early on was that the weather was pretty awful for air operations. We discovered the utility of having accurate weather forecasting. We found that to conduct those very surgical, precise air operations in that environment where you had civilians in close proximity to the other military forces that we had to use precision munitions and that the precision munitions were impacted by these adverse weather conditions. So being able to predict the periods of cloud cover and to predict the periods when the line of sight to the targets would be cloud-free enables us to schedule operations at the right point in time when we can have the maximum probability of success and avoiding any kind of collateral causalities in the civil population. Those are very important objectives for us there and we found we needed the space-based weather systems to help us that forecasting. We were asked to move our orbit slightly later and that provides data at the right time for the air operations planning.

"Each time our orbit crosses the equator in the ascending node at 2115 local time and crosses in a descending node at 0915 local time. So we are overhead everyday at the same time and we are overhead at any location on the globe at the same time of day."

"That is true. What we are talking about is the revolution at 2115 would be over Kosovo. But we also get that same view in the Korean Peninsula. We have a pass that is approximately 9:15 in the evening over Korea. So we get this increased performance not just in Kosovo, but globally."

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

T-minus 7 minutes. The booster readiness check of the Titan 2 rocket has been completed with no problems reported.

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

T-minus 8 minutes, 30 seconds. The Titan rocket's attitude control system pressures are being checked for launch.

1728 GMT (12:28 p.m. EST)

T-minus 10 minutes and counting. The next event will be a readiness check of the Titan 2 rocket's systems. There are no problems being reported and liftoff remains set to occur at 1738 GMT (12:38 p.m. EST).

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

T-minus 15 minutes and counting. The terminal countdown has begun for today's launch of a U.S. Air Force Titan 2 rocket and the DMSP F15 military weather satellite.

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

The launch team has been polled and the go has been given to enter terminal count at T-minus 15 minutes.

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

Now 20 minutes away from launch. All systems remain ready for liftoff. Coming up a readiness poll of the launch team.

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

There are no problems standing in the way of today's planned launch at 1738 GMT (12:38 p.m. EST). The U.S. Air Force has approved one waiver for the launch attempt. One weather balloon is not available today, but officials have decided to proceed without it.

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

Recently I interviewed Col. Jeff Quirk, U.S. Air Force program director of DMSP. He explained the purpose of the satellite being launched today:

"We are launching this latest vehicle (or satellite known as F15) into one of two of our operational planes. We have four vehicles that are currently operational and this satellite is replacing two of them. There are two older vehicles (F12 and F14) that each have some accumulated failures and they have some of the equipment still functioning. So we are going to replace those two vehicles with this newer vehicle that will have more capability of the two of them combined, because of the accumulated failures.

"The primary issue on those vehicles (F12 and F14) is that we've been having failures in our digital tape recorders on orbit. Those are fairly old technology, reel-to-reel tape recorders and our failure rate has been higher than we expected with that component. So one of the things that we have done on vehicle F15 (being launched today) is that we are going to fly two solid-state recorders. The solid-state technology is similar to the RAM memory in a personal computer, so it is that level of technology. Our expectation is that those will have a much longer operational line and will maintain the capability on orbit much better than the reel-to-reel tape recorders have done in the past."

The tape recorders are an important part of the DMSP satellite:

"We have two modes of operations. One is to record the data over the area that we are viewing on the recorders and then to replay that back over the ground stations. The second mode of operation is we also transpond that data in real-time. We have a network of direct-downlink terminals that we have deployed for our theater-based users around the world. Of course, what they will see is only the data from their particular area. What the tape recorders allow you to do is bring back information globally and then that information is processed at the Air Force weather agency in Omaha where they do global forecasts based on all that information."

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

Pressuziation of the first stage oxidizer tank on the Titan 2 rocket has been completed. The rocket remains go for launch.

1708 GMT (12:08 p.m. EST)

The U.S. Air Force launch weather officer just completing his final update prior to launch. All conditions remain acceptable and are forecasted to be perfect for launch in 30 minutes. Conditions are currently scattered clouds at 25,000 feet, unrestricted visibility, a temperature of 62 degrees F and southwesterly winds at 3 knots.

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

Today's launch will be the ninth for a converted Titan 2. The vintage booster once stood ready for U.S. national security as an Intercontinental Ballistic Missile. But it was the Titan 2 ICBM system was deactivated by June 1987. The U.S. government decided to refurbish some of the leftover missiles and convert them into space launch vehicles. Lockheed Martin Astronautics is resonsible for the work. Fourteen Titan 2s were converted to launch U.S. government payloads. The eight launched so far have been successful.

1651 GMT (11:51 a.m. EST)

The Titan 2 rocket's flight termination system has just completed a check. The system would be used to destroy the rocket if a problem occurred during launch.

1648 GMT (11:48 a.m. EST)

Officials report all personnel are in the launch operations building and the doors are being sealed in preparation for the Titan 2's liftoff.

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

The launch conductor has given the go to begin pressurizing the oxidizer tank of the Titan 2 rocket's first stage.

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

A new generation U.S. Air Force weather satellite remains ready for launch in one hour from Vandenberg Air Force Base along Central California's Pacific coast. Liftoff is scheduled for 1738 GMT (12:38 p.m. EST), the opening of a 10-minute window.

The Defense Meteorological Satellite Program 5D-3-15 spacecraft will be placed into a polar orbit by a converted Titan 2 intercontinental ballistic missile. Spacecraft separation from the Titan 2 rocket is expected six minutes and 14 seconds after launch. The satellite will then rely on its onboard rocket motor to complete the trip to space and circularize its orbit.

The DMSP system depends on two operational satellites in space to provide weather information. The data is used by U.S. military officials for strategic and tactical forecasting for land, sea and air operations around the globe.

The satellite being launched today is the first of a new series of enhanced DMSP satellites. The advancements include a new spacecraft structure, two additional panels on the solar array for more power, one additional battery, larger computer memory and improved software and two solid state recorders that replace the older reel-to-reel tape recorders on previous DMSPs.

1633 GMT (11:33 a.m. EST)

The final few workers are preparing to leave Space Launch Complex-4 West in preparation for today's liftoff in just over an hour. Once the pad is cleared, the launch team will begin pressurizing the rocket for flight.

1628 GMT (11:28 a.m. EST)

The countdown is ticking along at Vandenberg Air Force Base in California for today's launch of a U.S. Air Force Titan 2 rocket carrying a military weather satellite. Launch is still scheduled for 1738 GMT (12:38 p.m. EST).

Earlier today the retraction of the mobile service tower was delayed by about two hours due to a mechanical problem. However, the issue was fixed and the tower was rolled into the launch position about one hour ago.

Weather conditions are reported to be near perfect for launch. There are clear skies, a temperature of 60 degrees and light wind at the Space Launch Complex-4 West pad.

SATURDAY, DECEMBER 11, 1999
2100 GMT (4 p.m. EST)

The U.S. Air Force plans to launch its Defense Meteorological Satellite Program F15 spacecraft on Sunday aboard a Titan 2 rocket. Liftoff is planned during a window of 1738 to 1748 GMT (12:38-12:48 p.m. EST) from Space Launch Complex-4 West at Vandenberg Air Force Base, California.

The $250 million satellite will circle about 500 miles above Earth in a polar orbit to provide U.S. military officials with accurate weather information. The data is then used to plan military operations around the globe.

Sunday's launch attempt is running one day late so engineers could troubleshoot an unexpected power supply problem aboard the satellite. The issue was resolved on Friday, clearing the way for tomorrow's countdown and launch.

The Air Force Titan 2 booster, modified by Lockheed Martin, once served as an Intercontinental Ballistic Missile at McConnell Air Force Base in Kansas. It was decommissioned in 1987, and later refurbished to carry payloads into space. This will be the second DMSP weather satellite launched by a Titan 2.