BY SPACEFLIGHT NOW

Follow the preparations and launch of the DirecTV-4S communications satellite aboard an Arianespace Ariane 4 rocket. Reload this page for the very latest on the mission.

TUESDAY, NOVEMBER 27, 2001

A sophisticated communications spacecraft that will beam hundreds of local television channels to subscribers of the DirecTV satellite system across the U.S. was successfully launched Monday by an Ariane 4 rocket. Read our full launch story.

0101 GMT (8:01 p.m. EST Mon.)

Arianespace has confirmed success for today's launch of DirecTV-4S. This marks the 65th straight success for the Ariane 4 rocket dating back to 1995.

We'll have a full wrap-up story and pictures a bit later this evening.

0056 GMT (7:56 p.m. EST)

Plus+21 minutes, 9 seconds. SPACECRAFT SEPARATION! The DirecTV-4S direct-to-home television broadcast spacecraft designed to relay programming to subscribers across America has been released into space from the Ariane 4 rocket's third stage, completing today's launch of Arianespace Flight 146.

0054 GMT (7:54 p.m. EST)

Plus+19 minutes, 40 seconds. Altitude 290 km, velocity 9.68 km/sec.

0054 GMT (7:54 p.m. EST)

Plus+19 minutes. Confirmation of third stage shut down, completing the powered phase of flight. Orbit has been achieved. The stage will now provide the necessary pointing for deployment of the DirecTV-4S spacecraft over the next two minutes.

0053 GMT (7:53 p.m. EST)

Plus+18 minutes, 15 seconds. Standing by for cutoff of the third stage. The Libreville tracking station in Africa has acquired the rocket's signal.

0053 GMT (7:53 p.m. EST)

Plus+18 minutes. Altitude is 212 km, velocity 9.27 km/sec.

0052 GMT (7:52 p.m. EST)

Plus+17 minutes. The Ariane 4 is now gaining altitude again. Altitude is 193.3 km, velocity 8.78 km/sec.

0051 GMT (7:51 p.m. EST)

Plus+16 minutes, 20 seconds. About two minutes remaining in the third stage burn. Altitude is 187.9 km, velocity 8.47 km/sec.

0050 GMT (7:50 p.m. EST)

Plus+15 minutes, 30 seconds. Altitude 187.7 km, velocity 8.0 km/sec.

0049 GMT (7:49 p.m. EST)

Plus+14 minutes, 25 seconds. The Ariane rocket continues to gain speed. Altitude is 194.8 km, velocity 7.6 km/sec.

0047 GMT (7:47 p.m. EST)

Plus+12 minutes, 50 seconds. The Ascension Island tracking station in the Atlantic Ocean has acquired the rocket's signal as it heads eastward away from South America.

0047 GMT (7:47 p.m. EST)

Plus+12 minutes, 30 seconds. The third stage is performing well, Arianespace reports. Altitude is 215 km, velocity 6.95 km/sec.

0046 GMT (7:46 p.m. EST)

Plus+11 minutes, 30 seconds. Altitude is 225.4 km, velocity 6.6 km/sec.

0045 GMT (7:45 p.m. EST)

Plus+10 minutes. This is now the period in flight where the Ariane rocket gives up some altitude in order to gain velocity. Altitude is 232.5 km, velocity 6.1 km/sec.

0044 GMT (7:44 p.m. EST)

Plus+9 minutes, 15 seconds. Arianespace is not reporting any problems in today's climb too orbit. Altitude 231 km, velocity 5.97 km/sec.

0043 GMT (7:43 p.m. EST)

Plus+8 minutes, 15 seconds. Third stage burn is continuing. Altitude 222 km, velocity 5.7 km/sec.

0042 GMT (7:42 p.m. EST)

Plus+7 minutes, 5 seconds. The Natal tracking station in Brazil has picked up the rocket's signal as it travels downrange. Altitude is 201 km, velocity 5.4 km/sec.

0041 GMT (7:41 p.m. EST)

Plus+6 minutes. The second stage has burned out and separated. And the cryogenic upper stage has ignited for its lengthy burn to deliver the DirecTV-4S satellite payload into the desired geosynchronous transfer orbit.

0040 GMT (7:40 p.m. EST)

Plus+5 minutes, 30 seconds. No problems reported thus far in the flight of the Ariane 4 rocket. Altitude is 148 km, velocity 5.08 km/sec.

0039 GMT (7:39 p.m. EST)

Plus+4 minutes, 50 seconds. The payload fairing has been jettisoned since it is no longer needed to shield the DirecTV-4S spacecraft.

0039 GMT (7:39 p.m. EST)

Plus+4 minutes, 30 seconds. Altitude is 112 km, velocity 3.6 km/sec.

0038 GMT (7:38 p.m. EST)

Plus+3 minutes, 45 seconds. The four first stage main engines have shut down and stage separation confirmed. The second stage has now ignited.

0038 GMT (7:38 p.m. EST)

Plus+3 minutes. Altitude 56 km, velocity 2.0 km/sec.

0037 GMT (7:37 p.m. EST)

Plus+2 minutes, 35 seconds. The two liquid-propellant strap-on boosters have shut down and jettisoned from the base of the Ariane 4 rocket.

0036 GMT (7:36 p.m. EST)

Plus+1 minute, 40 seconds. Altitude 17.9 km, velocity 0.5 km/sec.

0036 GMT (7:36 p.m. EST)

Plus+71 seconds. The two solid-propellant strap-on boosters have burned out and separated from the Ariane 4's first stage. The spent casings fall into the Atlantic Ocean. The first stage main engines and twin liquid-fueled strap-on motors are still burning to continue the climb to orbit.

0035 GMT (7:35 p.m. EST)

Plus+30 seconds. Ariane has pitched to the proper eastward trajectory away from the launch site. The rocket is riding the thrust of eight engines -- four liquid-fueled main engines, two liquid-fueled strap-on boosters and two solid motors.

0035 GMT (7:35 p.m. EST)

LIFTOFF! Liftoff of the Ariane 4 rocket with the DirecTV-4S satellite to beam television programming directly to homes across America. And the vehicle has cleared the tower!

0034 GMT (7:34 p.m. EST)

Minus-30 seconds. The three-stage rocket is set to deliver DirecTV-4S into a geosynchronous transfer orbit of approximately 200 km on the low end and 35,786 km on the high end, with an inclination of 7 degrees. Ariane 4 is going for its 65th consecutive successful launch.

0034 GMT (7:34 p.m. EST)

Minus-1 minute. Equipment aboard the Ariane 44LP rocket is being switched off ground-supplied power and to onboard batteries for launch.

In the final seconds of the countdown, activities will include releasing the inertial platform at minus 9 seconds, and the release command to the retraction system for the two cryogenic arms will be given at Minus-5 seconds.

0033 GMT (7:33 p.m. EST)

Minus-90 seconds and counting. The local tracking stations at the launch site should have a firm lock on the rocket at this time.

0033 GMT (7:33 p.m. EST)

Minus-2 minutes and counting. The third stage liquid oxygen tank has been pressurized for the launch.

0032 GMT (7:32 p.m. EST)

Minus-3 minutes and counting. Flight 146 will be the eighth and final Arianespace launch in 2001 and the 145th in the entire Ariane program. It will be the 107th Ariane 4 mission and the 26th for the Ariane 44LP version with two liquid-fueled and two solid-propellant strap-on rocket boosters.

0031 GMT (7:31 p.m. EST)

Minus-4 minutes and counting. The launch team is monitoring the final topping off of liquid oxygen and liquid hydrogen supplies aboard the rocket's third stage.

In the next half-minute, the launch time will be loaded aboard the Ariane rocket's guidance system. Also, the DirecTV-4S spacecraft will be confirmed on internal power and declared ready for launch.

0029 GMT (7:29 p.m. EST)

Minus-6 minutes and counting. The synchronized launch sequence has started. Computers are now in control of this final portion of the launch countdown. Liftoff is set for 0035 GMT (7:35 p.m. EST).

During the next six minutes, the Ariane 44LP rocket, satellite payload and ground systems will be configured for launch. There are two master computers running the countdown. One is responsible for fluids and propellants and the other for final preparation of the electrical systems such as initiating the flight program, activation of the engine steering systems and power transfer from ground supplies to onboard batteries. The computers will control until minus 5 seconds when a majority logic sequencer takes over for first stage engine start at zero seconds. Engine performance checks are done in parallel by the two computers starting at plus 2.8 seconds. The solid rocket motors will be ignited at plus 4.2 seconds. Finally, the command will be issued to open the launch table clamps for liftoff between ignition +plus 4.4 and 4.6 seconds.

0026 GMT (7:26 p.m. EST Mon.)

Minus-9 minutes and counting. Weather conditions at the Guiana Space Center have been verified acceptable for liftoff throughout tonight's available 38-minute launch window. The countdown continues smoothly for blastoff at 0035 GMT.

0024 GMT (7:24 p.m. EST Mon.)

Minus-11 minutes and counting. A network of tracking stations are standing ready to relay data from the Ariane 4 rocket to engineers in Kourou. The early portion of flight will be monitored through the Kourou and Cayenne stations in French Guiana. About 6 minutes, 50 seconds into flight the Natal station in Brazil will pick up the rocket's signal as the third stage burn gets underway. At T+plus 12 minutes, 50 seconds the site on Ascension Island in the Atlantic Ocean will begin coverage. Libreville in Gabon will provide services beginning at T+plus 17 minutes, 40 seconds for spacecraft separation and the conclusion of Arianespace Flight 146.

0020 GMT (7:20 p.m. EST Mon.)

Minus-15 minutes. The Ariane 44LP rocket stands 56.3 meters tall and weighs 418 metric tons at liftoff. This particular version of the Ariane 4 features four strap-on boosters -- two liquid-fueled and two solids. The DirecTV-4S spacecraft accounts for 4,300 kg (9,460 pounds) of the launch weight.

0017 GMT (7:17 p.m. EST Mon.)

Minus-17 minutes, 30 seconds. Arianespace reports there are no technical problems being worked and the countdown continues on schedule for liftoff as planned at 0035 GMT (7:35 p.m. EST).

0015 GMT (7:15 p.m. EST Mon.)

Minus-20 minutes and counting down to today's launch of the Ariane 44LP rocket with the DirecTV-4S direct-to-home TV broadcasting satellite.

The three-stage rocket has been fully fueled and prepared for liftoff at 0035 GMT from the ELA-2 pad at the Guiana Space Center in South America.

Launch team members are watching systems on the Ariane 4 rocket, the spacecraft and ground support equipment. There are no problems being reported. The status panel in the Jupiter control center green across the board, indicating all systems are "go" at this time.

2345 GMT (6:45 p.m. EST)

The countdown has entered the final hour for this evening's launch of the Ariane 4 rocket carrying the DirecTV-4S broadcasting satellite from the Guiana Space Center in Kourou on the northeastern coast of South America. Launch of Arianespace Flight 146 is scheduled for 0035 GMT (7:35 p.m. EST).

We'll begin our play-by-play coverage of the countdown and flight of the Ariane 4 rocket in about 30 minutes.

MONDAY, NOVEMBER 26, 2001

Arianespace's eighth and final launch of 2001 is scheduled for liftoff Monday evening on a mission to carry an American television broadcast satellite into space.

Flight 146 will take to the skies at 7:35 p.m. EST (0035 GMT Tuesday) from the ELA-2 launch pad at the Guiana Space Center in Kourou, French Guiana. The launch window extends for 38 minutes.

The mission will use an Ariane 44LP rocket, which consists of two liquid-fueled and two solid-fueled strap-on boosters. It will be the 145th Ariane launch overall, the 107th Ariane 4 launch, and the 26th flight of an Ariane 44LP launcher.

Awaiting liftoff atop the Ariane 4 is the DirecTV 4S direct-to-home television broadcast satellite. The craft will work alongside the rest of DirecTV satellite fleet. It is also the first DirecTV spacecraft to utilize a spot beam to provide local channels for certain urban regions. With that technology, DirecTV 4S will build upon efforts already in place to broadcast local programming directly to customers in large cities.

The other half of DirecTV 4S's multi-beam payload is a national beam that will provide general programming to users across the United States.

The spot beam will use 38 Ku-band transponders, while the national beam consists of 10 Ku-band transponders.

DirecTV 4S was built by Boeing Satellite Systems and is based on the Boeing 601HP spacecraft design. At liftoff, the satellite will have a mass of around 9,360 pounds. At the beginning of the craft's operational lifetime, that mass will be reduced to around 5,733 pounds. Once deployed, its solar panels will extend 86 feet tip-to-tip.

The satellite will use on-board thrusters and kick motors to place itself into its final geostationary orbit, where it will be positioned 22,300 miles above the Pacific Ocean, west of the Galapagos Islands, at 101 degrees West. There it will operate for around 15 years.

Preparations for Flight 146 began on October 26 with the lifting of the Ariane 4's first stage into position on the mobile launch table. The rocket's second stage was put into place on October 29.

The launcher's pair of liquid-fueled boosters were latched into place on the first stage on October 31 and November 2. The third stage was hoisted into position atop the second stage of the Ariane 44LP on November 5.

DirecTV 4S arrived in Kourou on November 6 to begin its processing flow. Fueling of the payload began on November 12.

The nearly complete Ariane 44LP emerged from the launcher integration building for the one kilometer rail trip to the launch pad on November 14. The rocket received its twin solid-fueled boosters on November 15 and 16.

The mission's payload was placed inside the Ariane 4's protective payload fairing on November 19. The completed payload unit -- including the payload, fairing, and adapter -- was transported to the ELA-2 launch pad on November 20.

The satellite composite was attached atop the rocket on Wednesday, completing the launcher.

On Thursday, the launch team took part in a final launch rehearsal to hone their skills before the launch. The launch readiness review and ordnance connections took place on Friday.

Fueling of the first stage, second stage, and the two liquid-fueled strap-on boosters was to take place Saturday.

Looking ahead to Monday's key events, the final countdown will commence at 1205 GMT (7:05 a.m. EST). The protective mobile service tower will begin retracting into its launch position at 1900 GMT (2:00 p.m. EST). At 2100 GMT (4:00 p.m. EST), the third stage will begin to be filled with its liquid hydrogen/liquid oxygen propellant combination. The launcher's telemetry, radar transponder, and telecommand systems will be activated at 2330 GMT (6:30 p.m. EST). The synchronized launch sequence will begin at 0029 GMT (7:29 p.m. EST). Following that critical milestone is a series of fast-paced events that will culminate in the ignition of the Ariane 44LP's first stage and liquid-fueled booster engines at T-0.

After liftoff, Flight 146 will follow a standard Ariane 44LP ascent profile. The solid-fueled boosters will ignite four seconds after T-0, followed immediately by liftoff. The two solid-fueled strap-on boosters will burn for around one minute before being jettisoned. The liquid-fueled boosters will burn for around two minutes, 30 seconds. The first stage will burn out and be separated three minutes, 31 seconds into flight. The protective payload fairing will jettison at a point four minutes, 40 seconds after launch. After a two-minute burn, the second stage will separate from the remainder of the Ariane 44LP five minutes, 43 seconds into flight. The third stage will then ignite for a marathon 12-minute, 30-second burn before shutting down. Spacecraft separation will occur around 21 minutes after launch.

Stay with Spaceflight Now for live play-by-play updates during the final countdown and launch of Flight 146.