viernes, 17 de junio de 2016

Ariane 5 launch of two U.S.-built satellites delayed to Saturday


18:18 Launch rescheduled for Saturday



The Ariane 5 launch has been rescheduled for Saturday at 2030 GMT (4:30 p.m. EDT), the opening of a 70-minute launch window, according to Stephane Israel, Arianespace's CEO.

Unfavorable upper level winds this evening kept the Ariane 5 grounded at the Guiana Space Center.

"The altitude winds are not compatible with a launch tonight, and it's perfectly normal that the first priority is to take care of the safety here in Guyane," Israel said in remarks a few minutes ago.

All systems with the EchoStar 18 and BRIsat satellites, and the Ariane 5 launcher, were go for liftoff Friday, Israel said.

"The weather is maybe the only thing we do not master, but we have to live with it," Israel said.

18:09 SCRUB

Arianespace CEO Stephane Israel says launch will not happen today.

18:04

The liftoff is tentatively set for 2130 GMT (5:30 p.m. EDT; 6:30 p.m. French Guiana time), pending confirmation of favorable upper level winds.

17:30

Minus-7 minutes and holding. The Ariane 5 countdown is in a hold to wait out the unfavorable upper level winds over Kourou, French Guiana.

17:14 Launch slips to 2130 GMT (5:30 p.m. EDT)

Liftoff of the Ariane 5 has been delayed until 2130 GMT (5:30 p.m. EDT) due to unfavorable upper level winds, according to Stephane Israel, Arianespace's CEO.
The launch window today extends for 70 minutes until 2140 GMT (5:40 p.m. EDT). The rocket and the satellites are reported in good condition during this hold in the countdown.

17:03 Minus-27 minutes

Minus-27 minutes. Today's launch will deliver the EchoStar 18 and BRIsat communications satellites to an orbit targeting a planned high point of 22,224 miles, a targeted low point of 155 miles and an inclination of 6 degrees.

Both built in Palo Alto, California, by Space Systems/Loral, the satellites will use their on-board engines to raise their orbits and position themselves over the equator.

The EchoStar 18 telecom satellite occupies the upper position in the rocket’s dual-payload berth. Owned by EchoStar and DISH Network, the satellite is beginning a 15-year service life broadcasting direct television services to millions ot homes and businesses across the United States. The 13,889-pound EchoStar 18 satellite will deploy first from the Ariane 5’s payload stack at T+plus 29 minutes, 20 seconds.

A Sylda 5 adapter will be discarded a few minutes later, revealing the 7,804-pound BRIsat spacecraft, the mission’s other satellite passenger.

BRIsat is the first communications satellite dedicated for a financial institution. Separation of the BRIsat spacecraft from the Ariane 5 rocket is scheduled at T+plus 42 minutes, 5 seconds.

The payloads have a combined mass of approximately 23,657 pounds, or 10,731 kilograms, including the barrel-shaped Sylda dual-payload adapter. That is a world record for an unclassified payload going to geostationary transfer orbit.

16:50 Launch statistics

Minus-40 minutes. All parameters continue to look good for launch in 45 minutes. A communications check between ground stations and the rocket should have concluded by now.

Some statistics on today's flight:

230th launch of an Ariane rocket since 1979

86th launch of an Ariane 5 rocket since 1996

56th launch of an Ariane 5 ECA rocket since 2002

61st flight of a Vulcan 2 engine

188th flight of an HM7B engine

74th Ariane 5 launch targeting GTO

5th EchoStar satellite launched by Arianespace

1st BRI satellite launched by Arianespace

54th and 55th Space Systems/Loral satellites launched by Arianespace

5th launch from the Guiana Space Center in 2016

3rd Ariane 5 launch in 2016

16:41 Mission poster



16:29 Minus-60 minutes

Minus-60 minutes. The Ariane 5's first and second stages are now loaded with cryogenic liquid hydrogen and liquid oxygen propellants.

The 17.7-foot-diameter first stage's Vulcain 2 engine burns 149.5 metric tons, or about 329,000 pounds, of liquid oxygen and 25 metric tons, or about 55,000 pounds, of liquid hydrogen. The cryogenic upper stage's HM7B engine consumes about 14.7 metric tons, or more than 32,000 pounds, of oxygen and hydrogen.

The fluids are stored at super-cold temperatures and naturally boil off in the warm tropical atmosphere in French Guiana. More propellant is slowly pumped into the rocket for most of the countdown to replenish the cryogenic fuel.

The topping sequence ends in the final few minutes of the countdown as the fuel tanks are pressurized and the fueling system is secured.

Built by a consortium of European contractors led by Airbus Safran Launchers in Vernon, France, the Vulcain 2 engine generates up to 300,000 pounds of thrust during its 9-minute firing. It burns about 320 kilograms, or 705 pounds, of liquid oxygen and liquid hydrogen propellant per second.

The engine's nozzle has an exit diameter of 2.1 meters, or about 6.9 feet. It weighs more than 4,600 pounds and its liquid oxygen and liquid hydrogen turbopumps spin at 12,300 rpm and 35,800 rpm, respectively.

The Vulcain 2 replaced the Vulcain engine used on the initial version of the Ariane 5. The newer engine produces 20 percent more thrust.

The Ariane 5's upper stage is powered by an HM7B engine, a modified version of the HM7 engine used on the upper stage of the Ariane 4 rocket. The 364-pound HM7B engine is manufactured by Airbus Safran Launchers in Ottobrunn, Germany.

The HM7B engine produces more than 14,500 pounds of thrust in vacuum.

The Ariane 5 configuration with a Vulcain 2 engine and HM7B-powered cryogenic upper stage is known as the Ariane 5 ECA.

The Ariane 5's twin solid rocket boosters are packed with propellant near the launch site in French Guiana before they are assembled and positioned on each side of the cryogenic core stage.

With the rocket now fully fueled for launch, the vehicle weighs 1.7 million pounds. At liftoff, the rocket produces 2.9 million pounds of thrust.

14:49 Fueling underway

Minus-2 hours, 41 minutes. The Ariane 5 rocket's first and second stages, known by the French acronyms EPC and ESC-A, are being filled with liquid oxygen and liquid hydrogen. The first stage Vulcain 2 engine and the upper stage HM7B engine both consume the super-cold propellants.

The cryogenic propellant will be gradually pumped inside the rocket to maintain proper levels as the fuel evaporates over the rest of the countdown.

The weather is predicted to favorable for launch at 2030 GMT (4:30 p.m. EDT).

05:59

Countdown operations will begin early Friday for launch of an Ariane 5 rocket with two U.S.-built communications satellites for DISH Network and BRI, a major Indonesian bank.

Packaged inside the Ariane 5's nose cone are the EchoStar 18 and BRIsat communications satellites, both manufactured by Space Systems/Loral in Palo Alto, California.

EchoStar 18 will broadcast hundreds of channels of television programming to millions of DISH Network subscribers across the United States over the next 15 years. With a fueled mass of approximately 13,889 pounds, or 6.3 metric tons, EchoStar 18 will operate from geostationary orbit at 110 degrees west longitude, eventually replacing the EchoStar 10 or EchoStar 11 satellites at that location.

EchoStar 18's co-passenger is BRIsat, a 7,804-pound (3,540-kilogram) satellite owned by Bank Rakyat Indonesia. BRIsat is the first satellite dedicated to a financial institution, and from its position at 150.5 degrees east longitude, the craft will help BRI provide enhanced secure banking communications for more than 10,600 operational branches, 236,939 electronic channel outlets, and almost 53 million customers across the Indonesian archipelago.


The countdown will begin at 0900 GMT (5 a.m. EDT), with clocks programmed for liftoff of the Ariane 5 ECA rocket at 2030 GMT (4:30 p.m. EDT), or 5:30 p.m. local time at the launch site in French Guiana. The launch window extends for 70 minutes.

A check of electrical systems is scheduled to occur around 1300 GMT (9 a.m. EDT).

Workers will also put finishing touches on the launch pad, including the closure of doors, removal of safety barriers and configuring fluid lines for fueling. The flight program for today's launch will be loaded into the rocket's computer.

The launch team will begin the process to fuel the rocket with super-cold liquid hydrogen and liquid oxygen propellants around 1530 GMT (11:30 a.m. EDT). First, ground reservoirs will be pressurized, then the fuel lines will be chilled down to condition the plumbing for the flow of super-cold liquid hydrogen and liquid oxygen, which are stored at approximately minus 423 degrees Fahrenheit and minus 298 degrees Fahrenheit, respectively.

It will take approximately two hours to fill the Ariane 5 core stage tanks.

A similar procedure for the Ariane 5's cryogenic upper stage will commence at 1630 GMT (12:30 p.m. EDT).

Chilldown conditioning of the Vulcain 2 first stage engine will occur at 1730 GMT (1:30 p.m. EDT), and a communications check between the rocket and ground telemetry, tracking and command systems is scheduled for 1920 GMT (3:20 p.m. EDT).

The computer-controlled synchronized countdown sequence will begin seven minutes before launch to pressurize propellant tanks, switch to on-board power and take the rocket's guidance system to flight mode.


The Vulcain 2 engine will ignite as the countdown clock reaches zero, followed by a health check and ignition of the Ariane 5's solid rocket boosters seven seconds later to send the 1.7 million-pound launcher skyward.

Five seconds after blastoff, the rocket will begin pitching east from the ELA-3 launch pad, surpassing the speed of sound less than a minute into the mission. The Ariane 5's twin solid rocket boosters will jettison 2 minutes, 21 seconds after liftoff.


Once above the dense atmosphere, the launcher's payload fairing will fall away at an altitude of more than 70 miles -- about 112 kilometers. The Ariane 5's first stage will shut down 8 minutes, 54 seconds after liftoff, followed moments later by stage separation and ignition of the hydrogen-fueled cryogenic HM7B upper stage engine.

The rocket's upper stage will fire for more than 16 minutes, accelerating to a velocity of 21,000 mph, or more than 9.3 kilometers per second, to reach an orbit with a planned high point of 35,766 kilometers (22,224 miles), a targeted low point of 250 kilometers (155 miles) and an inclination of 6 degrees.

The release of EchoStar 18 is scheduled for 29 minutes, 20 seconds, after liftoff. The rocket's barrel-shaped Sylda 5 dual-payload adapter will be jettisoned a few minutes later.

BRIsat will separate from the lower portion of the payload stack at 42 minutes, 5 seconds.

05:40 Launch timeline



A European Ariane 5 rocket will propel two communications satellites from a standstill to a speed of nearly 21,000 mph (9,365 meters per second) in 25 minutes during a launch Friday from French Guiana.

04:14



The third Ariane 5 flight of the year is on track for a late afternoon liftoff Friday from French Guiana with two U.S.-built communications satellites to broadcast television channels to millions of DISH Network subscribers and improve banking services across the islands of Indonesia.

The heavy-duty rocket, comprised of a hydrogen-fueled core engine, twin powerful solid rocket boosters and a dual-satellite payload, rolled out to its launch pad Thursday morning in Kourou, French Guiana.

Towering nearly 180 feet (55 meters) tall, the Ariane 5 is scheduled to blast off at 2030 GMT (4:30 p.m. EDT; 5:30 p.m. French Guiana time) Friday at the opening of a 70-minute launch window.

http://spaceflightnow.com

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