Автор Salo, 12.10.2009 02:02:17
0 Пользователей и 1 гость просматривают эту тему.
ЦитатаNov. 18/19 Delta 4 • WGS 3Launch window: 0045-0130 GMT on 19th (7:45-8:30 p.m. EST on 18th)Launch site: SLC-37B, Cape Canaveral Air Force Station, FloridaThe United Launch Alliance Delta 4 rocket will launch the third Wideband Global SATCOM spacecraft, formerly known as the Wideband Gapfiller Satellite. Built by Boeing, this geostationary communications spacecraft will serve U.S. military forces. The rocket will fly in the Medium+ (5,4) configuration with four solid rocket boosters. Delayed from Sept. 30. [Sept. 24]
Цитата16.10.2009 / 18:30 Спутник связи Пентагона WGS-3 доставлен на мыс Канаверал Как сообщает пресс-служба компании Boeing, третий по счёту спутник связи ВВС США нового поколения WGS-3 (Wideband Global SATCOM satellite) доставлен на космодром на мысе Канаверал на борту военно-транспортного С-5. Предыдущий спутник WGS-2 был принят в штатную эксплуатацию в августе 2009 года. Запуск спутника запланирован на ноябрь 2009 года, пишет R&D CNews. - И.С.
ЦитатаNov. 19/20 Delta 4 • WGS 3Launch window: 0045-0130 GMT on 20th (7:45 p.m.-8:30 p.m. EDT on 19th)Launch site: SLC-37B, Cape Canaveral Air Force Station, FloridaThe United Launch Alliance Delta 4 rocket will launch the third Wideband Global SATCOM spacecraft, formerly known as the Wideband Gapfiller Satellite. Built by Boeing, this geostationary communications spacecraft will serve U.S. military forces. The rocket will fly in the Medium+ (5,4) configuration with four solid rocket boosters. Delayed from Sept. 30 and Nov. 18. [Nov. 3]
ЦитатаWGS 1, 2, 3, 4, 5, 6 WGS 1 [Boeing BSS]In early 2001, a satellite communications industry team led by Boeing Satellite Systems was selected to develop the Wideband Gapfiller Satellite (WGS) system as successors to the DSCS-3 series of communication satellites. This high-capacity satellite communications system is intended to support the warfighter with newer and far greater capabilities than provided by current systems. In March 2007 the acronym WGS was changed to Wideband Global Satcom.A joint-service program funded by the U.S. Air Force and Army, WGS includes options for up to six BSS-702 satellites and their associated spacecraft and payload control equipment. Operational and logistics support and training are also included in the program.WGS will augment DoD communications services currently provided by the Defense Satellite Communications System (DSCS), which provides Super High Frequency (SHF) wideband communications, and by the Ka-band Global Broadcast Service (GBS), which uses direct broadcast satellite technology to provide critical information to U.S. and allied forces. With an initial launch scheduled for mid-2004 aboard an Air Force Evolved Expendable Launch Vehicle, WGS will provide early transformational capabilities supporting government objectives for a Transformational Communications Architecture in 2009 and beyond. WGS combines unique commercial spacecraft capabilities that Boeing has developed, including phased array antennas and digital signal processing technology, into a powerful, flexible architecture. Based on the Boeing BSS-702 bus, the satellite will have a dry mass of more than 3,000 kg and will produce more than 11 kilowatts of power at the end of its 14-year design life. The system provides tremendous operational flexibility and delivers the needed capacity, coverage, connectivity and control in support of demanding operational scenarios. Capacity: WGS will offer 4.875 GHz of instantaneous switchable bandwidth. The system will provide capacity ranging from 1.2 Gbps to more than 3.6 Gbps to tactical users, depending on the mix of ground terminals, data rates and modulation schemes employed. Thus, each WGS can supply more than 10 times the capacity of a DSCS-3 Service Life Enhancement Program (SLEP) satellite. Coverage: The WGS design includes 19 independent coverage areas that can be used throughout the field of view of each satellite to serve warfighters between 65 degrees North and South latitude. This includes eight steerable/shapeable X-band beams formed by separate transmit and receive phased arrays; 10 steerable Ka-band beams served by independently steerable, diplexed gimbaled dish antennas, including three with selectable polarization; and one X-band Earth coverage beam. Connectivity: The enhanced connectivity capabilities of WGS enable any user talk to any other user with very efficient use of satellite bandwidth. A digital channelizer divides the uplink bandwidth into nearly 1,900 independently routable 2.6 MHz subchannels providing any-coverage-to-any-coverage connectivity (including X-to-Ka and Ka-to X crossbanding) for maximum operational flexibility. In addition, the channelizer supports multicast and broadcast services and provides an extremely effective and flexible uplink spectrum monitoring capability for network control. In January 2002, the customer exercised options worth $336.4 million authorizing Boeing to build the first two WGS spacecraft and to procure long-lead material for a third satellite. The first satellite was scheduled to launch in early 2004, with the second one to follow in 2005, both aboard a U.S. Air Force Evolved Expendable Launch Vehicle. The program has been delayed to a first launch in 2007. Boeing and the U.S. Air Force MILSATCOM Systems Wing have signed in October 2006 a $1.067 billion contract for up to three more Wideband Gapfiller Satellites (WGS), if all options are exercised. The Option for WGS 4 was execised in November 2006.The Block II satellites will be similar to the three Block I satellites already in production. Under Block II, Boeing will add a radio frequency bypass capability designed to support airborne intelligence, surveillance and reconnaissance platforms requiring ultra-high bandwidth and data rates demanded by unmanned aerial vehicles. The Block II contract calls for the launch of F4 by the first quarter of 2011 and subsequent launches every year thereafter.
ЦитатаBoeing 702 FleetSatellite operators have responded enthusiastically to the vastly increased capabilities represented by the Boeing 702. Boeing announced the innovative satellite series in October 1995. Evolved from the popular, proven 601 and 601HP (high-power) spacecraft, the body-stabilized Boeing 702 is the world leader in capacity, performance and cost-efficiency.As of 2008, 22 of these powerful satellites had been ordered. The first Boeing 702 satellite was launched in 1999. The satellite can carry more than 100 high-power transponders, and deliver any communications frequencies that customers request.The Boeing 702 design is directly responsive to what customers said they wanted in a communications satellite, beginning with lower cost and including the high reliability for which the company is renowned. For maximum customer value and producibility at minimum total cost, the Boeing 702 offers a broad spectrum of modularity. A primary example is payload/bus integration. After the payload is tailored to customer specifications, the payload module mounts to the common bus module at only four locations and with only six electrical connectors. This design simplicity confers major advantages. First, nonrecurring program costs are reduced, because the bus does not need to be changed for every payload, and payloads can be freely tailored without affecting the bus. Second, the design permits significantly faster parallel bus and payload processing. This leads to the third advantage: a short production schedule.High resolution image available here Further efficiency derives from the 702's advanced xenon ion propulsion system (XIPS), which was pioneered by Boeing. XIPS is 10 times more efficient than conventional liquid fuel systems. Four 25-cm thrusters provide economical stationkeeping, needing only 5 kg of fuel per year - a fraction of what bipropellant or arcjet systems consume. Using XIPS for final orbit insertion conserves even more mass as compared to using an on-board liquid apogee engine. Customers can apply the weight savings to substantially increase the revenue-generating payload at small marginal cost, to prolong service life, or to change to a less expensive launch vehicle (when cost is based on satellite mass).For even more versatility, the Boeing 702 also incorporates a bipropellant propulsion system, which can lift the satellite into final orbit after separation from the launch vehicle.Innovation extends to the Boeing 702 power systems as well. The Boeing 702 offers a range of power up to 18 kW. Dual and triple-junction gallium arsenide solar cells enable such high power levels. Spectrolab, Inc. a Boeing subsidiary, developed the cells.The Boeing 702 separates the bus and payload thermal environments and substantially enlarged the heat radiators to achieve a cooler, more stable thermal environment for both bus and payload. This increases unit reliability over service life. Deployable radiators use flexible heat pipes, which increase packageable radiator area. Further thermal control occurs through passive primary rejection via heat pipes.The baseline Boeing 702 is compatible with several launch vehicles. These include the Delta IV, Atlas V, Ariane 5, Proton, and Sea Launch.Wideband Global SATCOM SystemSpace and Missile Systems Center, U.S. Air Force Space Command In early 2001, a satellite communications industry team led by Boeing was selected to develop the Wideband Global SATCOM(WGS) system. This high-capacity satellite communications system is intended to support the warfighter with newer and far greater capabilities than provided by current systems.A joint-service program funded by the U.S. Air Force and Army, WGS includes options for up to six Boeing 702 satellites and their associated spacecraft and payload control equipment. Operational and logistics support and training are also included in the program.In 2002, the customer exercised options authorizing Boeing to build the first three WGS spacecraft and in 2006 ordered a fourth satellte and long-lead items for a fifth. The first satellite WGS-1 was launched in 2007, and WGS-2 and WGS-3 are scheduled to launch in 2009, all aboard a U.S. Air Force Evolved Expendable Launch Vehicle. WGS provides two-way X-band and Ka-band communications as well as Ka-band broadcast services to U.S. Armed Forces and other agencies worldwide.
ЦитатаCAPE CANAVERAL, Nov. 30, 2009 -- Boeing [NYSE] announced today that the third Wideband Global SATCOM (WGS) satellite it has built for the U.S. Air Force has completed prelaunch testing. The satellite is ready for its scheduled Dec. 2 launch aboard a United Launch Alliance Delta IV rocket from Cape Canaveral Air Force Station in Florida.WGS is the U.S. Department of Defense's highest-capacity communications satellite system. The launch of WGS-3 will mark the completion of the initial constellation of three satellites that provide high-data-rate communications for U.S. forces and allies around the world."This launch represents another huge leap in communications capabilities for U.S. warfighters and allies around the world," said Craig Cooning, vice president and general manager, Boeing Space and Intelligence Systems. "These satellites support a broad range of communications, from full-motion video beamed down from unmanned aerial vehicles, to distribution of maps and imagery to ground troops, to quality-of-life services such as news broadcasts and e-mail delivery to deployed troops. For all branches of our military, WGS saves lives and makes lives better every day."WGS-3 will be placed into geosynchronous Earth orbit over the Atlantic Ocean. The satellite joins WGS-1, which entered service over the Pacific Ocean in April 2008, and WGS-2, which began operations over the Middle East in August 2009. Both operational satellites meet and, in some cases, exceed mission requirements.WGS satellites are built on the proven Boeing 702 platform with 13 kilowatts of power. The payload features reconfigurable coverage areas and the ability to connect X-band and Ka-band users anywhere within their field of view via an onboard digital channelizer -- features not available on any other military communications satellite.Boeing is building three more WGS satellites for the Air Force with enhancements that include a radio frequency bypass to support airborne intelligence, surveillance and reconnaissance platforms requiring additional bandwidth. Satellites four through six are planned for launch in 2011 and 2013.
ЦитатаWeather delays military rocket launch to ThursdayA hotrod version of the Delta 4 rocket, souped up with extra solid-fueled boosters, takes its first trip into space Thursday evening on a mission for the U.S. military. The launch was delayed from Wednesday due to the forecast of stormy weather.
ЦитатаDec. 3/4 Delta 4 • WGS 3Launch window: 0022-0143 GMT on 4th (7:22 p.m.-8:43 p.m. EST on 3rd)Launch site: SLC-37B, Cape Canaveral Air Force Station, FloridaThe United Launch Alliance Delta 4 rocket will launch the third Wideband Global SATCOM spacecraft, formerly known as the Wideband Gapfiller Satellite. Built by Boeing, this geostationary communications spacecraft will serve U.S. military forces. The rocket will fly in the Medium+ (5,4) configuration with four solid rocket boosters. Delayed from Sept. 30 and Nov. 18. Delayed from Nov. 19 due to winds holding up payload's mounting atop the rocket and the need to recharge spacecraft batteries back at processing facility. Delayed from Dec. 2 due to poor weather forecast. [Dec. 1]
ЦитатаWednesday, December 02, 2009Stormy Weather Expected To Clear For Delta Launch A huge mobile service tower is scheduled to be backed away from a Delta IV Medium rocket at Cape Canaveral Air Force Station early Thursday, a move that will set the stage for the planned launch Thursday evening of a new military communications satellite.The United Launch Alliance rocket and its payload -- a Widefield Global SATCOM spacecraft -- are slated to blast off from Launch Complex 37 at 7:22 p.m. Thursday. The launch window will extend through 8:43 p.m. that night.The launch had been slated for 7:21 p.m. tonight, but managers pushed the flight back 24 hours as a result of an approaching storm that is expected to swamp parts of central Florida tonight and early Thursday.Launch Weather Officer Joel Tumbiolo of the Air Force 45th Space Wing Weather Squadron is forecasting a 60 percent chance conditions will be acceptable for flight Thursday night. The primary concerns are the chance of rains showers and thick, electrically charged clouds that could cause the rocket to trigger destructive bolts of lightning in flight.Here is a synopsis of the forecast: Strong line of thunderstorms currently over the Gulf of Mexico will move through central FL this evening. Cold frontal boundary will slow as it passes through the area during the day tomorrow, while becoming stationary over southern FL. Cloud cover and precipitation will still be a concern as warm, moist air flows over the shallow cool surface layer left in the wake of the frontal boundary. Coverage of rain will increase from south to north Thursday night and Friday as upper level impulses ride along the stalled frontal boundary from west to east. The primary concern on launch day and the following day will be the Thick Cloud Rule and flight through precipitation. Vehicle exposure pre-liftoff and liftoff wind constraints are not expected to be at risk.
ЦитатаT-00:05.5 Engine startThe RS-68 main engine begins to ignite as the liquid hydrogen fuel valve is opened, creating a large fireball at the base of the rocket. The engine powers up to full throttle for a computer-controlled checkout before liftoff.T-00:00.0 LiftoffThe rocket's four strap-on solid rocket motors are lit, the four hold-down bolts are released and the Delta 4 lifts off from Cape Canaveral's pad 37B. The pad's three swing arms retract at T-0 seconds.T+00:49.9 Max-QThe vehicle experiences the region of maximum dynamic pressure. The solid motors and the RS-68 liquid hydrogen/liquid oxygen engine continue to fire as the vehicle heads downrange, arcing over the Atlantic along a 101-degree flight azimuth.T+01:40.0 Jettison two solid motorsHaving used up all their solid-propellant and experienced burnout six seconds ago, the two strap-on boosters with fixed nozzles are jettisoned from the Delta's first stage.T+01:42.4 Jettison two solid motorsThe pair of strap-on boosters with steerable nozzles are jettisoned from the Delta's first stage and fall into the ocean.T+03:26.5 Jettison payload fairingThe five-meter diameter composite payload fairing that protected the WGS 3 cargo atop the Delta 4 during the atmospheric ascent is no longer needed, allowing it to be jettisoned in two halves.T+03:59.3 Begin engine throttlingWith the maximum axial acceleration reached, the RS-68 powerplant starts throttling down in preparation for finishing its firing.T+04:06.3 Main engine cutoffThe hydrogen-fueled RS-68 rocket engine completes its burn and shuts down to complete the first stage of flight.T+04:12.3 Stage separationThe Common Booster Core first stage and the attached interstage are separated in one piece from the Delta 4's upper stage. The upper stage engine's extendible nozzle drops into position as the first stage separates.T+04:25.3 Second stage ignitionThe upper stage begins its job to place the WGS 3 satellite into space with the first of two firings by the RL10B-2 liquid hydrogen/liquid oxygen engine.T+20:11.9 Upper stage shutdownThe RL10 upper stage engine shuts down to complete its first firing of the launch. The rocket and attached satellite reach a parking orbit of 100 by 3,714 nautical miles with an inclination of 25.59 degrees.T+28:17.4 Restart upper stageAfter a short coast period, the upper stage is reignited to raise the orbit to the planned altitude for deploying the payload.T+31:21.8 Upper stage shutdownThe powered phase of the Delta 4's mission to loft WGS 3 concludes. The second burn will reach the planned supersynchronous orbit 237 by 36,167 nautical miles with an inclination of 24 degrees.T+40:31.8 Separate spacecraftThe Wideband Global SATCOM 3 military communications satellite is released into space from the Delta 4 rocket. The Boeing-built satellite will use its onboard propulsion to reach geostationary orbit where it will match Earth's rotation and appear fixed above the equator at 12 degrees West.Data source: Air Force/ULA
Цитата1828 GMT (1:28 p.m. EST)The weather outlook is looking more optimistic as that cold front continues to move deeper into South Florida and away from the Cape. As a result, Air Force meteorologists have increased the odds of acceptable conditions during the launch window to 70 percent. Current observations show no violation of the cloud rules, there's no rain in the area and ground winds are within limits. The revised forecast for this evening's window calls for some scattered low clouds and a broken deck above that, northwesterly winds of 8 peaking to 12 knots and a temperature around 68 degrees F. 1818 GMT (1:18 p.m. EST)Checks of the C-band beacon are beginning. This system is used in tracking the rocket during the flight downrange. 1807 GMT (1:07 p.m. EST)The call to "man stations for Terminal Count" just went out to the launch team. 1752 GMT (12:52 p.m. EST)T-minus 5 hours, 15 minutes and holding. The countdown has just entered a planned 60-minute built-in hold, giving the team time to catch up on any work that could be running behind schedule. Once the clocks resume ticking at 1:52 p.m. EST, the Terminal Countdown phase of today's launch operation will begin. 1730 GMT (12:30 p.m. EST)A gallery of photographs taken at the Complex 37 launch pad this morning when the mobile service gantry was retracted to unveil the Delta 4 rocket is posted here. 1635 GMT (11:35 a.m. EST)"It's truly my pleasure to be a member of this WGS launch team. The long hours and hard work the entire team has dedicated to ensuring we're able to place this incredible warfighting capability on-orbit is truly amazing," Lt. Col. Dave Hook, commander of the 5th Space Launch Squadron at Cape Canaveral, told reporters at a recent briefing. "With the successful launch (today), our government and industry team will continue this momentum into the next year and continue to successfully deliver these vitally important national assets to orbit for our joint forces deployed around the world." Hook's squadron is responsible for overseeing operations to fly the United Launch Alliance Atlas 5 and Delta 4 rocket fleets from the Eastern Range at the Florida spaceport. "For this mission alone, the 5th Space Launch Squadron monitored 380 critical ULA technical procedures over the span of seven months. The vital oversight of ULA procedures we provide ensures mission assurance is correctly and safely conducted throughout the duration of the entire launch flow." 1530 GMT (10:30 a.m. EST)The skies are clearing as that weather system continues to slowly drift southward. After the rainy and gloomy start the morning, the sun is now shining on Central Florida. The outlook for the launch still predicts a 60 percent chance of acceptable conditions. Meteorologists are concerned that the cold front will stall and allow the rain to move back northward. During this evening's window, the forecast calls for broken low clouds, overcast mid- and high-level clouds, showers in the vicinity, northerly winds of 8 peaking to 12 knots and a temperature around 68 degrees F. In the event of a 24-hour delay to Friday, the odds of good weather drop considerably to only 30 percent due to concerns about thick clouds and rain in the rocket's flight path. 1330 GMT (8:30 a.m. EST)The 330-foot tall mobile service tower has been retracted from the Delta 4 rocket at Cape Canaveral's pad 37B for today's launch that will place the third Wideband Global SATCOM military satellite into Earth orbit. The wheeled structure was moved along rail tracks to its launch position about the length of a football field away from the rocket. The 9-million pound tower shielded the Delta from the elements during the four-month stay on the pad, provided workers 360-degree access to the various areas on the vehicle and was used to attach the strap-on solid motors and the payload during the launch campaign. The tower is 90-feet wide and 40-feet deep. Crews will spend the next couple of hours securing the complex for launch before leaving the danger area around the pad. All workers must be clear of the area for the start of hazardous operations in the countdown, which include fueling the vehicle later this afternoon. Liftoff remains scheduled for 7:22 p.m. EST, the opening of an 81-minute window that extends to 8:43 p.m. EST (0022-0143 GMT). 1306 GMT (8:06 a.m. EST)Tower rollback is underway. 1225 GMT (7:25 a.m. EST)Good morning from soggy Cape Canaveral Air Force station were the heavy overnight rains have pushed to the south but the skies remain gray and overcast. Out at Complex 37, ground technicians are making final preps to retract the dual-purpose assembly gantry and mobile shelter away from the Delta 4 rocket for today's countdown to launch.
Цитата2158 GMT (4:58 p.m. EST)The first stage liquid hydrogen tank is being placed into its topping phase. 2155 GMT (4:55 p.m. EST)The weather board is still looking good. No constraints are posted. The updated forecast for launch time now includes scattered clouds at 3,000 feet, broken decks at 6,000 and 12,000 feet, visibility of 7 miles, northwesterly winds of 8 peaking to 12 knots and a temperature around 68 degrees F.2135 GMT (4:35 p.m. EST)The rocket team is not tracking any technical issues of note. 2130 GMT (4:30 p.m. EST)The first stage liquid hydrogen tank has been loaded. Vent and relief checks will be completed before topping is initiated. Post-filling tests on the first stage liquid oxygen system are complete and the tank is in topping mode. The upper stage tanks continue to be loaded. 2125 GMT (4:25 p.m. EST)A check of the current weather conditions shows none of the launch rules are being violated. The weather reconnaissance aircraft will be taking off around 6 p.m. EST to verify that the cloud thickness is not an issue. But so far, so good. 2122 GMT (4:22 p.m. EST)Now entering the last three hours of the countdown. Fueling of the Delta 4 rocket continues in work for the 7:22 p.m. EST launch of the WGS 3 military communications satellite from Cape Canaveral, Florida. 2056 GMT (3:56 p.m. EST)The upper stage conditioning on the liquid oxygen side has finished. Loading of the tank is starting. This is the last of the rocket's four cryogenic supplies to be filled in today's countdown to launch. 2052 GMT (3:52 p.m. EST)Now three-and-a-half hours till launch. 2050 GMT (3:50 p.m. EST)The chilldown of the upper stage stage liquid hydrogen system is reported complete, clearing the way for loading the rocket's tank. 2045 GMT (3:45 p.m. EST)To recap, the Delta 4 rocket's Common Booster Core first stage has been loaded with supercold liquid oxygen. The filling of liquid hydrogen propellant into the first stage is continuing along with the precursor preps for fueling the upper stage stage. 2039 GMT (3:39 p.m. EST)The "go" has been given for the upper stage liquid oxygen chilldown in advance of fueling. 2030 GMT (3:30 p.m. EST)The loading of liquid oxygen into the Common Booster Core first stage has been completed out at launch pad 37B as activities proceed toward a 7:22 p.m. EST liftoff of the Delta 4 rocket. Ahead in the countdown, the launch team plans to conduct vent and relief checks following the first stage LOX tanking and begin chilldown procedures for the upper stage liquid oxygen system. 2021 GMT (3:21 p.m. EST)The launch team has gotten the approval to start chilldown conditioning of the upper stage liquid hydrogen system. 2020 GMT (3:20 p.m. EST)First stage liquid oxygen loading continues in progress. The rocket's tank will be loaded with 40,000 gallons of the supercold oxidizer that's chilled to Minus-298 degrees F. 2012 GMT (3:12 p.m. EST)First stage liquid hydrogen tanking operation is switching from "slow-fill" to "fast-fill" mode. 2008 GMT (3:08 p.m. EST)Complex 37 has two giant sphere-shaped fuel tanks to store the cryogenic liquid oxygen and liquid hydrogen. The LOX tank holds 250,000 gallons and LH2 sphere about 850,000 gallons. Complex 37 has two giant sphere-shaped fuel tanks to store the cryogenic liquid oxygen and liquid hydrogen. The LOX tank holds 250,000 gallons and LH2 sphere about 850,000 gallons. The cryogenics are fed from the storage tanks through pipelines to the pad. For the Common Booster Core, the propellants are routed up to the launch table upon which the rocket sits. Tail service masts, the large box-like structures at the base of the vehicle, feed the oxygen and hydrogen to the booster via separate umbilicals. The upper stage will be filled in a little while. It receives the cryos from the middle swing arm that extends from the Fixed Umbilical Tower to the front-side of the rocket. 1955 GMT (2:55 p.m. EST)The start of liquid hydrogen fueling of the first stage is now confirmed. Some 110,000 gallons of LH2 will fill the rocket's tank. 1951 GMT (2:51 p.m. EST)The cold gas chilldown conditioning of the liquid hydrogen system has been accomplished. Liquid hydrogen propellant will start to flow into the first stage in "slow-fill" mode. That is sped up to "fast-fill" after a small portion of the tank is loaded. Chilled to Minus-423 degrees Fahrenheit, the liquid hydrogen will be consumed by the RS-68 main engine along with liquid oxygen during the first four minutes of the launch. 1946 GMT (2:46 p.m. EST)The first stage liquid oxygen chilldown is complete. Fueling is beginning in the "slow-fill" mode to load a small percentage of the tank. The process then speeds up to the "fast-fill" mode until the tank is nearly full. 1935 GMT (2:35 p.m. EST)We have posted another photo gallery from this morning. This new page features beautiful up-close views of the Delta 4 as it gets ready to fly in a configuration with four solid rocket boosters that's not been seen before. 1921 GMT (2:21 p.m. EST)A "go" has been given to start the cold gas chilldown conditioning of the first stage liquid hydrogen system. 1915 GMT (2:15 p.m. EST)Live streaming video of the Delta 4 rocket can be viewed on your iPhone. Check it out! 1914 GMT (2:14 p.m. EST)Chilldown of the first stage liquid oxygen system is beginning. This preps the tank and pumping to guard against shock when the supercold oxidizer begins flowing into the rocket a short time from now. 1903 GMT (2:03 p.m. EST)The launch director has given approval for the start of fueling operations as planned today. 1900 GMT (2:00 p.m. EST)A reminder that if you will be away from your computer but would like to receive occasional countdown updates, sign up for our Twitter feed to get text message updates on your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.) 1852 GMT (1:52 p.m. EST)T-minus 5 hours, 15 minutes and counting! The Terminal Countdown has commenced for this evening's scheduled launch of the Delta 4 rocket to deliver a new communications satellite into orbit for the United States military. The countdown has one planned built-in hold at T-minus 5 minutes lasting some 15 minutes, leading to liftoff at 7:22 p.m. EST (0022 GMT). The launch pad has been verified evacuated of all personnel in advance of fueling the rocket's two stages this afternoon. Pad systems and equipment stand ready for fueling activities, which should kick off shortly. 1841 GMT (1:41 p.m. EST)No technical problems are being reported in the countdown and the weather looks favorable. The launch pad has been buttoned up and the area cleared for the rest of the countdown. 1838 GMT (1:38 p.m. EST)The launch team has been polled to verify all consoles are manned and ready to begin the Terminal Countdown when this hold ends at 1:52 p.m. A briefing on countdown procedures is now underway.
Цитата2230 GMT (5:30 p.m. EST)Engineers are conducting the standard evaluation of the Delta 4 rocket's thermal insulation following the loading of supercold propellants into the vehicle. 2222 GMT (5:22 p.m. EST)Launch of the Delta 4 rocket with the third Wideband Global SATCOM spacecraft is just two hours away. The first two WGS satellites were hauled into space aboard Atlas 5 rockets. But WGS 3 is riding atop the Delta 4, the other rocket in the Air Force's Evolved Expendable Launch Vehicle fleet. Both vehicles are produced by United Launch Alliance, the firm created three years ago this month that joined Lockheed Martin's Atlas and Boeing's Delta rockets under one organization. "This mission is symbolic of why ULA formed for a couple of reasons," says James Bell, ULA's WGS mission manager. "First, it exemplifies why the government brought the Atlas and Delta programs together. The first two WGS satellites were launched on our Atlas vehicles and for WGS 3, instead of our Delta 4 team having to start from scratch, ULA was proactive in implementing a seamless integration and processing services for this repeat customer. "Also, because I was the WGS mission manger for those two Atlas launches, I was able to share the knowledge we gained from those launches with our Delta team. This is not only a tremendous benefit for ULA but also for our Air Force mission partners who are relying on us to provide them assured access to space. This simply wasn't possible prior to ULA. "Second, this mission marks the 36th launch for ULA in 36 months, which is quite a record of reliability and mission success. When ULA was formed, our primary goal was to provide safe and reliable assured access to space with mission success paramount in everything we do." 2218 GMT (5:18 p.m. EST)The upper stage liquid oxygen tank has been filled up, now making the Delta 4 a fully fueled rocket. 2203 GMT (5:03 p.m. EST)The countdown remains on track and current weather conditions are within limits for today's liftoff at 7:22 p.m. EST. Three of the cryogenic tanks of the rocket has been filled -- the first stage and upper stage liquid hydrogen supplies and the first stage liquid oxygen tank. The launch team continues to load upper stage liquid oxygen, which is about 67 percent full right now.
Цитата0150 GMT (8:50 p.m. EST Thurs.)Here's the official Air Force statement to the press: "The launch of the Air Force's Delta 4 Wideband Global SATCOM 3 (WGS 3) mission was scrubbed this evening due to additional time required to troubleshoot an anomaly with a ground launch control system. A second launch attempt has been preliminarily rescheduled for Friday, December 4, with a launch window of 7:22-8:45 p.m. EST."