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New Weather Satellite Rides Delta 4 Rocket to Orbit

New Weather Satellite Rides Delta 4 Rocket to Orbit
A Boeing Delta 4 rocket launches the GOES-N weather satellite spaceward from Cape Canaveral Air Force Station on May 24, 2006. (Image credit: Carleton Bailie/Boeing.)

The first member of arevitalized series of spaceborne weather watchers was shepherded into the highfrontier by a Delta4 rocket in a marathon Wednesday evening launch, giving Americanmeteorologists a sophisticated new tool to warn against dangerous severestorms.

Fitted with a pair of60-inch (152-centimeter) diameter solid rocket boosters for added kick, theBoeing-built Delta 4 zoomed away from Cape Canaveral's Complex 37B at 6:11 p.m.EDT (2211 GMT) with its hydrogen-fueled main engine blazing. In just under 13minutes, the Delta 4's second stage had arrived in a low-altitude parkingorbit. Two more firings of the RL10 cryogenic engine powered the stage higherabove Earth and moved the orbit closer to the equator.

The Delta 4 deployedAmerica's newest 6,900-pound (3,129-kilogram) weathersatellite at 10:32 p.m. EDT (0232 GMT Thursday). Orbital parameters werenot immediately released.

As the 13th member of the fleet of Geostationary Operational EnvironmentalSatellites, or GOES, the craft will appear fixed above Earth once it reachesits final orbit after a series of five adjustment burns due to begin Friday.

The maneuvers will last forabout a week, gradually raising the low point of the orbit until it reaches acircular geostationary altitude about 22,300 miles (35,888 kilometers) high. Itwill be glided into a slot positioned along the equator at 90 degrees Westlongitude for testing.

Now known as GOES-N, thecraft will be formally renamed GOES-13 after its circuitous trip to itsdestination orbit is complete.

The launch was conductedunder the commercial oversight of Boeing Launch Services on behalf of NASA.GOES-N was also built by Boeing's Space and Intelligence Systems unit and isbased on their heritage Boeing 601 model.

GOES-N's 27-foot (eight-meter)solar panel - critical to the mission due to its vital electricity production -will unfurl in two parts on June 5. Other activations and deployments willcontinue for a few more days until June 17, when control of the craft will behanded over from Boeing to a team consisting of NASA engineers for continuedpost-launch tests.

Tentative plans call forthe first visible image from GOES-N to be taken on June 27, followed a few dayslater by the first data from the Solar X-Ray Imager, which gives forecasterswarning of space weather events by looking at solar flare emissions.

After 200 days of testingand checkout activities, NASA will formally give its seal of approval for thecraft in December. The agency will then hand over the satellite to its operator- the National Oceanographic and Atmospheric Administration, or NOAA - to beginits 10-year mission, an improvement of three years above previous GOESsatellites. The weather observatory also has a larger load of fuel to lastalmost 14 years.

However, GOES-N won't enterservice immediately. NOAA officials will first put GOES-N into storage as anin-orbit standby satellite for the GOES constellation.

To see much of the westernhemisphere from the International Date Line to the central Atlantic Ocean, theGOES program has most recently used GOES-10 in a western location at 135degrees West and GOES-12farther east at 75 degrees West. GOES-11has served as a spare since its launch, while the aging GOES-9 is located at155 degrees East where its instruments help Japanese forecasters observeweather throughout much of Asia and the western Pacific Rim.

GOES-10 was formallyretired on Monday due to the depletion of its fuel system, and controllerscommanded GOES-11 to transition to the operational orbital slot currentlyoccupied by GOES-10. The nine-year-old craft has been operational since 1998,while GOES-11 has been on standby since its launch in 2000. However, GOES-10 willnot be taken out of the constellation until the health of GOES-N is confirmedin around three months. Next for GOES-10 will be a move to 60 degrees West tocover Latin America.

Assuming no unexpectedfailures, GOES-N could replace GOES-12 in daily operations sometime between2008 and 2011. Officials are pleased with the addition of GOES-N because itwould take just days to press the satellite into service if needed, whilespacecraft in ground storage could take a year to be launched and declared operational.It is also less expensive to store back-up satellites in orbit than for thecraft to occupy factory space on Earth.

The fleet collectivelytakes visible, infrared, and water vapor images every 15 minutes, or everyhalf-hour for each operational satellite. The pictures are used bymeteorologists to keep track of local weather events for short-term forecasts.

Such images are ideal fornot only looking at severe weather such as tornadoes and hurricanes, but alsofor observing more large-scale weather systems such as fronts and low and highpressure centers. They allow meteorologists to monitor the development andlives of storms, aiding in more rapid watches and warnings in threatenedregions.

"Images from GOES arenot just colorful images that we see on our weather forecasts every night onTV, but also will predict and warn of atmospheric triggers that change weatherand environmental conditions in an instant," said Steve Kirkner, GOESprogram manager at NOAA. "These warnings will lead directly to the savingof lives and the reduction of property damage."

The 2006 Atlantic hurricaneseason officially begins in one week. The National Hurricane Center earlierthis week predicted yet another active season this year.

"There's very littlein our arsenal which allows us to gather data from the entire ocean basinaround the storm and, in fact, the entire hemisphere to be able to look at theweather patterns that are taking place on an hourly basis and even more often,"said Steve Letro, meteorologist-in-charge at the National Weather Serviceforecast office in Jacksonville, Florida. "For that, we have to look tothe satellite community."

GOES-N designed with enhancements

An improved attitude control system debuting on GOES-N will help controllerspinpoint exactly where threatening storms and severe weather are located. Startrackers will produce navigation data to double the earlier precision fromthree kilometers to one-and-a-half kilometers.

The imager is the source ofthe pictures and loops often seen in television weather broadcasts, and is themost prominent instrument in the eyes of the general public.

In addition to the imager,an atmospheric sounder is also carried aboard GOES satellites. The sounderstudies temperatures, moisture content, and ozone distribution at different levelsof the atmosphere. This vertical data is better suited to long range outlooksover a few days in length.

GOES-N incorporates morecapable batteries to conserve enough power for the craft to continue capturingimages during long eclipse periods where the Sun's rays cannot charge itsbatteries. Thermal shields have also been added to block the damaging light ofthe Sun during certain parts of the satellite's orbit, which in the past haslimited imaging and sounding activities.

The enhancements will leadto over 600 more images and sounding runs per year, principally during thespring's active severe weather season and the autumn's peak of the hurricaneseason.

"Gaps in data woulddisrupt the National Weather Service's ability to predict not only hurricanesbut also tornadoes, flash floods, and other severe weather," Kirkner said.

"I can tell you thereare few things more frustrating as an operational weather forecaster than to besitting and depending on that data, and then all of a sudden it goes into aneclipse and it's no longer available," Letro said.

Other advances areconcentrated in the data collection and relay systems aboard GOES-N, yieldingmore communications and storage options for ground controllers.

"GOES-N will includetwo phases of improvement, first better measurements and second a betterdistribution of data products and warnings," Kirkner explained.

"You're not going tosee these things as big changes in the way satellite imagery is depicted on TV,or in the satellite loops that you see, or in the things that your TV weatherforecaster is going to use to try to get you to understand what the nature ofthe threat is," Letro said. Instead, new data gathered by GOES-N willgreatly contribute to the crucial behind-the-scenes analysis of storms.

GOES-N also carriesLockheed Martin's Solar X-Ray Imager that is designed to detect and preciselylocate solar flares and coronal mass ejections soon after they happen, givingforecasters an opportunity to determine which events will impact Earth. Chargedparticles reaching Earth can cause radio and electrical outages, damage toorbiting satellites, and dangerous exposure to humans outside the planet'snatural radiation shield.

The 30-year old program'sfirst solar imager was launched in July 2001 aboard GOES-12, but it experiencedan "instrument degradation" in November 2003 after about a year ofnormal operations. Improvements were made to GOES-N's solar instrument, and alonger life is expected for this imager.

A separate suite ofinstruments aboard GOES-N comprise the space environment monitor payload, whichkeeps tabs on the local conditions around the observatory and X-rays, extremeultraviolet levels, and other particles produced by solar activity.

The spacecraft will alsocontribute to the world's foremost international search and rescue system thatuses satellites to help track people, land vehicles, airplanes, and ships indistress by use of a dedicated on-board transponder and the GPS system.

GOES-N is the first ofthree upgraded Boeing-built weather satellites ordered by NOAA in 1998 tocontinue the highly successful GOES program for another decade. GOES-O iscurrently in ground storage and could be launched in September 2007, if needed.Otherwise, managers are planning for its launch in April 2008. GOES-P isundergoing thermal vacuum testing before being placed in storage before itsscheduled launch in October 2009. Officials will then prepare for the rolloutof the next-generation GOES-R series in about 2012.

Besides the high-altitudegeostationary-based GOES satellites, NOAA also utilizes a pair ofpolar-orbiting environmental satellites. These craft are used to monitorlong-term climate changes with an array of instruments to provide a closer lookat weather systems.

Long wait finally over

Wednesday's launch had been postponedfrom its initial target launch date last summer due to a slew of issues. TheDelta 4 rocket had been sitting on the launch pad since February 2005. Problemswith the rocket's flight termination system batteries, the replacement of theDelta 4's guidance computer, concerns with the GOES payload's communicationssystem, and other issues combined to force a delay until the middle of lastAugust, when two consecutive launch attempts endedin scrubs.

The mission was then pushedback to October because of expired flight termination system batteries and tobypass a period where the GOES spacecraft would not receive adequate sunlightfor power production during the mission's early test and commissioning phase.Continuing problems with flight termination batteries and a machinists' laborstrike conspired to further postpone the mission to May. Boeing eventuallychose a new battery supplier, while the machinist's union agreed to laborcontract terms and work resumed in early February.

During the lengthy delay,the Delta 4 rocket and the attached GOES-N satellite weathered a threat fromHurricane Wilma, whose 60 mile per hour winds lashed the launch complex in lateOctober.

In February, officials alsodecided to remove the spacecraft from atop the Delta 4 to return to the nearbyAstrotech processing facility for inspections, cleaning, and further testing.GOES-N was transported back to the launch pad on April 28 and hoisted on top ofthe Delta 4's second stage two days later. The rocket's first stage RS-68 mainengine gimbal actuators were then removed and replaced, delaying the launch toMay 24.

Schedule will keep Deltateam busy

Boeing'slaunch team can now focus preparations for the next mission of a Delta 2rocket that is slated to deliver two defense research satellites into orbitfrom Cape Canaveral on June 19. Components of that vehicle are already beingstacked at launch pad 17A.

Meanwhile, a Delta 4 rocketis currently scheduled to debut the company's new West Coast launch site atVandenberg Air Force Base, California, on June 27.

That flight will carry atop secret craft for the National Reconnaissance Office - the government agencyin charge of U.S. spy satellite operations.

Florida technicians willcontinue processing for the next Cape Canaveral Delta 4, due to fly in lateJanuary of next year. The last Defense Support Program missile detectionsatellite will ride aboard the second flight of the Delta 4-Heavy version ofBoeing's expendable family. That vehicle - already fully assembled - is slatedto be lifted atop its launch pedestal at Complex 37B in a few months. Beforethen, crews must complete a set of modifications to the launch pad to allow itto support the DSP launch.

Last year, engineersdevised a fix to a propellant cavitation problem with the Delta 4-Heavy's threegiant common booster core stages that are strapped together in the early phaseof ascent. That issue caused the trio of RS-68 main engines cut off a fewseconds earlier than planned on the maiden launch of Delta 4-Heavy in December2004, resulting in a failure to reach the mission's desired orbit.

Wednesday's launch markedthe first Delta 4 mission since that Heavy test flight. To date, Boeing's newrocket program has now amassed a total of five launches since its first inNovember 2002, and the entire Delta fleet has flown 315 times in over 40 yearsof service.

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Stephen Clark

Stephen Clark is the Editor of Spaceflight Now, a web-based publication dedicated to covering rocket launches, human spaceflight and exploration. He joined the Spaceflight Now team in 2009 and previously wrote as a senior reporter with the Daily Texan. You can follow Stephen's latest project at (opens in new tab) and on Twitter (opens in new tab).