Twenty-five months after the WorldView-3 commercial Earth-imaging satellite was launched into orbit, its near-twin is set to rocket out of Vandenberg Air Force Base, Calif., no sooner than Friday, 16 September, atop a United Launch Alliance (ULA) Atlas V 401 rocket. Built by Lockheed Martin and described as “a big telescope with a little satellite wrapped around it,” WorldView-4 has followed a long and convoluted journey from factory floor to launch pad. Originally known as “GeoEye-2,” both the satellite and its parent company came under the ownership of Longmont, Colo.-based DigitalGlobe in early 2013.
However, for a time it seemed unclear if GeoEye-2—subsequently renamed WorldView-4—would ever launch. Then, in the summer of 2014, following a U.S. Department of Commerce decision to allow DigitalGlobe to commercially sell Earth imagery at far higher resolutions than previously allowable under U.S. law, the need for WorldView-4 became more acute. In tandem with WorldView-3, launched in August 2014, the new satellite will provide a panchromatic resolution of 12.2 inches (31 cm) and a multispectral resolution of 4 feet (1.2 meters). And since early 2015, this has been increased to just 10 inches (25 cm) for panchromatic and 3.3 feet (1 meter) for multispectral, offering resolutions previously unobtainable outside the military.
DigitalGlobe was founded in 1992 as WorldView Imaging Corp. by Dr. Walter Scott and received the first high-resolution commercial remote sensing satellite license in 1993, under the provisions of the 1992 Land Remote Sensing Policy Act. Two years later, it was renamed EarthWatch, Inc., merging WorldView with the commercial remote sensing operation of the defense and space contractor Ball Aerospace, also based in Colorado. The license from the U.S. Department of Commerce enabled Ball to build the Early Bird-1 satellite, which was delivered into orbit atop a Start-1 booster from Svobodny in Russia’s Far East in December 1997. Its imaging payload was intended to deliver a panchromatic resolution of just 9.8 feet (3 meters) and a multispectral resolution of 49 feet (15 meters), but a power failure caused Early Bird-1 to lose communications capability after just four days in orbit.
Three years later, in November 2000, EarthWatch’s first QuickBird satellite—again built by Ball Aerospace and expected to deliver a panchromatic resolution as fine as 24 inches (60 cm) and a multispectral resolution of 8 feet (2.4 meters)—was lost in a launch failure out of northern Russia’s Plesetsk Cosmodrome. Success finally came in October 2001, when a Delta II roared aloft from Vandenberg Air Force Base, Calif., boosting the QuickBird-2 satellite into an orbit of 280 miles (450 km). Still aloft today, QuickBird-2’s resolution produced a level of detail which enabled it to image buildings and other infrastructure at ground level. By the time of QuickBird-2’s launch, EarthWatch, Inc., had been renamed DigitalGlobe.
QuickBird-2 formed the initial element of a three-satellite system. Its second member was WorldView-1, part-financed by the National Geospatial-Intelligence Agency (NGA), and was launched into a 300-mile (490-km) orbit by a Delta II from Vandenberg in September 2007. Its panchromatic camera achieved a resolution of 20 inches (50 cm), making it the most powerful commercial imaging satellite of its time. In October 2009, WorldView-2 was launched into an orbit of 480 miles (770 km), again via a Delta II from Vandenberg, with the capability to achieve a panchromatic resolution of 18 inches (46 cm) and an eight-band multispectral resolution of 72 inches (184 cm). Both WorldView satellites can revisit the same spot on Earth’s surface every 1.1 days.
More recently, in August 2014, WorldView-3 was launched atop an Atlas V 401 booster from Vandenberg. Equipped with a mixture of panchromatic and Visible-Near-Infrared (VNIR) and Short-Wave Infrared (SWIR) sensors—together with the 12-band Cloud, Aerosol, Water Vapor, Ice and Snow (CAVIS) atmospheric sounder—the satellite operated in an orbit of 383 miles (617 km). It provides panchromatic and multispectral resolutions of 12.2 inches (31 cm) and 4 feet (1.2 meters), which was expandable to 10 inches (25 cm) and 3.3 feet (1 meter) from early 2015 onward.
In early 2013, DigitalGlobe finalized a $900 million purchase of one of its key competitors, GeoEye, Inc. (formerly Space Imaging), which had launched the Ikonos satellite in September 1999 and the GeoEye-1 satellite in September 2008. Prior to its acquisition by DigitalGlobe, the company planned a follow-on GeoEye-2 satellite, with an imaging capability as fine as 12.2 inches (31 cm). Contracts to build GeoEye-2 were awarded to Lockheed Martin in March 2010, with an expectation that the satellite would be launched in late 2012. Construction and testing of GeoEye-2 progressed smoothly, passing its Preliminary Design Review (PDR) in November 2010 and its Critical Design Review (CDR)—ahead of schedule—in June 2011. In tandem, the satellite’s camera system was under development and was integrated into the GeoEye-2 bus in May 2012.
With DigitalGlobe’s purchase of GeoEye, Inc., a few months later, there existed two Earth-imaging satellites from the two companies: WorldView-3 and GeoEye-2. Since the former carried multiple infrared channels and CAVIS, in addition to its panchromatic channels, it was decided to launch WorldView-3 and preserve GeoEye-2 in storage as a ground-based spare. It was noted that GeoEye-2 could be brought to launch readiness, if needed. In July 2014 DigitalGlobe announced that it had been renamed WorldView-4—in order to “mitigate any future market confusion and ensure that the satellite is clearly identified as part of the larger DigitalGlobe constellation”—and was being targeted for flight in mid-2016 aboard an Atlas V booster.
A significant driver in bringing the satellite out of storage was a U.S. Department of Commerce decision to allow DigitalGlobe to sell imagery at far higher resolutions than previously allowable under U.S. law. Earlier that summer, DigitalGlobe received the go-ahead to sell images as fine as 16 inches (40 cm) panchromatic and, from early 2015, as high as 10 inches (25 cm). Such resolutions had never previously been obtainable outside the military. “As a result of the U.S. Government’s recent decision to allow us to sell our highest quality imagery, we’ve seen sufficient demand that justifies the accelerated launch of WorldView-4,” said DigitalGlobe President and CEO Jeffrey R. Tarr. “This will extend our industry leadership, capture more of our customers’ mapping and monitoring missions, provide an even stronger foundation on which to grow our Geospatial Big Data and analytic capabilities and uniquely address pressing global challenges.”
The satellite at the center of this decision can trace its origins back to October 2007, when GeoEye, Inc., contracted with ITT Corp. to build the GeoEye Imaging System-2 telescope. With an aperture of 3.4 feet (1.1 meters), this telescope can discern objects on Earth’s surface as small as 12.2 inches (31 cm) at panchromatic resolution and 4 feet (1.2 meters) multispectral, equivalent to WorldView-3.
In April 2010, Lockheed Martin began fabricating the satellite on the framework of its LM-900 “bus,” previously used for Ikonos. The LM-900 is a three-axis-stabilized bus for precisely pointing remote sensing payloads in low-Earth orbit and is equipped with five deployable solar array “wings.” Under its new name of WorldView-4, the 4,600-pound (2,100-kg) satellite will enter a Sun-synchronous orbit, at an altitude of 383-423 miles (617-681 km). It will be able to image as much as 262,550 square miles (680,000 square km) of Earth’s surface—equivalent to the land area of the state of Texas—on a daily basis. Standing 18 feet (5.5 meters) tall, it has been described by DigitalGlobe founder and CTO Dr. Walter Scott as “a big telescope with a little satellite wrapped around it.”
“Only the DigitalGlobe constellation, with the addition of WorldView-4, offers the highest quality and most comprehensive global coverage of our changing planet through 2030, so customers can be confident they will have the information to make critical decisions,” said Dr. Scott. “WorldView-4 will help us continue to transform the way we see the world and advance our mission of keeping our planet and its people safe and secure.”
WorldView-4 will rise to orbit atop a United Launch Alliance (ULA) Atlas V 401 booster from Space Launch Complex (SLC)-3E at Vandenberg. The “401” is numerically designated to describe its 13-foot-diameter (4-meter) payload fairing, no strap-on rockets, and a single-engine Centaur upper stage. As the “barebones” member of ULA’s fleet, the 401 can haul up to 21,600 pounds (9,800 kg) into low-Earth orbit and up to 10,470 pounds (4,750 kg) into Geostationary Transfer Orbit (GTO). It has staged 32 of the 65 total Atlas V flights since the vehicle was introduced in August 2002.
In readiness for its impending launch, WorldView-4 arrived at Vandenberg from Lockheed Martin’s facility on 28 July for integration aboard the Atlas V. After final tests and fueling, the satellite was encapsulated within its payload shroud on 8 September. “Encapsulation is the last time people will ever lay eyes on this satellite before it launches to space,” said Steve Skladenek, president of Lockheed Martin Commercial Launch Services. “Our Atlas rocket is ready to provide WorldView-4 a smooth ride and precise delivery into orbit.”
Eager anticipation for the satellite’s capabilities was already clear. “DigitalGlobe has obtained six pre-launch contracts and letters of intent from international defense and intelligence customers for WorldView-4 imagery,” it was reported recently, “bringing the total contracted revenues for WorldView-3 and WorldView-4 to $415 million.”
According to DigitalGlobe, the opening launch attempt is targeted for 11:30 a.m. PDT on Friday, 16 September, at the start of a 14-minute “window.” The flight comes almost a year since the most recent launch from SLC-3E—last October’s classified NROL-55 payload for the National Reconnaissance Office—although the Vandenberg site is expected to more activity in the coming months, with NROL-79 due to fly in mid-December. Friday’s mission comes after more than a half-century of operational service at the SLC-3E site, which hosted dozens of Atlas-Agena and Atlas IIAS launches between July 1961 and December 2003. It subsequently underwent a $200 million facelift to ready it for Atlas V operations. Between March 2008 and October 2015, SLC-3E has seen 11 Atlas Vs deliver seven classified NROL payloads, two Defense Meteorological Satellite Program (DMSP) weather sentinels, DigitalGlobe’s WorldView-3, and NASA’s Landsat-8 to orbit.
At the time of writing, the 35-minute rollout of the 196-foot-tall (60-meter) Atlas V 401 from the Vertical Integration Facility (VIF) to the SLC-3E pad surface will take place later today (Thursday, 15 September). Pad connections, pneumatic checks and tests of the vehicle’s flight control systems will then be undertaken, ahead of purging of the fuel lines with inert gaseous nitrogen. This will allow the loading of liquid oxygen and a highly refined form of rocket-grade kerosene (known as “RP-1”) aboard the first stage, which is known as the Common Core Booster (CCB). On launch day, cryogenic tanking will get underway, with liquid oxygen and hydrogen loaded aboard the Centaur upper stage to feed its restartable engine. These will be continuously topped-off until close to T-0, in order to ensure that boiled-off cryogens are replenished and tanks kept at Flight Ready levels.
Weather conditions for the Vandenberg area on Friday are expected to be sunny, with a low probability of rain and winds from the northwest at 11 mph (18 km/h). “Looking good for WorldView launch,” tweeted ULA President and CEO Tory Bruno late Wednesday, noting an 80-percent likelihood of acceptable weather conditions. Assuming an on-time liftoff, the Atlas V 401 will climb for four minutes under the thrust of its dual-nozzle RD-180 engine, which produces 860,000 pounds (390,000 kg) of propulsive yield. The CCB will then separate and the Centaur’s own RL-10-4-2 engine—capable of 22,300 pounds (10,100 kg) of thrust—will boost WorldView-4 into orbit. The single Centaur “burn” is expected to run for 11 minutes, with spacecraft separation scheduled to occur about 19 minutes after launch, kicking off a mission whose duration should run for up to 12 years.
Missions » WorldView 4 »