To the Launch Pad
Later than its developers would have liked but
promising unprecedented imaging capability and
mapping accuracy, the GeoEye-1 Earth-imaging
satellite is headed for launch late this summer.
Later than its developers would have liked but promising unprecedented imaging capability and mapping accuracy, the GeoEye-1 Earth-imaging satellite is headed for launch late this summer.
The satellite, which completed final integration and environmental testing this spring, is due to be shipped to Vandenberg Air Force Base, Calif., in July, with a scheduled August 22 launch aboard a Boeing Delta 2 rocket.
When operational, GeoEye will be the world’s highest resolution commercial earth imaging satellite. From an orbit of 425 miles in space, it will be able to look down on Earth and see objects on the ground as small as 16 inches in size. That means that as it moves around the Earth in a polar orbit at 17,000 mph, or about 4 miles per second, it will be able to look down and image an object the size of home plate on a baseball diamond.
Perhaps most importantly, noted Mark Brender, GeoEye vice president for marketing and corporate communications, the satellite will be able to map an object that size to within nine feet of its true location on the surface of the globe.
“GeoEye-1 is more than a picturetaking satellite. It is a mapping machine in orbit,” said Brender, adding, “Commercial remote sensing is mainly used by the government and intelligence community for broad area mapping. The imagery is all map accurate, and can be used in updating maps and charts that our military or government may be using.”
GeoEye-1 is currently at the Gilbert, Ariz., facilities of General Dynamics Advanced Information Systems, which is the prime contractor and integrator of the satellite and telescope.
While pointing out that the satellite is fully funded, Brender acknowledged that the launch schedule had slipped. “The integration and testing took longer than we originally anticipated, and as a result the satellite is going to be late to the launch pad,” he said. “But all that will be forgotten as soon as the satellite is launched, and we see the high quality imagery.”
GeoEye-1 was developed as part of a National Geospatial-Intelligence Agency program called NextView, which is backing two geospatial companies in developing next-generation imaging satellites. The other NextView satellite, WorldView-1, was orbited last year by Digital Globe, which is currently providing high-resolution imagery to NGA and commercial customers.
For both satellites, the imagery has to be resampled to half-meter ground resolution in order to make it available for commercial sale. The government will get access to higher resolution imagery, but because of a two-tier licensing agreement with the government, both companies are required to sell imagery from the NextView satellite at half-meter ground resolution.
HOT AND COLD
‘During the recent environmental testing, engineers sought to simulate the harsh space environment that GeoEye-1 will encounter once operational. The tests sought to reproduce the temperatures of space and the vibrations the satellite will encounter during the launch, and also checked out individual components of the satellite to be sure they will be compatible with the space environment.
“For example, in environmental testing, which was the last test completed in February and March, we put the 4,300 pound satellite in a thermal vacuum chamber at the General Dynamics facility, pulled out the air to create a vacuum, and then heated the temperature to simulate the hot temperature of space,” Brender explained. “Then we cooled the chamber to simulate the cold part of space, because a satellite could be getting sunlight on one side, and get very hot, yet be very cold on the shady side. We simulate these conditions as best we can in a chamber, so that we’ll explained. “Then we cooled the chamber to simulate the cold part of space, because a satellite could be getting sunlight on one side, and get very hot, yet be very cold on the shady side. We simulate these conditions as best we can in a chamber, so that we’ll know what to expect once it is on orbit.”
Because the satellite will remain at the Gilbert facility until mid-summer, GeoEye plans to do additional training, rehearsals and risk-reduction procedures on the satellite to take advantage of the extra time before it must be packed and shipped.
When the time for departure arrives, the satellite will be encapsulated and put into a temperature-controlled tractor- trailer. With several chase cars and additional drivers, it will then be driven 12-14 hours from Phoenix to Vandenberg. Once it’s at Vandenberg, it will be put into another clean room, the Payload Processing Facility, where all systems will be double-checked again to make sure nothing was damaged in transit.
The satellite will remain in the processing facility until it is delivered to the launch pad, where it will be positioned and bolted onto the rocket.
The program is hitting its marks, but a few tests remain, Brender said. “We had 24 major milestones, and we’re moving through all of them. As of May, we have completed 20 of the 24 milestones, and the remaining four are associated with launch and checkout of the satellite once it’s on orbit.
“Once the satellite is on orbit, there will be an engineering checkout period of about 45 days, when we’ll do all of the testing and calibration, as well as the analysis of the imagery that we get during the period, to make sure everything is working perfectly. When that is done, the satellite will then be able to start imaging for commercial customers,” he continued.
With its ability to collect imagery in both black and white and color, GeoEye-1 will be the only NextView satellite that can provide customers with color imagery, Brender said. ♦
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