- SPECIAL REPORTS
- THE MAGAZINE
GPS IIR-9, We Have Lift Off!A new member of the GPS family was introduced late this March. A Boeing (St. Louis, Mo.) Delta II booster carrying the NAVSTAR GPS IIR-9 satellite built by Lockheed Martin of Bethesda, Md., for the U.S. Air Force, lifted off from Cape Canaveral Air Force Station in Florida on March 31st at 5:09 p.m. EST, after a brief delay due to range safety issues.
A New Addition to the GPS Constellation
The satellite was successfully positioned in geosynchronous orbit 68 minutes later. The elliptical orbit is 101 nautical miles above Earth at its nearest point and 10,998 nautical miles away at its farthest. This latest addition to the constellation is SVN 45 and will go into the D Plane, Slot 3, where it will share the slot with SVN 17.
GPS IIR-9 was launched to replenish the U.S. military’s space-based navigation network, replacing an aging satellite launched in December 1989 that sometimes goes off-line, according to the U.S. Air Force. The satellite was the eighth successful launch of the new-generation GPS IIR spacecraft and will join the GPS IIR-8 satellite launched on Jan. 29, 2003, which is now fully operational along with the 26 other operational GPS satellites now in orbit.
The Block IIR next-generation series of GPS satellites debuted in 1997 and offer technological advancements, additional radiation protection, greater fuel capacity, the ability to determine their own positions and two atomic clocks working at all times, providing a “hot backup” in case one fails.
This new satellite helps in the effort to improve global coverage and enhance the overall performance of the GPS constellation, an important concern not only for civilian surveyors and mappers, but also for the military and its recent war efforts. Air Force Col. Gregg Billman, who flew missions during 1991’s Operation Desert Storm in jets both with and without GPS capability, said the difference is like night and day. “Flying my old 1968-era F-111 E over the expansiveness of Iraq with nothing but a stopwatch, a radar and a map is a big difference,” compared to the accuracy afforded by GPS-guided aircraft, he said.
This is the second launch in 2003. Two more GPS launches are scheduled in the next eight months—July 24 and Feb. 17, 2004—from Cape Canaveral on Delta II rockets. Twelve satellites remain in storage to support future launches.
To bring new capabilities to the GPS constellation, Lockheed Martin is under contract to modernize up to eight existing GPS IIR spacecraft already built and in storage. These spacecraft, designated GPS IIR-M, will incorporate two new military signals and a second civil signal, thus providing military and civilian users of the navigation system with improved capabilities much sooner than previously envisioned. For more information about the future of GPS see the GPS Observer column on page 48. The first launch of a GPS IIR-M satellite is scheduled to be available by July 2004.
As of now, the GPS IIR-9 is a full-fledged member of the GPS constellation, providing three-dimensional position, velocity and timing information 24 hours a day to land, sea and airborne users virtually anywhere on Earth.
Lewis and Clark Dedication Held at Harpers FerryThe shopping list that Meriwether Lewis brought to the U.S. Armory and Arsenal at Harpers Ferry, W.Va., when he arrived there on March 16, 1803, included 15 rifles, 15 powder horns, 30 bullet molds, 30 ball screws, extra rifle and musket locks, gunsmith’s repair tools, several dozen tomahawks and 24 large knives, as well as a collapsible iron boat frame. These supplies seem like the procurements of those preparing for a battle, not a survey. But Lewis was preparing for a battle of sorts, a battle with the unknown western wilderness that he, William Clark (who had not yet been chosen for the task), and the other members of the Corps of Discovery expedition would attempt to explore, chart and record.
On April 12, 2003, the National Geodetic Survey (NGS) dedicated a survey marker to commemorate the bicentennial celebration of the Lewis and Clark Expedition at Harpers Ferry. This marker is the second in a series to be placed at sites along Lewis and Clark’s route during the bicentennial celebration now underway. Aside from its historical and commemorative significance, the marker also provides surveyors with a link to highly accurate positioning via the global positioning system. The exact positions (within two centimeters) of the markers in the series are determined through GPS sessions and then entered into the NGS database.
Challstrom presented Todd Bolton, NPS ranger at Harpers Ferry, with a small replica of the marker. Bolton responded, “This marker provides a really exciting opportunity to tell the Meriwether Lewis story at Harpers Ferry. By showing the marker, we can talk about navigation 200 years ago and today.”
NGS currently has plans to place markers at 14 more signature sites along the Lewis and Clark National Historic Trail. The next dedication ceremony will take place at the Falls of the Ohio State Park in Indiana, Oct. 24-26, 2003.