The beginning and the end: GPS IIF-12 launches on first ULA flight of the year
CAPE CANAVERAL, Fla. — It was the first flight of the year for Colorado-based United Launch Alliance (ULA) and the final (the twelfth) Block IIF GPS satellite to be sent into orbit. To complete the GPS IIF constellation, ULA used the venerable Atlas V booster in its 401 configuration.
The launch window extended for approximately 20 minutes and opened at 8:38 a.m. EST (13:38 GMT). Even though technical conditions might have caused a delay in the launch, it was not the primary issue which threatened the mission. The weather conditions deteriorated some over the evening before clearing with the morning Sun. Forecasters only gave a 40 percent chance of favorable conditions for launch – as the countdown clock ticked down to “T-minus” zero, it was obvious that the chances for launch were 100 percent.
Weather along Florida’s historic Space Coast simply could not have been better with the sky being as what pilots refer to as “severe clear”. In short? There was not a cloud in the sky.
In the end, the only concern was the wind (which also did not prevent this morning’s launch), with the clear, cold sky greeting the booster and its precious cargo as it slowly left SLC-41 for orbit.
Today’s launch had been slated to take place on Feb. 3, but issues revolving around the integrity of electrical connectors on the Atlas V booster caused engineers to take a closer look – pushing the flight back until earlier today.
At about 2.7 seconds before the countdown clock ticked down to zero, the launch vehicle’s single Russian-built RD-180 rocket engine roared to life, its thrust directed Earthward by the first stage’s two engine nozzles.
The 401 version of the Atlas V uses a 14-foot (4-meter) payload fairing, has no Aerojet Rocketdyne AJ60A solid rocket motors in its first stage, and a single Centaur engine in its upper stage.
Due to the lack of solids on this flight, the Atlas V rose languidly off the pad and into Florida’s morning skies. Some 17.2 seconds into the mission, the rocket carried out a pitch/yaw maneuver.
One minute and 18 seconds after leaving the pad, the rocket was traveling faster than the speed of sound.
About a minute-and-a-half after the rocket and the navigation satellite it carried had left the pad, the booster’s speed, along with atmospheric pressure outside, placed the vehicle stack under the greatest amount of stress during the flight.
Four minutes after it had launched from SLC-41, Booster Engine Cutoff or “BECO” took place. Staging took place six seconds later, with the rocket’s first stage falling back to Earth.
Ten seconds later and the Centaur’s Aerojet Rocketdyne RL-10C activated, which is capable of generating some 22,900 lbf (101.9 kN) of thrust. The Payload Fairing (PLF), its job of shielding the GPS IIF-12 satellite through Earth’s atmosphere finished, separated and was jettisoned – revealing the GPS IIF-12 satellite to the harsh environment of space.
Measuring some 12.5 feet (3.81 meters) in diameter and 106.5 feet (32.5 meters) tall, the Atlas V is composed of aluminum barrels, domes, and tanks. The NPO Energomash is fueled by Rocket Propellant 1 (RP-1); this highly refined form of kerosene uses liquid oxygen as the oxidizer. The RD-180 is able to produce 860,200 lbf (3,826.4 kN) of thrust at sea level. The booster itself is controlled by the Centaur avionics system which gives the booster guidance and control as well as sequencing functions.
The Block IIF fleet of satellites is designed as an interim step to maintain navigational services until the Block IIIA fleet can be brought online. While used by the U.S. military, the system is also used by civilian operators across the globe. The satellites provide accurate time, location, and velocity data services.
“We launched the first Block IIF GPS satellite in May 2010, on a United Launch Alliance Delta IV rocket, so this will be the last in this series of satellites,” ULA’s Victoria Porto told SpaceFlight Insider. “If you’ve ever used your GPS on your phone to either figure out where you’re going or hopefully not get lost, that is because ULA and the United States Air Force worked together to get those satellites into orbit – some 11,000 miles above the Earth.”
The launch of GPS IIF-12 marks the 60th operational GPS payload to be sent aloft using either a ULA or heritage launch vehicle. It was also the 30th flight of an Atlas V 401 since this version of the rocket was first launched on Aug. 21, 2002.
On any given mission, there are an array of contractors and subcontractors, each contributing a part of the complex machines which roared aloft this morning.
“Every launch is exciting but today’s mission caps nearly six years of Aerojet Rocketdyne propulsion, successfully placing all 12 of these next-generation satellites into orbit,” said Ron Felix, vice president and general manager of the Space Systems at Aerojet Rocketdyne. “Our objective is always 100 percent mission success, and it’s an honor to know we have fulfilled that promise each and every time – not just with the first GPS Block IIF satellite placed into orbit in May 2010, but with each GPS spacecraft placed into orbit since the inception of the program in the late 1970s.”
The Atlas V 401 is capable of sending a launch mass of some 10,470 lbs (4,750 kg) into a geostationary orbit and 21,600 lbs (9,800 kg) to low-Earth orbit. It has been used to loft everything from navigational, communications, and classified payloads for the National Reconnaissance Office to probes and rovers on missions of exploration deep into space.
“This GPS IIF milestone builds on our 40-plus years of GPS experience and a strong government-Boeing partnership,” said Dan Hart, vice president, Boeing Government Satellite Systems. “We continue investing in GPS innovation while driving down costs, keeping GPS prepared to meet current and future demands.”
Video Courtesy of SpaceVids.tv
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.