Next SBIRS missile detection satellite set for launch
An artist’s rendering of an SBIRS GEO spacecraft. Image Credit: Lockheed Martin
CAPE CANAVERAL, Fla. — United Launch Alliance (ULA) is set to send the third Space Based Infrared System Geosynchronous Earth Orbit (SBIRS GEO-3) into space for the U.S. military. The $1.2 billion satellite will be part of a system designed to spot missiles threatening the United States or its allies.
SBIRS GEO-3 being encapsulated prior to launch. Photo Credit: Lockheed Martin
The Lockheed Martin-built spacecraft will ride to space atop an Atlas V 401 rocket, the most basic version of ULA’s workhorse rocket, from Cape Canaveral Air Force Station’s Space Launch Complex 41. Liftoff will be during a 40-minute window that opens at 7:46 p.m. on Jan. 19, 2017 (00:46 GMT on Jan. 20, 2017).
The 45th Weather Squadron at the Cape is predicting an 80 percent chance of acceptable launch conditions with the only concern being cumulus clouds.
SBIRS comprises satellites at 22,300 miles (35,900 kilometers), the altitude of GEO, and sensor payloads in highly elliptical orbits (HEO). So far, two spacecraft are in GEO while three HEO payloads have launched. Additionally, ground assets will manage SBIRS data and the older Defense Support Program (DSP).
The DSP started in 1970 and was primarily tuned toward seeking out Cold War era intercontinental ballistic missile launches. SBIRS systems include support for detecting smaller short-range missile threats by using newer technology that can spot dimmer engine burns and help determine the weapon’s point of origin.
The first two SBIRS GEO satellites were launched in 2011 and 2013. The fourth is planned for Nov. 9, 2017. Lockheed Martin is currently building a fifth and sixth satellite, which are expected to be delivered in 2020 and 2021.
GEO-3, which is a duplicate of the first two satellites, weighs in at around 10,000 pounds (4,500 kilograms) at launch. It is built on Lockheed Martin’s A2100 platform and has nuclear-hardened electronics with a range of shielding options to extend its orbital life if needed.
With its two solar panels extended, GEO-3 will span 49 feet (15 meters) and produce 2,800 watts of power. Additionally, it has a light shade for the payload and communications antennas that gimbal to allow secure, spot beam transmissions.
ULA’s Atlas V will actually place the spacecraft into a geostationary transfer orbit (GTO) with a high point of 22,237 miles (35,787 kilometers) and lower point of 115 miles (185 kilometers).
After the satellite separates from the booster (about 43 minutes after launch), onboard fuel and thrusters will then begin to raise its orbit. It is expected to take six firings over nine days to circularize its orbit. Only then will the solar panels and antennas deploy.
The planned orbital location of SBIRS GEO-3 has not been revealed by the Air Force.
Thursday’s launch will be ULA’s first launch of the year and the first rocket flight from Cape Canaveral Air Force Station in 2017.
ULA is expected to launch 11 rockets skyward this year – seven from the Cape and four from Vandenberg Air Force Base in California. Eight will be Atlas V, two Delta 4, and one Delta 2.
Four of those missions will be for the U.S. military, while another four will be for the National Reconnaissance office. Two will be for NASA, while the one in March will be for Orbital ATK’s Cygnus cargo spacecraft to the International Space Station.
An artist’s rendering of the DSP and SBIRS constellations. Image Credit: Lockheed Martin
Derek Richardson
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.
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