Space-Based Infrared System (SBIRS)January 2017 by Kristin Horitski and Zach Berger
|Mobility||Satellites and sensors in GEO and HEO|
|Role||Mission areas include missile defense, missile warning, technical intelligence and battlespace awareness|
|Status||Three GEO satellites and three HEO sensors are currently operational|
The Space-Based Infrared System (SBIRS) is designed to support the defense and intelligence communities and provide global surveillance capabilities in four key mission areas: missile defense, missile warning, technical intelligence, and battlespace awareness. SBIRS is made up of numerous satellites and payloads in geosynchronous earth orbit (GEO) and highly elliptical orbit (HEO), as well as ground-based hardware and software. The SBIRS satellites and sensors are designed as a follow-on capability to the Defense Support Program (DSP) with greater flexibility and sensitivity, in addition to the ability to detect short- and mid-wave infrared signals.
SBIRS currently consists of two GEO satellites and two HEO sensors. The GEO satellites are made up of a GEO spacecraft bus, which is militarized, and radiation-hardened, providing power, altitude control, command and control, and communications subsystem for the satellite. The GEO payload consists of two infrared sensors: a scanning sensor and a step-staring sensor. The scanning sensor aboard the GEO satellite is able to continuously scan the earth to provide 24/7 global missile warning coverage and collect data that contributes to theater and intelligence missions. The step-staring sensor is designed for theater missions and intelligence areas of interest, since it contains a highly-accurate pointing and control system and is highly-agile with a fast revisit rate and high sensitivity.  The two HEO sensors are scanning sensors similar in nature to the GEO scanning sensors, but sensor pointing is performed by slewing the full telescope on a gimbal. Both the GEO and HEO sensors provide unprocessed data to the ground for mission processing, although the GEO sensors are able to perform on-board signal processing and transmit detected events to the ground. 
Missile Defense and Missile Warning – Two of the main mission areas of SBIRS are missile warning and missile defense. SBIRS HEO and GEO sensors enable it to detect missile launches around the world, providing accurate and early warning through the Mission Control Station (MCS). SBIRS is able to detect strategic and short range ballistic missile launches, determine their flight trajectory, and provide a location for where the missile will hit. The early warning provided by SBIRS when a launch is detected, gives warfighters the necessary alert to intercept the weapon as part of the OODA loop (Observe, Orient, Decide and Act). Early warning detection of missile launches and other infrared events also helps alert and protect allies and U.S. deployed troops.
Technical Intelligence – The mobility and accuracy of SBIRS sensors allows them to provide a variety of data to Combatant Commanders, decision makers, and the intelligence community. SBIRS is able to characterize infrared event signatures, phenomenology, and threat performance data; and can quickly revisit areas of interest for theater missions and intelligence coverage.
Battlespace Awareness – The SBIRS constellation also provides comprehensive infrared data to Combatant Commanders, Joint Task Force Commanders and other users to help increase situational awareness in order to support force protection, strike planning and other missions.
Elements of the SBIRS program, particularly the ground-based MCS, were first used in conjunction with existing DSP legacy satellites in December 2001.  After several program delays, the first HEO sensor was launched into orbit in November 2006, followed by HEO-2 in June 2008. HEO-1 received its certification in December 2008. The first and second GEO satellites were launched on a United Launch Alliance Atlas V rocket from Space Launch Complex (SLC) 41 at Cape Canaveral Air Force Station, Florida in May 2011 and March 2013 respectively. As part of the follow-on production contract, HEO-3 was launched into orbit and completed its checkout in May 2015. In January 2017, GEO-3 was launched into orbit.
The SBIRS program has been highly successful, exceeding expectations in several mission areas. Currently, HEO-4 and GEO-3 have been delivered, and GEO-3, delivered in 2014, successfully entered geosynchronous orbit in January 2017.  Lead contractor, Lockheed Martin, has been awarded a contract to produce the GEO-5 and GEO-6 satellites. SBIRS is also currently undergoing Block 10 upgrades, which includes consolidating all SBIRS operations, including DSP and SBIRS GEO satellites and HEO sensors, into one facility. The Block 10 upgrades also consists of major software revisions, additional computer processing hardware at the MCS, and additional hardware components at each relay ground station. Block 10 upgrades achieved operational acceptance in December 2016. 
- January 20, 2017: the Air Force’s GEO-3 satellite was launched from Cape Canaveral, Florida.
- December 2016: SBIRS Block 10 upgrades reach operational acceptance.
- June 2015: The HEO-4 sensor was delivered to the Air Force as part of the SBIRS follow-on contract.
- May 2015: HEO-3, operating over the northern hemisphere, successfully completed its on-orbit checkout. 
- June 27, 2014: Lockheed Martin was awarded a contract to produce the fifth and sixth SBIRS GEO missile-warning satellites.
- 2014: HEO-3 launched into orbit.
- November 2013: The GEO-2 satellite received operational acceptance from the AFSPC.
- May 2013: The GEO-1 satellite received operational acceptance from the Air Force Space Command (AFSPC).
- March 19, 2013: The second GEO satellite was successfully launched into orbit.
- July 7, 2011: GEO-1 successfully delivered its first infrared imagery.
- May 7, 2011: GEO-1 successfully launched into orbit.
- March 7, 2011: The U.S. Air Force and Lockheed Martin delivered the first GEO satellite.
- December 2008: HEO-1 received certification from the U.S. Strategic Command (USSTRATCOM) to operate in strategic and theatre missile warning missions. 
- June 2008: Second HEO payload announced on-orbit.
- November 2006: First HEO payload announced on-orbit.
- December 2001: SBIRS Mission Control Station declared operational.
- 1995: SBIRS was announced as a follow-on program to the successful DSP. 
- U.S. Missile Defense
- U.S. Deployed Intercept Systems
- Aegis Ashore
- Aegis Afloat
- Ground-Based Midcourse Defense
- Patriot Missile Defense System
- Terminal High Altitude Area Defense (THAAD)
- Avenger Air Defense System
- Counter-Rocket, Artillery, Mortar (C-RAM)
- SeaRAM Anti-Ship Missile Defense System
- U.S. Deployed Sensor Systems
- Command and Control
- U.S. Missile Defense Policy
- U.S. MDA Funding
- U.S. Deployed Intercept Systems
- Missile Defense of U.S. Parnters
- U.S. Partners in Missile Defense
- Allied Intercept Systems
- Allied Sensor Systems
- Other BMD Systems
- Missile Defense Intercept Test Record
- Operational Intercepts by System
- Future BMD Systems
- Boost Phase Missile Defense
- Directed Energy
- Electromagnetic Railgun
- Hyper-Velocity Powder Gun
- LPD Based Ballistic Missile Defense Ship
- Long Range Discrimination Radar (LRDR)
- Medium Extended Air Defense System (MEADS)
- Multi-Mission Launcher (MML)
- Multi-Object Kill Vehicle (MOKV)
- Space-based Kill Assessment (SKA) Experiment
- Discontinued Programs