The STSS is an experimental space tracker consisting of two low-Earth orbiting satellites launched from Cape Canaveral, FL on September 25, 2009 and an associated ground system.

Each satellite has two sensors:

a short-wave infrared, wide field of view acquisition sensor that autonomously detects and tracks missiles during boost phase.

a narrow field of view, gimbaled track sensor capable of tracking missiles, post boost through midcourse and through intercept or re-entry using multiple infrared bands.

The Air Force Satellite Control Network is used to send data from the satellites to the ground station in the Missile Defense Integration and Operations Center (MDIOC) at Schriever AFB, CO. The ground data mission processor receives the data from each satellite and fuses it into a three dimensional track of each object.

Northrop Grumman Systems Corporation – Aerospace Systems located in Redondo Beach, CA is the prime contractor for the satellites and ground system. Raytheon Space System is the subcontractor responsible for the payload.

The STSS is participating in integrated Ballistic Missile Defense System (BMDS) testing and provides risk reduction in support of a future missile defense tracker.

MDA has contracted Northrop Grumman Systems Corporation – Aerospace Systems to provide operations and sustainment of STSS. Satellite operations personnel monitor and communicate with the satellites 24 hours a day/7 days a week from the MDIOC at Schriever AFB, CO.

STSS has exceeded its original four year design life. It is currently operating three years past design life and continues to deliver engineering and integration data to influence future tracking systems. The MDA plans to operate STSS for as long as it provides valuable data and analysis to the missile defense mission.

The program office receives health and status telemetry from the satellites daily. Engineers perform trending analysis to determine what changes need to be made in order to keep the satellites operating at full capability. Some components are redundant and we can switch over to the secondary if the primary unit fails.

Today, we require fewer operators and engineers to operate STSS and analyze the data. Our annual operating budget is less than half of what it was at launch. We have automated many data analysis processes that used to be done manually.

The two STSS satellites serve as a demonstrator system to validate missile tracking technology from space and pave the way towards deployment of an operational missile defense satellite system. STSS has achieved this goal and there are no plans to build additional STSS satellites.

STSS participates in the MDA’s missile defense tests. Since launch, STSS has participated in 55 MDA integrated test events. Some of the major accomplishments include:

• Autonomous acquisition-to-track sensor handover of a boosted target
• Birth-to-death track of a boosted target
• Track of short-range target
• Track of multiple targets simultaneously
• Cue other sensors to a target

STSS is supporting more mission areas than missile defense, such as Battlespace Awareness, Technical Intelligence and Space Situational Awareness. Some of the organizations STSS has provided information to include NASA, weather agencies and the national labs.

Data gathered by STSS is providing unique insight on the Concept of Operations for the next generation system. We are determining the optimal orbit, wavelengths, data processing techniques and what sensors are required to meet the MDA mission objectives.

The first valuable lesson we have learned is the importance of having an integrated test bed on the ground that emulates the space vehicles. Our Integrated Test Bed has been a valuable tool during anomaly resolution to identify root cause of certain failures. Another lesson learned is the importance of having fault management on-board the spacecraft. Errors can occur when the operators are not in communication with the spacecraft. Fault management enables the system to detect, correct malfunctions autonomously and keep operating.

All of the elements of the BMDS are described in our System section.
If you still have questions, check out the FAQs for:

• Aegis Ballistic Missile Defense (BMD),
• Command and Control, Battle Management, and Communications (C2BMC),
• Ground-based Midcourse Defense (GMD),
• PATRIOT Advanced Capability-3 (PAC-3), and
• Terminal High Altitude Area Defense (THAAD).