The U.S. Air Force launched a second effort to develop sensor technologies for future-generation missile warning satellites with the recent award of two contracts worth nearly $31 million combined through mid-2012.

The contracts, awarded in late June to divisions of BAE Systems and Teledyne Technologies, are worth $15.3 million and $15.5 million, respectively, and are focused on designing integrated electronic chip assemblies for infrared sensor payloads. BAE’s contract runs through June 2012, while Teledyne’s runs through January of that year.

The program, dubbed High Stare, is separate from the sensor-development component of the Alternative Infrared Satellite System (AIRSS), although both are aimed at a similar capability: Sensors that can keep continuous watch for missile launches over the entire portion of the Earth that is visible from geosynchronous orbit. That area is equivalent to about a third of the Earth’s surface.

The Air Force’s current Defense Support Program missile warning satellites feature what are known as scanning sensors, which cover large areas of the Earth’s surface one section at a time. Although these satellites have proven highly effective and reliable over the past 25 or so years, so-called staring sensors in theory would provide quicker warning of missile launches and other heat-intensive events such as explosions.

The Space Based Infrared System (SBIRS) missile warning satellites, which are slated to begin replacing the Defense Support Program spacecraft in late 2008, feature both scanning and staring sensors. The former will cover wide areas, while the latter will maintain continuous watch over smaller areas of particular interest.

The Air Force initiated the AIRSS program in 2006 after SBIRS was restructured due to technical difficulties that led to soaring costs and lengthy delays. AIRSS, billed as a possible early replacement for SBIRS, features parallel efforts: one to design an overall system architecture, including the satellites; and one to develop wide-area staring sensors. Divisions of Raytheon Co. of Waltham, Mass., and SAIC Corp. of San Diego won contracts last year to design AIRSS sensors that stare continuously at a third of the Earth’s surface.

Air Force Lt. Shirali Patel, a spokeswoman for the AIRSS program at the Air Force Space and Missile Systems Center in Los Angeles, said AIRSS “supports all efforts to broaden the industrial base in this field.” But she said AIRSS program officials currently are not involved in the High Stare effort, which is managed by the Air Force Research Laboratory, Kirtland Air Force Base, N.M.

Allan Hahn, group lead for advanced electro-optical space sensors at the laboratory’s Space Vehicles Directorate, said through a spokesman that the High Stare contracts call for BAE and Teledyne to deliver prototype chip assemblies in 18 months for testing. Updated samples are to be delivered at six-month intervals thereafter, he said.

Luis Benet, program manager for High Stare at BAE Systems’ Space Systems & Electronics division in Nashua, N.H., said the effort entails developing a single integrated chip assembly that can perform the functions of several such devices on current-generation satellites. The chip assemblies, in a nutshell, absorb infrared data and convert it into electrons that are then processed to create visible images, he said.

Combining multiple sensor-payload functions into a single chip assembly reduces overall system complexity by eliminating the need to integrate the circuitry of several such assemblies, according to Keith Sage, senior program manager for Teledyne Imaging Sensors of Thousand Oaks, Calif. The business was formerly known as Rockwell Scientific’s Imaging Division.

Both companies plan to leverage past experience with satellite-based missile sensors on their respective High Stare efforts.

BAE designed chip assemblies for the SBIRS program, Benet said, noting that the High Stare assemblies will be four times larger because of the multiple functions they must perform.

Teledyne, meanwhile, is developing sensor technology for possible use on future Space Tracking Surveillance System satellites, Sage said. That program today features a pair of missile-tracking demonstration satellites slated for launch late this year

that do not include Teledyne-built components.

While High Stare could help reduce the complexity, weight

and power requirements for future missile-warning satellites, it is hard to quantify the savings in the absence of a program and host satellite design

, Benet said.

The technology also might be applicable to future space surveillance satellites, Sage said.