Engineering Tomorrow For SBIRS-High With Avtec's WING Gateway

Avtec supports ballistic missile defense on the ground by transporting mission data for SBIRS-High

SOLUTION AT-A-GLANCE: Avtec contributes to the next-generation U.S. ballistic missile defense shield by deploying WINGs to manage ground transmission of wideband isochronous serial data (principally telemetry, command and payload data) across the SBIRS-High ATM network.

THE CUSTOMER
In the 1990s, when laying the groundwork for its missile defense shield, the Pentagon realized that if it wanted to provide an effective defense against ballistic missile attack, it needed to create a quick and efficient method of detecting and tracking enemy launches. In other words, it needed to build a highly capable constellation of high-orbiting infrared satellites that would serve as the primary watchtower for the entire Ballistic Missile Defense System.

Currently in an advanced engineering, manufacturing, and development phase, the majority of the constellation is expected to launch before 2008. Now called the Space-Based Infrared System-High (SBIRS-High), it will replace the current Defense Support Program (DSP) satellites, which have provided early missile warning information for more than 30 years.

Administered by the Air Force Space Command, the SBIRS High constellation will include four geosynchronous earth orbit (GEO) satellites, two highly elliptical earth orbit (HEO) payloads, and associated ground hardware and software. As envisioned, the four GEO satellites in the constellation will keep a fixed position with respect to the equator, while the two HEO spacecraft will orbit the poles in elliptical patterns, enhancing the GEO satellites' field of vision. As compared to the present DSP system, SBIRS-High will have greatly enhanced sensor flexibility and sensitivity. Spacecraft sensors will cover short-wave infrared like their DSP predecessors, and will also provide enhanced mid-wave infrared and see-to-the-ground capabilities. SBIRS-High satellites will be able to detect objects that are much cooler and dimmer than those currently tracked by DSP satellites, increasing the overall effectiveness of SBIRS-High and the entire missile defense shield.

THE CHALLENGE
To support the SBIRS-High program, the Air Force Space Command needed to implement an Asynchronous Transfer Mode (ATM) wide-area ground network for transport of mission telemetry, command and payload data. Initially, during spacecraft integration and test, the WAN would connect three nodes - the main processing site in Colorado, the SBIRS-High payload manufacturing facility in southern California, and the spacecraft bus manufacturing facility in northern California. Post-launch, similar ground equipment would be employed for ground data transport between SBIRS-High remote ground stations and the Mission Control Station, located at Buckley Air Force Base in Colorado.

The challenge: provide equipment to manage transmission of mission data across the SBIRS-High WAN. Packetize 100 Mbps serial high-rate wideband isochronous satellite payload clock and data for transmission across the ATM WAN, then reserialize the stream from incoming ATM AAL5 Protocol Data Units (PDUs) at the termination node.

THE SOLUTION
Avtec's commercial-off-the-shelf (COTS) Wideband Isochronous Network Gateway (WING) was an ideal solution for the SBIRS-High program. The only solution of its type available off the shelf, WING integrates support for ATM as well as IP networks. At the source, a WING transparently packetizes and transfers a wideband, isochronous serial data stream across an ATM or IP WAN at rates up to 400 Mbps. At the destination, a second WING receives the ATM PDUs or IP packets sent by its counterpart, and can identify and fill missing PDUs with a user specified fill pattern. The data is then retransmitted out the destination WING's high-speed serial interface at a fixed rate, or at the same rate that it was originally received (via automatic rate tracking).

THE CUSTOMER RESULT
Because WING exceeded the requirements of the SBIRS-High ground network in terms of speed, functionality and robustness, Avtec was able to meet a very sophisticated customer need without hardware or software customization. Subsequent to delivery, Avtec provided high-quality on-site systems engineering support and user training, enabling activation of the ground network less than 60 days after contract.