The development of small, low-cost off-the-shelf satellite technology is enabling new capabilities for military as well as civilian users. The US Army is taking advantage of this technological revolution by developing three new satellites to provide tactical imaging for the warfighter.

Kestrel Eye

The Technology Center at the US Army Space and Missile Defense Command is developing Kestrel Eye, an imaging reconnaissance nanosatellite that can be tasked by warfighters on the ground. Kestrel Eye will produce images with a resolution of 1.5 meters (5 feet), which can be downlinked directly to soldiers in the field.

The Kestrel Eye 1 Tactical Imaging Satellite is scheduled to be launched in 2013 as a secondary payload on a SpaceX Falcon 9 rocket. Right now, Kestrel Eye is merely a demonstrator, but the intent is to demonstrate a capable tactical-imaging satellite that can be deployed in large numbers at low cost.

Kestrel Eye will weigh about 10 kilograms (22 pounds). An operational system would have a constellation of 30 satellites, which would cost about $1 million apiece. Each satellite would have an operational lifetime of a little over one year. Allowing for some launch failures, this implies a requirement for about 30 satellite launchers per year.

Soldiers in the field will be able to request imaging by clicking on targets using a Kestrel Eye Field Portable Ground Station (laptop computer and S-Band antenna) and receive images within 10 minutes of tasking. The US Army believes this tactical imaging capability will be as revolutionary as the move from film-based photorecon satellites to digital imaging.

Compared to existing satellites, Kestrel Eye satellites will be smaller and deployed in greater numbers, offering affordable persistent presence, lower probability of detection, and lower vulnerability to antisatellite weapons. The system will be designed for graceful degradation. No single shot, launch failure, or satellite anomaly will cause a complete loss of service. Compared to UAVs, Kestrel Eye will operate at a higher altitude, providing coverage over wider areas, coverage over denied areas, and invulnerability to surface-to-air missiles.

NanoEye

Another low-cost satellite being developed by the US Army Space and Missile Defense Command is NanoEye. NanoEye will provide tactical imaging capabilities similar to Kestrel Eye but with better resolution (less than 1 meter).

NanoEye will be a larger satellite than KestrelEye, with a dry mass of 20.6 kilograms (45 pounds). The wet mass will be several times that, giving the satellite significant propulsion capability on orbit. The propellant tank forms the primary satellite structure, and the solar-array structure is designed with an aerodynamic shape to lower drag. These design features permit NanoEye to operate in a very low orbit (between 100 and 190 miles) for six months to a year.

Flying in a low orbit, NanoEye can achieve higher optical resolution while using the same 10-inch telescope as Kestrel Eye. The basic NanoEye satellite is expected to cost about $900,000 when produced in quantity. An advanced version with infrared capabilities would cost about $1,400,000.

Small Agile Tactical Spacecraft (SATS)

The third satellite being developed by the US Army Space and Missile Defense Command is the Small Agile Tactical Spacecraft, or SATS.

SATS will be somewhat larger than Kestrel Eye or NanoEye, with a mass of about 32 kilograms (70 pounds). SATS is expected to have a unit cost of $3,000,000 per satellite and an on-orbit life of 36 months.

SATS imaging resolution is expected to be similar to Kestrel Eye. What makes SATS unique is its additional operating modes. In scene mode, it will be able to capture 5-megapixel still images at four frames per second, with 50% overlap between the frames, along a preplanned path defined by latitude and longitude. In realtime video mode, it will be able to stream low-frame-rate video with human-in-the-loop control by a soldier in the field.