16 Feb, Signal Online: One Tiny Satellite, One Big Change for Space

One Tiny Satellite, One Big Change for Space
The first satellite built by the U.S. Army in more than five decades launched last week, ushering in a new phase of space use for the military branch. Officials with the program intend experiments with the demonstration technology to lead to a number of identical satellites that could be deployed together in low Earth orbit to simulate tactical communications capabilities and to evaluate nanosatellite performance.

U.S. Army Space and Missile Defense Command/Army Forces Strategic Command (SMDC/ARSTRAT) has the lead for the Space and Missile Defense Command-Operational Nanosatellite Effect (SMDC-ONE), which launched as a secondary payload on a Falcon 9 two-stage booster; the primary payload was a Dragon spacecraft built by Space Exploration Technologies Corporation. Technology advancements made the recent Army nanosatellite possible. According to John London, SMDC/ARSTRAT nanosatellite technology manager, very small satellites—1- to10-kilogram nanosatellites and 10- to 100-kilogram microsatellites—can be developed and demonstrated relatively inexpensively. The SMDC-ONE weighs 4 kilograms.

Leaders have identified many applications for this satellite class as potentially relevant to the dismounted ground component warfighter. For example, the Army expects the small satellites to provide over-the-horizon communications and imaging to troops currently restricted from such services by location or time.

London says the demonstration has progressed well so far. Four to five satellite passes occur daily over the SMDC ground stations in Huntsville, Alabama, and Colorado Springs, Colorado. Both stations have made numerous contacts with the SMDC-ONE. During these information exchanges, the ground stations acquire the nanosatellite's state-of-health data as well as detailed buffered on-board sensor data.

Approximately 45 minutes after its initial launch, the SMDC-ONE deployed from the Falcon 9 trunk unit and was maneuvered into low Earth orbit. After lying dormant for 30 minutes, it deployed its receiver antennas. Despite its tumbling mode, the nanosatellite contacted the ground station at SMDC/ARSTRAT on Redstone Arsenal, Alabama.

Now that initial actions in the deployment have proven successful, the next step is to experiment with a higher data rate to transfer more data faster. "Following transfer of all buffered data, we hope to transfer files including simulated unattended ground sensor [UGS] data between the ground stations via SMDC-ONE," London explains. "Upon successful completion of those transfers, we plan to incorporate an actual UGS set with a gateway which sends real-time UGS data to the satellite. We also will use a UGS ground station to receive and display that real-time UGS data."

In addition, the command could perform additional experimentation during the nanosatellite's approximately 30-day deployment. After that time, the satellite should drop out of orbit and, because of its small size and weight, burn up during re-entry into the atmosphere.

The SMDC expects that the Army will continue to develop more small satellite systems in the future. Currently, the command has several imaging and communications nanosatellites and microsatellites under development for technology demonstrations. The nanosatellite now in orbit is one of eight, 4-kilogram satellites that the SMDC took delivery of in April 2009. Ducommun Miltec, Pericle Communications Company and Clyde Space Limited produced the equipment at the end of a 1-year contract. Of the seven remaining flight-ready SMDC-ONE nanosatellites, two are scheduled to fly in late 2011 with another slated on a flight in early 2012.