The U.S. Coast Guard (USCG) is preparing to launch two small satellites, in 2018, that are capable of detecting transmissions from emergency position indicating radio beacons (EPIRB), which are carried on board vessels to broadcast their position if in distress.
These satellites, or “cubesats,” will provide the Cost Guard with the opportunity to test the effectiveness of satellite communications (SATCOM) in supporting Arctic search and rescue (SAR) missions.
The Coast Guard will deploy the cubesats in cooperation with the Department of Homeland Security (DHS) Science and Technology Directorate’s Polar Scout program, the Air Force Operationally Responsive Space (ORS) Office, and the National Oceanographic and Atmospheric Administration (NOAA).
NOAA operates a group of satellites to detect EPIRB transmissions in the Arctic but is currently in the process of replacing that system. DHS and the Coast Guard are using the opportunity to see if cubesats could help augment that system while NOAA deploys the new satellites.
The satellites consist of 10-centimeter cubes that are designed to carry small payloads and can be stacked to make a custom-sized vehicle. Because satellite electronics have increased in capability while decreasing in size, equipment that used to require a larger vehicle can be housed in a cubesat at a much lower cost. Normally, a large number of cubesats are launched at once, and the cost is split among the vehicles’ owners to further save money. Sometimes, a mission launching a large satellite will have extra space to accommodate a cubesat at significantly lower cost as well.
Each Polar Scout cubesat will pass over the North Pole every 90 to 100 minutes and will be able to detect EPIRB signals from vessels in the Arctic for about 12 minutes on each orbit. The cubesats will circle the earth 15 or 16 times a day, providing more than three hours of search and rescue coverage in the Arctic daily.
Millennium Engineering and Integration is preparing the satellites for launch in mid-2018 with the help of Space Dynamics Laboratory and Raytheon.
The Coast Guard Research and Development Center (RDC) built a ground control station in Fairbanks, Alaska, and plans to build an additional station at the U.S. Coast Guard Academy in New London, Connecticut. The ground control stations will allow command and control of the cubesats and their payloads while providing a downlink for data.
Involving the cadets and faculty of the academy is very important,” noted Lt. Cmdr. Samuel Nassar, RDC assistant branch chief for command, control, communications, computers, intelligence, surveillance and reconnaissance. In addition to helping with the ground control station, academy students have also helped design an attitude control system that the cubesats will use to orient themselves in space. “The Coast Guard Academy can join the adventure and challenges of space while helping the Coast Guard realize the potential benefit of cubesats,” Nassar said.
To better understand how to build, launch and operate cubesats, the RDC is working with the Naval Postgraduate School, which is conducting extensive research on small satellite systems. For example, “we’re using their standard ground station design as a template and tailoring that for our own plans,” Nassar said. “We’re going through their equipment list piece by piece to see what will work for us and what we can modify to withstand winters in New England and Alaska.”
Once the ground stations are installed and the satellites are in orbit, the RDC will run a series of tests to evaluate their ability to detect EPIRB transmissions. The test team will measure the satellites’ ability to detect and process the EPIRB signal, identify its point of origin and send the information to the nearest ground station. The team is putting together a number of scenarios to test the system’s capabilities.
The RDC will compare the performance data with the Coast Guard’s current search and rescue systems to evaluate how useful satellite technology might be for the service. “Our final product will be a cubesat roadmap, where we will make recommendations for how the Coast Guard can use the technology and explain the operations, maintenance and logistical issues involved,” Nassar said.
While the first two satellites will support the search and rescue mission, the ultimate goal of the project is to develop a long-term plan for Coast Guard satellite technology to potentially support a wider mission set. The RDC is meeting with representatives from throughout the Coast Guard to better understand the capabilities they need and researching cubesat technologies to see what the market has to offer. “We’re asking ourselves, ‘What utility do these cubesats have, and how can they enhance Coast Guard mission effectiveness?’” Nassar said. He expects to finish a report in mid-2018 that will include an assessment that will highlight cubesat payloads addressing each of the mission needs expressed by the stakeholders.
U.S. Coast Guard (USCG)