Astronomy and Space News - Astro Watch: Polar Scout Program: Space-based Sensors

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Friday, March 1, 2019

Polar Scout Program: Space-based Sensors

Credit: Department of Homeland Security Science and Technology Directorate

The Department of Homeland Security (DHS) Science and Technology Directorate (S&T) launched two miniature cube-shaped satellites (CubeSats) into space on December 3, 2018, via the SpaceX Falcon 9 rocket. Named Yukon and Kodiak, the CubeSats, which are approximately the size of a shoebox, neatly squeezed into a 20-ft. payload stack with 62 other small satellites (SmallSats), and began orbiting our planet.

DHS S&T’s Polar Scout program began a little more than two years ago as an effort to identify potential technology bridges for the current aging space-based search and rescue S(AR) infrastructure, Cosmicheskaya Systema Poiska Aariynyich Sudov SAR Satellite-Aided Tracking (COSPAS-SARSAT), with its next-generation successor, the Medium-Earth Orbit SAR (MEOSAR) system.

Mariners have relied on COSPAS-SARSAT for SAR since 1982. The system has aided more than 41,000 rescue operations around the world. With MEOSAR expected to complete no earlier than the mid-2020’s, and COSPAS-SARSAT’s increasing risk of outage, S&T and Coast Guard have sought small, cost-effective, easily-deployable satellites to help rapidly bridge these space-based architectures should the need arise.

“In space, things don’t last,” said S&T Border Immigration and Maritime Director Jon McEntee. “You can’t wait for them to fail. You have to have a solution in the cargo pocket, so when it fails you can implement it quickly.”

Smaller satellites allow much easier transport, and they can launch in bulk at significantly lower cost. Yukon and Kodiak might be mistaken for shoeboxes, while satellites on the COSPAS-SARSAT and MEOSAR systems are more comparable to a small cargo van. The time, funds and materials required to develop the CubeSats are significantly less due to the size of the craft and by using commercial-off-the-shelf components instead of designing every spacecraft component from scratch.

“Launching an ordinary satellite with a specific, targeted mission could take up to a decade and cost billions of dollars, but all we wanted was to get our smaller CubeSats into orbit,” said McEntee. “This significantly reduced the development cycle, as well as the cost.”

The Polar Scout project targets the Arctic for its exponentially increasing volume of cargo in transit, making it a major trade thoroughfare of increasing significance. Yukon and Kodiak are equipped with sensors to detect emergency distress beacons in the area, providing insight as to how these new CubeSat capabilities can benefit other remote regions around the world. They are programmed to detect a distress signal, determine its location, and then push the information to the nearest rescue hub, where it can be fused with other data on local conditions to aid in planning.

Though it sounds like a tall order for such compact technologies, the powerful sensor systems behind Yukon and Kodiak will aim to demonstrate potential support for quick and efficient response in maritime emergencies.

Much of the cost-effectiveness of the Polar Scout project is also due to “ridesharing” arrangements facilitated by Spaceflight Industries, which allowed 15 SmallSats and 49 CubeSats, from 34 organizations representing 17 different countries, to be packaged onto a shared launch booster before being deployed into sun-synchronous orbit on their own respective missions. To date, this is the largest number of payloads (64 spacecraft) to be launched from American soil.

Another record broken was by the SpaceX Falcon 9 rocket B1046, becoming the first Falcon 9 to be reused for a third mission. Rockets of the past are not known for their reuse, and are typically expected to fall into the ocean and not be recovered.

Similar to prior SpaceX missions, a crowd of spectators cheered as the Falcon 9 prepared to re-enter Earth’s atmosphere which they viewed on a video feed. They watched the rocket booster slow down with the help of a “re-entry burn,” remaining intact until the final “landing burn.” Once the Falcon 9 touched down on its designated drone ship anchored off the California coast, 50 km from the initial launch pad at Vandenberg Air Force base, the crowd went wild.

Meanwhile, in space, payloads were released over a four to six hour period. The S&T Polar Scout team eagerly awaited contact with their satellites. It was not until around 10:40 p.m., nearly seven hours after launch, that they made contact with Kodiak for about 35 seconds, followed later into the night by a six minutes contact with Yukon.

The Falcon 9 took under seven minutes to fly to space and return back to earth, but for the S&T Polar Scout program, this was two-and-a-half years in the making. The team partnered with Coast Guard and industry to design and build the CubeSats and plan the mission.

“Undoubtedly, the results and knowledge gained by the Polar Scout Satellite Project will lead to force-multiplying solutions for the Department,” said Bryan, “which is a big priority in this age of complex threat cycles.”

The CubeSats will continue to monitor the Arctic’s growing cargo traffic. Thousands of ships will be better prepared for any danger that might arise along those treacherous waters.

The Polar Scout team will now begin characterization of the spacecraft payload performance. These efforts will culminate in a capstone demonstration in July 2019 using exercise SAR beacons deployed on a research vessel near the Arctic Circle.

Credit: dhs.gov

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