The Coordinated Ionospheric Reconstruction CubeSat Experiment (CIRCE) satellites are scheduled to manifest aboard Virgin Orbit, which is targeting its first satellite launch later this year. Virgin Orbit’s Launcher One rocket takes off horizontally and is carried aloft by a modified Boeing 747 jet, creating new lower-cost research opportunities to access space.
CIRCE is a joint experiment by the NRL and the United Kingdom Defense Science and Technology Laboratory (Dstl) designed to image the Earth’s ionosphere and particle radiation environment from a circular orbit at 555 km (344 miles) altitude in a lead/trail Formation 300-500 km (186-310 miles) apart in the same orbital plane.
“We are excited and grateful for the international partnership we have through the CIRCE program. It has been a wonderful experience working with the people at Dstl and their UK academic and industry partners,” said Andrew Nicholas, CIRCE Principal Investigator. “We look forward to a successful start and look forward to continuing the work with our UK partners to begin downlinking real observational data and embarking on the research that will enable these observations.”
Funded by the Office of Naval Research’s Space Weather S&T program and supported by the DoD Space Test Program, the twin satellites push the boundaries of CubeSat platform technology, challenging the platform’s size, weight and power limitations and integrating complex operational concepts .
“The CIRCE probe is the size of a cereal box, and we managed to fit five sensors into each of them,” Nicholas said. “So they’re very compact and heavily loaded with technology that’s really tightly integrated with it.”
The NRL developed the Triple Tiny Ionospheric Photometer (Tri-TIP) to measure O at night+ 135.6 nm airglow emissions in the atmosphere. Each CIRCE CubeSat carries two Tri-TIPs configured to look along coordinated lines of sight to perform in-orbital plane ionospheric tomography.
The UK contribution to CIRCE is the In situ and Remote Ionospheric Sensing (IRIS) suite, comprising three highly miniaturized payloads and complementing NRL sensors. An IRIS suite containing an ion/neutral mass spectrometer, a tri-band receiver for a global positioning system for ionospheric remote sensing and a radiation environment monitor will be flown on each satellite.
“A lot of this program was done during the pandemic, where we didn’t have the typical face-to-face business that usually comes with programs like this,” Nicholas said. “It was really nice to be side by side at Spaceport Cornwall preparing for launch with the Dstl guys we have been working with for so many years.”
During its mission, CIRCE will help researchers better understand how the ionosphere changes from day to day, hour to hour and even minute to minute, which is important for the Navy, especially for over-the-horizon communications and radar .
“If you really want to understand the ionosphere tomorrow, you also need to understand the ionosphere and the thermosphere today. So it’s great that we have the INMS from the UK to also measure the neutral composition.” Nikolaus said.
The UK instrument suite will demonstrate academic collaboration with payloads provided by University College London’s Mullard Space Science Laboratory, the University of Bath and Surrey Satellite Technology Limited (SSTL), drawing on the expertise of the University of Surrey.
“We are delighted to be working with NRL on the CIRCE mission and proud of the valuable contribution from our UK payload providers,” said Gemma Attrill, Ph.D., CIRCE Director of Dstl. “The data returned by CIRCE will provide unprecedented temporal and spatial detail on the dynamic behavior of the ionosphere, allowing us to develop our understanding of system impacts relevant to both the defense and civilian sectors.”
This historic mission will be the first orbital launch from the UK, the first international launch for Virgin Orbit and the first commercial launch from Western Europe. CIRCE is scheduled to launch from Spaceport Cornwall at Newquay Airport in Cornwall, England later in 2022.
About the US Naval Research Laboratory
NRL is a scientific and engineering command dedicated to research that drives innovative advances for the US Navy and Marine Corps from the seabed to space and information. NRL is located in Washington, DC with key field locations at Stennis Space Center, Mississippi; Key West, Florida; Monterey, California, and employs approximately 3,000 civilian scientists, engineers and support staff.
For more information, contact NRL Corporate Communications at (202) 480-3746 or [email protected]
Dstl – The science within British defense and security
The Defense Science and Technology Laboratory (Dstl) delivers high-impact science and technology (S&T) for the defence, security and prosperity of the UK. Dstl is an executive agency of the MOD with around 4,500 employees at three locations; Porton Down near Salisbury, Portsdown West near Portsmouth and Alverstoke near Gosport.
E-mail: [email protected]
Social media: @dstlmod