The U.S. Naval Research Laboratory oversaw the delivery and preparation for launch of its twin 6U CubeSat satellites on Oct. 15 at Spaceport Cornwall in Newquay in the United Kingdom (U.K.).
The Coordinated Ionospheric Reconstruction CubeSat Experiment (CIRCE) satellites are scheduled for manifest aboard Virgin Orbit, which is targeting their first satellite launch later this year. Virgin Orbit’s Launcher One rocket takes off horizontally, carried aloft by a modified Boeing 747 jet, pioneering new lower cost research opportunities for space access.
CIRCE is a joint NRL-United Kingdom Defence Science and Technology Laboratory (Dstl) experiment designed to measure 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 orbit plane.
“We are excited and thankful for the international partnership that we have on the CIRCE program. It’s been a wonderful experience working with the folks at Dstl and their university and industry partners in the U.K.,” said Andrew Nicholas, CIRCE’s principal investigator. “We are looking forward to a successful launch and are excited to continue work with our U.K. partners, to start getting real observational data downlinked, and to start the research these observations will enable."
Funded by the Office of Naval Research’s Space Weather S&T program with the launch supported by the DoD Space Test Program, the twin satellites push the boundaries of the CubeSat platform technology, challenging the size, weight and power constraints of the platform as well as integration and complex concepts of operations.
“The CIRCE spacecraft are the size of a cereal box and we've managed to sandwich five sensors in each of them,” Nicholas said. “So, they are very compact and heavily laden with technology that is really tightly integrated in there.”
NRL developed the Triple Tiny Ionospheric Photometer (Tri-TIP) to measure nighttime O+
135.6nm airglow emissions in the atmosphere. Each CIRCE CubeSat has two Tri-TIPs onboard, configured to look along coordinated lines of sight to perform ionospheric tomography in the orbital plane.
The U.K. contribution to CIRCE is the In situ and Remote Ionospheric Sensing (IRIS) suite, which comprises three highly miniaturized payloads and complements NRL sensors. One IRIS suite will be flown on each satellite, and incorporates an ion/neutral mass spectrometer, a tri-band global positioning system receiver for ionospheric remote sensing, and a radiation environment monitor.
“A lot of this program has been done during the pandemic where we haven't had the typical, in-person business that usually happens with programs like this,” Nicholas said. “It was really nice to be side–by-side at Spaceport Cornwall, preparing for launch with the Dstl folks that we've been working with for so many years.”
During the life of its mission, CIRCE will help researchers better understand how the ionosphere is changing day-to-day, hour-to-hour and even minute-to-minute, which is important to the Navy, especially for over-the-horizon communications and radar.
“In addition, if you really want to understand the ionosphere tomorrow, you have to understand the ionosphere and thermosphere today, so it is great that we have the INMS from the U.K. to measure the neutral composition as well.” Nicholas said.
The U.K. instrument suite showcases academic collaboration, with payloads provided by University College London's Mullard Space Science Laboratory, University of Bath, and Surrey Satellite Technology Limited (SSTL), drawing on expertise from University of Surrey.
“We are delighted to be working with NRL on the CIRCE mission, and proud of the valuable contribution made by our U.K. payload providers,” said Gemma Attrill, Ph.D., Dstl’s CIRCE lead. “The data returned by CIRCE will provide unparalleled temporal and spatial detail regarding the dynamic behavior of the ionosphere, allowing us to develop our understanding of system impacts relevant to both defense and the civil sector.”
This historic mission will be the first orbital launch from the U.K., the first international launch for Virgin Orbit, and the first commercial launch from Western Europe. CIRCE is scheduled to launch from Spaceport Cornwall located at Newquay Airport in Cornwall, England, later in 2022.
About the U.S. Naval Research Laboratory
NRL is a scientific and engineering command dedicated to research that drives innovative advances for the U.S. Navy and Marine Corps from the seafloor to space and in the information domain. NRL is located in Washington, D.C. with major field sites in Stennis Space Center, Mississippi; Key West, Florida; Monterey, California, and employs approximately 3,000 civilian scientists, engineers and support personnel.
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Dstl – The science inside U.K. defence and security
The Defence Science and Technology Laboratory (Dstl
) delivers high-impact science and technology (S&T) for the U.K.'s defence, security and prosperity. Dstl is an Executive Agency of the MOD with around 4,500 staff working across three sites; Porton Down, near Salisbury, Portsdown West, near Portsmouth, and Alverstoke, near Gosport.