NRL’s Narrow Field Imager Captures First Light

WASHINGTON, D.C  –   The U.S. Naval Research Laboratory’s (NRL) Narrow Field Imager (NFI) captured its first light images on April 14, offering a preliminary glimpse of the Sun’s corona, as NASA’s Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission opened two of its four instrument doors for the first time in space.
 
On April 16, the other two Wide Field Imagers (WFI) opened their doors and also started capturing images.
 
These initial images from NFI are primarily focused on calibrating the instrument and confirming its pointing accuracy. The NFI image was filtered to show the star field surrounding the Sun, with part of the constellation Pisces highlighted. The Sun itself is hidden behind the instrument's occulter, a disk that blocks direct sunlight, appearing as a bright ring in the center.
 
Launched on March 11 into space aboard a SpaceX Falcon 9 rocket, the NFI deployed from Falcon 9 on March 12. PUNCH is a four-satellite constellation, collecting observations in low Earth orbit. It will conduct global, 3D observations of the inner heliosphere to investigate the solar corona's evolution into the solar wind.
 
The NRL-developed NFI, sponsored by NASA, is a compact, externally occulted coronagraph. The external occulter blocks direct sunlight from entering the main optical aperture, which views the corona and starfield around the Sun using a compound lens system. Polarization is resolved using a polarizing filter wheel and the image is digitized using a CCD camera with a 2K x 2K active detector area.
 
"We are thrilled to see these first light images from NFI," said NRL Coronal and Heliospheric Physics Section Head Robin Colaninno, Ph.D. "This is a major milestone for the PUNCH mission and a testament to the hard work and dedication of the entire team. We are eager to begin using NFI to study the Sun's corona in unprecedented detail and learn more about how the solar wind is generated."
 
Over the next few weeks, the PUNCH team will refine the spacecraft's pointing and calibrate the NFI to reduce stray light. Once this process is complete, the NFI will be able to capture detailed images of the Sun's corona, similar to those taken by its predecessor, the NRL-developed Compact Coronagraph (CCOR-1).
 
By capturing the evolution of coronal mass ejections (CMEs), PUNCH will provide scientists new data on their formation and propagation. This is essential for understanding and predicting these events, which can cause significant disruptions on Earth, including satellite damage, radio communication blackouts, and power grid failures. Enhanced predictions will also safeguard robotic explorers operating in interplanetary space.
 
PUNCH is currently in a 90-day commissioning phase, during which time the four spacecraft will be maneuvered into their final orbital configuration and the instruments will be calibrated. Following commissioning, PUNCH will begin its two-year primary science mission.
 
 
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, 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.
 
For more information, contact NRL Corporate Communications at (202) 480-3746 or nrlpao@nrl.navy.mil. Please reference package number at top of press release.