An image of a “halo” type CME surrounding the LASCO C2 occulting disk and a prominence eruption to the South of the Sun.  The white circle in the center is the size and location of the Sun, which is obscured by the occulting disk.  The bright linear feather to the lower left is a coronal streamer.  CMEs were observed to occur up to 6 times per day during the maximum of the solar cycle.  The halo is a CME headed toward Earth.
An image of a “halo” type CME surrounding the LASCO C2 occulting disk and a prominence eruption to the South of the Sun. The white circle in the center is the size and location of the Sun, which is obscured by the occulting disk. The bright linear feather to the lower left is a coronal streamer. CMEs were observed to occur up to 6 times per day during the maximum of the solar cycle. The halo is a CME headed toward Earth.

Objective
Advance the understanding of the structure of the Sun’s corona, the origin of Coronal Mass Ejections (CMEs), and the dynamic coupling between CMEs and Earth.
CMEs, the most energetic phenomena in the solar system, are major drivers of geomagnetic space weather storms that adversely affect ISR, precision engagement, missile detection and intercept, Comms on the Move, spacecraft anomaly assessment, orbital tracking, polar flight activities, and the power grid. CMEs were discovered by NRL, with an NRL-built solar coronagraph, in 1971.

Approach
LASCO: the coronagraphic instrument on the ESA/NASA Solar and Heliospheric Observatory (SOHO) Mission

  • NRL is LASCO PI institution for NASA; consortium of US and international partners
  • NRL led development of the 3 telescopes of the suite
  • Builds on successful NRL P78-1 (SOLWIND) coronagraph on DoD STP P78-1 Mission launched in 1979

SOHO Mission: December 1995 Launch - present

  • The European Space Agency (ESA) was the prime in developing the SOHO payload, which was launched and operated by NASA into a halo orbit about the L1 Lagrangian Point that is 1 million miles toward the Sun
  • The first solar mission to continuously view the Sun

Deliverable/Value/Accomplishment

  • NRL delivered the LASCO instrument suite to NASA; this included NRL in-house conception and optical design of the LASCO C3 coronagraph, the development of the CCD detectors and cameras for all the telescopes, the Fabry-Perot subsystem, the electronics control and software, leading the Max Planck Institute in the LASCO C1 coronagraph, and leading Laboratoire de Marseille in completion of the LASCO C2 coronagraph
  • NRL currently delivering to NASA the LASCO Mission operations and data analysis
  • LASCO results demonstrated the importance of CMEs in determining space weather impacts at Earth

Left: Using a special type of telescope (“coronagraph”) that blocks the blinding direct sunlight, we obtain detailed images of Coronal Mass Ejections (CMEs)—explosive ejections of solar plasma into the heliosphere. Solar coronal images such as these are taken by the NRL coronagraphs on the NASA SOHO and NASA STEREO spacecraft and relayed to Earth in near-real time. These solar storms can reach Earth within 24 to 72 hours, so immediate detection and tracking is critical to evaluate the impact on space based assets and prepare if necessary. Data from LASCO is useful towards validating HPC computer codes such as HiFi that simulate solar coronal dynamics including solar flares, coronal loops, and CMEs.