PUNCH News

Commissioning of the PUNCH instruments is ongoing. As part of that activity, we ran the first full-orbit NFI (Narrow Field Imager) science sequence on Sunday, April 27. NFI captured several images of the Moon passing by the Sun in the sky, as seen in this unfiltered “Level 0” image in the standard PUNCH pseudocolor palette. The new Moon appears full, because it is illuminated by Earthshine from the full Earth (as seen from the lunar surface). This image is useful to demonstrate that the Moon does not directly interfere with NFI’s primary science, as it is not bright enough to impact the existing pattern of glinting stray light.

There've been lots of stories about this week’s triple-conjunction smiley moon in the media. We happened to catch the conjunction during PUNCH commissioning, along with two other planets besides!

This beautiful, ghostly polarimetric rainbow reveals the direction and degree of polarization of the ghostly zodiacal light, in a preliminary data product from the WFI-2 spacecraft. On 18-April, WFI-2 executed its first polarimetric triplet imaging, collecting images through all three of its polarizers in succession. The polarimetric triplet image, expressed as RGB color channels, reveals the direction (via hue) and degree (via saturation) of polarization everywhere in the field of view all at once. WFI looks to one side of the Sun (marked with a star glyph). This image, made with Level 0 (uncalibrated) data direct from the WFI-2 camera, is consistent with existing results (Leinert et al. 1998) on the direction and degree of polarization of the zodiacal light. Stars appear white because they are mostly unpolarized compared to the 7% polarization of the zodiacal light. PUNCH uses a novel mathematical formalism (“MZP”, DeForest et al. 2022) to manipulate and background-subtract the polarimetric values from each of its four cameras. Chromatic treatment of coronal polarization was demonstrated at the 2023 total solar eclipse (Patel et al. 2023), highlighting the long-term synergy between ground- and space-based observations of the corona.

PUNCH opened the protective doors of its first two instruments, the Narrow Field Imager (NFI) and one of its three Wide Field Imagers (WFI-2) on 14-April. First-light images from WFI and NFI reveal that they are in focus, functioning nominally, and able to collect the deep field images needed for PUNCH science. The first image from WFI-2 is a spectacular view of approximately 40° of sky, including zodiacal light, several constellations, and various other astronomical objects. The first image from NFI reveals in-focus performance and resolution of the faint starfield close to the Sun. These two images are composited here to show how the instruments’ data will fit together once commissioning is finished.

During the week of 2025 April 7, PUNCH collected calibration data from the instruments – our last chance to take advantage of closed doors, before they open. Even these “dark frames”, taken with the doors closed, are interesting to look at. These images are “Level 0” (unprocessed) data products generated by the Science Operations Center (SOC), with full flight metadata attached. The cameras are working properly, with low noise levels. The images are brighter on the right because PUNCH uses dual readout detectors, with separate digitizers for the two halves of the images; they have slightly different zero points, an effect we remove at “Level 1” and higher. There is a very small amount of light visible in the upper left, which we believe is stray light scattered by the closed instrument door itself. Over the South Atlantic Anomaly in Earth’s magnetic field, an area of enhanced cosmic ray flux, we see significant particle impacts on the detector. The rate of impacts agrees with calculations performed over six years ago, during the mission’s Phase A concept study.

PUNCH will maintain the constellation with a novel, water-powered, shot-glass-sized rocket engine attached to each spacecraft. Each spacecraft carries about a British pint (600 g) of water in a small canister. To run the engine, PUNCH electrolyzes about 1/10 tsp (0.5 mL) of water, building up small stores of hydrogen and oxygen at about 200 psi. Then it burns the fuel in just a few seconds. Each cycle delivers a “kick” of about one inch/sec (2 cm/sec): just enough to correct for small orbital shifts and keep the constellation stable. PUNCH is the first space mission to use this type of engine, which carries safe propellant but is complex to operate.

On March 29, 2025, many folks went outside to catch a glimpse of the partially eclipsed Sun, as the Earth carried them through the Moon’s shadow. PUNCH, orbiting high overhead, also passed through the shadow. Orbital velocities are high, so each spacecraft passed through the darkest part of the partial eclipse (the Moon’s penumbra) at a slightly different time, about eight minutes apart. Even though the instruments’ doors are still closed for commissioning, PUNCH registered the eclipse. During the brief interval of darkest shadow, the solar arrays couldn’t keep up with on-board power usage and each spacecraft briefly switched to battery power, using slightly less than 1% of its battery capacity to keep operating normally through the brief gap.

While making its unique observations, PUNCH will augment a fleet of international spacecraft observing the Sun and solar system, including NASA's Parker Solar Probe and STEREO missions, the European Space Agency's (ESA) Solar Orbiter and Jupiter Icy Moon Explorer (JUICE) missions, and the ESA/Japanese Space Agency's (JAXA) BepiColombo mission, all of which afford unique joint science opportunities. The longitudinal trajectories of these missions are shown along with the orbits of Mercury, Venus, and Mars relative to an Earth-stationary frame of reference. On this scale, PUNCH is always located at Earth. Trajectories were generated by the Austrian Space Weather Office / GeoSphere Austria (Möstl/Davies/Weiler) – further details and additional movies available.

The Science Operations Center (SOC) for PUNCH received the first data packets from the four spacecraft. The data downlinks included both engineering and test image packets. The SOC successfully decompressed the packets and reconstructed the expected striped test pattern image. Using a test pattern allows the SOC to verify that data is properly transmitted and formed into images. The spacecraft sends engineering packets down alongside the images that indicate spacecraft parameters such as orientation and position. The SOC’s automated processing routines ingested this data and confirmed the spacecraft are pointing toward the Sun as expected. A good estimate of the spacecraft pointing is critical for the SOC’s data processing; it would not be possible to construct the seamless mosaics required to answer PUNCH’s science questions without it. The next step is to collect and process calibration images without light on the sensor, commonly called dark images. More information about the SOC processing can be found on GitHub.

The heliophysics community came out to celebrate the impending launch by presenting and discussing the latest developments in PUNCH science, including the origin and evolution of the ambient solar wind and turbulence within it, and the physics, tracking and predictability of transient events such as coronal mass ejections, corotating interaction regions, and shocks. Beyond these primary PUNCH science topics, the workshop provided a forum for exploring PUNCH connections to the magnetosphere and aurora, zodiacal dust, and sun-grazing comets and other solar system objects. PUNCH's readiness to engage scientists around the world was demonstrated through presentations and a hands-on tutorial on data access, and its synergies with a range of community missions and models explored through panel discussions. The meeting took place February 25th and 26th, 2025 at Cal Poly in San Luis Obispo, CA, and benefited from the support and involvement of Cal Poly students and faculty. It was further enriched by PUNCH outreach events before and during the meeting.

The four PUNCH spacecraft are separating nominally and performing well sixty hours post-launch, as they prepare for their groundbreaking science. All four have demonstrated high speed S-band communications, entered fine pointing mode, and are in good health and ready to transition to “normal operations”. Commissioning will continue, but will be staffed single shift only (rather than 24-hours) and use nominal pass priority with the ground data network provider. Ground tracks from the spacecraft themselves (using on board GPS) agree with NORAD tracks and are consistent with both the mission design and deployment videos from launch day. The PUNCH Observatories carry orbital-trim thrusters; a midcourse correction is planned for later in March, to ensure identical orbital planes and even spacing as the PUNCH WFI Observatories drift to 120° relative spacing in mean anomaly.

In the predawn hours of March 4, the PUNCH spacecraft – now encapsulated in a 43-foot-tall Falcon 9 fairing – were transported across Vandenberg Space Force Base to the SpaceX hangar and pad failiities at Space Launch Center 4, on the south side of the base. The moment was captured by a passenger on the morning Amtrak train from San Luis Obispo to Los Angeles, visible through the tinted window of a passenger car as the train paused at the Surf Beach station west of VSFB. Photo credit: Catherine Bandy.

The four PUNCH spacecraft are now at Vandenberg Space Force Base (VSFB) in California, undergoing final test and integration to the “launch stack” with the SPHEREx spacecraft. All five spacecraft are planned to launch on a Falcon 9 rocket from Vandenberg Space Force Base no earlier than February 27, 2025.

On 15 January, PUNCH passed a combined pre-shipment & operational readiness review, clearing us to ship the four spacecraft and necessary ground equipment from SwRI’s headquarters in San Antonio, TX to to Vandenberg Space Force Base. There they will undergo final integration with the launch carrier, the SPHEREx spacecraft, and a Falcon 9 rocket. The PUNCH team's operational plans, tools, training, and personnel were found to be sufficient to operate and commission the constellation from the Mission Operations Center at SwRI’s offices in Boulder, Colorado. Congratulations to everyone on a hard-fought and hard-won I&T campaign!

We invite the community to the sixth PUNCH (Polarimeter to UNify the Corona and Heliosphere) Science Meeting on February 25th and 26th, 2025 at Cal Poly in San Luis Obispo, CA. Major science topics include the origin and evolution of the ambient solar wind and turbulence within it and the physics, tracking, and predictability of transient events including CMEs, CIRs, and shocks.

We invited the community to the fifth PUNCH (Polarimeter to UNify the Corona and Heliosphere) Science Meeting (June 20-21, 2024) in Boulder, Colorado. Major science topics included the origin and evolution of the ambient solar wind and turbulence within it and the physics, tracking, and predictability of transient events including CMEs, CIRs, and shocks.

The WFI-1 Observatory is now fully integrated! It is the PUNCH fleet leader through environmental testing, which is scheduled to begin this week. On Friday 26-April, the WFI-1 Observatory collected its first science image through the WFI instrument: a team selfie in the Building 299 clean room where PUNCH I&T is proceeding. The image includes the WFI baffle “horizon” (at left, as the Observatory was on its side in the mounting cage), the massive doors into the high bay, one of the other Observatories in the background, and seven team members who were conducting the test. From left to right: Kelly Smith, Jim Foster, Ronnie Killough, Glenn Laurent, Emily Fisher, Brandon Perez, and Tonya Brody, all in cleanroom garb, with another PUNCH spacecraft visible just over Tonya’s shoulder.

The PUNCH PI Craig DeForest and PUNCH Outreach Lead Cherilynn Morrow presented, live at the Cotton Bowl Stadium, the mission and its relevance to solar eclipse viewing and sunwatching across time and space.

After six years in use the PUNCH logo got a makeover in April. The newer rendering is similar to the old, but with some important fixes. The central swoops now reproduce better in more different media. The diffraction spikes on the stars work correctly (all facing the same direction). Additionally, the new render is a scalable SVG file, allowing reproduction on media of all sizes from pop-sockets to Falcon 9 stages.

The PUNCH instrument, spacecraft, and integration teams presented the status of the mission to NASA and the PUNCH Standing Review Board (SRB) on the 27th and 28th of February, in the first SRB meeting since Critical Design Review in 2022. The PUNCH instruments are being integrated to the spacecraft now, in preparation for flight. The Pre-Environmental Review (PER) ensures that all is well before the completed Observatories undergo final testing for flight: vibration, thermal performance in vacuum, etc.

The Southwest Research Institute WFI team have delivered their first flight instrument (WFI-1) to the Integration and Test team for integration onto a flight PUNCH Observatory! WFI is a wide-field heliospheric imager, similar to an externally occulted coronagraph with a linear geometry. It will view a 40° wide field-of-view extending from 4.5° to approximately 45° from the Sun. WFI-1 will be integrated to a PUNCH spacecraft later this winter, in preparation for observatory environmental testing through the spring of 2024. PUNCH is scheduled to launch by early April of 2025.

The topic of this telecon was in-situ/remote-sensing/modeling synergies. Click to go to meeting page with links to presentations.

The Naval Research Laboratory team has completed integration and test of the PUNCH Narrow Field Imager (NFI), and delivered the instrument to SwRI for integration into the PUNCH Observatories! NFI is an externally occulted coronagraph based on NRL’s CCOR design. it covers the central part of the PUNCH field of view, from approximately 5 to 32 solar radii from the Sun itself. NFI will be the first primary instrument integrated to a PUNCH Observatory, in late calendar year 2023, and will fly with the rest of PUNCH when the mission launches (est. April 2025).

The Colorado Space Grant Consortium successfully delivered its student collaboration instrument, the STudent Energetic Activity Monitor (STEAM), for integration into the PUNCH OBservatories! STEAM is a soft X-ray spectrometer build around a solid state detector, with a small microprocessor to interface with the spacecraft. STEAM will view the Sun as a star, and probe the energetics of solar falres and coronal heating throughout the PUNCH mission. STEAM will be integrated onto the Narrow Field imager (NFI) Observatory and fly with NFI when the mission launches (est. April 2025).

The fourth PUNCH (Polarimeter to UNify the Corona and Heliosphere) Science Meeting was successfully held in the summer of 2023 in Boulder, CO. We solicited abstracts for poster/oral presentations from the community on subjects related to this topic. Click to go to meeting page with links to presentations and posters.

The topic of this telecon was synergies with other missions/projects. Click to go to meeting page with links to presentations.

The team of STEM professionals carrying out the outreach program for the PUNCH mission convened its first, in-person Annual Retreat of ~30 core team members, collaborators, advisors, and other partners during the last week of September 2022. The COVID pandemic had prevented the PUNCH outreach team from meeting in person last year after NASA approved our mission-embedded outreach proposal in January 2021. This year’s gathering joined diverse collaborators who had been working together remotely on PUNCH Outreach since the Spring of 2020.

The third PUNCH (Polarimeter to UNify the Corona and Heliosphere) Science Meeting was on August 12th, 2022. Attendance was high and the attendees were highly engaged. Major science topics included the origin and evolution of the ambient solar wind and turbulence within it, mission outreach, and the physics, tracking, and predictability of transient events including CMEs, CIRs, and shocks.

PUNCH has passed its Critical Design Review, a major milestone in the course of the mission. The three-day design review was a hybrid meeting, held in person at SwRI headquarters in San Antonio, TX, March 1-3. The team presented current mission design, and fabrication, integration, and test plans, to representatives from NASA and from the mission’s independent Standing Review Board. This was the first mission milestone meeting to be held in-person, since the initial Phase B kickoff meeting held in 2019 immediately after selection.

PUNCH science and outreach development continues, with presentations at the Fall 2021 AGU. PDFs of posters are available on the PUNCH publications / presentation page, and videos of talks on the PUNCH Youtube Playlist.

The PUNCH 2 Science Meeting took place August 9-11, 2021. If you missed the talks, or just want to see them again, they are available via a Youtube Playlist, and also through the workshop agenda with time-stamped access to specific talks.

If you are a research scientist, educator, science writer, or other communicator of Sun-related science, heliophysics, or space weather to non-specialist audiences, please complete this survey. The survey results will have a powerful influence on the development of PUNCH Outreach products, PUNCH News Items, and any other efforts in the communication of our science. Your responses will validate our selection of an appropriate set of misunderstandings to include in a product that will provide proven strategies for addressing each misunderstanding.

NASA has funded a five-year outreach program in association with the Polarimeter to UNify the Corona and Heliosphere (PUNCH), a solar mission led by Southwest Research Institute (SwRI). The PUNCH Outreach Program, also led by SwRI, is collaborating with five planetariums and science centers in four states, plus other multicultural partners in the southwestern United States.

PUNCH has passed its Key Decision Point C, and has been confirmed as a “GO” for development and flight. The decision was made in a hybrid in-person & remote meeting at NASA Headquarters between project management, the Explorers Program, the Mission Directorate, the joints heads of the Science Divisions, and the Associate Administrator for Science. The mission is transitioning to a merged Phase C (Final Design) and Phase D (Assembly, Integration, & Test). PUNCH Phase C/D continues through launch plus 90 days. More details will be posted shortly.

The PUNCH mission consists of four spacecraft in Earth orbit that together will be uniquely capable of imaging the space environment from the outer corona of the Sun all the way to Earth orbit. There is a Near Field Imager and three Wide Field Imagers (WFIs).

PUNCH 2 Science Meeting First Announcement (March 31, 2021) We invite the community to the second PUNCH (Polarimeter to UNify the Corona and Heliosphere) Science Meeting (August 9-11, 2021), an in-development NASA mission that will image the outer corona and solar wind throughout the inner heliosphere. Major science topics include origin and evolution of the ambient solar wind and turbulence within it, and the physics and predictability of transient events including CMEs, CIRs, and shocks.

During June, the PUNCH Outreach Program deployed the first two expeditions to collect photography at an ancient Sun-watching site in Chaco Canyon, New Mexico. Our friends in the Native community emphasized that these sites are as alive today as they were to the ancestors, and in working at such places it is critical that we respect them and have a pure heart. We need to honor the ancestors. As such, the photography team learned to engage in a moment of reflection and appreciation each day before starting work at the site.

SAN ANTONIO — May 24, 2021 — On May 20, 2021, the Polarimeter to UNify the Corona and Heliosphere (PUNCH) mission achieved an important milestone, passing NASA’s Preliminary Design Review (PDR) of its spacecraft and payload experiments. Southwest Research Institute is leading PUNCH, a NASA Small Explorer (SMEX) mission that will integrate understanding of the Sun’s corona, the outer atmosphere visible during total solar eclipses, with the “solar wind” that fills the solar system.

PUNCH has instituted a program to recognize and encourage early-career scientists working with the Science Team on problems that support and enhance PUNCH mission science. PUNCH Associate Investigators (AIs) pursue science projects with mentorship from PUNCH co-I(s), attend team meetings, participate in PUNCH working group activities, and present at PUNCH science meetings. They act as liaisons, communicating PUNCH science to the broader community and community needs back to the project. In this way, they help grow the PUNCH user base, and also benefit from the career-enriching experience of being embedded in a NASA mission at an early stage of their careers.

PUNCH, the Polarimeter to UNify the Corona and Heliosphere, is an in-development NASA mission that will image the outer corona and solar wind throughout the inner heliosphere. Major science topics include origin and evolution of the ambient solar wind and turbulence within it, and the physics and predictability of transient events including CMEs, CIRs, and shocks.

The first PUNCH Science Team meeting was held virtually June 3-5, 2020. 44 team members and colleagues attended, sharing information about the mission, instruments, science goals, and planned data products. We also learned about STEAM, our student enhancement option, and plans for PUNCH Outreach. The Outreach presentation included a member of the Hopi tribe who read aloud his letter of support for our envisioned plan. There are many Science Team members who are experienced and interested in contributing to Outreach and Communications for PUNCH.

On April 8, 2020, the Polarimeter to UNify the Corona and Heliosphere (PUNCH) mission achieved an important milestone, passing NASA's critical System Requirements Review/Mission Definition Review (SRR/MDR). Southwest Research Institute is leading PUNCH, a NASA Small Explorer (SMEX) mission that will integrate understanding of the Sun's corona, the outer atmosphere visible during eclipses, with the tenuous "solar wind" filling the solar system.

The Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission has entered Phase B, which marks the transition from concept study to preliminary flight design. The mission, led by Southwest Research Institute, is set to launch in early 2023 and will image the Sun’s outer corona and beyond.