Polarimeter to Unify the Corona and Heliosphere

Polarimeter to Unify the Corona and Heliosphere (PUNCH)
PUNCH satellites being prepared for launch at Vandenberg Space Force Base in January 2025
NamesExplorer · SMEX-15
Mission typeHeliophysics
OperatorNASA
COSPAR ID
  • 2025-047A (NFI)
  • 2025-047B (WFI 1)
  • 2025-047D (WFI 2)
  • 2025-047C (WFI 3)
Websitepunch.spaceops.swri.org
Spacecraft properties
Spacecraft typeOrbiters × 4
BusCustom, CYGNSS heritage
ManufacturerSouthwest Research Institute (SwRI)
Launch mass40 kg (88 lb) each
160 kg (350 lb) total
Start of mission
Launch date12 March 2025, 03:10:00 UTC (11 March 2025, 8:10 pm PDT)
RocketFalcon 9 Block 5
Launch siteVandenberg, SLC-4E
ContractorSpaceX
Orbital parameters
Reference systemGeocentric orbit
RegimeSun-synchronous, low Earth orbit
Altitude570 km (350 mi)
Instruments
Narrow Field Imager (NFI) – 1 satellite
Wide Field Imagers (WFIs) – 3 satellites

Mission insignia

Polarimeter to Unify the Corona and Heliosphere (PUNCH), also known as SMEX-15, is a mission by NASA to study the unexplored region from the middle of the solar corona out to 1 AU from the Sun. The PUNCH flight assets are a constellation of four microsatellites that through continuous 3D deep-field imaging, will observe the corona and heliosphere as elements of a single, connected system. The four microsatellites were initially scheduled to be launched in October 2023, but were moved to launch alongside (rideshare) the SPHEREx space observatory on a Falcon 9 Block 5 rocket from Vandenberg Space Force Base, from which all five satellites were successfully deployed on 11 March 2025.

On 20 June 2019, NASA announced that PUNCH and TRACERS were the winning candidates to become the next missions in the agency's Small Explorer program (SMEX).

PUNCH is led by Craig DeForest at the Southwest Research Institute (SwRI) in Boulder, Colorado. Including launch costs, PUNCH is being funded for no more than US$165 million.

On 14 April 2025, PUNCH captured its first image with the Narrow Field Imager (NFI) and one of its three Wide Field Imagers (WFI). Two days later, the remaining two WFIs captured their first image.