The PUNCH Mission: System Trades and Surviving The Evolving LV Market

The Polarimeter to UNify the Corona and Heliosphere (PUNCH) mission comprises a constellation of four micro-satellites that will produce 3D images of the solar wind by imaging the faint traces of sunlight reflected from free electrons in the solar corona and solar wind. Three of the PUNCH observatories host a Wide Field Imager (WFI) instrument each, and one hosts a Narrow Field Imager (NFI). The mission is funded by the NASA Explorers Program. This paper highlights some of the design decisions that went into enabling what has been described as an elegant design, enabling a common spacecraft as well as significant commonality in instrument components for the four PUNCH observatories hosting three very different instruments. The design approach minimized risk while enabling big science in the context of a Small Explorer mission budget. Although well into flight development and fabrication, PUNCH was recently transitioned from a prime mission to a rideshare mission for deployment from a secondary payload adaptor. We briefly discuss some of the challenges encountered to-date in this transition, assumptions that had to be made, and impact to the mission schedule.