Mission Overview

IMPRESS (IMpulsive Phase Rapid Energetic Solar Spectrometer) is a solar science mission that will fly a hard X-ray (>10 keV) spectrometer on a 3U CubeSat to investigate particle acceleration in solar flares.  IMPRESS will perform soft and hard X-ray (SXR and HXR, respectively) spectroscopy of solar flares in the rising phase of a solar cycle. IMPRESS is optimized to observe high-cadence HXR and SXR spectra from a wide range of solar flares (targeting C1 to X1 class flares) without saturating the detector and without the need for disruptive movable attenuators.  These measurements will be used to (1) investigate sub-second variations in HXR flux that strongly constrain flare acceleration timescales; (2) perform a mission of opportunity by co-observing HXRs from solar flares along with the Spectrometer/Telescope for Imaging X-rays (STIX) onboard Solar Orbiter, systematically studying directivity; and serve as a HXR monitor of flares associated with solar eruptive events that will drive space weather in the next solar cycle.[1]

SSEL is responsible for development of the IMPRESS instrument payload, while the University of Minnesota SmallSat Program is responsible for construction of the 3U CubeSat platform.

Instrument Overview

The IMPRESS detectors are four CeBr scintillator crystals read out by silicon photomultipliers and one Amptek X123 silicon drift diode.  To capture fast time variations, these detectors will produce 4-12 keV SXR spectra at a 1 Hz cadence and 8-100 keV HXR spectra at a 32 Hz cadence.

Status

Flight hardware for the IMPRESS instrument has been procured and fabricated. The SSEL team is in the process of putting final touches on the hardware before assembling the instrument. The instrument will be delivered to the University of Minnesota team so that they can finish development of their software interface and run some preliminary tests. With the conclusion of those tests, the instrument will be returned to SSEL for final assembly and environmental testing.

 

[1] Courtesy of the University of Minnesota SmallSat Program, https://smallsat.umn.edu/impress