MinXSS-2 CubeSat mission overview: Improvements from the successful MinXSS-1 mission

James Paul Mason,Thomas N Woods,Phillip C Chamberlin,Andrew Jones,Rick Kohnert,Bennet Schwab,Robert Sewell,Amir Caspi,Christopher S Moore,Scott Palo,Stanley C Solomon,Harry Warren

doi:10.1016/j.asr.2019.02.011

Abstract

The second Miniature X-ray Solar Spectrometer (MinXSS-2) CubeSat, which begins its flight in late 2018, builds on the success of MinXSS-1, which flew from 2016-05-16 to 2017-05-06. The science instrument is more advanced – now capable of greater dynamic range with higher energy resolution. More data will be captured on the ground than was possible with MinXSS-1 thanks to a sun-synchronous, polar orbit and technical improvements to both the spacecraft and the ground network. Additionally, a new open-source beacon decoder for amateur radio operators is available that can automatically forward any captured MinXSS data to the operations and science team. While MinXSS-1 was only able to downlink about 1 MB of data per day corresponding to a data capture rate of about 1%, MinXSS-2 will increase that by at least a factor of 6. This increase of data capture rate in combination with the mission’s longer orbital lifetime will be used to address new science questions focused on how coronal soft X-rays vary over solar cycle timescales and what impact those variations have on the earth’s upper atmosphere.

Highlights

CubeSats are a valuable component of a healthy portfolio of satellite missions
Even though the first flight of the Miniature Xray Solar Spectrometer (MinXSS-1; Mason et al, 2016) far surpassed all success criteria, the team learned much from the spacecraft’s year on orbit and those lessons have been applied to the MinXSS-2 program
This paper focuses on the improvements made from MinXSS-1 to MinXSS-2

Summary

Introduction

CubeSats are a valuable component of a healthy portfolio of satellite missions. While their scope is necessarily more targeted, they offer several advantages compared to large spacecraft programs. The primary instrument, a modified Amptek X123 silicon drift detector, measures the solar soft x-ray spectrum from 0.5 to 30 keV with nominal 0.137 keV full-width halfmaximum spectral resolution at 5.9 keV (Moore et al, 2016, 2018) It communicates with the ground in the ultra high frequency (UHF) band. MinXSS1 generated much more data than could fit in the narrow pipe to the ground Both MinXSS spacecraft generate about 1 KB/s of data2 – or 86.4 MB/day – while in nominal science operations. With the improvements made to the MinXSS-2 spacecraft, ground network, and mission profile we expect to increase the data capture percentage by at least a factor of 6 and extend the mission life by a factor of 5.

Mission Overview

Improvements Over MinXSS-1

Open-Source MinXSS UHF Beacon Decoder

Discussion