Xinlin Li, Laboratory for Atmospheric and Space Physics (LASP) and Department of Aerospace Engi-neering Sciences (AES) of University of Colorado at Boulder (CU)

Title:  "Three Generations of CubeSat in University of Colorado to Address Heliospheric Physics"  (video)

Abstract: The Colorado Student Space Weather Experiment (CSSWE), a 3-unit (10cm x 10cm x 30cm) CubeSat, has been on its low earth orbit for over two years, continuing to send back high quality measurements of energetic particles: differential fluxes of 0.58 to >3.8 MeV electrons and 9-40 MeV protons. Significant science results about radiation belt physics have been produced and over a dozen peer-reviewed papers about the sciences as well as the engineering efforts have been published.

Following the tremendous success of this simple and robust CubeSat mission, our new generation of CubeSat: a 3-axis-controlled platform to observe the solar soft X-ray (SXR) spectrum between 0.04 - 3 nm, is to be on orbit next year. This new CubeSat mission, nicknamed MinXSS (Miniature X-ray Solar Spectrometer), has been developed over the past three years, utilizing the very successful Space Hardware Design (CubeSat) course in the department of ASE at CU and the invaluable mentorship from LASP professionals. The science objective of the MinXSS CubeSat is to better understand the energy distribution of solar flare soft X-ray (SXR) emissions and its impact on Earth’s ionosphere, thermosphere, and mesosphere (ITM). Energy from SXR radiation is deposited mostly in the ionospheric E-region, from ~80 to ~150 km, but the precise altitude is strongly dependent on the SXR spectrum because of the steep slope and structure of the photo-ionization cross sections of atmospheric gases in this wavelength range. MinXSS mission will provide this needed spectrum information. This mission was supported by NSF for its early development and it has been selected by NASA/H-TIDeS program and will be delivered by the end of this year and to be launched from the International Space Station next year.

Our next generation of CubeSat, L5 Solar Wind and Eruptive Event Probe (SWEEP), is designed to meet a 6-unit CubeSat specification and utilize the rare, but almost perfect, launch opportunity of the first Explorer Mission (EM)-1 to the Moon (Orion’s maiden flight). Instead of following EM-1 into lunar orbit, L5 SWEEP will execute a small maneuver to fly past the Moon toward L5 (Lagrangian point trailing the Earth by 60 deg), leading to an L5 insertion approximately two years later. Both in situ and remote sensing measurements of the solar wind and Sun at L5 have unique advantages for studying some of the most geoeffective solar eruptive events.

L5 SWEEP will have a suite of well-developed and miniaturized instruments onboard: a Faraday Cup and Vector Helium Magnetometer for in situ measurements of the solar wind properties (e.g., density, speed, temperature, magnetic field) and solar X-ray sensor and EUV spectrometer for remote sensing of the solar eruptive event properties (e.g., flare intensity and location, coronal dimming as CME proxy, evolution of coronal holes and active regions). The primary phase of this mission starts when L5 SWEEP moves off the Sun-Earth line and is on its journey toward L5. This ambitious and extraordinary mission is under review by NASA/H-TIDeS program.