User:CSSWE/Colorado Student Space Weather Experiment (2nd copy)

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File:CSSWE CubeSat and PPOD prior to integration.pdf
CSSWE (foreground) and P-POD Deployer prior to integration. [1]
Operator CU/LASP
Bus 3U CubeSat
Mission type Science
Launch date 2012-09-13
Launch vehicle Atlas V
Mass 3 kilograms (6.6 lb)
Orbital elements
Regime Inclination: 66.28°

Colorado Student Space Weather Experiment (CSSWE) is the sixth National Science Foundation sponsored CubeSat mission [2] [3]. It was built by students at the University of Colorado at Boulder with advising from professionals at the Laboratory for Atmospheric and Space Physics. The CSSWE mission is an effort by the University of Colorado's Laboratory for Atmospheric and Space Physics. The mission principle investigators were Profs. Xinlin Li and Scott Palo.

CSSWE launched on an Atlas V rocket operated by the United Launch Alliance as part of the NASA ELaNa launch initiative[4]. CSSWE is releasing its science products to the public for download [5].

Mission Objective[edit]

CSSWE's mission objective is to study space weather from a near-Earth orbit (490km x 790km).[6] Specifically, CSSWE works in conjunction with concurrent missions (such as the Van Allen Probes, BARREL, and SAMPEX) to address the following questions: 1) How does solar flare location, magnitude, and frequency elate to the timing, duration, and energy spectrum of solar energetic particles (SEPs) reaching Earth and 2) How the spectrum and dynamics of Earth's radiation belt electrons evolve[7].

Science Instrument[edit]

CSSWE's science instrument, the Relativistic Electron and Proton Telescope integrated little experiment (REPTile), is the only science instrument aboard and meets the mission objectives. It is a scaled-down version of the Relativistic Electron and Proton Telescope (REPT) instrument[6], which is part of the Energetic Particle, Composition, and Thermal Plasma (ECT) Instrument Suite[8] onboard the Van Allen Probes. REPTile fulfills the mission objectives by measuring electrons from 0.5 to >3.3 Megaelectronvolts (MeV) and protons from 8 to 40 MeV [9] [10]. Also on the CubeSat is an onboard magnetometer to provide knowledge of spacecraft and instrument orientation with respect to Earth's magnetic field.

Pre-Flight Testing[edit]

CSSWE underwent the same rigorous testing that all space-based assets at LASP do. In addition to component and subsystem level testing, the spacecraft underwent numerous system level tests. It passed the thermal vacuum chamber test, in which 11 orbital cycles of the spacecraft were simulated in vacuum by increasing and decreasing the spacecraft temperature to reproduce thermal models which predict actual on-orbit temperatures. The first few hours of the mission were reproduced by simulating launch (in which the deployment switch is released, initiating automated commissioning phase) from a mesa nearby the LASP ground station. CSSWE passed this test by completing the initial commissioning phase, deploying its antenna, and establishing contact with the LASP ground station. Orbital attitude tests were performed as well, including Helmholtz cage and error elipse tests.


CSSWE was originally scheduled to launch on August 2, 2012 aboard the National Reconnaissance Office Launch-36 (NROL-36). However, the launch was delayed three times to provide additional time for resolution of a range instrumentation issue, according to the United Launch Alliance official statement[11]. The Atlas V 401 eventually launched on September 13, 2012 from Vandenberg AFB Space Launch Complex 3 [12] [13].

The primary payload aboard NROL-36 was a classified NRO payload, so no spacecraft or orbit information was provided. However, there were 11 CubeSats onboard the rocket as secondary payloads. The launch vehicle delivered the CubeSats into a 490x765 km orbit with an inclination of 66.28 degrees. The CubeSats were carried in eight PPOD dispensers attached to the end of the Centaur rocket via the Aft Bulkhead Carrier, which replaced an unnecessary Helium tank[11]. Four of the CubeSats were launched as part of the NASA's Educational Launch of Nanosatellites (ELaNa) program - CSSWE (University of Colorado - Boulder), CINEMA 1 (University of California - Berkeley et al.), CXBN (Morehead State University), and CP5 (California Polytechnic University). The remaining seven were Aeneas (operated by the University of Southern California), two SMDC-ONE (US Army), STARE-A (Lawrence Livermore National Laboratory), and three AeroCube-4 (Aerospace Corporation) [14].

On Orbit Success[edit]

CSSWE was first heard beaconing telemetry packets by amateur radio operator call sign DK3WN almost exactly two hours after deployment from the PPOD, overcoming its first major hurdle. The spacecraft completed science commissioning and was commanded into full science mode 22 days later on October 5th. Full mission success occurred on January 5th, 2013 after three months of science data. As of March 5th, CSSWE has doubled its expected mission lifetime and is still operational, taking valuable science data.

The first science results were presented at the 2012 Fall American Geophysical Union in San Francisco, CA[15].


  1. ^ Jonathan Brown (2008). "Dnepr 2 Satellite Identification and the Mk.III P-POD" (PDF). California Polytechnic State University. Retrieved 2010-07-30.  Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ NSF Award Details
  3. ^ University of Colorado Press Release
  4. ^ ULA NROL-36 Launch Highlights
  5. ^ CSSWE Homepage
  6. ^ a b Li, X., S. Palo, R. Kohnert, L. Blum, D. Gerhardt, Q. Schiller, and S. Califf (2013), Small mission accomplished by students - big impact on space weather research, Space Weather, Accepted, DOI: 10.1002/swe.20025
  7. ^ Li, X., S. Palo, and R. Kohnert (2011), Small Space Weather Research Mission Designed Fully by Students, Space Weather, 9, S04006, doi:10.1029/2011SW000668
  8. ^ Van Allen Probes Instrument Suites
  9. ^ Blum, L. and Q. Schiller (2012), Characterization and testing of an energetic particle telescope for a CubeSat platform, Proceedings of the AIAA/USU Conference on Small Satellites, Frank J. Redd Student Scholarship Competition, SSC12-VIII-4
  10. ^ Schiller, Q. and A. Mahendrakumar (2010), REPTile: a miniaturized detector for a CubeSat mission to measure relativistic particles in near-Earth space, Proceedings of the AIAA/USU Conference on Small Satellites, Frank J. Redd Student Scholarship Competition, SSC10-VIII-1
  11. ^ a b Launch Summary
  12. ^ ULA Launch Press Release
  13. ^ NRO Launch Press Release
  14. ^ NROL-36 2012 CubeSat Workshop Presentation
  15. ^ RBSP 2012 AGU Presentation List