CSSWE

About This Satellite

The Colorado Student Space Weather Experiment, or CSSWE, launched on September 13, 2012. Students at the University of Colorado Boulder developed the 3U SmallSat under LASP supervision. It carried an energetic-particle telescope to investigate connections between solar activity and the changing populations of energetic particles around Earth.

Space weather was measured with particles, not cloud pictures

The payload was the Relativistic Electron and Proton Telescope integrated little experiment, abbreviated REPTile. The mission investigated particle flux and energy, including the gain and loss of outer-radiation-belt electrons. Its use of the word "weather" concerns the space environment; the satellite was not a conventional meteorological camera mapping rain clouds.

A catalog position is not a continuing science measurement

LASP dates the end of the mission to December 2014. A retained orbital record must not be read as evidence of new particle observations after that date. The science archive and subsequent publications can remain valuable even after the spacecraft has stopped collecting or returning data.

Mission reference: LASP: Colorado Student Space Weather Experiment mission record. Editorial review: 2026-09-14.

A stack of silicon detectors reveals particle behaviour

LASP describes REPTile as a stack of four solid-state silicon detectors. Incoming particles deposit energy and generate electron-hole pairs; higher-energy particles can penetrate farther into the stack. The instrument uses this detector response to study energetic electrons and protons. It does not take a visible image of a radiation belt, so a global illustration of the belts should be understood as context, not a photograph produced by CSSWE.

Reference: LASP: REPTile silicon detectors and interpretation of particle observations.

A 2017 result used observations from a mission that had ended

LASP reported that CSSWE data helped identify electrons near the inner edge of the inner radiation belt associated with cosmic ray albedo neutron decay, or CRAND. The finding concerned a particular particle population, not a claim that all radiation-belt electrons have one origin. Its publication after shutdown illustrates why mission end and the end of scientific usefulness are different dates.

Reference: LASP: 2017 CSSWE result on inner-belt electrons and CRAND.

Reading this orbital snapshot

Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 400 km at perigee to 442 km at apogee, a difference of 43 km. The orbital period is about 93.0 minutes. Eccentricity 0.00314 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.01 times apogee speed. These are mean-element estimates, not instantaneous measurements. Distance per orbit uses an ellipse approximation.

Saved build snapshot. If a valid TLE is retrieved, this explanation and the orbit panel update together. Otherwise this dated snapshot is retained.

Ground track is not sensor coverage

An inclination of 64.66 degrees implies approximate geocentric ground-track limits of 64.7 degrees north and south. This is a prograde orbit, moving in the same general direction as Earth rotation. The plotted line marks the point beneath the object. It does not represent camera coverage, radio reception, or a guaranteed visible pass.

Accuracy and missing information

The introductory record describes the build snapshot. The orbital snapshot explanation and orbit panel share any successfully retrieved TLE; check the displayed epoch. Reentered objects retain historical data only. Mission history is not rewritten by TLE updates. TLE/SGP4 positions are predictions and can change after maneuvers or updated observations. The 14-day stale-data cutoff is a display safeguard, not an accuracy guarantee. Local passes are geometric predictions, not a visibility forecast. No verified operator or mission status means unknown, not active. Do not use this catalog for collision avoidance or operational flight decisions.

Catalog sources: CelesTrak SATCAT: NORAD 38761 · GCAT: S38761 (source update 2026 Sep 4 2345:57). Supplementary metadata: SatNOGS DB, retrieved 2026-09-05T12:57:25.375Z. Page assembled 2026-09-15. GCAT phase codes describe trajectory phases, not mission health.

Learn more: TLE data · Perigee and apogee · Ground tracks · JOT (Jewawud Live Orbital Map)

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