Please make a donation to support Gunter's Space Page.
Thank you very much for visiting Gunter's Space Page. I hope that this site is useful and informative for you.
If you appreciate the information provided on this site, please consider supporting my work by making a simple and secure donation via PayPal. Please help to run the website and keep everything free of charge. Thank you very much.

CXBN 1, 2 (Unbridled Spirit)


CXBN (Cosmic X-Ray Background) is a nanosatellite designed to make observations of the diffuse X-ray background and publish the data. It is build on a double CubeSat form factor.

The goals of the mission are:

  • Goal is to increase the precision of measurements of the Cosmic X-Ray Background (CXRB) in the 30-50 keV range
  • Constrain models that explain the relative contribution of cosmic X-Ray sources to the CXRB
  • Produce data that will lend insight into the underlying physics of the Diffuse X-Ray Background
  • Provide flight heritage for CZT-based X-Ray-gamma-ray detectors and CubeSat technologies
  • ConOps: Sun pointing, 1 Hz rotation, maps entire sky in the X-Ray spectrum

The project team at MSU and their partners tracked the CXBN satellite for 4.5 months (until the end of January 2013). The team collected some data and telemetry, but the SNR (Signal-to-Noise Ratio) was too low on most passes to allow the project to download a significant amount of data. Most of the technology demonstration objectives were met, but the team was not able to begin the science mission in earnest because of the weak transmit SNR owing to an anomalous low power mode.

The science objective of taking a 5% measurement of the diffuse X-ray background will be continued with CXBN-2. In February 2013, CXBN-2 was down-selected for a launch opportunity through the NASA ELaNa program.

Nation: USA
Type / Application: Astronomy, X-ray
Operator: Morehead State University
Contractors: Morehead State University
Configuration: CubeSat (2U)
Propulsion: none
Power: 4 deployable solar arrays, batteries
Mass: 2.6 kg
Orbit: 770 km × 480 km, 64 (#1); 400 km × 400 km, 51 (#2)
Satellite COSPAR Date LS Launch Vehicle Remarks
CXBN (Unbridled Spirit) 2012-048E 13.09.2012 Va SLC-3E Atlas-5(401) with Intruder 10A, Intruder 10B, Aeneas, SMDC-ONE 2.1, SMDC-ONE 2.2, STARE A, CINEMA 1, CSSWE, AeroCube 4A, AeroCube 4B, AeroCube 4C, CP 5, OUTSat
CXBN 2 TBD 18.04.2017 CC SLC-41 Atlas-5(401) with Cygnus CRS-7, ALTAIR 1, SUSat, UNSW-EC0, i-INSPIRE 2, ZA-AeroSat, nSIGHT 1, Ex-Alta 1, LilacSat 1, NJUST 1, Aoxiang 1, SOMP 2, QBITO, Aalto 2, X-CubeSat, SpaceCube, DUTHSat, UPSat, Hoopoe, LINK, SNUSAT 1, SNUSAT 1b, qbee50-LTU-OC, BeEagleSat, HAVELSAT, Phoenix, PolyITAN-2-SAU, QBUS 1, QBUS 2, QBUS 4, IceCube, CSUNSat 1, KySat 3, SHARC, Biarri-Point, Lemur-2 30, ..., 33


  • eoPortal Directory: CXBN