C/NOFS

C/NOFS

An artist's concept of C/NOFS
Mission type	Technology
Operator	STP / AFRL / DMSG
COSPAR ID	2008-017A
SATCAT №	32765
Spacecraft properties
Manufacturer	General Dynamics
Launch mass	395 kilograms (871 lb)
Start of mission
Launch date	16 April 2008, 17:02:48 (2008-04-16UTC17:02:48Z) UTC
Rocket	Pegasus-XL
Launch site	Stargazer Bucholz Runway 6/24
End of mission
Decay date	28 November 2015 UTC
Orbital parameters
Reference system	Geocentric
Regime	LEO
Eccentricity	0.032
Perigee	405 kilometers (252 mi)
Apogee	853 kilometers (530 mi)
Inclination	13.0& degrees
Period	97.3 minutes

C/NOFS, or Communications/Navigation Outage Forecasting System was an American satellite developed by the Air Force Research Laboratory Space Vehicles Directorate to investigate and forecast scintillations in the Earth's ionosphere. It was launched by an Orbital Sciences Corporation Pegasus-XL rocket at 17:01 GMT on 16 April 2008. It decayed on 28 November 2015.

The satellite, which was operated by the USAF STP, allowed the US military to predict the effects of ionospheric activity on signals from communication and navigation satellites, outages of which could potentially cause problems in battlefield situations.

C/NOFS had a three-axis stabilisation system, and was equipped with seven sensors. It was placed into a low Earth orbit with orbital inclination of 13°, a perigee of 400 km and an apogee of 850 km. It carried the CINDI experiment for NASA. Launch was originally scheduled for 2003, but was delayed due to a number of issues.

Scientific instruments on board

The spacecraft payload consists of the following instruments:

• Ion Velocity Meter (IVM): IVM consists of a pair of sensors designed to measure the in situ ion velocity vector, ion temperature, and ion composition. The IVM is provided by the William B. Hanson Center for Space Sciences at the University of Texas at Dallas. IVM is a component of the CINDI package funded by NASA. PI: Rod Heelis
• Planar Langmuir Probe (PLP): A two sensor package consisting an ion trap designed to measure ion density fluctuations and a Langmuir probe. PLP is provided by the Air Force Research Laboratory. PI: Patrick Roddy. Formerly, Donald Hunton.
• Neutral Wind Meter (NWM): A two sensor package designed to measure the neutral wind velocity. NWM is provided by the William B. Hanson Center for Space Sciences at the University of Texas at Dallas. Like IVM, NWM is a component of the CINDI package funded by NASA. PI: Greg Earle
  • Ram Wind Sensor (RWS): RWS measures the ram component of the neutral wind by ionizing a fraction of the incoming neutral gas then performing retarding potential analysis on those ions.
  • Cross Track Sensor (CTS): The cross track sensor is a hollow hemispherical dome divided into four independent chambers with a miniaturized Bayard-Alpert hot filament ionization gauge in each chamber. Four small holes in the dome allow the neutral gas to stream into the chambers. The pressure in any chamber will depend on the arrival angle of the neutral wind.
• CORISS: The C/NOFS Occultation Receiver for Ionospheric Sensing and Specification (CORISS) instrument is a GPS dual-frequency receiver designed to measure line-of-sight TEC. CORISS is provided by the Aerospace corporation. PI: Paul Straus
• CERTO: the Coherent Electromagnetic Radio Tomography (CERTO) experiment is a radio beacon that will provide plasma density profiles and information on phase and amplitude scintillation of radio signals. CERTO is provided by the Naval Research Laboratory. PI: Paul Bernhardt
• Vector Electric Field Instrument (VEFI): VEFI is a collection of instruments including 6 electric field booms, a 3-axis magnetometer, a spherical Langmuir probe, and a lightning detector. VEFI is provided by NASA Goddard with funding from the Air Force Research Laboratory. PI: Rob Pfaff

Scientific Data

C/NOFS science data is now available online for general use. VEFI and PLP data are available through NASA Goddard's Coordinated Data Analysis Web (CDAWeb). CINDI data are available through the William B. Hanson Center for Space Science at The University of Texas at Dallas.

Current status

On 2008-05-28 the USAF Space Development and Test Wing announced its launch and early orbit portion of the spacecraft's operations had been completed successfully.^[1] On 2008-06-09 the manufacturer of the separation systems used to deploy the C/NOFS solar panels, payload antennas and magnetometer boom indicated they had all functioned correctly.^[2]

On September 9, 2011 SMC announced that it had extended the C/NOFS satellite maintenance contract from 1 October 2011 to 31 March 2012 to Orbital Sciences corp. for the continued On-Orbit Support of the C/NOFS mission.^[3]

As of 2013-06-03 the C/NOFS satellite has been placed in safe mode, with all scientific instruments turned off, due to budgetary restrictions.

As of 2013-10-21 the C/NOFS satellite is out of safe mode and operating nominally.

On 28 November 2015 C/NOFS burned in Earth’s atmosphere during a planned reentry.^[4]

C/NOFS Related Publications

• "A new satellite-borne neutral wind instrument for thermospheric diagnostics", Earle et al., Reviews of Scientific Instruments 78, 114051 (2007)
• "C/NOFS: a mission to forecast scintillations", O. de La Beaujardiere, Journal of Atmospheric and Solar-Terrestrial Physics, 66 (2004) 1573-1591
• "Behavior of the O+/H+ transition height during the extreme solar minimum of 2008", Heelis et al., Geophysical Research Letters, doi:10.1029/2009GL038652 (2009)
• "Broad Plasma Decreases in the Equatorial Ionosphere", Huang et al., Geophysical Research Letters, doi:10.1029/2009GL039423 (2009)
• "Comparing F region ionospheric irregularity observations from C/NOFS and Jicamarca", Hysell et al.", Geophysical Research Letters, doi:10.1029/2009GL038983 (2009)
• "C/NOFS observations of intermediate and transitional scale-size equatorial spread F irregularities", Rodrigues et al., Geophysical Research Letters, doi:10.1029/2009GL038905 (2009)
• "Assimilative modeling of equatorial plasma depletions observed by C/NOFS", Su et al., Geophysical Research Letters, doi:10.1029/2009GL038946 (2009)
• "Longitudinal and seasonal dependence of nighttime equatorial plasma density irregularities during solar minimum detected on the C/NOFS satellite", Dao et al., Geophysical Research Letters, doi:10.1029/2011GL047046 (2011)
• "Assimilative modeling of observed post-midnight equatorial plasma depletions in June 2008", Su et al., Journal of Geophysical Research, doi:10.1029/2011JA016772 (2011)
• "Multiple phase screen modeling of ionospheric scintillation along radio occultation raypaths", Carrano et al., Radio Science, doi:10.1029/2010RS004591 (2011)

References

External links

• NSSRM - C/NOFS
• Gunter's Space Page - C/NOFS
• CINDI home page
• CINDI in Space comic book
• List of C/NOFS related publications with abstracts.