C/NOFS
606338main CNOFS-orig full.jpg
An artist's concept of C/NOFS satellite
NamesCommunications/Navigation Outage Forecasting System
Mission typeTechnology demonstration
OperatorSTP / AFRL
COSPAR ID2008-017A Edit this at Wikidata
SATCAT no.32765
Mission duration3 years (planned)
7.5 years (achieved)
Spacecraft properties
ManufacturerGeneral Dynamics
Launch mass384 kg (847 lb)[1]
Start of mission
Launch date16 April 2008, 17:02:48 UTC
RocketPegasus-XL (F39)
Launch siteBucholz, Stargazer, Runway 6/24
ContractorOrbital Sciences Corporation
End of mission
Decay date28 November 2015
Orbital parameters
Reference systemGeocentric orbit[2]
RegimeLow Earth orbit
Perigee altitude405 km (252 mi)
Apogee altitude853 km (530 mi)
Inclination13.00°
Period97.30 minutes
Instruments
C/NOFS Occultation Receiver for Ionospheric Sensing and Specification (CORISS)
Coherent Electromagnetic Radio Tomography (CERTO)
Coupled Ion-Neutral Dynamics Investigation (CINDI)
Planar Langmuir Probe (PLP)
Vector Electric Field Instrument (VEFI)
Explorer program
← TRUMPET 5 (TWINS-B)
Astro-H (NeXT) →
 

C/NOFS, or Communications/Navigation Outage Forecasting System was an USAF satellite developed by the Air Force Research Laboratory (AFRL) Space Vehicles Directorate to investigate and forecast scintillations in the Earth's ionosphere. It was launched by an Orbital Sciences Corporation Pegasus-XL launch vehicle at 17:02:48 UTC on 16 April 2008 and decayed on 28 November 2015.

The satellite, which was operated by the Space Test Program (STP), allowed the U.S. 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 13.00°, a perigee of 405 km (252 mi) and an apogee of 853 km (530 mi).[2] 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:

Experiments

C/NOFS Occultation Receiver for Ionospheric Sensing and Specification (CORISS)

The C/NOFS Occultation Receiver for Ionospheric Sensing and Specification (CORISS) is a Global Positioning System (GPS) dual-frequency receiver that measures the total electron content (TEC) along the line-of-sight from C/NOFS to GPS satellite. TEC measurement can help to constrain C/NOFS ionospheric models. Limb profiles of TEC obtained during occultations can be inverted to produce vertical profiles of electron density. It may be also possible to measure L-band scintillations caused by electron density irregularities.[3]

Coherent Electromagnetic Radio Tomography (CERTO)

The Coherent Electromagnetic Radio Tomography (CERTO) is a tri-band (150, 400, 1067 MHz) radio beacon that permits direct measurement of ionospheric scintillation parameters at several frequencies by ground receivers. CERTO measurements can also be used for tomographic reconstruction of electron density profiles.[4]

Coupled Ion-Neutral Dynamics Investigation (CINDI)

The Coupled Ion-Neutral Dynamics Investigation (CINDI) payload is funded by NASA as an Explorer Mission of Opportunity. CINDI consists of two instruments: the Ion Velocity Meter (IVM) and the Neutral Wind Meter (NWM). The IVM instrument includes a ion drift meter and a retarding potential analyzer. IVM measure the ion drift vector, the ion temperature, and the major ion composition with a spatial resolution of about 4 km (2.5 mi) along the satellite track; the ion drift meter also provides vertical and horizontal ion drift components at 500 m (1,600 ft) resolution. The NWM consists of a cross track wind sensor and a ram wind sensor providing a direct measure of the neutral wind vector with a spatial resolution of about 8 km (5.0 mi) along the satellite track.[5]

Planar Langmuir Probe (PLP)

The Planar Langmuir Probe (PLP) is a dual-disk probe designed to provide in situ measurements of plasma density and density fluctuations. Low time-resolution density measurements are intended as inputs for background ionosphere models and high time-resolution density irregularity measurements to specify disturbance conditions. PLP also monitors the spacecraft surface potential.[6]

Vector Electric Field Instrument (VEFI)

The Vector Electric Field Instrument (VEFI) consists primarily of three orthogonal 20 m (66 ft) tip-to-tip double probe antennas. It measures the alternating current (AC) and Direct current (DC) electric fields related to plasma drift and irregularity development. The VEFI instrument package also includes a fluxgate magnetometer, a optical lightning detector and a fixed-bias Langmuir probe.[7]

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.[8] CINDI data are available through the William B. Hanson Center for Space Science[9] at the University of Texas at Dallas.

Current status

On 28 May 2008, the USAF Space Development and Test Wing announced its launch and early orbit portion of the spacecraft's operations had been completed successfully.[10] On 9 June 2008, 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.[11]

On 9 September 2011, SMC announced that it had extended the C/NOFS satellite maintenance contract from 1 October 2011 to 31 March 2012 to Orbital Sciences Corporation for the continued On-Orbit Support of the C/NOFS mission.[12]

On 3 June 2013, the C/NOFS satellite has been placed in safe mode, with all scientific instruments turned off, due to budgetary restrictions. On 21 October 2013, the C/NOFS satellite is out of safe mode and operating nominally.

On 28 November 2015, C/NOFS burned in the atmosphere of Earth during a planned reentry.[13]

C/NOFS related publications

See also

References

  1. ^ ESA. "C/NOFS (Communication/Navigation Outage Forecast System)". Retrieved 31 March 2020.
  2. ^ a b "Trajectory: C/NOFS (2008-017A) CINDI". NASA. 28 October 2021. Retrieved 20 December 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  3. ^ "Experiment: C/NOFS Occultation Receiver for Ionospheric Sensing and Specification (CORISS)". NASA. 28 October 2021. Retrieved 19 November 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  4. ^ "Experiment: Coherent Electromagnetic Radio Tomography (CERTO)". NASA. 28 October 2021. Retrieved 19 November 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  5. ^ "Experiment: Coupled Ion-Neutral Dynamics Investigation (CINDI)". NASA. 28 October 2021. Retrieved 19 November 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  6. ^ "Experiment: Planar Langmuir Probe (PLP)". NASA. 28 October 2021. Retrieved 19 November 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  7. ^ "Experiment: Vector Electric Field Instrument (VEFI)". NASA. 28 October 2021. Retrieved 19 November 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  8. ^ CDAWeb Public Domain This article incorporates text from this source, which is in the public domain.
  9. ^ "Home | CINDI Education". cindispace.utdallas.edu.
  10. ^ "C/NOFS Satellite Successful LEO Operations". USAF. Archived from the original on 18 June 2008. Public Domain This article incorporates text from this source, which is in the public domain.
  11. ^ "SpaceDev hardware successfully operates aboard C/NOFS mission". SpaceDev. 9 June 2008. Archived from the original on 15 June 2008. Retrieved 9 June 2008.
  12. ^ "Communication/Navigation Outage Forecasting System (C/NOFS) On-Orbit Contract Extension". FedBizOps.gov. Public Domain This article incorporates text from this source, which is in the public domain.
  13. ^ "Satellite's Last Days Improve Orbital Decay Predictions". NASA. 14 December 2015. Retrieved 15 December 2015. Public Domain This article incorporates text from this source, which is in the public domain.