 SNOE satellite | |||||||||
| Names | Explorer 72, STEDI 1 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Mission type | Atmospheric research | ||||||||
| Operator | CU Boulder (LASP)[1] | ||||||||
| COSPAR ID | 1998-012A | ||||||||
| SATCAT no. | 25223 | ||||||||
| Website | lasp | ||||||||
| Mission duration | Final: 5 years, 9 months, 17 days | ||||||||
| Spacecraft properties | |||||||||
| Manufacturer | CU Boulder (LASP)[1] | ||||||||
| Launch mass | 115 kg (254 lb)[2] | ||||||||
| Dimensions | 1.0 × 0.9 m (3.2 × 3.1 ft)[3] | ||||||||
| Power | 37 watts | ||||||||
| Start of mission | |||||||||
| Launch date | February 26, 1998, 07:07 UTC[4] | ||||||||
| Rocket | Pegasus XL HAPS F20 | ||||||||
| Launch site | Vandenberg (Stargazer) | ||||||||
| Contractor | Orbital Sciences | ||||||||
| End of mission | |||||||||
| Disposal | Atmospheric reentry | ||||||||
| Decay date | ≈December 13, 2003, 09:34 UTC[1] | ||||||||
| Orbital parameters | |||||||||
| Reference system | Geocentric | ||||||||
| Regime | Sun-synchronous | ||||||||
| Eccentricity | 0.00324 | ||||||||
| Perigee altitude | 535 km (332 mi) | ||||||||
| Apogee altitude | 580 km (360 mi) | ||||||||
| Inclination | 97.7° | ||||||||
| Period | 95.80 minutes | ||||||||
| Epoch | February 26, 1998, 02:07 UTC[4] | ||||||||
| |||||||||
The Student Nitric Oxide Explorer (SNOE) was a small earth orbiting atmospheric research NASA spacecraft, launched on February 26, 1998, and destroyed upon re-entering the earth's atmosphere on December 13, 2003. Its objective was a detailed study of variations in nitric oxides (NOx) in the Earth's atmosphere. NOx strongly affects the ion composition of the ionosphere and the thermal structure of the thermosphere. The density of NOx in the lower thermosphere may be correlated with variations in solar soft X-radiation.
SNOE was the first satellite launched in NASA's Student Explorer Demonstration Initiative (STEDI) program. The SNOE was built at the University of Colorado's Laboratory for Atmospheric and Space Physics. It was lifted into space along with the Teledesic T1 ("BATSAT") satellite, using a Pegasus stratospheric launching system.
Instruments edit
SNOE carried three instruments aboard:
- an ultraviolet spectrometer to measure nitric oxide altitude profiles,
- a two-channel auroral photometer to measure auroral emissions beneath the spacecraft, and
- a five-channel solar soft X-ray photometer.
Mission edit
The limb-scanning ultraviolet spectrometer on SNOE observed polar mesospheric clouds.[5]
SNOE has helped CU-Boulder scientists and students map the effect of global X-rays on the atmosphere.[6]
Enhanced fluxes of solar soft X-rays have been detected by the SNOE satellite.[6] Solar soft X-ray irradiance is measured by the solar X-ray photometer (SXP) from 2 to 20 nm.[6] The measurements do not cover solar minimum or maximum conditions.[6] For the 2–7 nm wavelength range, the solar soft X-ray irradiance ranged upwards from 0.3 mW m-2 to ~ 1.5 mW m-2.[6] The 6–19 nm range yielded 0.5 to ~2.1 mW m-2.[6] These values are about a factor of 2 or more higher than predicted by current models.[6]
See also edit
References edit
- ^ a b c Wade, Mark. "SNOE". Encyclopedia Astronautica. Retrieved March 26, 2017.
- ^ Solomon, Stanley C.; Bailey, Scott M.; Barth, Charles A.; Davis, Randal L.; Donnelly, John A.; et al. (1998). The SNOE Spacecraft: Integration, Test, Launch, Operation, and On-orbit Performance (PDF). 12th AIAA/USU Conference on Small Satellites. 1998. Logan, Utah.
- ^ "Launch vehicle dynamic envelope diagram". University of Colorado Boulder. Laboratory for Atmospheric and Space Physics. Retrieved March 26, 2017.
- ^ a b "SNOE - Trajectory Details". National Space Science Data Center. NASA. Retrieved June 28, 2016.
- ^ Bailey SM, Merkel AW, Thomas GE, Carstens JN (July 2005). "Observations of polar mesospheric clouds by the Student Nitric Oxide Explorer". Journal of Geophysical Research. 110 (D13203): 13. Bibcode:2005JGRD..11013203B. doi:10.1029/2004JD005422.
{{cite journal}}: CS1 maint: date and year (link) CS1 maint: multiple names: authors list (link) - ^ a b c d e f g Bailey SM, Woods TN, Barth C, Solomon SC (December 2000). "Measurements of the solar soft X-ray irradiance by the Student Nitric Oxide Explorer- First analysis and underflight calibrations" (PDF). Journal of Geophysical Research. 105 (A12): 27179–93. Bibcode:2000JGR...10527179B. doi:10.1029/2000JA000188.
{{cite journal}}: CS1 maint: date and year (link) CS1 maint: multiple names: authors list (link)
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