Orbiting Carbon Observatory 2
.jpg)
Artist depiction of OCO-2
|
|
| Mission type | Climatology |
|---|---|
| Operator | NASA |
| COSPAR ID | 2014-035A |
| SATCAT № | 40059 |
| Website | http://oco.jpl.nasa.gov/ |
| Mission duration | Planned: 2 years Elapsed: Script error: The function "age_generic" does not exist. |
| Spacecraft properties | |
| Bus | LEOStar-2 |
| Manufacturer | Orbital Sciences[1] |
| Launch mass | 454 kg (1,001 lb)[1] |
| Dry mass | 409 kg (902 lb) |
| Payload mass | 131 kg (289 lb)[1] |
| Dimensions | Stowed: 2.12 × 0.94 m (6.96 × 3.08 ft)[1] |
| Power | 815 W[1] |
| Start of mission | |
| Launch date | 2 July 2014, 09:56 UTC |
| Rocket | Delta II 7320-10C |
| Launch site | Vandenberg SLC-2W |
| Contractor | United Launch Alliance |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Sun-synchronous |
| Semi-major axis | 7,080.44 km (4,399.58 mi) |
| Eccentricity | 0.000125 |
| Perigee | 701.42 km (435.84 mi) |
| Apogee | 703.19 km (436.94 mi) |
| Inclination | 98.19° |
| Period | 98.82° |
| RAAN | 77.38° |
| Argument of perigee | 76.42° |
| Mean anomaly | 283.72° |
| Mean motion | 14.57° |
| Velocity | 7.5 km/s (4.7 mi/s) |
| Epoch | 15 May 2015, 19:41:10 UTC[2] |
| Revolution number | 4623 |
| Main telescope | |
| Type | Near-IR Cassegrain (ƒ/1.8)[3] |
| Wavelengths | 2.06 microns 1.61 microns 0.765 microns[1] |
| Instruments | |
| 3 grated spectrometers | |
 |
|
Orbiting Carbon Observatory 2 (OCO-2) is an American environmental science satellite which launched on 2 July 2014. A NASA mission, it is a replacement for the Orbiting Carbon Observatory which was lost in a launch failure in 2009.
Contents
Mission description
The OCO-2 satellite was built by Orbital Sciences Corporation, based around the LEOStar-2 bus.[4] The spacecraft is being used to study carbon dioxide concentrations and distributions in the atmosphere.[5]
OCO-2 was ordered after the original OCO spacecraft failed to achieve orbit. During the first satellite's launch atop a Taurus-XL in February 2009, the payload fairing failed to separate from around the spacecraft and the rocket did not have sufficient power to enter orbit with its additional mass. Although a Taurus launch was initially contracted for the reflight, the launch contract was cancelled after the same malfunction occurred on the launch of the Glory satellite two years later.[6]
.jpg)
United Launch Alliance launched OCO-2 using a Delta II rocket at the beginning of a 30-second launch window at 09:56:23 UTC (2:56:23 PDT) on 2 July 2014. Flying in the 7320-10C configuration, the rocket launched from Space Launch Complex 2W at Vandenberg Air Force Base.[7] The initial launch attempt on 1 July at 09:56:44 UTC was scrubbed at 46 seconds on the countdown clock due to a faulty valve on the water suppression system, used to flow water on the launch pad to dampen the acoustic energy during launch.[8]
OCO-2 joined the A-train satellite constellation, becoming the sixth satellite in the group. Members of the A-train fly very close together in sun-synchronous orbit, to make nearly simultaneous measurements of Earth. A particularly short launch window of 30 seconds was necessary to achieve a proper position in the train.[9] As of 15 May 2015 it was in an orbit with a perigee of 701.4 kilometres (435.8 mi), an apogee of 703.2 kilometres (436.9 mi) and 98.19 degrees inclination.[2]
Column CO2 measurements
OCO-2 makes measurements in three different spectral bands over four to eight different footprints of approximately 1.29 km × 2.25 km (0.80 mi × 1.40 mi) each.[10][11] About 24 soundings are collected per second while in sunlight and over 10% of these are sufficiently cloud free for further analysis. One spectral band is used for column measurements of oxygen (A-band 0.765 microns), and two are used for column measurements of carbon dioxide (weak band 1.61 microns, strong band 2.06 microns).[3]
In the retrieval algorithm measurements from the three bands are combined to yield column-averaged dry-air mole fractions of carbon dioxide. Because these are dry-air mole fractions, these measurements do not change with water content or surface pressure. Because the molecular oxygen content of the atmosphere ( i.e. excluding the oxygen in water vapour ) is well known to be 20.95%, oxygen is used as a measure of the total dry air column. To ensure these measurements are traceable to the World Meteorological Organization, OCO-2 measurements are carefully compared with measurements by the Total Carbon Column Observing Network (TCCON).[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 Osterman 2015, p. 7.
- ↑ Lua error in package.lua at line 80: module 'strict' not found. It has a mass of 454 kilograms (1,001 lb) and a design life of two years.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Osterman 2015, p. 5.
Bibliography
- Lua error in package.lua at line 80: module 'strict' not found.
External links
Media related to Lua error in package.lua at line 80: module 'strict' not found. at Wikimedia Commons
- Orbiting Carbon Observatory at NASA.gov
- Orbiting Carbon Observatory by the Jet Propulsion Laboratory
- Orbiting Carbon Observatory by the JPL Science Division
