TIMED

TIMED

TIMED in Low Earth orbit.
Mission type	Ionosphere Atmospheric science Space weather research.
Operator	NASA
COSPAR ID	2001-055B
SATCAT №	26998
Website	TIMED at APL
Mission duration	2 years (planned) 8+ years (ongoing)
Spacecraft properties
Manufacturer	Applied Physics Laboratory
Launch mass	660 kilograms (1,460 lb)
Power	300 W (nominal)
Start of mission
Launch date	7 December 2001, 15:07:35 UTC
Rocket	Delta II 7920-10 D289
Launch site	Vandenberg SLC-2W
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Semi-major axis	6,983.0 kilometers (4,339.0 mi)
Eccentricity	0.0000651
Perigee	611.7 kilometers (380.1 mi)
Apogee	612.6 kilometers (380.7 mi)
Inclination	74.0722º
Period	96.8 minutes
RAAN	302.7819 degrees
Argument of perigee	343.2534 degrees
Mean anomaly	16.86255 degrees
Mean motion	14.87734465
Epoch	26 June 2016
Revolution number	78858

The TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) is an orbiter mission dedicated to study the dynamics of the Mesosphere and Lower Thermosphere (MLT) portion of the Earth's atmosphere. The mission was launched from Vandenberg Air Force Base in California on December 7, 2001 aboard a Delta II rocket launch vehicle. The project is sponsored and managed by NASA, while the spacecraft was designed and assembled by the Applied Physics Laboratory at Johns Hopkins University. The mission has been extended several times, and has now collected data over an entire solar cycle, which helps in its goal to differentiate the Sun's effects on the atmosphere from other effects.^[1]

Atmospheric region under study

TIMED Mission diagram (NASA)

The Mesosphere and Lower Thermosphere (MLT) region of the atmosphere to be studied by TIMED is located between 60–180 km above the Earth's surface where energy from solar radiation is first deposited into the atmosphere. This can have profound effects on Earth's upper atmospheric regions, particularly during the peak of the Sun's 11-year solar cycle when the greatest amounts of its energy are being released. Understanding these interactions is also important for our understanding of various subjects in geophysics, meteorology, and atmospheric science, as solar radiation is one of the primary driving forces behind atmospheric tides. Changes in the MLT can also affect modern satellite and radio telecommunications.

Scientific instruments onboard

The spacecraft payload consists of the following four main instruments:

• Global Ultraviolet Imager (GUVI): A spatial-scanning, far-ultraviolet spectrograph designed to globally measure the composition and temperature profiles of the MLT region, as well as its auroral energy inputs.
• Solar Extreme Ultraviolet Experiment (SEE): A spectrometer and a suite of photometers designed to measure the solar soft X-rays, extreme-ultraviolet and far-ultraviolet radiation that is deposited into the MLT region.
• TIMED Doppler Interferometer (TIDI): Designed to globally measure the wind and temperature profiles of the MLT region.
• Sounding of the Atmosphere using Broadband Emission Radiometry (SABER): Multichannel radiometer designed to measure heat emitted by the atmosphere over a broad altitude and spectral range, as well as global temperature profiles and sources of atmospheric cooling.

Spacecraft stats

• Mass: 660 kilograms
• Dimensions:
  • 2.72 meters high
  • 1.61 meters wide (launch configuration)
  • 11.73 meters wide (solar arrays deployed)
  • 1.2 meters deep
• Power Consumption: 406 watts per orbit
• Data Downlink: 4 megabits per second
• Memory: 5 gigabits
• Control & Data Handling Processor: Mongoose-V
• Attitude:
  • Control - Within 0.5 degrees
  • Knowledge - Within 0.03 degrees
  • Processor: RTX2010
• Total Mission Cost:
  • Spacecraft: $195 million
  • Ground Operations: $42 million

United States

• University of Alaska, Fairbanks, Alaska
• University of California, Berkeley, California
• Jet Propulsion Laboratory, Pasadena, California
• University of Colorado, Boulder, Colorado
• National Center for Atmospheric Research, Boulder, Colorado
• National Oceanic and Atmospheric Administration, Boulder, Colorado
• The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
• Air Force Research Laboratory, Hanscom Air Force Base, Massachusetts
• Stewart Radiance Laboratory, Bedford, Massachusetts
• University of Michigan, Ann Arbor, Michigan
• Southwest Research Institute, San Antonio, Texas
• Utah State University, Logan, Utah
• Hampton University, Hampton, Virginia
• Computational Physics, Inc., Fairfax, Virginia
• Naval Research Laboratory, Washington, D.C.
• NASA Langley Research Center, Hampton, Virginia
• G&A Technical Software Inc., Hampton, Virginia

International

• Hovemere Limited, Kent, England, United Kingdom
• British Antarctic Survey, Cambridge, England, United Kingdom
• CREES-York University, Toronto, Canada
• Astrophysical Institute of Andalucia (IAA), Granada, Spain
• Rostock University, Rostock, Germany

See also

• Upper Atmosphere Research Satellite

References

1. Fox, Karen. "Ten Successful Years of Mapping the Middle Atmosphere". NASA.

External links

• TIMED mission page at JHU/APL
• TIMED mission page at NASA GSFC
• Solar EUV Experiment (SEE) page at the Laboratory for Atmospheric and Space Physics