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April 15, 1999 - present

Landsat 7

Figure 1. Landsat 7

Launch of Landsat 7
Click the image to watch the launch of Landsat 7
 

Participants

  • NASA
  • National Oceanic and Atmospheric Administration (NOAA) (initial participant)
  • Department of the Interior (DOI) U.S. Geological Survey (USGS)
  • Spacecraft bus: Lockheed Martin Missiles & Space
  • Enhanced Thematic Mapper Plus (ETM+): Hughes Santa Barbara Remote Sensing
     

Launch

  • Date: April 15, 1999
  • Vehicle: Delta II
  • Launched by: NASA
  • Site: Western Test Range at Vandenberg Air Force Base, California
     

Landsat 7 - Launch Image 1Landsat 7 - Launch Image 2Landsat 7 - Launch Image 3Landsat 7 - Launch Image 4Landsat 7 - Launch Image 5

Figure 2. Landsat 7
 

Spacecraft

  • Power provided by a single Sun-tracking solar array and two 50 Ampere-Hour (AHr), Nickel Cadmium (NiCd) batteries
  • Attitude control provided through four reaction wheels (pitch, yaw, roll, and skew); three 2-channel gyros with celestial drift updating; a static Earth sensor; a 1750 processor; and torque rods and magnetometers for momentum uploading
  • Orbit control and backup momentum unloading provided through a blow-down monopropellant hydrazine system with a single tank containing 270 pounds of hydrazine, associated plumbing, and twelve 1-pound-thrust jets
  • Weight: approx. 4,800 lbs (2,200 kg)
  • Length: 4.3 m (14 ft)
  • Diameter: 2.8 m (9 ft)
     

Communications

  • Direct Downlink with Solid State Recorders (SSR)
  • Data rate: 150 Mbps
     

Orbit

  • Worldwide Reference System-2 (WRS-2) path/row system
  • Sun-synchronous orbit at an altitude of 705 km (438 mi)
  • 233 orbit cycle; covers the entire globe every 16 days (except for the highest polar latitudes)
  • Inclined 98.2° (slightly retrograde)
  • Circles the Earth every 98.9 minutes
  • Equatorial crossing time: 10:00 a.m. +/- 15 minutes
     

Sensors

Enhanced Thematic Mapper Plus (ETM+)

  • Eight spectral bands, including a pan and thermal band:
    • Band 1 Visible (0.45 - 0.52 µm) 30 m
    • Band 2 Visible (0.52 - 0.60 µm) 30 m
    • Band 3 Visible (0.63 - 0.69 µm) 30 m
    • Band 4 Near-Infrared (0.77 - 0.90 µm) 30 m
    • Band 5 Near-Infrared (1.55 - 1.75 µm) 30 m
    • Band 6 Thermal (10.40 - 12.50 µm) 60 m Low Gain / High Gain
    • Band 7 Mid-Infrared (2.08 - 2.35 µm) 30 m
    • Band 8 Panchromatic (PAN) (0.52 - 0.90 µm) 15 m
  • Ground Sampling Interval (pixel size): 30 m reflective, 60 m thermal
  • Added the Band 6 Low and High gain 60 m thermal bands
  • On-board calibration was added to Landsat 7: a Full Aperture Solar Calibrator (FASC) and a Partial Aperture Solar Calibrator (PASC), in addition to the 2 calibration lamps
     

Other Characteristics

Landsat 7

Figure 3. Landsat 7
 

Landsat 1 Landsat 2 Landsat 3 Landsat 4 Landsat 5 Landsat 6 Landsat 7 Landsat 8 Landsat 9