Landsat Missions

Landsat 7

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

  • Scene size: 170 km x 185 km (106 mi x 115 mi)
  • Design Life: Minimum of 5 years
     

Landsat 7

Figure 3. Landsat 7
 

About

Landsat represents the world's longest continuously acquired collection of space-based moderate-resolution land remote sensing data. Four decades of imagery provides a unique resource for those who work in agriculture, geology, forestry, regional planning, education, mapping, and global change research. Landsat images are also invaluable for emergency response and disaster relief.

 

Contact Us

Landsat Updates

The Landsat Update is an informal communication tool, prepared periodically and distributed electronically to USGS Landsat partners, to provide information about Landsat activities and related topics of interest.

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: https://landsat.usgs.gov
Page Contact Information: Ask Landsat
Page Last Modified: 11/29/16 03:03 pm
Sitemap