Earth Observing 1 (EO-1) is a satellite launched by the New Millennium Program. It was launched from Vandenberg Air Force Base on November 21, 2000. It was inserted into a 705 km circular, sun-synchronous orbit at a 98.7 degrees inclination, so that it is flying in formation 1 minute of an arc behind Landsat Satellite 7 in the same orbit and maintaining the separation within 2 seconds.

Its mission is to test several new technologies to be used in future landsat satellites, as well as duplicating the USGS data that Landsat 7 provides. It produces 20 gigabits of data every orbit.

The Advanced Land Imager, the first of the three surveying technologies being tested on EO-1, is a basic land imager with three important improvements; a silicon carbide optics system which is lighter than the materials currently used, a larger field of view without using mechanical scanning by instead using mirrors, and multispectral imaging to increase data quality and lower the signal-to-noise ratio. Each of these technologies will lower weight and cost while increasing data quality and usable life of future satellites.

Design ideas based on EO-1 use one fifth as much power, weigh one fourth as much, and have twice the data rate (with one fourth the noise) as satellites currently in use.

Non-surveying technologies that debuted on EO-1, which will improve the usefulness of many future satellites include:

  • X-Band High Data Rate Array Antenna
  • Carbon-Carbon Passive Heat Radiator
  • Lightweight Flexible Solar Array
  • Wideband Advanced Recorder Processor
  • Pulsed Plasma Precision Attitude Control Thruster
  • Enhanced Formation Flying System
  • Improved Thermal Coating
  • After 2 and a half years, the technologies have all been validated, and the satellite is in full operation as a regular landsat imager under the aegis of the USGS