Introduction

The Earth Observing-1 (EO-1) Mission was developed as part of the NASA New Millennium Program (NMP). The NMP was established in 1994 to respond to the challenge of the NASA Administrator to develop faster, better, and cheaper missions.

The NMP was charged to develop and flight-validate revolutionary technologies; reduce development risks and life cycle costs of future science missions; enable highly capable and autonomous space systems; and, promote nationwide technology teaming and coordination.

Land Remote Sensing

In addition, the EO-1 Mission was to be responsive to the Land Remote Sensing Policy Act of 1992 (Public Law 102-55) wherein NASA was charged to ensure Landsat data continuity through the use of advanced technology. Consequently, EO-1 was designed to flight-validate breakthrough technologies applicable to Landsat follow-on missions. More specifically, EO-1 developed a multispectral imaging capability that addressed the traditional Landsat user community; hyperspectral imaging capability with backward compatibility that addressed the Landsat research-oriented community; calibration test bed to improve absolute radiometric accuracy; and atmospheric correction to compensate for intervening atmosphere effects. Noteworthy is the fact that the EO-1 multispectral land imaging instrument, containing advanced technology elements, has a significant improvement in performance over the Landsat-7 ETM+ instrument and at significantly lower cost.

The Jet Propulsion Laboratory (JPL) currently manages the overall NMP for the agency. The process of formulating an NMP mission, outlined above, was established by them. Certain Earth Observing missions have been assigned to GSFC as lead center. EO-1 was managed at GSFC, making it the EO-1 performing center. Overall program management was provided by the NMP/EO Program Office at the Goddard Space Flight Center (GSFC). Dr. Bryant Cramer is the EO-1 Program Manager, Mr. Dale Schulz was the EO-1 Mission Manager, and Dr. Stephen Ungar is the EO-1 Mission Scientist.

Mission Status
The EO-1 Mission was approved for flight on March 22, 1996 by the Earth Science Enterprise at NASA HQ and was launched on a Delta II rocket from Vandenberg Air Force Base on November 21, 2000. EO-1 was launched into a polar orbit with an equatorial crossing time of 10:03 a.m. (descending node), an altitude of 705 km, an inclination of 98.2 deg., and an orbital period of 98 minutes. The mission had a design life of 18 months and a nominal life of 12 months.

Baseline operations consisted of 5-7 ground station passes per day transmitting both S-and X-band data to stations in Norway and Alaska. Science data was transmitted by X-band at up to 120 Gbits per day which corresponds typically to 5-7 Data Collection Events (DCEs) each day at 105 Mb/s rate. Housekeeping data, as well as backup science data, is transmitted by S-band at up to 2 Mb/s. This downlink results in up to 200 Mbits of housekeeping data per day and up to 5 Gbits per day of backup science data.

Technologies within the NMP that are selected to fly on a certain missions are divided into three categories depending on their assigned role on a given validation flight.

EO-1 Technologies

Category 1 technologies are considered crucial to the flight. Should one encounter difficulty, the flight will be delayed and/or restructured to accommodate it.

Category II technologies proceed in parallel with an alternative approach based on a conventional technology. If the new technology encounters difficulty, then it is removed from the flight and the flight proceeds with the shadowing conventional technology. These technologies often represent an essential function in one of the instrument(s) or on the spacecraft.

Category III technologies are flight opportunities that are designed so that their failure to materialize does not critically impact the Category I or II technologies on the mission. In this case, should they encounter difficulty, they will simply be removed from the flight. These technologies represent non-critical payloads. A given NMP flight is a mixture of all three categories and is determined by the flight validation priorities, the nature of the individual technologies, and the aggregate risk acceptable to the NMP flight.


The objective of the EO-1 Mission, as established in NASA HQ’s Level 1 Requirements, was to validate the following breakthrough technologies:

• Multispectral Imaging Capability: Category I
• Wide Field, High Resolution, Reflective Optics: Category I
• Silicon Carbide Optics: Category I
• Hyperspectral Imaging Capability: Category III
• Atmospheric Corrector: Category III
• X-Band Phased Array Antenna: Category II
• Wideband Advanced Recorder and Processor: Category II
• Enhanced Formation Flying: Category III
• Lightweight Flexible Solar Array: Category III
• Carbon-Carbon Radiator: Category III
• Pulsed Plasma Thruster: Category III
• LA-II Thermal Coating: Category III

In addition, under a NASA Research Announcement (NRA-99-OES-01) jointly issued by NASA and the U.S. Geological Survey (USGS), an additional objective was established. The stated objective was to evaluate the ability of the instruments to produce images suitable for performing defined science validation investigations. As a result, 30 principal investigators were selected to form a Science Validation Team (SVT).