NASA Headquarters, Washington, DC

June 23, 1998


NASA's Earth-orbiting Lewis spacecraft failed last fall due to a combination of a technically flawed attitude-control system design and inadequate monitoring of the spacecraft during its crucial early operations phase, according to the report of the Lewis Spacecraft Mission Failure Investigation Board.

Lewis was launched on August 23, 1997, with the goal of demonstrating advanced science instruments and spacecraft technologies for measuring changes in Earth's land surfaces. The spacecraft entered a flat spin in orbit that resulted in a loss of solar power and a fatal battery discharge. Contact with the spacecraft was lost on Aug. 26, and it then re- entered the atmosphere and was destroyed on Sept. 28. The 890-pound spacecraft was designed and built by TRW Space & Electronics Group, Redondo Beach, CA, as part of NASA's Small Spacecraft Technology Initiative.

The design of the Lewis attitude control system was adapted by TRW from its design for the system on the Total Ozone Mapping Spectrometer spacecraft. The failure board found that this adaptation was done without sufficient consideration for applying the system's design to a different primary spacecraft spin-axis orientation on Lewis. As a result, minor rotational perturbations, possibly due to small imbalances in the forces produced by the spacecraft's attitude control thrusters, caused the Lewis spacecraft to enter a spin. This situation eventually overloaded the spacecraft's control system while it was in a safehold mode. Prelaunch simulation and testing of the spacecraft's safehold modes also was flawed because it failed to analyze this possibility, the failure board found.

The combination of these errors with the subsequent assumption that a small crew could monitor and operate Lewis with the aid of an autonomous safehold mode, even during the initial operations period, was the primary cause of the mission failure, according to the failure board's report.

The failure board also assessed the role of the "faster, better, cheaper" project management approach in the Lewis program.

"The Lewis mission was a bold attempt by NASA to jumpstart the application of the 'faster, better, and cheaper' philosophy of doing its business," said Christine Anderson, chair of the failure board and Director of Space Vehicles for the U.S. Air Force Research Laboratory at Kirtland Air Force Base, NM. "I do not think that this concept is flawed. What was flawed in the Lewis program, beyond some engineering assumptions, was the lack of clear understanding between NASA and TRW about how to apply this philosophy effectively. This includes developing an appropriate balance between the three elements of this philosophy, the need for well-defined, well-understood and consistent roles for government and industry partners, and regular communication between all parts of the team."

"The Lewis failure offers us some valuable lessons in program management and in our approach to technical 'insight.' Lewis was an extreme example of allowing the contractor to have engineering autonomy. In the end, however, NASA has the responsibility to assure that the project objectives are met, and our assurance process was ineffective in this case," said Dr. Ghassem Asrar, NASA Associate Administrator for Earth Science. "NASA's Office of the Chief Engineer is developing general 'lessons learned' from this project and other 'faster, better, cheaper' efforts, and we intend to apply them vigorously to all of our future missions, including the second generation of spacecraft in the Earth Observing System.

"I would like to commend Christine Anderson and the members of her panel for their thorough job, and thank all the participants in the Lewis program for their cooperation with this review," Asrar added.

The total cost to NASA of the Lewis mission, including its launch vehicle and one year of planned orbital operations, was $64.8 million. NASA incurred an additional cost of $6.2 million for storage and maintenance of the spacecraft during a one-year delay due to launch vehicle issues.

Lewis was part of NASA's Earth Science enterprise, a long-term research program designed to study the Earth's land, oceans, air, ice and life as a total system.

The report of the Lewis Spacecraft Mission Failure Investigation Board is available via the Internet at the following address: The report of the Lewis Spacecraft Mission Failure Investigation Board is available vis the Internet (PDF-format).

September 28, 1997


NASA's Lewis Earth-imaging mission ended in a ball of fire today as the experimental satellite plunged into the atmosphere. The U.S. Space Command confirms the satellite reentered above the Southern Atlantic Ocean at about 7:58 a.m. EDT.

U.S. Space Command News Release

September 27, 1997


United States Space Command has tracked NASA's Lewis Satellite beginning August 22, 1997 since its launch from Vandenberg Air Force Base, CA, and predicts it will re-enter the atmosphere sometime between the late evening of the 27th and afternoon of the 28th of September (MDT). It is too early for the command to predict a more precise time or an area over which the satellite might re-enter the Earth'satmosphere.

The Lewis Satellite was an earth-orbiting spacecraft built by TRW Space and Electronics Group, Redondo Beach, CA for NASA. Lewis was part of NASA's Small Spacecraft Technology Initiative.

The satellite is currently in an almost circular orbit that takes it just under 127 miles above the Earth's surface at its lowest point and over 135 miles at its highest point. It is traveling at approximately 17,000 mph and orbits the earth in just under 89 minutes.

United States Space Command, in performing this mission, monitors all man-made Earth orbiting objects greater than about four inches in diameter -- approximately 8,000 objects in all. Objects in orbit include expended rocket bodies, deactivated satellites, active satellites, and other debris. This is done partly to ensure their re-entry is not mistaken by the U.S. or other nations as the re-entry of a ballistic missile.

Sixteen worldwide ground-based radars and optical systems are tracking the Lewis Satellite. Crews from United States Space Command's Space Control Center and the U.S. Air Force's 1st Command and Control Squadron, both located in Cheyenne Mountain near Colorado Springs, will analyze the data and estimate a time and general area of the satellite's re-entry into the Earth's atmosphere.

As the satellite gets closer to the time of predicted re-entry, more frequent calculations will be performed to further refine the accuracy of our predictions. At this time it is not possible to predict over what part of the Earth the satellite might re-enter. It is also not possible to predict whether it will survive re-entry, however, the Lewis Satellite was not designed to survive re-entry and is expected to burn up in the atmosphere.

NASA Headquarters, Washington, DC
TRW Space & Electronics Group, Redondo Beach, CA

September 19, 1997


Repeated attempts to re-establish radio contact with NASA's Earth-orbiting Lewis spacecraft since it entered a slow spin on Aug. 26 have been unsuccessful. Due to increasing atmospheric drag, the spacecraft's orbit is deteriorating. Unless contact is regained early next week, it is expected to re-enter and burn up between Sept. 23-30, with Sept. 27 as the current most likely re- entry date, according to program officials.

"Based on our previous experience with this type of spacecraft, we expect Lewis to burn up in the atmosphere. The probability that any part of it will survive is very low, and it presents no significant threat to people on the ground," said Samuel Venneri, Chief Technologist at NASA Headquarters, Washington. "The potential loss of this mission is an obvious disappointment. However, the process of designing and building the spacecraft taught us a great deal about how to integrate cutting-edge technology into small missions and how to prepare the associated science teams, and we will apply those lessons to future projects."

Lewis was launched on Aug. 22 (Aug. 23 EDT) from Vandenberg Air Force Base, CA, aboard a Lockheed Martin Launch Vehicle (LMLV-1). Built by TRW Space & Electronics Group, Redondo Beach, CA, the 890-pound Lewis satellite is part of NASA's Small Spacecraft Technology Initiative.

"We are aggressively applying the company's resources in our ongoing attempt to recover the satellite, and we greatly appreciate the tremendous support that NASA and other government agencies have given us in this effort," said Paul Sasaki, vice president and general manager of the TRW Civil & International Systems Division.

Initial operations and check-out of Lewis were proceeding satisfactorily until telemetry received early August 26 indicated that the spacecraft was spinning at approximately two revolutions per minute. Preliminary indications are that unbalanced thruster firings occurred on the spacecraft, inducing a spin rate that went unchecked as Lewis remained in a previously commanded safehold.

The solar arrays on Lewis were unable to generate significant power due to the spinning motion and their alignment with the Sun, and thus the spacecraft's batteries became almost fully discharged. Initial hopes that sunlight would "trickle charge "the batteries sufficiently to allow the spacecraft's transmitter and computer to be accessed were not borne out by subsequent operations.

An independent Lewis spacecraft anomaly review board, to be chaired by a non-NASA official, is being established. It is expected to report its findings approximately 60 days after re- entry.

Outfitted with advanced technology Earth-imaging instruments and subsystems intended to push the state-of-the-art in scientific and commercial remote sensing, Lewis featured remote-sensing instruments designed to split up the spectrum of light energy reflected by Earth's land surfaces into as many as 384 distinct bands. Potential commercial applications included pollutant monitoring, analysis of endangered species habitats, estimation of forest and agricultural productivity, soil resources and crop residue mapping and assessments of environmental impacts from energy pipelines.

The total cost to NASA of the Lewis mission, including its launch vehicle and one year of planned orbital operations, is $64.8 million. NASA incurred an additional cost of $6.2 million for storage and maintenance of the spacecraft during a one-year delay due to launch vehicle issues.

Lewis is part of NASA's Mission to Planet Earth enterprise, a long-term research program designed to study the Earth's land, oceans, air and life as a total system. Upcoming Mission to Planet Earth spacecraft such as the New Millennium program's Earth Orbiting-1 mission, due for launch in June 1998, should help scientists address some of the planned applications of Lewis data.

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