Print PDF

Satellite Patent Not Invalid

04-1501
April 20, 2005

Decision icon Decision

Last Month at the Federal Circuit - May 2005

Judges: Newman (author), Michel, and Gajarsa

In Space Systems/Loral, Inc. v. Lockheed Martin Corp., No. 04-1501 (Fed. Cir. Apr. 20, 2005), the Federal Circuit reversed a judgment that U.S. Patent No. 4,537,375 (“the ‘375 patent”) is invalid for violating the written description requirement of 35 U.S.C. § 112. Space Systems/Loral, Inc. (“Loral”) owns the ‘375 patent, which is directed to an improved method for maintaining the orientation and attitude of a satellite. To maintain a correct position in space, a satellite forms station-keeping maneuvers by firing its thrusters. The ‘375 patent is directed to a method of reducing fuel consumption during such stationkeeping maneuvers. The claims of the ‘375 patent concern a two-step process, wherein the satellite conducts a first firing of the thrusters based on a correction estimated from historical data of prior stationkeeping maneuvers (called the “prebias” step) and a second firing based on the actual remaining error in its position.

Loral brought suit against Lockheed Martin Corporation (“Lockheed”) for infringement of claim 1. Lockheed moved for SJ of invalidity based on the written description requirement of 35 U.S.C. § 112, arguing that the specification does not adequately describe the second step in which the satellite calculates the position after the first firing and performs a second firing of the thrusters. The district court adopted Lockheed’s position.

On appeal, the Federal Circuit disagreed with the district court’s conclusion, noting that even Lockheed’s own expert had conceded that the second step was shown in the specification. Although Lockheed criticized the expert’s testimony as being conclusory, the Federal Circuit found that that expert’s testimony was quite specific, pointing to specific circuitry of the figures. Accordingly, the Federal Circuit reversed the SJ of invalidity and remanded the case.