Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-cand-3_96-cv-03418/USCOURTS-cand-3_96-cv-03418-11/pdf.json

Nature of Suit Code: 830
Nature of Suit: Patent
Cause of Action: 35:271 Patent Infringement

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United States District Court

For the Northern District of California

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After the Court announced its tentative ruling at oral argument, counsel for plaintiff requested

the opportunity to file supplemental briefing addressing the Court’s proposed construction of “net

position error.” Further briefing was thereafter received both from plaintiff and from defendant.

United States District Court

For the Northern District of California

IN THE UNITED STATES DISTRICT COURT

FOR THE NORTHERN DISTRICT OF CALIFORNIA

SPACE SYSTEMS/LORAL, INC.,

Plaintiff,

 v.

LOCKHEED MARTIN CORP.,

Defendant. /

No. C 96-03418 SI

ORDER GRANTING DEFENDANT’S

MOTION FOR RECONSIDERATION OF

CLAIM CONSTRUCTION

Presently before the Court is defendant Lockheed Martin Corp.’s (“Lockheed”) motion for

reconsideration of claim construction.1 Having considered the parties’ arguments and the papers

submitted, and for good cause appearing, the Court GRANTS defendant’s motion. 

BACKGROUND

Plaintiff, Space Systems/Loral, Inc. (“SSL”), is the owner of the patent at issue, U.S. Patent No.

4,537,375 (“the ’375 patent”). SSL filed this patent infringement suit against Lockheed in 1995, adding

claims for infringement of the ’375 patent in 1998. 

As this Court has described in its previous orders, the ’375 patent discloses an improved method

of performing satellite “station-keeping” maneuvers. The Federal Circuit has described the ’375 patent

as follows:

Loral is the owner of the ’375 patent for an improved method of maintaining the

orientation and attitude of a satellite in space. Satellites in orbit around the earth tend to

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be pulled out of their proper position by the gravitational effects of the sun, earth, and

moon. To maintain the requisite position the satellite conducts “station-keeping

maneuvers” by firing its thrusters, based upon measurements of its position. However,

the station-keeping maneuvers may over-correct or may introduce new errors in position

and orientation, and the general procedure has been to conduct a second firing to correct

the errors of the first firing. These procedures require fuel, the on-board supply of which

is limited, and limits the useful life of the satellite. The ’375 patent is directed to a

method of reducing the fuel consumption during station-keeping, by enhancing the

efficiency of the corrective procedure.

According to the ’375 patent, the satellite first estimates the probable correction based

on historical data from prior station-keeping maneuvers, and conducts a first firing of the

thrusters based on the estimated correction. This is called the “prebias” step of the

modulating response. After the prebias firing, the satellite measures the remaining actual

error in its position, adds the actual error to the historical error, and conducts a second

firing. This procedure overall uses less fuel than the prior method whereby a first firing

was calculated to attempt full correction, followed by a second firing. The fuel saving

that is achieved extends the life of the satellite.

Space Sys. v. Lockheed Martin Corp., 405 F.3d 985, 987 (Fed. Cir. 2005); see also Space Sys. v.

Lockheed Martin Corp., 271 F.3d 1076, 1077-78 (Fed. Cir. 2001).

At issue in the current motion is this Court’s construction of two terms in Claim 1 of the ’375

patent. First, the parties dispute the meaning of what they refer to as “step [b]” of claim 1; second, the

parties dispute the meaning of the term “net position error.” Claim 1 reads as follows:

1. For use in a spacecraft during a change in velocity maneuver, the spacecraft

employing a plurality of thrusters, at least a first thruster and a second thruster

being disposed to develop mutually counteractive moment arms of thrust relative

to at least one axis through a center of mass of the spacecraft, said first thruster

and said second thruster being capable of developing unequal moment arms of

force, a method for counteracting disturbance transients comprising the steps of:

[a] storing prior to said man[eu]ver a value representative of an estimated

disturbance torque;

[b] modulating in response to said stored value one of said first and second

thrusters during said maneuver to counteract an actual disturbance torque

a sufficient amount to compensate for said actual disturbance torque in

order to minimize a net position error without initially detecting said net

position error; thereafter

[c] detecting said net position error, said net position error being indicative

of a difference between said estimated disturbance torque and said actual

disturbance torque with respect to said axis; and thereafter

[d] modulating in response to a sum of said stored value and said net position

error one of said first and second thrusters during said man[eu]ver to

counteract said actual disturbance torque to further minimize said net

position error.

’375 patent, col. 9, lines 7-33 (emphases and bracketed step delineations added).

The Court has twice before addressed the construction of the terms at issue in the current motion.

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On September 17, 1999, the Court held a Markman hearing that resulted in a claim construction order

dated October 18, 1999. That order construed “net position error” to mean “an attitude error arising

after a modulated firing of a thruster pair.” Based on the patent’s prosecution history, however, the

Court limited step [b] by prohibiting the first thruster modulation from being based on “position error

in general.”

On April 16, 2002, the Court issued an order in response to a motion for reconsideration of its

prior claim construction order. In that order the Court refused defendant’s request to reexamine its

construction of “net position error.” However, the Court granted SSL’s motion to reconsider the

construction of step [b]. The Court abandoned its earlier limitation on step [b], finding that it had

erroneously interpreted the prosecution history, and removed the limitation that the first thruster

modulation could not be based on position error in general. Thus, the Court construed step [b] to cover

“modulating in response to the stored value without reference to or depending upon net position error.”

Following this second claim construction order, the Court granted summary judgment in favor

of defendant, finding that the ’375 patent was invalid because it violated the written description

requirement. In April 2005, the Federal Circuit reversed and remanded. In light of the Federal Circuit’s

decision, Lockheed now moves for the Court to reconsider its claim construction orders. The Court

GRANTS Lockheed’s motion. 

LEGAL STANDARD

“[T]he claims of a patent define the invention to which the patentee is entitled the right to

exclude.” Innova/Pure Water, Inc. v. Safari Water Filtration Sys., Inc., 381 F.3d 1111, 1115 (Fed. Cir.

2004); see also Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996) (“[W]e look

to the words of the claims themselves . . . to define the scope of the patented invention.”); Markman v.

Westview Instruments, Inc., 52 F.3d 967, 980 (Fed. Cir. 1995), aff’d, 517 U.S. 370, 116 S. Ct. 1384

(1996) (“The written description part of the specification itself does not delimit the right to exclude.

That is the function and purpose of claims.”). Words of a claim are to be given their “ordinary and

customary meaning,” in light of the understanding of a person of ordinary skill in the art in question at

the time of the invention. Innova, 381 F.3d at 1116. A person of ordinary skill in the art, however, is

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deemed to read the claim term “not only in the context of the particular claim in which the disputed term

appears, but in the context of the entire patent, including the specification.” Phillips v. AWH Corp., 415

F.3d 1303, 1313 (Fed. Cir. 2005); see also Medrad, Inc. v. MRI Devices Corp., 401 F.3d 1313, 1319

(Fed. Cir. 2005) (“We cannot look at the ordinary meaning of the term . . . in a vacuum. Rather, we must

look at the ordinary meaning in the context of the written description and the prosecution history.”).

“Quite apart from the written description and the prosecution history, the claims themselves

provide substantial guidance as to the meaning of particular claim terms.” Phillips, 415 F.3d at 1313;

see also Vitronics, 90 F.3d at 1582; ACTV, Inc. v. Walt Disney Co., 346 F.3d 1082, 1088 (Fed. Cir.

2003) (“[T]he context of the surrounding words of the claim also must be considered in determining the

ordinary and customary meaning of those terms.”). “Because claim terms are normally used

consistently throughout the patent, the usage of a term in one claim can often illuminate the meaning

of the same term in other claims.” Phillips, 415 F.3d at 1313.

DISCUSSION

Lockheed’s overarching argument is that the Federal Circuit necessarily construed the claims

of the ’375 patent when it evaluated SSL’s appeal of this Court’s summary judgment order. The Court

cannot agree with this interpretation. In support of its argument, Lockheed cites only to the Federal

Circuit’s general description of the ’375 patent, which the Court has in large part quoted above. Def.

Br. at 8. Conspicuously absent from the Federal Circuit’s opinion is case law discussing the process of

claim construction, or reference to standard claim construction materials, such as the patent’s

prosecution history. Indeed, aside from the patent itself the Federal Circuit does not mention any of the

materials that this Court considered in its claim construction order, or even the order itself. Thus, the

Court rejects Lockheed’s claim that the Federal Circuit construed the claims of the ’375 patent when

it reversed this Court’s written description order.

Nonetheless, while the Federal Circuit’s opinion is not controlling on this Court’s claim

construction, the Federal Circuit’s opinion is undoubtedly relevant and influential. And it is clear from

this Court’s review of the Federal Circuit’s opinion that the Federal Circuit understood the ’375 patent

to disclose an invention in which the first thruster firing was modulated in response to the estimated,

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“prebias,” correction, without taking actual error into account. For example, the Federal Circuit wrote,

the satellite first estimates the probable correction based on historical data from prior

station-keeping maneuvers, and conducts a first firing of the thrusters based on the

estimated correction. This is called the “prebias” step of the modulating response. After

the prebias firing, the satellite measures the remaining actual error in its position, adds

the actual error to the historical error, and conducts a second firing. This procedure

overall uses less fuel than the prior method whereby a first firing was calculated to

attempt full correction, followed by a second firing. The fuel saving that is achieved

extends the life of the satellite.

Riley Decl., Exh. 4, at 3 (emphasis added). In the rest of the opinion, the Federal Circuit was fully

consistent with this interpretation of the ’375 patent. After describing the sequence leading up to the

second firing of the thrusters, in which “[t]he actual error information and the prebias or historical error

information are both fed into the summer,” the Federal Circuit stated, “[t]hese are the two outputs of the

error detection system used to modulate the thrusters; the prebias information is fed directly into the

pulse-width, pulse frequency (PWPF) modulating devices, col. 6, lines 30-35, and the sum of the actual

and historical error from [the summer] is also fed into the PWPF modulating devices. Id. Thus the

thrusters are modulated by both the historical (prebias) information and by the sum of the actual and

historical information.” Id. at 5. Thus, the Federal Circuit understood the patent to disclose two

thruster-firing steps in the station-keeping process, the first based only upon prebias error and the second

based in part upon the satellite’s actual error. 

The Federal Circuit’s opinion is not the only evidence in support of this Court revisiting its prior

claim construction order. Lockheed has also made a convincing argument that this Court’s current claim

construction is internally inconsistent. As it stands, step [b] of claim 1 is construed as “modulating in

response to the stored value without reference to or depending upon net position error.” Because “net

position error” – the remaining actual error in the satellite’s position – arises only after the thrusters fire,

the phrase “without reference to or depending upon net position error” is superfluous; it is by definition

impossible to detect or rely on “net position error” before the thrusters fire.

Based on the above, the Court believes that its claim construction should be revisited. Lockheed

suggests two alternative options: First, the court could re-adopt its initial claim construction and prohibit

step [b] from utilizing “any position error”; second, the Court could remove the timing restriction on

its construction of “net position error,” that the error only exist after the thrusters fire. The Court finds

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the former approach to be preferable.

1. Construction of “Net Position Error”

In both its claim construction orders, this Court has consistently interpreted “net position error”

to mean “attitude error arising after a modulated firing of a thruster pair, and is indicative of a difference

between an estimated disturbance torque and an actual disturbance torque.” Given the description of

“net position error” in step [c] of claim 1, the Court continues to believe that this interpretation is the

most sensible. See ’375 patent, col. 9, lines 25-28 (describing “net position error” in step [c] as “being

indicative of a difference between said estimated disturbance torque and said actual disturbance

torque”). Moreover, the Federal Circuit appears to have accepted this definition. See Riley Decl., Exh.

4 at 6 (“[Dr. Kaplan] explained that only after the firing maneuver starts does net position error exist.”).

Thus, the Court declines to revisit its construction of “net position error.”

Lockheed argues that the Court should change its construction of “net position error” because

the current construction renders a portion of step [b] superfluous. Specifically, Lockheed contends that

the phrase “without initially detecting said net position error” has no meaning under the Court’s current

construction, given that “net position error” as currently defined cannot exist until after the thrusters fire.

The Court disagrees with Lockheed’s reading of step [b]. Lockheed reads the quoted language

in isolation, and as a concrete limitation on the modulation process of step [b] that prohibits the

measurement of “net position error” before the first modulation takes place. Under this interpretation,

it is indeed superfluous to explicitly bar “net position error” from being measured before net position

error can exist. Rather than reading the language as an explicit bar, however, the Court believes that

the language is best read in the abstract and in connection with the preceding phrase, as a statement of

the purpose of the first modulating step. Thus, the Court believes the disputed language is best

interpreted as follows: “[The first modulating step is performed] in order to minimize a net position error

without initially detecting said net position error.” Read in this way, the language serves to make clear

the manner in which the claimed invention differs from the prior art – the prior art minimized net

position error by detecting it and reacting to it, while the current invention initially minimizes net

position error without detecting it. This interpretation of the disputed language gives the most sensible

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meaning to net position error without rendering any portion of the patent’s claims superfluous.

2. Construction of Step [b]

In its original claim construction order, the Court found that the prosecution history of the ’375

patent created a limitation in step [b]. Specifically, the Court found that the inventor’s statement during

prosecution of the patent that “the invention generates a counter-torque which does not depend on a

detected position error” was made to overcome a prior art rejection, and therefore prohibited the

modulation in step [b] from relying on “position error in general.” In its second claim construction

order, however, the Court changed this construction, finding that nothing prohibited the first modulation

step from relying on position error in general. The Court reached this conclusion based on its

determination that the claim language and the patent’s specification supported a broader reading of the

first modulating step. The Court then found that the inventor’s statement during patent prosecution was

not sufficiently explicit to overcome the claim language and specification and to place a limitation on

the claims.

As is evident from the fact that this is the Court’s third claim construction order, the questions

presented in this matter are close, and the patent is by no means a model of clarity. But given the

Federal Circuit’s understanding of the patent, the Court no longer adheres to the view that the patent’s

claims and specification support plaintiff’s proposed construction. To the contrary, the Federal Circuit

found support in the specification for its view that the first modulating step was based on estimated,

historical error alone. See Riley Decl., Exh. 4 at 5; see also Phillips v. AWH Corp., 415 F.3d 1303, 1317

(Fed. Cir. 2005) (“It is therefore entirely appropriate for a court, when conducting claim construction,

to rely heavily on the written description for guidance as to the meaning of the claims.”). This view,

combined with the patent inventor’s consistent statements during the prosecution of the patent, which

were made to overcome a prior art rejection, convince the Court that step [b] should be limited to

modulating in response to the stored value without referencing or depending upon any position error.

Accordingly, the Court will revert to its original construction of step [b].

SSL raises three arguments against this interpretation. First, it argues that the Court is

erroneously reading the word “exclusively” into step [b], so it would read “modulating [exclusively] in

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response to said stored value.” While it is generally error to read a limitation into a claim from the

specification, it is not error to do so when a patent’s specification and prosecution history make clear

that the inventor intended his invention to be limited. See Seachange Int’l, Inc. v. C-COR, Inc., 413 F.3d

1361, 1372-73 (Fed. Cir. 2005). Here, the patent’s inventor distinguished the prior art based on his

invention’s use of a prebias. In doing so, he emphasized that “the invention generates a counter-torque

which does not depend on a detected position error.” Riley Decl., Exh. 7 at 8-9; see also id. at 9 (“[T]he

Cavanaugh control system reacts to a man[eu]ver during a man[eu]ver, whereas the present invention

involves the step of reacting to an unmeasured, estimated error prior to any measurement.”) (emphasis

added). Because of its new understanding of the patent’s specification, the Court once again believes

the inventor’s statements are sufficient to limit the patent’s scope.

SSL’s second and third arguments are closely related, as both are based on the specification’s

disclosure of a “single feedback loop” used for both thruster modulations. SSL argues that because

“actual error information and prebias or historical error information” are summed in the single feedback

loop, they must necessarily be summed during both thruster modulations. See Riley Decl., Exh. 4 at 5

(“The actual error information and the prebias or historical error information are both fed into the

summer . . . where they are added together or summed.”). Thus, SSL argues that a person of ordinary

skill in the art would understand the first modulating step to be based on actual error because the single

feedback loop must necessarily include actual error data. For the same reason, SSL argues that

Lockheed’s proposed construction would exclude a preferred embodiment of the invention. See Anchor

Wall Sys. v. Rockwood Retaining Walls, Inc., 340 F.3d 1298, 1308 (Fed. Cir. 2003) (“[I]t is axiomatic

that a claim construction that excludes a preferred embodiment such as the circular protrusions disclosed

in Figure 3A ‘is rarely, if ever correct and would require highly persuasive evidentiary support.’”).

The Court disagrees with SSL; a single-feedback-loop embodiment would still be entirely

possible under this Court’s construction. The “single feedback loop” would simply not contain any

actual error data during the calculation of the first modulation, but would contain actual error data

during the second modulation. The patent contemplates this result; because of a delay caused by

processing the actual error data, the specification makes clear that in the preferred embodiment the

prebias is utilized immediately, without actual error information, and that the actual error information

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is only utilized later. See ’375 patent , col. 5, lines 15-18 (“[The] prebias command [is] directed into

the modulation control system of the thrusters thereby to overcome the time delay associated with realtime generation of initial position error signals.”); ’375 patent, col. 5, lines 24-27 (“The force calibration

factor is applied as a prebias command bypassing the servo loop time delay associated with the position

sensor.”). Thus, the Court’s construction is entirely consistent with the preferred embodiment.

CONCLUSION

For the foregoing reasons and for good cause shown, the Court hereby GRANTS Lockheed’s

motion for reconsideration of claim construction (Docket No. 659). The Court’s construction of “net

position error” remains unchanged, but the Court reverts to its original construction of step [b]:

“modulating in response to the stored value without referencing or depending upon any position error.”

IT IS SO ORDERED.

Dated: September 19, 2006 

SUSAN ILLSTON

United States District Judge

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