How Spacecraft Calculate Maneuvers to Change Orbits Near Another Satellite
A mathematical method for onboard computers to calculate the precise engine burns needed for one satellite to change its orbital plane while moving relative to another satellite.
Original patent title: “Control system and method for a plane change for satellite operations”
A mathematical method for onboard computers to calculate the precise engine burns needed for one satellite to change its orbital plane while moving relative to another satellite. Granted to US Department of Navy in 2018 with 10 claims and 1 forward citation.
Key facts
Coverage
What does this patent actually cover?
This patent describes a computational method for a secondary spacecraft to adjust its orbital path relative to a primary spacecraft. It uses a specific mathematical framework called the apocentral coordinate system to simplify the complex geometry of relative motion. By calculating the difference between a pre-maneuver velocity vector and a desired post-maneuver velocity vector, the system determines the exact impulsive velocity change (delta-V) required. This allows an onboard computer to automatically calculate the necessary engine burns to shift either the slant or the colatitude of the orbit without needing ground-based mission control.
The gap
What does this patent NOT cover?
- Does not cover maneuvers that change both slant and colatitude simultaneously.
- Does not cover orbital changes for spacecraft that are not in a relative orbit around a primary spacecraft.
- Does not cover non-impulsive propulsion systems like continuous low-thrust electric ion drives.
- Does not cover maneuvers where the primary spacecraft is in an elliptical rather than circular orbit.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The innovation lies in using the apocentral coordinate system, which aligns the math with the geometry of the relative orbital ellipse itself, making the calculation of plane changes significantly more efficient for onboard processors.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Autonomous satellite formation flying
On-orbit satellite servicing and refueling
Space debris inspection missions
Why it matters
The bigger picture
As space becomes more crowded, the ability for satellites to autonomously navigate around each other—known as proximity operations—is becoming critical. This technology reduces the reliance on ground stations for calculating complex maneuvers, which is essential for deep space missions or scenarios where communication latency makes real-time ground control impossible.
Filed
April 15, 2016
Granted
March 20, 2018
Market context
Who's building on this
Companies in this space
The US Department of Navy holds this patent, and it is highly relevant to the work of the Space Force and contractors like Northrop Grumman or Lockheed Martin who develop autonomous satellite systems. Startups focused on in-orbit servicing, such as Astroscale or Orbit Fab, are also working on the types of proximity maneuvers this patent addresses.
Market impact
This patent provides a standardized, computationally efficient way to handle relative orbital mechanics. It helps enable the emerging market for satellite servicing by providing a reliable, automated method for satellites to safely approach and reposition themselves relative to target vehicles.
Claim 1 — Plain English
What this patent covers
This patent describes a computational method for a secondary spacecraft to adjust its orbital path relative to a primary spacecraft. It uses a specific mathematical framework called the apocentral coordinate system to simplify the complex geometry of relative motion. By calculating the difference between a pre-maneuver velocity vector and a desired post-maneuver velocity vector, the system determines the exact impulsive velocity change (delta-V) required. This allows an onboard computer to automatically calculate the necessary engine burns to shift either the slant or the colatitude of the orbit without needing ground-based mission control.
The clever bit
The innovation lies in using the apocentral coordinate system, which aligns the math with the geometry of the relative orbital ellipse itself, making the calculation of plane changes significantly more efficient for onboard processors.
What it does not cover
- Does not cover maneuvers that change both slant and colatitude simultaneously.
- Does not cover orbital changes for spacecraft that are not in a relative orbit around a primary spacecraft.
- Does not cover non-impulsive propulsion systems like continuous low-thrust electric ion drives.
- Does not cover maneuvers where the primary spacecraft is in an elliptical rather than circular orbit.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Early stage
Citation count
6/40
Early citations
Claim breadth
7/20
Moderate scope
Recency
10/20
Granted 5–10 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$34K – $108K
Midpoint $68K · 9.8 yr remaining · industry ×0.9
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
10 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Healy, L. M. (2018). How Spacecraft Calculate Maneuvers to Change Orbits Near Another Satellite (U.S. Patent No. 9,919,813). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/9919813/fairing-recovery-system
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Spacecraft Calculate Maneuvers to Change Orbits Near Another Satellite cover?
A mathematical method for onboard computers to calculate the precise engine burns needed for one satellite to change its orbital plane while moving relative to another satellite.
Who owns patent US 9919813?
US Department of Navy owns this patent, granted in 2018.
When does this patent expire?
This patent is expected to expire on March 20, 2038, when the invention enters the public domain.
What is patent US 9919813 cited by?
This patent has been cited by 1 later patents that build on its ideas.
What problem does this patent solve?
As space becomes more crowded, the ability for satellites to autonomously navigate around each other—known as proximity operations—is becoming critical. This technology reduces the reliance on ground stations for calculating complex maneuvers, which is essential for deep space missions or scenarios where communication latency makes real-time ground control impossible.
What does this patent NOT cover?
Does not cover maneuvers that change both slant and colatitude simultaneously.
Same assignee
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