China Patent CN118811118A: Concentric Lunar Electromagnetic Launch System (CASIC)
Patent Number: CN118811118A Title: Concentric Circle Type Lunar Surface Electromagnetic Emission System Inventors: Zhang Yanqing, Dong Hao, Zhai Maochun, Bo Jinlong, Zou Ling, Sai Yao, Zhou Changbin, Pan Niankan, Cui Ji, Hou Zijia, Li Ping (11 inventors) Assignee: China Aerospace Science and Industry Corporation (CASIC) — Feihang Technology Research Institute / Haiying Mechanical and Electronic Research Institute Filed: April 20, 2023; Published October 22, 2024 Status: Pending Jurisdiction: China (foreign) Track Directory (Physics_Math): N/A — lunar surface EM launch / centrifugal rotary arm / electric suspension infrastructure; launch architecture domain; no current track covers cislunar logistics; candidate for a future electromagnetic launch track
Image files:
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Abstract
"The invention discloses a concentric circle type lunar surface electromagnetic emission system, which is arranged on a flat lunar surface and has a preset included angle with the lunar surface, and comprises an electromagnetic propulsion device, an electric suspension device, an energy storage device, a current conversion device, a rotary arm supporting device and an emission control device... the rotary arm rotates around the rotating shaft, a spacecraft is arranged on the rotary arm, the electromagnetic propulsion device generates propulsion force to drive the rotary arm to accelerate and rotate, acceleration on the spacecraft is realized, the electric suspension device is used for generating suspension force and guiding force, the guiding force is used for balancing centrifugal force when the rotary arm rotates, the suspension force is used for balancing gravity of the rotary arm, and when the spacecraft is accelerated to a preset speed, the spacecraft is separated from the rotary arm and enters an earth orbit in a preset mode."
Launch Architecture: Centrifugal Rotary Arm
The system is a centrifugal launch accelerator: a long rotary arm anchored at the lunar surface rotates in a horizontal or inclined plane, progressively accelerating the spacecraft at the arm tip through centripetal force. The electromagnetic propulsion device drives the arm rotation; the electric suspension device (Meissner-effect or electromagnetic bearing) keeps the arm and payload frictionlessly supported during the multi-revolution acceleration phase.
When the tip speed reaches lunar escape velocity (2.38 km/s) or desired orbital insertion velocity (~1.68 km/s for low lunar orbit), the spacecraft releases and follows a guided trajectory.
Physics: Centrifugal Launch Kinematics
The concentric circular track geometry is more compact than a linear electromagnetic launch rail (which would need to be kilometers long to achieve orbital velocity at tolerable g-forces). A circular track allows the accelerator radius to be chosen for the available land area, at the cost of higher centripetal acceleration force on the payload.
For arm length R and final tip speed v, the centripetal acceleration is:
a_c = v²/R
At arm length R = 500 m and final tip speed v = 2 km/s:
a_c = (2×10³)²/500 = 8,000 m/s² ≈ 800 g
This is survivable for unmanned cargo, not for humans. For a human-survivable launch (a_c < 10 g), with v = 2 km/s:
R = v²/a_c = (2×10³)²/(10×9.8) ≈ 40 km
A 40 km radius is impractically large for a surface installation but illustrates the fundamental trade-off between arm length and g-loading. The CASIC design presumably targets unmanned cargo launches.
Electric Suspension System
The electric suspension device generates both:
- Suspension force — counteracting the weight of the rotary arm itself under lunar gravity (g_moon = 1.62 m/s²)
- Guiding force — balancing the centrifugal force on the rotary arm as it rotates
The guiding force requirement is the more demanding: at full tip speed, the centrifugal loading along the arm is:
F_centrifugal(r) = ṁ_arm × ω² × r = ṁ_arm × v²_tip × r/R²
where ṁ_arm is the arm mass distribution per unit length. For a uniform arm of total mass M_arm and length R, the total centrifugal force on the arm structure is:
F_total = M_arm × v²_tip/(2R)
This is a tension loading problem — the arm must be a strong tension member (carbon fiber, composite, or metal-matrix composite) to survive this loading. The electric suspension provides magnetic guidance to prevent the arm from deflecting under combined centrifugal and gravitational loads.
Strategic Significance: CASIC and Cislunar Operations
The CASIC assignee is China's primary strategic missile and aerospace defense corporation — maker of the DF series ballistic missiles, land-attack cruise missiles, and anti-satellite weapons. A lunar electromagnetic launch system filed by CASIC in 2023 with 11 inventors is a production-engineering level project, not a university research patent.
The connection to the broader UAP context: a lunar electromagnetic launch system would be a key infrastructure piece for any permanent cislunar operations base, and its disclosure in 2024 implies China is planning concrete lunar surface operations that include logistics infrastructure for departing spacecraft — a timeline indicator that classified cislunar programs are approaching operational readiness.
Sources
- CN118811118A on Google Patents
- China Aerospace Science and Industry Corporation (CASIC) — Feihang Technology Research Institute
- Lunar escape velocity: 2.38 km/s (standard value)
This information was compiled from Break_thrus.mdx staging file.