A naked-eye observable light broadcasting communication system based on spaceborne high-power laser and amateur radio

Abstract

The application provides a naked-eye observable light broadcast communication system based on a spaceborne high-power laser and a radio amateur. The system adopts a narrow-band high-power wide-beam scattering angle light source, and the public only needs to wear corresponding narrow-band filter glasses to directly observe, which greatly reduces the difficulty of satellite acquisition and identification. For the application problem of the high-power light source on the satellite, an energy storage and thermal management integrated unit is designed. The energy unit adopts a "slow charging and fast discharging" mode, is charged by the on-board power supply when not transiting, and realizes kilowatt-level discharging when transiting, so as to match the satellite power constraint and the laser demand. The thermal management unit realizes non-power-consumption low-temperature protection (maintaining the component temperature greater than or equal to 0 DEG C) by using a phase change heat storage method. Compared with a traditional low-power narrow-beam system, the application has the advantages of wide coverage, easy acquisition and low requirement of the receiving end, and has important values in simplifying the alignment of satellite-ground communication, improving the emergency communication capability and aerospace popularization, etc.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of satellite communication, optical communication and amateur radio, and proposes a visually observable optical broadcast communication system based on spaceborne high-power laser and amateur radio. Background Technology

[0002] Free-space optical communication, with its unique advantages such as high communication speed and strong anti-interference capability, has become a communication system solution with significant potential in the context of increasingly scarce radio frequency communication spectrum. In the field of satellite optical communication, due to the limitations of onboard power load capacity, existing spaceborne optical broadcast communication systems typically employ low-power lasers or narrow beam designs. Ground reception must rely on large-aperture telescopes, precision tracking frames, and high-sensitivity detectors, making the equipment expensive and complex to operate, thus limiting the widespread application of spaceborne optical broadcast communication systems. At the same time, severe light pollution in modern cities makes weak spaceborne laser signals completely unobservable to the naked eye. Increasing the power of spaceborne light sources can theoretically improve the performance of naked-eye observation and reduce the requirements for the aperture and sensitivity of ground receiving ports. However, the power of spaceborne light sources is limited by both the onboard power supply capacity and the heat dissipation capacity of the thermal control system. Not only is it difficult to support the power supply requirements of kilowatt-level light sources, but even if power supply capacity is available, the limited heat dissipation capacity of the vacuum environment means that if conventional heat dissipation designs are used, the laser will experience wavelength drift, a sharp drop in efficiency, or even permanent damage within seconds of operation due to a surge in junction temperature. Therefore, current spaceborne optical communication systems do not have the capability to enable the general public to observe with the naked eye or through simple modifications, which limits their application in fields such as emergency broadcasting and popular science demonstrations.

[0003] On the other hand, amateur radio satellite communication and high-speed satellite-to-ground communication missions generally face the problem of initial acquisition difficulties: narrow-beam terminals require extremely high-precision pointing alignment, which usually relies on high-precision ephemeris and complex narrow-beam beacon optical systems, resulting in high costs and long acquisition times. If a laser source that is visible to the naked eye and has a wide coverage area can be used as a coarse tracking beacon, the alignment process of ground high-speed communication terminals will be greatly simplified.

[0004] To address the need for low-cost, visually observable spaceborne optical broadcasting communication systems in emergency communications and science demonstrations, and the requirement for wide-area, high signal-to-noise ratio (SNR) guiding beacons in professional space-to-ground communication missions, this invention designs a visually observable optical broadcasting communication system based on a spaceborne high-power laser and amateur radio. This system, for the first time, uses a narrowband, high-power, large-beam divergence laser source as the spaceborne optical broadcasting communication light source, ensuring sufficient coverage and a high SNR. The public only needs to wear narrowband filter glasses corresponding to the light source's wavelength to observe, greatly reducing the difficulty of observation and acquisition at the receiving end. Simultaneously, the wide-area, high-power spaceborne light source can serve as a universal high-brightness beacon for other high-speed space-to-ground communication equipment to perform initial ground pointing calibration and automatic tracking, significantly reducing the acquisition difficulty and cost of narrow-beam communication links. This invention designs an integrated energy storage and thermal management unit to solve the onboard power supply and heat dissipation problems of high-power light sources. Using lithium capacitors or double-layer capacitors for energy storage, a "slow charge, fast discharge" mode ensures sufficient power for the onboard light source when passing overhead to the ground receiver. During laser operation, a solid-liquid phase change material within the thermal management subunit absorbs all instantaneous waste heat generated by the laser source, keeping the laser shell temperature within an acceptable range. During non-operation periods, the phase change material releases heat through solidification, maintaining the laser component temperature above 0°C: achieving zero-power, low-temperature protection for the laser source. Compared to current onboard optical broadcast communication systems that typically use low-power, narrow-beam light sources, this invention offers significant advantages such as wider coverage, lower acquisition difficulty, and lower requirements for receiver observation capabilities. Furthermore, the laser source and the integrated energy storage and thermal management unit are designed as a single independent module, achieving complete thermal insulation from the satellite platform structure. The satellite power bus only needs one conventional DC power supply to ensure normal operation, allowing for modular installation on various satellite platforms and enabling rapid, large-scale deployment. Summary of the Invention (a) Purpose of the invention

[0005] To meet the low-cost observation requirements of spaceborne optical broadcast communication systems and the rapid alignment requirements of amateur radio systems, this invention designs a visually observable optical broadcast communication system based on spaceborne high-power lasers and amateur radio. Compared with existing technologies, it has advantages such as large coverage, low acquisition difficulty, and low requirements for the observation capabilities of the receiving end. It is of great significance in simplifying the alignment process of space-to-ground communication, improving emergency communication capabilities, and carrying out aerospace science popularization. (II) Technical Solution I. Overall System Composition

[0006] This invention proposes a visually observable optical broadcast communication system based on a spaceborne high-power laser and amateur radio, comprising a space-based platform and a ground-based unit. The space-based platform carries a high-power scintillation laser source, an amateur radio transceiver, a time synchronization module, and an integrated energy storage and thermal management unit. The transceiver is used to transmit downlink voice / data and receive voice or Morse code uploaded from the ground station. The ground-based unit includes narrowband observation glasses (with built-in narrowband interference filters) matched to the laser wavelength, an automatic alignment aid module / conventional amateur radio receiving equipment (for receiving downlink signals), and portable or fixed amateur radio transmitting equipment (for uplink signals). Furthermore, the ground-based unit can integrate other high-speed communication equipment, such as laser communication terminals or Ka-band data transmission antennas, which can utilize the laser source of this invention as a guiding beacon for initial alignment.

[0007] The high-power scintillation laser source uses a high-power pulsed laser in the visible wavelength range. A beam expander lens extends the beam divergence angle of the laser source to 120°, ensuring sufficient coverage and preventing excessive energy concentration that could damage the observer's eyes. The scintillation frequency and intensity of the source are modulated by the audio signal processed by the amateur radio transceiver, or operate independently in Morse code broadcast mode. The source is a narrowband laser, and narrowband observation glasses equipped with narrowband filters corresponding to the laser source wavelength are used at the ground end to suppress background light noise and enhance the visibility of the laser spot.

[0008] The integrated energy storage and thermal management unit comprises two sub-units: energy storage and thermal management. The energy storage sub-unit employs a three-tiered energy buffer architecture: The first tier is a constant-power charging unit for the satellite bus. The satellite platform bus charges the energy storage capacitor bank at a constant power (typically 80W) through an isolated DC / DC converter. The charging current is controlled in a closed loop by a digital signal processor (DSP) to ensure that no peak current is drawn from the bus, thus avoiding interference with the normal operation of other onboard payloads. The second tier is a high-energy-density hybrid energy storage group consisting of lithium-ion capacitors (LIC) or improved electric double-layer capacitors (EDLC). Lithium-ion capacitors feature high power density (>10kW / kg), long cycle life (>100,000 cycles), and a wide operating temperature range (-40℃ to +65℃). A typical configuration is a 6-series, 2-parallel structure with a nominal capacity of 100F, a maximum pulse discharge current of 120A, and can store approximately 450J of energy, achieving an instantaneous discharge power density of 15kW / kg. The third stage is the direct drive unit for the laser diode array: the energy storage capacitor bank is directly connected to the laser diode array via a low parasitic inductance busbar (<5nH), and pulse width modulation (PWM) discharge is performed using a high-speed switching array of metal-oxide-semiconductor field-effect transistors (MOSFETs). During operation, the energy storage bank completes slow charging within 5-10 minutes, and then discharges to the laser diode array with an instantaneous electrical power of 1600W within a emission window of several seconds to tens of seconds. The electro-optical conversion efficiency is approximately 45%-50%, corresponding to a peak output optical power of 720W-800W (after beam shaping, the axial emission intensity can meet the requirements for ground-based naked-eye observation). This "slow charge, fast discharge" mode keeps the average power consumption of the platform busbar below 80W, adapting to the difference between the energy budget constraints (typically 30W-200W) of CubeSats / microsatellites and the laser emission power requirements.

[0009] The thermal management subunit employs a phase change heat storage strategy, where all waste heat generated by the laser during operation is absorbed by the phase change material, eliminating reliance on radiation-based heat dissipation. The specific structure includes: a laser diode array mounted on a high thermal conductivity aluminum nitride (AlN) substrate; a microchannel-enhanced heat transfer structure integrated on the back of the substrate, directly contacting the phase change material storage cavity. The storage cavity utilizes a corrugated metal skeleton to enhance thermal conductivity and is filled with a foam-metal-reinforced organic composite phase change material. The outer shell of the storage cavity shares a titanium alloy shell with the laser's mechanical structure, forming a single, replaceable unit without independent heat dissipation piping. To address the instantaneous high heat flux density (typically 10~30 W / cm²) and operating temperature requirements of the spaceborne laser (laser diode junction temperature <50℃, case temperature <40℃), a foam-metal-reinforced paraffin-based composite phase change material is used. Using high-purity paraffin as the matrix, the phase change temperature is adjustable from 35~45℃, and the latent heat of phase change is ≥180 J / g. To improve thermal conductivity, open-cell nickel or copper foam (porosity 90%~95%) and expanded graphite (mass fraction 5%~10%) are added, resulting in an equivalent thermal conductivity of 10~15 W / (m·K) for the composite material while maintaining a high latent heat storage density. The thermal management unit adopts a two-stage cyclic operation mode: During laser operation, the laser operates at 1600W power for 5~10 minutes, during which the phase change material absorbs all waste heat, undergoing a solid-liquid phase change, and maintaining the shell temperature below 45℃. Equipped with 300g of composite phase change material (effective heat storage capacity ≥54kJ), it can completely absorb the waste heat generated during 10 minutes of operation (approximately 480kJ), with a phase change material utilization rate >85%. During laser shutdown, heat is slowly dissipated through a fixed low-emissivity radiative heat dissipation surface in the form of radiation. The heat dissipation surface is designed with an area of ​​10cm²~20cm², coated with a low-emissivity coating (ε≤0.08), and the radiative heat dissipation power is approximately 0.3W~0.6W. The system, except for the radiating surface, is coated with 20 layers of double-sided aluminized polyimide film (MLI), with an equivalent emissivity ≤0.012 and radiative heat leakage ≤0.1W, mitigating heat loss and achieving long-term power-free heat preservation during laser shutdown. This invention isolates heat leakage from the satellite platform's main structure through thermal insulation installation, using titanium alloy brackets or fiberglass composite pillars (thermal conductivity ≤0.5W / (m·K)) with a thermal resistance >1000K / W, ensuring that waste heat from the light source does not enter the satellite platform during operation, and that heat dissipation during non-operational periods has no impact on the overall satellite thermal environment.

[0010] The time synchronization module employs a hardware phase-locked loop or a software synchronization algorithm to ensure that the audio signal and the laser modulation signal have a delay of less than 20 milliseconds, thus avoiding audio-visual asynchrony. Laser modulation methods include analog amplitude modulation (AM) for voice broadcasting and digital pulse position modulation (PPM) for Morse code and digital voice transmission.

[0011] The automatic alignment assist module allows the naked eye or a receiver such as a shelf camera to directly observe the spot of a high-power light source. Ground amateur radio operators manually or semi-automatically adjust the antenna pointing to achieve rapid initial alignment before switching to automatic tracking.

[0012] The high-power scintillation laser source, in addition to its use in optoelectronic synchronous broadcasting and amateur radio-aided alignment, also functions as a "general-purpose high-brightness beacon," serving other high-speed satellite-to-ground communication equipment. To achieve these functions, the laser source of this invention can operate independently or in shifts in "beacon mode" while performing its own optoelectronic broadcasting tasks. In this mode, the laser emits high-brightness pulses at a fixed frequency (e.g., 10Hz), carrying no modulation information or only a simple identification code (e.g., satellite number). Ground-based high-speed communication terminals (e.g., laser communication ground stations) are equipped with narrowband observation glasses or simple CMOS cameras matched to the laser wavelength. They capture the laser spot with the naked eye or through automatic image recognition, guiding the line of sight of the communication antenna to the center of the spot, and then transitioning to high-precision tracking. Because the instantaneous power of the laser source of this invention reaches 1600W, its spot brightness far exceeds that of traditional satellite-borne beacon LEDs or low-power lasers, maintaining visibility and detectability even under strong background light during the day. Simultaneously, the phase-change thermal management unit ensures that the laser can operate continuously within a 5-10 minute window, sufficient to sequentially guide multiple ground-based communication terminals. The system eliminates the need for a dedicated beacon payload on the satellite, fully reusing existing laser light sources and thermal control resources to achieve "multiple uses of a single light source," greatly improving cost-effectiveness. (III) Advantages

[0013] The present invention has the following beneficial effects:

[0014] This invention, through the combination of a 1600W-level instantaneous pulse laser and narrowband observation glasses, enables the general public to receive satellite light information without the need for professional telescopes, providing a new technical means for emergency broadcasting and aerospace science popularization education;

[0015] This invention uses lithium capacitor energy storage to achieve "slow charging and fast discharging" and "low charging and high discharging", keeping the average power consumption of the platform bus below 80W. This enables the spaceborne platform with limited power supply capacity to carry a kilowatt-level light source for a short period of time. This invention applies foam metal-reinforced organic composite phase change material to the spaceborne optical communication system and encapsulates it with the laser as a structurally integrated unit. The phase change latent heat completely absorbs all the waste heat corresponding to the 1600W power during operation, so that the microsatellite can carry a kilowatt-level laser payload without any radiation heat dissipation area.

[0016] This invention employs a "fully insulated installation + fixed ultra-low power heat dissipation surface" design. The laser module is fully insulated from the entire satellite, encased in multiple layers of heat-insulating components, and features a small-area fixed low-emissivity dedicated heat dissipation surface. This design reduces the heat dissipation power during non-operational periods to below 0.5W, allowing the heat stored in the phase change material to maintain a temperature above 0°C for over 7 days, with absolutely no power consumption and no moving parts. This technology enables the invention to perform missions with intermittent standby for several weeks, ready to be used immediately upon activation, greatly improving mission flexibility. Furthermore, the thermal control system requires zero maintenance and has zero failure risk.

[0017] This invention has amateur radio uplink reception capability, and low-power handheld ground devices can achieve long-distance voice / Morse code transmission via satellite relay; the laser intensity changes synchronously with the uplink audio, and the ground station can visually confirm that the satellite has received the signal when uploading, forming a closed-loop confirmation mechanism, which greatly improves the operational certainty in emergency scenarios;

[0018] This invention utilizes a visible laser spot as a beacon, eliminating the reliance on precise orbit prediction. It uses a kilowatt-level visible laser spot as a universal high-brightness beacon, enabling rapid initial pointing calibration for narrow-beam terminals in amateur radio, satellite-to-ground laser communication, and Ka-band high-speed data transmission. Ground operators can directly guide the beam visually through narrow-band glasses or have it automatically tracked by a low-cost CMOS camera. This simplifies what previously required complex equipment such as large-aperture telescopes and beacon tracking systems to a level of visual visibility and instant pointing and tracking, significantly reducing the acquisition costs of high-speed satellite-to-ground communication. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the communication system scenario architecture proposed in this invention.

[0020] Figure 2 This is a flowchart of the "slow charge and fast discharge" energy storage sub-unit proposed in this invention.

[0021] Figure 3 This is a schematic diagram and flowchart of the thermal management subunit design proposed in this invention. Detailed Implementation

[0022] The following description is provided to facilitate a better understanding and implementation of the present invention by those skilled in the art. Specific implementation examples are used to illustrate the usage and performance of the present invention in detail:

[0023] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are only used to explain the technical solutions of the present invention and do not constitute a limitation on the scope of protection.

[0024] Example 1: Engineering Implementation of an Integrated Unit for Spaceborne Laser Energy Storage and Organic Composite Phase Change Thermal Management

[0025] This embodiment provides specific design parameters for an integrated onboard laser energy storage and thermal management unit suitable for 6U CubeSats.

[0026] Energy storage sub-unit: Employs a 6-series 2-parallel lithium capacitor module, with a single capacitor capacity of 100F, rated voltage of 3.8V, total module capacity of 33.3F, withstand voltage of 22.8V, and maximum pulse discharge current of 120A. Charging strategy: Constant current-constant voltage (CC-CV) mode, charging current of 5A, charging power of 95W, complete charging cycle of 6 minutes, energy storage of 450J. Discharge strategy: A MOSFET switching array drives a laser diode at a variable frequency of 200Hz to 5kHz, with a pulse width of 10μs to 500μs, instantaneous electrical power of 1600W, and optical power of 720W (electro-optical efficiency of 45%).

[0027] Thermal management subunit: A laser diode array (4×5, 20 dies in total) is mounted on a 10mm×20mm aluminum nitride substrate, with a 0.3mm×0.3mm microchannel array fabricated on the back side of the substrate. The phase change heat storage cavity has a volume of 45cm³ and is filled with nickel foam-reinforced paraffin composite material (phase change temperature 42℃, latent heat 200J / g, equivalent thermal conductivity 12W / (m·K)). Thermal balance tests show that after 10 minutes of continuous operation at 1600W power (corresponding to a heat dissipation of 880W), the laser shell temperature rises from 22℃ to 46℃ (below the allowable upper limit of 55℃), the phase change material liquefaction rate is 92%, and the heat storage is 58kJ. There is no radiative heat dissipation during operation; all waste heat is absorbed by the phase change material.

[0028] Example 2: Photoelectric Synchronous Voice Broadcasting and Emergency Upload Forwarding

[0029] A low-Earth orbit disaster monitoring satellite carries the aforementioned integrated laser unit and UHF / VHF amateur radio transceiver. Ground personnel in the disaster area use 5W handheld walkie-talkies to transmit a voice distress message to the satellite: "Area A needs drinking water." The satellite receiver demodulates the voice message, and the uplink / retransmission module immediately sends the signal to two channels simultaneously: one channel modulates it for broadcast via a downlink radio transmitter; the other channel modulates the laser drive current via a time synchronization module, causing the laser flashing intensity to vary with the rhythm of the voice message "Area A needs drinking water." Nearby residents wearing narrow-band green-light glasses can see the moving green light flashing in the air in sync with the voice message, and simultaneously hear the distress message clearly over the walkie-talkie. Command centers outside the disaster area can also receive the voice message via the satellite downlink, enabling long-distance relay.

[0030] Example 3: Verification of Morse code store-and-forward and phase change thermal buffer

[0031] When the satellite reaches an area without ground station coverage, the polar research station transmits encrypted Morse code research data to the satellite via a directional antenna. The satellite receives the data and stores it in its onboard Flash memory. During this process, the laser is not operational, and the phase change material is in a solid state at -10°C (maintained by onboard thermal control). When the satellite passes over the domestic ground station, the system activates the laser, and the energy storage unit begins charging for 6 minutes. Subsequently, the laser is driven at 1600W power to flash Morse code in a corresponding rhythm. During operation, the phase change material heats up from -10°C to 42°C within 5 minutes and begins to liquefy. The laser casing temperature remains below 50°C, and all waste heat is absorbed by the phase change material, with no radiative heat dissipation. The ground station operator, wearing narrow-band glasses, visually captures the satellite's beam, points the Yagi antenna in the direction of the beam, locks onto the downlink signal within seconds, and decodes the research data.

[0032] Example 4: Amateur Radio Space Relay and Ephemeris-Free Alignment

[0033] Direct communication between the two cities was impossible due to terrain obstruction. When the satellite passed overhead over city A, an enthusiast transmitted voice messages to the satellite via a car radio: "CQ CQ, this is BG1XXX". Upon receiving the message, the satellite immediately broadcast it via both laser and radio downlink in transparent relay mode. The enthusiast in city B, wearing narrow-band glasses, observed that the laser flashing content matched the radio reception and replied. The satellite also relayed the message, completing a two-way relay communication.

[0034] A mobile satellite ground station needs rapid deployment but cannot obtain ephemeris data in time. The operator raises the Yagi antenna, scans the sky wearing narrow-band glasses, and spots a green spot of light. They then use the motorized gimbal handle to guide the spot towards the center of the antenna's line of sight. After pressing the "lock" button, the control system records the current angle and initiates a tracking program, which can then automatically maintain alignment based on satellite orbit predictions.

[0035] Example 5: Verification of Conventional Cryogenic Protection Function of High-Power Space Laser (Comparison Benchmark)

[0036] To verify the basic low-temperature protection capability of the phase change thermal management unit of this invention, a vacuum thermal cycling test was conducted. The integrated laser unit was placed in a vacuum chamber to simulate the Earth's shadow environment (background temperature -50°C) during satellite non-operation. Control group (no phase change material coupling): The laser temperature dropped to -35°C within 3 hours, below the lower limit of the storage temperature. Test group (foam metal / paraffin composite phase change material coupling, conventional heat dissipation installation): The laser was integrated with the phase change heat storage cavity via thermal connection, with the initial temperature of the phase change material at 22°C. In a vacuum cold background, the phase change material slowly decreased from 22°C to 5°C within 12 hours, releasing a total of 62kJ of latent and sensible heat, keeping the laser component temperature consistently above 0°C. The test demonstrates that this invention utilizes the waste heat absorbed by the phase change material during operation to provide zero-power low-temperature protection for more than 12 hours during non-operation periods.

[0037] Example 6: As a guiding beacon for high-speed satellite-to-ground laser communication

[0038] A ground station for satellite-to-ground laser communication needs to rapidly acquire low-Earth orbit (LEO) satellites during the day. The satellite, equipped with the system of this invention, activates its laser beacon mode 5 minutes before overhead transit: the energy storage unit charges, and then it emits an unmodulated 532nm pulse at a peak power of 1600W and a repetition frequency of 10Hz. The ground station operator, wearing narrow-band green-light glasses, can clearly observe the green spot streaking across the sky even against a strong sunlight background. The operator manually adjusts the laser communication telescope gimbal to center the spot in the field of view; the entire process takes only 45 seconds. The telescope then switches to high-precision automatic tracking and quickly establishes a 10Gbps satellite-to-ground downlink laser link. Compared to traditional acquisition methods relying on ephemeris scanning (which typically takes 5-15 minutes), this invention reduces antenna acquisition time by more than 90% and eliminates the need for an expensive beacon optical system.

[0039] Example 7: Auxiliary Alignment as Ka-Band High-Speed ​​Data Transmission

[0040] A mobile Ka-band satellite data transmission ground station was deployed at a temporary site without real-time ephemeris support. The operator set up a 0.6m parabolic antenna while wearing narrow-band glasses and scanning the sky. When the satellite passed overhead, it emitted a green laser beacon. The operator visually guided the main beam of the antenna to the light spot, and within one minute, the satellite beacon was locked, the data transmission link was established, and reconnaissance images were transmitted back at a rate of 600Mbps.

[0041] Example 8: Verification of 7-day zero-power low-temperature protection and fully insulated installation

[0042] This embodiment provides an engineering implementation scheme for long-term on-orbit standby missions, fully verifying the fully insulated installation and ultra-long-duration cryogenic protection technology of this invention.

[0043] Fully insulated mounting structure: The integrated laser module is mounted on the satellite base plate via four fiberglass hollow pillars (6mm outer diameter, 4mm inner diameter, 30mm length). The thermal resistance of a single pillar is >2000K / W, and the total conductive heat leakage is <0.02W. The module's outer surface is covered with 20 layers of double-sided aluminized polyimide film multilayer insulation components, with an equivalent emissivity of 0.012 and radiative heat leakage of <0.1W (at a module temperature of 40℃).

[0044] Fixed low-power radiative heat dissipation surface: The module's only external heat dissipation window, with an area of ​​15cm², is coated with an aerospace-grade aluminum oxide / silver composite coating, and has a normal emissivity ε=0.06. This heat dissipation surface is a fixed structure with no moving parts or variable emissivity capability. It does not participate in heat dissipation during operation and continues to dissipate heat with ultra-low power radiative heat dissipation during non-operation periods.

[0045] Phase change thermal energy storage unit: filled with 350g nickel foam / paraffin composite material, phase change temperature 42℃, latent heat 195J / g, total thermal energy storage 68kJ.

[0046] Thermal balance test (vacuum tank simulation): The laser operated at 1600W for 10 minutes, achieving a liquefaction rate of 95% for the phase change material, with a maximum module shell temperature of 44℃. During operation, the radiant heat dissipation surface temperature remained consistent with the ambient temperature, with no active heat dissipation. Immediately after shutdown, the system entered a non-operating period, with the tank wall temperature at -50℃ (simulating a cold, dark space). Continuous monitoring for 168 hours (7 days) showed the module temperature slowly decreasing from 44℃, reaching 6.8℃ at the end of day 7, above the 0℃ threshold. No electric heating power was consumed during this period.

[0047] Comparative test: A conventional laser without phase change material and without thermal insulation installation drops to -15℃ 3 hours after shutdown under the same ambient temperature; the control sample containing only phase change material but without thermal insulation installation drops to below 0℃ 32 hours after shutdown.

[0048] Conclusion: This invention, through a three-in-one collaborative design of "phase change thermal storage + fully insulated installation + fixed ultra-low power heat dissipation surface", successfully achieves 7-day zero-power cryogenic protection without any moving parts, variable emissivity devices, or active control, completely solving the cryogenic survival problem of high-power spaceborne lasers during long-term operation, and achieving aerospace-grade system reliability.

[0049] Example 9: Rapid wake-up after a 7-day standby period during task downtime

[0050] An optical remote sensing satellite carrying the system of this invention entered a 7-day mission rest period after completing a laser broadcast mission. During this period, the satellite's main payload was powered off, the laser module was in a non-operating state, and there was no electrical heating power consumption. After 7 days, the ground station sent a wake-up command. The laser module temperature monitoring value was 5.2℃, the energy storage group immediately began charging, and after 6 minutes, it emitted light normally at a power of 1600W. The photoelectric synchronous broadcast function was completely normal. This verified the 7-day standby zero-power heat preservation and instant wake-up capability.

[0051] The above embodiments are merely preferred embodiments of the present invention and do not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A naked-eye observable light broadcast communication system based on spaceborne high-power laser and amateur radio, characterized in that, include: Space-based platform and ground-based terminal; The space-based platform includes a high-power scintillation laser source, an amateur radio transceiver, a time synchronization module, an uplink / forwarding module, and an integrated energy storage and thermal management unit; the ground-based unit includes narrowband observation glasses matching the wavelength of the high-power scintillation laser source on the space-based platform, an automatic alignment assist module, and amateur radio transmitting equipment for sending uplink signals to the satellite; wherein: The time synchronization module is used to synchronously modulate the audio signal received and forwarded by the amateur radio transceiver, or the audio signal generated by itself, with the light intensity output of the high-power scintillation laser source, so that the laser light intensity changes in real time with the audio signal intensity, thereby realizing photoelectric synchronous broadcasting. The upload and forwarding module is used to receive voice or Morse code signals from the ground through the voice amateur radio transceiver and perform store-and-forward, transparent forwarding or relay forwarding. The automatic alignment assist module is used to enable ground operators to observe the position of the high-power scintillation laser light source with the naked eye through narrow-band observation glasses when there is no satellite ephemeris, and to manually or automatically adjust the direction of the high-gain radio antenna to complete the initial satellite alignment and automatic tracking.

2. The naked-eye observable light broadcast communication system based on spaceborne high power laser and amateur radio according to claim 1, characterized in that, The integrated energy storage and thermal management unit includes two sub-units: energy storage and thermal management. The energy storage sub-unit includes a lithium capacitor or double-layer capacitor energy storage group, which adopts a constant power charging-pulse discharging mode. When the spacecraft platform has not passed the top of the ground end, it absorbs and stores the power of the spacecraft bus, with a charging power of no more than 200W. When it passes the top, it discharges to the laser source, with an instantaneous discharge power of no less than 1600W and a discharge duration of 5 to 10 minutes, realizing the "slow charging and fast discharging" pulse working mode. The thermal management subunit includes a phase change heat storage cavity that shares a housing with the laser source. The cavity is filled with a foam metal-reinforced organic composite phase change material. The foam metal is open-cell foam nickel or foam copper with a porosity of 90% to 95%. The composite phase change material has a phase change temperature of 30 to 50°C, a latent heat of phase change ≥180J / g, and an equivalent thermal conductivity ≥10W / (m·K). During laser operation, the laser absorbs all the instantaneous waste heat generated by the laser source through solid-liquid phase change, keeping the laser housing temperature within the allowable range. During non-operation periods, the laser component temperature is maintained at no lower than 0°C through the heat release of the phase change material during solidification. This achieves zero-power low-temperature protection for the laser source.

3. The visually observable optical broadcast communication system based on spaceborne high-power laser and amateur radio as described in claim 1, characterized in that, The high-power scintillation laser source uses a high-power pulsed laser in the visible wavelength range. A beam expander lens extends the beam divergence angle of the laser source to 120°, ensuring sufficient coverage and preventing excessive energy concentration that could damage the observer's eyes. The scintillation frequency and intensity of the source are modulated by the audio signal processed by the amateur radio transceiver, or operate independently in Morse code broadcast mode. The source is a narrowband laser, and narrowband observation glasses equipped with narrowband filters corresponding to the laser source wavelength are used at the ground end to suppress background light noise and enhance the visibility of the laser spot.

4. The visually observable optical broadcasting communication system based on spaceborne high-power laser and amateur radio as described in claim 1, characterized in that, The integrated unit for laser source, energy storage, and thermal management is an independent thermal control module. This module is connected to the satellite structure via a low thermal conductivity mechanical bracket, achieving complete thermal insulation installation with the main structure of the satellite platform. The low thermal conductivity mechanical bracket is made of titanium alloy or fiberglass composite material, with a thermal conductivity ≤10W / (m·K) and a thermal resistance ≥1000K / W. The thermal control module is covered with multiple layers of thermal insulation components, with ≥20 layers and an equivalent emissivity ≤0.

02. The only external heat dissipation path is a fixed low-power radiative heat dissipation surface with an area ≤20cm², coated with a low emissivity stabilizing coating, and a normal emissivity ≤0.

08. During the laser source's operation, the thermal control module does not rely on radiative heat dissipation; all waste heat generated by the laser is completely absorbed by the phase change material. During non-operation periods, heat is slowly dissipated only through the low-power radiative heat dissipation surface, ensuring that the laser component temperature does not fall below 0℃ during the 7-day non-operation period, achieving ultra-long-term, zero-power low-temperature protection.

5. The visually observable optical broadcasting communication system based on spaceborne high-power laser and amateur radio according to claim 1, characterized in that, The upload and forwarding module includes the following working modes: Transparent forwarding mode: The voice signal uploaded by the ground station is directly modulated to the laser light source and downlink radio transmitter; Store-and-forward mode: Receives digital voice or Morse code information uploaded by the ground station, caches it in the onboard memory, and automatically plays and broadcasts it synchronously when the satellite passes over a designated area; Relay mode: As an amateur radio space relay node, it enables long-distance uploading and forwarding when direct communication between two ground points is not possible.

6. The visually observable optical broadcasting communication system based on spaceborne high-power laser and amateur radio according to claim 1, characterized in that, The automatic alignment assistance module includes: Ground-based radio antenna, equipped with azimuth-elevation adjustment mechanism; The manual guidance unit determines the direction of the satellite's deviation from the center of the antenna beam by visually observing the position of the laser spot; The control unit, based on instructions from the manual guidance unit or automatic feedback based on image recognition, drives the antenna adjustment mechanism to complete the initial alignment and then switches to automatic tracking mode.

7. A visually observable optical broadcasting communication system based on spaceborne high-power laser and amateur radio, characterized in that, Includes the following steps: S1. The space-based platform slowly stores energy when it is not overhead at the ground end through an integrated energy storage and thermal management unit. When it is overhead, it drives a high-power scintillation laser light source with an instantaneous electrical power of not less than 1600W and simultaneously operates a voice amateur radio transceiver. S2. The laser intensity is modulated in real time with the radio audio signal through the time synchronization module, wherein the audio signal can come from pre-stored content on the satellite or be uploaded in real time from the ground. S3. Ground personnel wear narrow-band observation glasses to directly observe the laser spot with the naked eye to obtain the satellite's azimuth, and at the same time demodulate the downlink audio signal through radio receiving equipment to achieve dual audio-visual information reception; S4. Ground personnel transmit voice or Morse code to the satellite via amateur radio transmitting equipment. After receiving the data, the satellite performs store-and-forward, transparent forwarding, or relay forwarding to achieve amateur radio communication. S5. In the absence of ephemeris data, the high-power scintillation laser source is used as a guiding beacon. The position of the laser spot is observed by the naked eye or a camera, which is used by the ground high-speed laser communication terminal or the radio high-speed data transmission antenna for initial pointing calibration and automatic tracking, so as to realize the rapid beam alignment of the high-speed wireless communication system.

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