3 years in orbit, full-stack independent R&D, aerospace-grade thermal control solution provider "Ruilai Thermal Control" has secured tens of millions of yuan in Series A+ financing | 36Kr Exclusive

Thermal management is evolving from an auxiliary subsystem of satellites to a core variable that restricts the large-scale and commercial implementation of constellations.

36Kr learned that Ruilai Thermal Control Technology (Beijing) Co., Ltd. (hereinafter referred to as "Ruilai Thermal Control"), a supplier of aerospace-grade thermal control solutions, has recently completed a multi-million-yuan Series A+ financing. This round of financing was jointly invested by InnoAngel Fund, Fangguang Capital, Jicui Huacai and Xiangjiang Xincheng, with continued support from existing shareholder Jinyu Maowu. The funds will be mainly used for R&D of aerospace active liquid cooling business, expansion of passive thermal management production lines and extended layout of upstream and downstream industrial chains.

Ruilai Thermal Control is one of the few private enterprises in China that masters the full technical stack of active thermal management. Its core founding team has backgrounds from the Chinese Academy of Sciences and the 5th Academy of Aerospace, and has deeply participated in major national projects such as manned spaceflight, space station and lunar exploration program, with full-process experience from payload design to whole satellite integration, orbit insertion and project management.

According to Chen Jiangping, co-founder and CTO, Ruilai Thermal Control's liquid-cooled satellite systems have occupied 90% of the domestic market share, and most of the pump-driven liquid cooling solutions and products in the construction of major domestic computing constellations are provided by Ruilai Thermal Control.

In addition, the Galaxy Lingxi 03 satellite equipped with its single-phase fluid loop has been operating stably in orbit for 3 years. In July and August this year, the liquid cooling fluid loops carried by Chenguang-1, Landspace Hongqing and Honghu 03 satellites have successively operated smoothly in orbit. It is expected that by the end of 2026, there will be 5 high-power in-orbit satellites for space computing equipped with Ruilai's active thermal control system.

Satellite Power Upgrade, Active Liquid Cooling Becomes a Mandatory Option

The 20 Starlink V3 satellites launched by SpaceX not long ago have a power consumption of about 50kW per satellite; while the latest AI1 computing satellite has a power consumption rising to 120kW-150kW per satellite, which is rewriting the power consumption standards of commercial aerospace satellites.

From the communication bandwidth of more than ten Gbps of the V1 version to 100Gbps of the V2 version, and now to 1Tbps, in just a few years, the single-satellite processing capacity of Starlink has increased by two orders of magnitude, but the soaring energy consumption is also challenging the "body temperature" limit of satellites.

In the field of spacecraft thermal control, traditional solutions are dominated by passive heat dissipation, relying on heat pipes, radiation plates, coatings, etc. for heat conduction and heat rejection. However, when the satellite power reaches tens to hundreds of kW, the traditional passive solution reaches the physical upper limit, and active liquid cooling must be introduced, that is, the pump drives the fluid working medium to circulate in the pipeline, "transports" heat from the heating elements to the radiator, and then dissipates it to space.

Liquid cooling technology has become a trend in the field of foreign internet satellites. SpaceX adopted a pump-driven liquid cooling solution on the Starlink V2 version of satellites, and the AI1 computing satellite even used this solution from the initial version; Amazon's Kuiper satellite realizes on-board edge computing through microchannel liquid cooling; the second-generation OneWeb satellite adopts the method of "overall liquid cooling + local heat pipe" to increase the efficiency of the thermal control system by 40%.

At present, the domestic low-orbit internet communication satellite constellation is in a critical period of transformation from "manufacturing test satellites" to "manufacturing service satellites", and the power consumption of single satellites in computing satellite constellations is generally equivalent to that of AI1, starting at a level close to 100kW.

For high-power service satellites to be launched into space, active liquid cooling is no longer an optional item in the thermal control management system, but a mandatory item related to whether the constellation can truly generate commercial value.

Three Years in Orbit, Vacuum Trial of Full-Stack Capabilities

"Satellites in the future will definitely move towards higher integration and lower cost, and liquid cooling is the only way to solve the power consumption bottleneck." Based on this judgment, Ruilai Thermal Control has determined the layout of "active liquid cooling as the core, passive thermal control as the supplement" since its inception.

Chen Jiangping explained that even in the active liquid cooling system, radiator coatings and some heat pipes are still indispensable links for auxiliary heat dissipation: "The active part faces the future, and the passive part covers the stock, and the two are not in a substitution relationship."

According to the introduction, Ruilai Thermal Control currently has the independent R&D and mass production capabilities of a full set of active and passive thermal control products, including filling/draining valves, fluid loop pumps, radiators, heat pipes, aluminum VCs, and thermal control coatings.

"Our full-stack capabilities, with full independent controllability from the underlying material process to the top-level system design, make our system integration accuracy several orders of magnitude higher than that of competitors, and our products can be smaller in size and lighter in weight." Chen Jiangping said. At the same time, the team also innovatively introduced the civilian product supply chain and processes into the production and manufacturing of aerospace-grade products, further reducing redundant costs.

Full-stack self-development also brings advantages and guarantees at the delivery level. Facing different needs of customers, production capacity can be deployed in advance and flexibly adapted, avoiding the uncertainty brought by the external supply chain.

However, for aerospace-grade thermal control systems, no matter how much calculation data and environmental simulation there are, they cannot replace the real space working conditions. The ground-based liquid cooling system allows regular maintenance, replenishment of working medium and even replacement of components, while once the liquid cooling system carried by the satellite is launched into orbit, it means that the possibility of physical maintenance is completely cut off.

Actual in-orbit operation experience is the ultimate standard for testing full-stack capabilities.

The first answer sheet submitted by Ruilai Thermal Control is the Galaxy Lingxi 03 satellite. According to the introduction, its equipped active liquid cooling system has been operating continuously in orbit for more than 3 years, with all indicators performing stably during the period. Based on the on-orbit measured data and reliability deduction model, Ruilai Thermal Control judges that its liquid cooling system has an in-orbit life of at least 7-10 years.

It is worth noting that aerospace-grade liquid cooling also has extremely strict requirements on the selection of working medium.

Ruilai Thermal Control currently mainly follows the mainstream international fluorine working medium and ammonia working medium routes, and at the same time promotes the application R&D of water-based working medium in specific scenarios. From the perspective of physical and chemical properties, water-based working medium has more advantages in heat dissipation efficiency, but it lacks long-term in-orbit life verification data, which puts forward extremely high anti-corrosion and sealing thresholds for the system structure, and special design is required to avoid risks.

"Ground accelerated test + in-orbit data return + reliability model deduction" is a general closed loop for aerospace product verification.

The advantage of Ruilai Thermal Control is that this verification window is opening at a speed visible to the naked eye — recently, the Chenguang-1 satellite, Landspace Hongqing and Honghu 03 satellites equipped with Ruilai's liquid cooling system have successively entered orbit, and 2 more satellites will be launched into orbit before the end of 2026. These traceable and reproducible in-orbit data are clearing the last trust barrier for the upcoming mass delivery.

Standardization Path and Cross-Scenario Extension

The currently booming vision of space computing is certainly grand, but to realize the real value closed loop, the key lies in whether the mass delivery and engineering capabilities at the supply chain end are already in place.

"We are currently promoting the standardized reuse of thermal control solutions through modular and systematic design, laying an engineering foundation for mass supply to constellations." Chen Jiangping said.

Similar to the reuse of the same set of thermal management core components on different models of new energy vehicles, aerospace thermal control systems will also follow the logic of "standardized core components and modular system configuration", and make adaptation adjustments according to the power consumption and layout characteristics of different satellite platforms.

In terms of overall strategy, Ruilai Thermal Control is positioned to take aerospace business as its basic business base, and become a thermal management platform with cross-scenario systematic problem-solving capabilities. In addition to aerospace business, it is also delivering thermal control products in batches in scenarios such as military industry, data centers, rail transit and new energy.

This layout can be understood as a kind of "two-way dimensionality reduction".

On the one hand, the extreme requirements of aerospace-grade liquid cooling systems in terms of weight, performance and life determine that their key components have performance redundancy and reliability advantages in the civilian product market; on the other hand, the introduction of civilian product supply chains and processes can effectively reduce the cost of aerospace-grade products on the premise of ensuring quality.

In addition, the quality control system and delivery support capabilities accumulated in aerospace-grade projects enable it to have higher engineering literacy than traditional ground thermal control manufacturers when facing civilian product customers.

"Thermal management is still an emerging industry in rapid iteration, with various new materials, new technologies and new system architectures emerging in endlessly. When we communicated with some large internet companies, we put forward many new solutions, which are often directions that other manufacturers in the market have not thought of." Chen Jiangping added.

However, cross-scenario extension also faces challenges. The ground thermal control market is fiercely competitive and highly cost-sensitive. Whether the aerospace-grade endorsement can be truly converted into a premium still needs to be tested by the market one by one in different scenarios.

At present, the revenue ratio of Ruilai Thermal Control's aerospace business and civilian product business is basically maintained at 1:1. In the past few years, both business segments have maintained a 100% annual compound growth rate.

With the successive substantial progress in reusable rocket technology, the launch cost has decreased step by step, and the networking rhythm of high-power service satellites will inevitably accelerate.

For thermal control manufacturers, the incremental market is clear. But this is not a market that can be won only by cognitive gaps. Between "being able to see the opportunity" and "being able to undertake the business", there are many tests such as aerospace-grade reliability verification and production capacity ramp-up speed.