On July 10, 2026, the Long March‑10B launch vehicle accomplished the world’s first precision sea‑based net‑capture recovery test, creating a new paradigm for lightweight and flexible rocket recovery. Departing from the conventional hard‑landing scheme with landing legs, this technology follows the design philosophy of “minimize on‑rocket machinery, maximize measurement‑and‑control capability”. The first‑stage booster is safely retrieved via rocket‑ship coordinated net capture, substantially cutting launch and reusability costs. The stable, high‑precision capture of this flexible recovery system cannot be achieved without full‑link signal assurance from space‑grade RF passive components — a key differentiator from traditional recovery approaches.
Conventional landing‑leg‑based recovery relies on heavy mechanical structures to guarantee accuracy and stability, which suffers from excessive structural mass, high maintenance costs and limited application scenarios. By contrast, the innovative net‑capture scheme removes landing hardware entirely. Its whole capture sequence is built upon closed‑loop dynamic navigation, real‑time communication and high‑precision positioning. This imposes stringent requirements on RF link stability, anti‑interference performance and signal fidelity. High‑performance RF passive components are therefore an essential enabler for the practical deployment of next‑generation flexible rocket recovery.
Note: The radio blackout induced by plasma sheath is an electromagnetic shielding effect and cannot be eliminated directly by filters. A multi‑band diversity receiving architecture combined with inertial navigation enables seamless data continuity during blackout periods. Reliable positioning and telemetry data are output within communication windows to support high‑precision net docking.
Ⅰ. On‑board RF System: Passive Components Underpin Full‑range Re‑entry Operations
During high‑speed re‑entry, the first stage is exposed to extreme conditions including sharp temperature swings, intense vibration and shock, space electromagnetic noise, and signal attenuation caused by plasma sheath. These hazards may lead to signal degradation, positioning drift and even link dropout. Core flight tasks such as attitude monitoring, telemetry downlink and command reception are fulfilled by the RF system. Various passive components work synergistically to maintain reliable RF links throughout the flight mission.
- Circulators & Isolators
Mounted at the front‑end of on‑board telemetry and telemetry‑tracking transmitters, circulators and isolators provide critical power protection for transmitting chains. Antenna impedance and standing‑wave ratio vary drastically under re‑entry conditions, generating reflected reverse power that poses risks of power‑amplifier damage. Circulators and isolators enforce unidirectional RF transmission, isolate and dissipate reverse reflected energy to stabilize links and ensure continuous signal output. Compatible with pulse‑mode exterior ballistic measurement terminals, they support integrated telemetry, ranging and safety‑control functions for robust flight monitoring and remote command reception.
- RF Filters
Spurious emissions from rocket engines and space‑borne electromagnetic interference can couple into navigation and receiver channels and degrade signal‑to‑noise ratio. High‑performance band‑pass and low‑pass filters suppress out‑of‑band interference and purify BeiDou/GNSS navigation and telemetry‑tracking signals. Filters cannot mitigate plasma‑caused radio blackout, but they maintain spectral purity across operating bands. Inertial navigation bridges data gaps during blackout silence. Accurate positioning and telemetry data are delivered in available communication windows, laying the signal foundation for high‑precision net capture.
- Power Dividers, Couplers & Hybrids
Multi‑element diversity antennas are deployed to mitigate blind spots brought by attitude manoeuvres. Power dividers, couplers and 3 dB hybrids realize balanced signal distribution, power sampling and signal combining for multi‑antenna networking. Flight parameters including attitude, velocity and position are accurately acquired; telemetry data are stably down‑converted to deliver high‑quality raw datasets for rocket‑ship cooperative computation.
- Attenuators & Matched Loads
Antenna port impedance dynamically fluctuates in flight and triggers port reflection that perturbs system status. Space‑qualified fixed attenuators adjust signal levels and prevent receiver overloading. Matched loads provide absorbing termination for unused ports to suppress spurious reflection, improve overall RF transmission performance and reduce standing‑wave disturbances for enhanced system robustness under harsh flight conditions.
Ⅱ. Ship‑borne TT&C System: Passive Components Enable High‑precision Dynamic Rocket‑Ship Coordination
This net‑capture mission adopts closed‑loop bidirectional rocket‑ship coordination. Dynamic flexible capture is realised by ship‑borne TT&C radar and high‑speed servo‑driven net hardware, breaking constraints of conventional fixed‑site landing. Ocean waves, vessel sway and sea‑surface multi‑path reflections severely degrade detection accuracy, demanding outstanding stability and low latency for radar tracking, ranging and duplex communication. RF passive components serve as critical hardware for precise ship‑borne TT&C operation.
High‑power ship‑borne TT&C radar integrates waveguide circulators, waveguide filters and couplers to efficiently separate transmit‑receive channels for long‑range high‑power detection. Sea‑surface multi‑path clutter is suppressed and faint rocket echo signals are reliably extracted. Real‑time processing computes relative rocket‑ship position, driving fast net attitude adjustment to compensate vessel offset induced by ocean disturbances and achieve “net follows rocket” flexible capture.
III. Demanding Technical Specifications for Passive Components in Space Recovery Missions
Reusable rockets operate under extreme environments. Commercial‑grade RF components cannot satisfy long‑term high‑reliability space requirements. Passive components for net‑capture recovery must comply with space‑grade specifications balancing environmental resilience, mechanical robustness and electrical performance:
- Wide‑temperature endurance: Operate stably from ‑55 °C to +125 °C across high‑altitude cold and re‑entry thermal conditions with minimal performance degradation.
- Superior mechanical survivability: Withstand severe vibration and shock loads throughout launch and re‑entry to avoid component failure and link loss.
- Low insertion loss & high isolation: Low transmission loss with port isolation ≥40 dB to suppress transmit‑receive crosstalk and guarantee clean signal transmission.
- Miniaturisation & reusability: Compact lightweight form‑factor matching launch‑vehicle mass‑reduction targets. High consistency enables multiple flight cycles for commercial space operations.
Ⅳ. Technical Value & Industry Outlook
Compared with mechanically‑oriented legacy recovery schemes, the innovation of flexible net‑capture recovery lies in the paradigm shift: from mechanical‑structure backup to RF measurement‑and‑control‑dominated operation. System accuracy, stability and safety no longer rely heavily on bulky hardware, but depend on high‑fidelity RF TT&C links — this explains why RF passive components are irreplaceable in new‑generation reusable rocket architectures.
Within the complete flexible‑recovery workflow, on‑rocket passive components secure reliable flight telemetry while ship‑borne passive components guarantee dynamic cooperative precision. Core RF building blocks including circulators, isolators, filters and power dividers constitute the signal hardware foundation for net‑capture technology. In the future, this high‑reliability RF solution will be ported to broader reusable space assets and continuously drive commercial‑space advances toward lightweight design, higher precision and lower operational costs.