Producible Radiation-hardened Interconnects Technology

Navy SBIR 21.1 - Topic N211-096
SSP - Strategic Systems Programs
Opens: January 14, 2021 - Closes: February 24, 2021 March 4, 2021 (12:00pm est)

N211-096 TITLE: Producible Radiation-hardened Interconnects Technology

RT&L FOCUS AREA(S): Nuclear Modernization

TECHNOLOGY AREA(S): Materials / Processes

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop and evaluate cable manufacturing techniques and compatible connectors that are easy to produce, reliable, and can function in strategic radiation environments. Designed with lifecycle and maintenance costs in mind. Designed with producibility/manufacturability in mind.

DESCRIPTION: With a new ballistic missile submarine under development (OHIO-Replacement Class SSBN), the capability delivered by the Trident II (D5) missile will be needed into the 2080s. Current D5 missile performance will remain a top priority for life extension efforts while achieving Navy Strategic Systems Programs (SSP) affordability objectives. Currently, hand-built filled and unfilled cables are used, which represent a significant production cost for D5. Finding approaches to improve the producibility of radiation hardened cables and connectors while reducing the impact of nuclear-event induced effects on electronics has the potential for reducing program lifecycle costs.

Missile modernization will result in avionics architectures that are highly data bus-centric, with electrical connections consisting primarily of power lines and data lines. Such data bus-centric designs require higher data rates over longer distances and require unique interconnect (cables and connectors) interfaces to achieve maximum data transmission while operating in a harsh environment. Operation in a nuclear environment imposes many design challenges, one of which is reducing cable System Generated Electromagnetic Pulse (SGEMP) effects on interface electronics. Current cable designs reduce SGEMP/radiation; however, fabrication is labor-intensive and difficult to replicate in large quantities, since they are hand-built. Because all conductors are point-to-point copper wire throughout the missile, the current design carries a high weight penalty. Producibility and manufacturing repeatability of radiation-hardened interconnects are the subjects of this SBIR topic. An ideal solution must be efficient, reliable, and meet the requirements defined below.

Using readily available and common interconnect hardware across the Avionics subsystem will reduce interconnect complexity, thereby reducing overall cost. Rigid flex cabling, fiber optic cabling, and new, robust cable manufacturing techniques must be considered for potential applicability.

Requirements of the solution:

� Data transmission rates in excess of 100Mbps (Goal of 10 Gb/s)

� Radio Frequency (RF)/Electromagnetic Interference (EMI)/SGEMP shielding protection (radiation-hardened)

� Ruggedness/space flight environment survivability (nuclear, shock, vibration, extreme heat, temperature/humidity cycling)

� Ease of integration with small form factor and RF-sensitive electronics

� Design architecture flexibility (low and high current capacity, modular, easily-adaptable interconnects)

Current technology analysis includes:

� Feasibility of modern printed circuit "Flex Cable" manufacturing techniques for missile applications.

o Maximum "Flex Cable" length practical with current manufacturing techniques

o Feasibility of using "Trapped Electron Reduction cable" SGEMP control techniques, or other alternatives, in Flex cabling

o Feasibility of Incorporating SGEMP terminal protection means (e.g., resistors, caps, diodes) in cable itself

o Ability to support high speed data (>100Mbps) over 40 feet with SGEMP mitigations

o Effectiveness of SGEMP control techniques

o Producibility and cost assessment relative to alternatives

� Discrete Wire cable techniques (e.g., Trapped Electron Reduction cable [Ref 4]) and potential limitations

o Incorporate SGEMP terminal protection means (e.g., resistors, caps, diodes) in cable itself

o Ability to support high speed data (>100Mbps) over 40 feet with proposed SGEMP mitigations

o Effectiveness of SGEMP control techniques

o Producibility and cost assessment relative to alternatives

� Fiber/Ethernet/Datalink for high speed data communications and potential limitations o Application considerations in a Strategic Missile environment

Radiation darkening of fiber

Fiber connector contamination concerns/mitigation

Fiber Transmitters/Receivers survivability for Strategic radiation-hardened environments o Explore inclusion of fiber with copper in same cable to reduce cable quantity

o Producibility and cost assessment relative to alternatives

o Effectiveness of SGEMP control techniques

o Maintenance cost risk associated with repair/rework/replace compared to traditional copper

o Consider and assess existing high bandwidth/speed cable options (i.e., fiber vs. Ethernet vs. Datalink) and assess risks/tradeoffs

� Analysis of new/emerging technologies, to include:

o Ultra-miniature connectors that provide robust capability in smaller form factor

o Ability to integrate high speed data transmission contacts with traditional copper contacts

o Explore options in connector grommet seal techniques/processes to reduce well-known fleet issues (e.g., silicone migration, damaged pins/tines, Foreign Object Damage (FOD) contamination)

o Producibility/repeatability of EMI-shielding techniques and processes

o Producibility of new connectors that meet or exceed the current solution functionality and reliability

o Alternate backshell/connector accessories. Current configuration requires special tooling and difficult processes

PHASE I: Develop approaches for the fabrication and production of radiation-hardened cables and connectors that reduce the effects of SGEMP while maintaining the performance characteristics of a high bandwidth interconnect for use in strategic missile environments. With the basic cable design understood, construct a decision matrix and analyze several feasible interconnect solutions. Utilize aforementioned analyses to begin connector down-select process. Ensure that the proposed approaches are low cost and use high-reliability interconnect hardware and simple, proven fabrication techniques.

Conduct a feasibility assessment for the proposed application, assessing benefits and drawbacks of various approaches that address, at a minimum, the capabilities/limitations listed in the topic description. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II. Develop a Phase II plan.

PHASE II: Fabricate and produce radiation-hardened interconnect prototype(s) in sufficient quantities to accomplish the following:

-Assess manufacturing costs, time constraints/limitations, and ease of consistent, controllable repeatability for scaling up to a future production environment.

-Simulate/test producible interconnects in relevant "Test Like You Fly" (TLYF) environments.

-Collect performance data that can be used to characterize feasibility and application for use over a long production lifecycle.

Prepare a Phase III development plan to transition the technology for Navy combat systems and potential commercial use.

PHASE III DUAL USE APPLICATIONS: Missile cables and interconnects will be manufactured, demonstrated, and transitioned into the missile and submarine. Provide support in transitioning the technology for Navy use in SSP. Support the Navy with certifying and qualifying the system for SSP use with assets and test support provided by the Navy as Government Furnished Equipment and Services.

Radiation-hardened interconnects required for Navy SSP that are developed under this SBIR topic will be applicable to many commercial satellite and rocket programs, especially in applications that have restrictive physical space and/or harsh EMI/Radiation environment requirements.

REFERENCES:

  1. Maher, Michael. "AN-926 Radiation Design Considerations Using CMOS Logic." Texas Instruments, National Semiconductor Note 926, January 1994. http://www.ti.com/lit/an/snoa254a/snoa254a.pdf
  2. Fang-Chichton, Su. US Patent 6,093,893 Radiation Hardened Electrical Cable Having Trapped-electron Reducers. https://patentimages.storage.googleapis.com/43/7a/07/afea80a66c2955/US6093893.pdf
  3. Girard, Sylvain et al. "Recent advances in radiation-hardened fiber-based technologies for space applications." Journal of Optics 20, 2018. https://iopscience.iop.org/article/10.1088/2040-8986/aad271/pdf

KEYWORDS: Materials Development; Cables; Interconnect; Connectors; Production Techniques; Producibility; Radiation Hardened

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