MIL-STD-810: environmental qualification at the heart of ECRIN Systems’ ruggedised systems

In the defence, aerospace, naval and critical embedded systems sectors, a computer’s performance is not measured solely by its CPU, GPU or FPGA power.

A piece of equipment may have very high computing capacity yet still be unsuitable for a mission if it cannot operate reliably in its real-world environment: constant vibrations, mechanical shocks, extreme temperatures, low pressure, humidity, rain, sand, dust or a saline atmosphere.

This is precisely the aim of MIL-STD-810 – Environmental Engineering Considerations and Laboratory Tests: to provide an engineering framework for taking into account the environmental stresses likely to affect equipment throughout its life cycle.

For ECRIN Systems, this issue is an integral part of the design and qualification of systems intended for the aerospace, defence, military, naval and harsh embedded applications markets.

From the ultra-compact nanoONYX computers to the ONYX and µTOPAZE mission computers, right through to the OPALE-Rugged servers and the Quartz Ethernet switch, the qualification levels are tailored to the environments for which each product family is intended.

MIL-STD-810 is a US Department of Defence Test Method Standard dedicated to environmental engineering considerations and laboratory testing.

The standard aims to take into account the influence of environmental stresses on equipment during the various phases of its life cycle.

One point is essential for a proper understanding of MIL-STD-810: the standard does not define a universal level of hardening applicable in the same way to all equipment.

The Department of Defense explicitly states that MIL-STD-810 does not directly impose single design or test specifications. Rather, it describes an approach known as ‘environmental tailoring’, i.e. the adaptation of environmental stresses and tests to the actual environment in which the equipment is to operate.

This approach is fundamental to ECRIN Systems’ areas of expertise. A computer installed in a military vehicle, a server housed in a shelter, equipment on board an aircraft and a naval system do not necessarily have:

• The same operating temperatures;
• The same vibration profiles;
• The same shock levels;
• The same altitude constraints;
• The same exposure to humidity;
• The same exposure to sand, dust or salt spray.

Qualification must therefore be consistent with the target environment and the mission profile.

In an industrial or military programme, the MIL-STD-810 framework can be summarised as follows: mission environment → environmental constraints → test methods → test levels → system validation.

The aim is not to systematically subject all equipment to the full range of MIL-STD-810 test methods. Rather, it is to select tests that are representative of the conditions the equipment is likely to encounter in practice.

The stresses examined may include, in particular:

• Low pressure and altitude;
• High temperatures;
• Low temperatures;
• Humidity;
• Rain;
• Shock;
• Vibration;
• Acceleration;
• Sand and dust;
• Salt spray;
• Other specific environments depending on the application.

This approach explains why not all ECRIN products have exactly the same MIL-STD-810 profile. They are not all designed for the same operational environment.

An embedded computing system comprises a set of components that are sensitive to environmental stresses:

• Electronic boards;
• Processors;
• GPUs and FPGAs;
• Memory modules;
• SSDs;
• PCIe or VPX boards;
• Connectors;
• Power supplies;
• Heat sinks;
• Mounting systems;
• Internal cabling;
• External interfaces.

→ Repeated vibration, for example, can place stress on connectors, expansion boards and their mounting systems.

→ An impact can exert significant mechanical stress on heavy components.

→ A rise in temperature can reduce the thermal margins of processors or GPUs.

→ A drop in atmospheric pressure can affect the performance of cooling systems that rely on convection.

→ Salt spray, sand or dust can have a significant impact on systems installed directly in close proximity to the external environment.

Environmental qualification must therefore focus on the behaviour of the system as a whole.

Temperature: adapting the computer to its actual environment

ECRIN applications cover a wide range of environments.

Industrial rack-mounted servers and computers directly embedded in platforms therefore do not necessarily have the same operating ranges.

• The OPALE V2 Compact, a 2U rack-mounted server, is, for example, designed to operate from 0 to +50°C, in accordance with MIL-STD-810G methods 501.5 and 502.5.
• The µOPALE V2, in a 1U rack format, is designed for operation from 0 to +45°C, also in accordance with the relevant temperature methods of MIL-STD-810G.

For applications more directly exposed to the mission environment, the operating conditions become more severe.

• The OPALE-Rugged supports operation from -20 to +50°C and storage from -40 to +71°C (MIL-STD-810G 501.5 and 502.5).
• The ONYX, nanoONYX and µTOPAZE mission computers, on the other hand, support operating temperatures starting at -40°C.

This difference perfectly illustrates the MIL-STD-810 philosophy: qualification is tailored to the product’s intended use, rather than being applied as a generic standard identical across all platforms.

Shocks: protecting the integrity of the system and its components

Mechanical shocks may occur during:

• Transport;
• Handling;
• Installation;
• Vehicle movement;
• Certain phases of flight;
• Specific operational events.

For an electronic control unit, the risk is not limited to the chassis. Expansion cards, GPUs, storage media, connectors and various mechanical assemblies are also subject to stress.

The qualifications specify several levels tailored to the product families:

• The OPALE V2 Compact is specified to withstand an in-operation shock of 15 G for 11 ms across six axes, in accordance with MIL-STD-810G Method 516.6.
• The OPALE-Rugged achieves 30 G for 11 ms across six axes, again in accordance with Method 516.6 under its MIL-STD-810G qualification.
• The µTOPAZE VPX computer, meanwhile, is documented as having a shock level of 40 G for 11 ms.

These differences reflect distinct levels of integration and mission environments.

Vibration: a major constraint for aeronautical, land-based and naval platforms

In many embedded systems, vibration is a constant constraint.

It can originate from:

• The engine;
• The vehicle;
• Surrounding mechanical equipment;
• Aeronautical structures;
• Propulsion systems;
• Transport.

Unlike a one-off impact, vibration subjects the equipment to repetitive stress.

The system’s behaviour therefore depends, in particular, on:

• The rigidity of the chassis;
• The secure mounting of the circuit boards;
• The mass of the components;
• The mounting of PCIe cards, GPUs or other expansion cards;
• The connectors;
• The storage;
• The overall mechanical behaviour.

During operation, the OPALE-Rugged exhibits a vibration profile ranging from 5 to 2,000 Hz at 4 Grms and complies with MIL-STD-810G Method 514.6.

The high-performance myOPALE-RS server, capable of accommodating two dual-slot GPUs, is specified at 5 to 2,000 Hz / 2 Grms, also in accordance with Method 514.6.

On a system of this calibre, mechanical ruggedisation therefore does not simply concern the enclosure: it must also take into account the mounting of the GPUs, expansion cards, power supplies and storage.

Altitude and low pressure: a particular challenge for the aerospace industry

The qualification of aerospace equipment cannot be separated from its pressure environment. As altitude increases, the decrease in air density can notably affect heat transfer. This issue becomes particularly significant when processors, GPUs or power supplies dissipate several tens or hundreds of watts.

ECRIN systems cover several usage classes. The OPALE-Rugged is qualified for operation up to 5,000 m / 16,000 ft, with MIL-STD-810G Method 500.5 among the explicitly stated test methods.

For many microcontrollers intended for aerospace applications, the RTCA DO-160 specifications supplement MIL-STD-810. The nanoONYX family, for example, supports pressures of up to 116 mbar – corresponding to approximately 50,000 ft – with the DO-160 specification associated with this characteristic.

The µTOPAZE also has a pressure range of up to 116 mbar / 50,000 ft.

This coexistence of MIL-STD-810 and DO-160 is important in aerospace applications: the standards are complementary and must remain linked to the tests to which they actually relate.

Humidity, rain, dust and saline environments

Military environments are, of course, not limited to mechanical stresses. For a naval, land-based or vehicle-mounted system exposed to the external environment, exposure to humidity, water, sand or a saline environment can become a major design criterion.

OPALE-Rugged lists the following methods in its MIL-STD-810G qualification:

• 506.5 – Rain;
• 507.5 – Humidity.

The Quartz ruggedised Ethernet switch features a particularly extensive set of MIL-STD-810G methods: 500.5, 501.5, 502.5, 506.5, 507.5, 508.6, 509.5, 510.5, 513.6, 514.6 and 516.6.

These include, in particular, methods relating to:

• Low pressure;
• Temperatures;
• Rain;
• Humidity;
• Salt spray;
• Sand and dust;
• Vibrations;
• Shocks.

Quartz also has an IP67 protection rating and uses MIL-DTL-38999 connectors.

For naval, aeronautical or land-based platforms, this approach is essential: the robustness of the network must be consistent with that of the computers it interconnects.

The ECRIN Systems range covers several levels of integration, from rack-mounted servers to compact mission computers.

The aim is not to offer a single system intended to suit all environments.

Rather, it is to provide product platforms suited to a range of mission profiles, and then to select or configure the platform according to the programme’s requirements.

For rack and shelter environments: OPALE

The OPALE V2, OPALE V2 Compact and µOPALE V2 families are specifically designed to meet the requirements for rack-mountable computing, PCIe expansion and industrial-grade durability, with environmental ratings specified for each product.

In particular, they are suitable for environments where the equipment remains protected by its enclosure but must nevertheless withstand mechanical and climatic stresses greater than those encountered by a conventional IT server.

For servers directly exposed to harsh environments: OPALE-Rugged

OPALE-Rugged takes ruggedisation to a whole new level.

The platform features, in particular:

• Aluminium chassis;
• Configurable MIL-DTL-38999 connectors;
• IP65 protection;
• Multi-method MIL-STD-810G qualification;
• MIL-STD-461G;
• MIL-STD-1275E;
• DO-160G certifications depending on the relevant components;
• Intel Xeon Scalable;
• PCIe expansion capabilities.

→ It thus enables the functionality of a high-performance server to be maintained when the system needs to be integrated into a significantly more demanding military or aerospace environment.

For mission computers: ONYX

ONYX is designed for air, land and sea systems.

The platform is documented as qualified to DO-160, MIL-STD-810 and MIL-STD-461 and features, in particular:

• Intel Xeon processors;
• ECC memory;
• Option for GPU integration via MXM;
• PMC and mini-PCIe expansion slots;
• Fanless cooling;
• MIL-DTL-38999 connectors;
• Operating temperature down to -40 °C.

→ ONYX is designed as a mission computer integrated directly into the platform, rather than simply a ruggedised rack-mounted server.

For stringent SWaP-C constraints: nanoONYX

The nanoONYX family incorporates the rugged computer architecture into a highly compact, low-power format.

In particular, it combines:

• Fanless design;
• Conduction/convection/radiation cooling;
• MIL-DTL-38999 connectors;
• Intel Atom or Intel Core processors, depending on the version;
• AcroPack / mini-PCIe expansion slots;
• MIL-STD-810 / DO-160 environmental qualification in accordance with the documented specifications.

The same base design can be adapted to suit mission requirements:

• nanoONYX-CAN for applications requiring multiple CAN buses;
• nanoONYX-SDI for HD-SDI video acquisition;
• nanoONYX-USB3 for USB 3.0 interfaces;
• nanoONYX-rd for applications requiring a removable SSD.

→ Environmental qualification thus remains integrated into the base platform, whilst the interfaces are adapted to the mission.

For embedded AI: ONYX-AGX

ONYX-AGX applies this approach to Edge AI workloads.

Based on the NVIDIA Jetson AGX Orin Industrial, the system is rated at up to 248 TOPS and features:

• Passive cooling;
• MIL-DTL-38999 connectors;
• Operating temperature range: -40 to +55 °C;
• IP67;
• Qualification to DO-160 and MIL-STD-810/461;

Ethernet, CAN, serial, USB and video interfaces, depending on configuration.

→ The aim here is to maintain AI processing capability directly within the mission environment, as close as possible to the sensors and data.

For very high-performance heterogeneous computing: µTOPAZE

The µTOPAZE is a 3U VPX system designed specifically for radar, sonar, EWR, C4ISR, AI and signal processing applications, as detailed in its documentation.

It can combine:

• Intel Xeon CPU;
• NVIDIA GPU;
• FPGA or additional interfaces;
• VITA 62 power supply;
• MIL-STD-461 / MIL-STD-1275E filtering;
• MIL-DTL-38999 connectors;
• Internal and removable storage.

Its published operating environment includes, in particular:

• Operation down to –40 °C;
• Altitude up to 50,000 ft under documented DO-160 conditions;
• IP67;
• 40 G shock / 11 ms;
• MIL-STD-810G Method 514.6 vibration.

→ It thus represents ECRIN’s solution for programmes requiring high computing power, heterogeneous processing and operation in harsh mission environments simultaneously.

For the on-board network: Quartz

Finally, Quartz extends this approach to Ethernet communications. Depending on the version, the rugged switch features Gigabit and 10 Gigabit Ethernet interfaces, L2/L3 functions, PTP synchronisation or TSN functions.

→ Its extended environmental qualification and MIL-DTL-38999 connectors enable the network to be integrated with the same level of robustness as the computers.

In ECRIN Systems applications, MIL-STD-810 forms part of a broader set of requirements.

Several products therefore combine MIL-STD-810 with other standards.

MIL-STD-461

MIL-STD-461 covers the electromagnetic interference characteristics of military equipment and subsystems.

A computer may therefore be mechanically and climatically qualified in accordance with MIL-STD-810 whilst also having to demonstrate its electromagnetic behaviour.

OPALE-Rugged and Quartz, for example, publish MIL-STD-461G test cases such as CE101, CE102, CS101, CS114, CS115, CS116, RE101, RE102, RS101 and RS103.

MIL-STD-1275

MIL-STD-1275 applies in particular to the power supply for equipment installed on military land vehicles.

This standard is referenced in the documentation for OPALE-Rugged, Quartz, nanoONYX and µTOPAZE.

RTCA DO-160

DO-160 is a key standard for aeronautical equipment.

It features in the qualifications of several ECRIN platforms intended for aeronautical or MIL-AERO applications, notably ONYX, nanoONYX, ONYX-AGX, µTOPAZE, Quartz and OPALE-Rugged, depending on the functions in question.

These standards are therefore not competing.

They address complementary sets of requirements which, taken together, enable the characterisation of a system intended for a complex mission environment.

ECRIN Systems’ approach therefore involves bringing together two worlds that are often treated separately:

the system’s functional requirements and the platform’s environmental constraints.

A programme may require:

• High CPU power;
• Multiple GPUs;
• FPGA processing;
• Video capture;
• Avionics interfaces;
• CAN;
• 10 Gb Ethernet;
• Removable storage;
• Embedded AI.

However, these functions must then be integrated into an environment that may impose the following conditions:

• -40 °C;
• Constant vibrations;
• Severe shocks;
• Low atmospheric pressure;
• High humidity;
• Dust;
• Salty environments;
• EMI/EMC constraints;
• Military-grade power supply.

Choosing an ECRIN product therefore involves matching a functional capability with a qualified environmental domain.

Another key feature of ECRIN systems is their adaptability.

Products can be configured or customised to meet the requirements of a programme:

• Processor;
• Memory;
• Storage;
• Expansion cards;
• Interfaces;
• Connectors;
• Front panel;
• Power supply;
• Software functions, depending on the range.

However, in a ruggedised system, every modification must be carefully considered.

Adding a board or changing a component may affect:

• Mass;
• Thermal dissipation;
• Power consumption;
• Mechanical behaviour;
• Vibration resistance;
• Interfaces;
• Electromagnetic compatibility.

This is why environmental qualification must always be aligned with the configuration actually intended for the programme.

Modified COTS therefore does not simply involve customising an existing PC.

It is a matter of maintaining consistency between: performance, interfaces, mechanical design, thermal management, power supply, environmental constraints and the system’s service life.

For any aerospace, military, land-based or naval project, the selection process must begin with the environmental profile.

In particular, the following must be characterised:

• Operating and storage temperature;
• Altitude or pressure;
• Shock;
• Vibration;
• Humidity;
• Rain;
• Sand and dust;
• Salty environment;
• Required mechanical protection;
• Power supply;
• Electromagnetic constraints.

This data can then be cross-referenced with the functional requirements:

• Need for a rack-mounted server in a protected but constrained environment → OPALE V2 / OPALE V2 Compact / µOPALE V2
• Need for a truly ruggedised military server → OPALE-Rugged
• Need for very high CPU/GPU power in a ruggedised server → myOPALE-RS
• Need for a fanless x86 mission computer → ONYX
• Need for a very compact, low-power computer → nanoONYX and its variants
• Need for Edge AI based on NVIDIA Jetson AGX Orin → ONYX-AGX
• Need for CPU + GPU + FPGA / specialised I/O in VPX → µTOPAZE
• Need for a ruggedised Ethernet network compatible with the computers → Quartz

This initial selection must then be validated against the exact configuration and the qualification dossier corresponding to the project.

In a mission-critical programme, environmental qualification is not merely a contractual requirement. It plays a direct role in risk management.

It enables the anticipation of failures related to:

• Thermal behaviour;
• Mechanical stresses;
• Impacts;
• Vibrations;
• The external environment;
• Integration conditions.

For ECRIN Systems, the aim is therefore to offer platforms in which computational, integration and environmental considerations have already been taken into account right from the design stage.

This enables integrators to start with a ruggedised, well-documented and configurable COTS platform, rather than having to develop the entire system from standard IT components.

MIL-STD-810 should be regarded as an environmental engineering tool.

Its purpose is not to create a generic category of ‘military’ products.

Its purpose is to ensure that the actual mission conditions align with the environmental capabilities of the equipment. It is this approach that guides the various ECRIN Systems product families.

An OPALE V2, an OPALE-Rugged, an ONYX, a nanoONYX, a µTOPAZE or a Quartz are not designed for exactly the same environment. They have been developed to cater for different levels of integration and mission profiles.

The value of the ECRIN approach therefore lies in its ability to combine: the required computing functionality, the necessary level of ruggedisation, the platform’s constraints and the appropriate environmental qualification.

For a critical defence, aerospace, naval or embedded programme, the question is ultimately not: ‘Is this product MIL-STD-810 compliant?’ but: ‘Is this system qualified for the constraints actually encountered by my mission?’

It is this question that the choice of platform must address.

Further reading

The ECRIN Systems teams can assist design bureaux and system integrators in selecting a platform based on the programme’s functional and environmental constraints.

A requirements analysis helps to determine, in particular, the appropriate system family, the hardware configuration and the environmental qualifications to be taken into account prior to integration.

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• Discover the related guide: Everything you need to know about the DO-160 aerospace test standard