The space industry is moving faster than ever.
From lunar and multi-planetary exploration to growing satellite constellations, commercial space stations, advanced payloads and increasingly sophisticated ground systems, today’s space programs are being asked to accomplish more—and do it on compressed development schedules. At the same time, spacecraft are becoming increasingly software-defined, autonomous and data-intensive.
That combination creates a fundamental challenge:
How do you validate behavior when a system is too complex to fully test in flight?
This was the focus of a recent presentation at Southwest Research Institute (SwRI) in Texas, where Circuit Check and NI came together to discuss the testing and validation challenges facing modern space systems—and how organizations can build greater confidence before hardware ever reaches the launch pad.
Modern spacecraft are no longer simply collections of hardware components. They increasingly rely on software, onboard decision-making, high-speed communications and large volumes of sensor and payload data.
At the same time, development schedules are becoming more compressed. Teams have less time to design, build and test increasingly complex systems.
And while commercial off-the-shelf (COTS) components can help accelerate development, they also introduce a greater expectation for verification and validation.
The result is a difficult balancing act: move quickly without sacrificing reliability.
Testing needs to evolve alongside the systems being tested.
When space programs experience schedule pressure, the problem isn't always the test itself. Delays can begin much earlier in the development process.
Three common sources of risk discussed during the presentation were requirements instability, system integration challenges and supply-chain disruptions.
Mission requirements can change. Payloads can evolve. Customers may add functionality after design work has already begun. Each change can trigger design rework, software changes, new test procedures and additional qualification testing.
Integration introduces another layer of complexity. Timing issues, data-format mismatches, communications-protocol problems and insufficient unit testing can all create problems once individual components need to operate together.
And outside the engineering organization, material availability, geopolitical events, natural disasters, pandemics and tariffs can disrupt the supply chain.
These challenges highlight an important lesson: testing cannot be an afterthought.
The earlier a team can identify problems, the less expensive—and less disruptive—they are to fix.
Leading aerospace organizations are thinking about testing before they have a piece of flight hardware.
That means making deliberate decisions about observability, instrumentation, synchronization, fault simulation and traceability during the development process.
Consider a flight computer that unexpectedly resets.
A basic test system might tell an engineer that the reset occurred at 14:23:12.
A system designed for greater observability can provide the surrounding context: CPU and memory utilization, a communications timeout that occurred milliseconds earlier, a power-rail disturbance, execution of a fault handler and the eventual watchdog reset.
Both systems detect the same failure.
Only one provides enough information to help engineers determine why it happened.
That distinction becomes increasingly important as spacecraft become more autonomous and complex. Engineers need the ability to see not only what happened, but also the conditions leading up to it.
One of the key concepts presented at SwRI was the progression from functional testing to parametric testing and ultimately hardware-in-the-loop (HIL) system validation.
Functional testing verifies the basic operation of a unit or subsystem.
Does the power turn on? Do the inputs and outputs work? Are the communication buses operating correctly?
At this stage, testing is often interactive and performed at the benchtop.
Circuit Check contributes through integration, interfaces, automation and test fixtures, while NI provides the software, I/O and communications capabilities that form the foundation of the test environment.
Once basic functionality is established, the next question is whether the hardware performs within its required specifications.
Parametric testing provides automated characterization of measurements such as timing, accuracy and operating margins. The goal is repeatable, data-rich testing that provides much more information than a simple pass/fail result.
NI TestStand and PXI instrumentation can provide a reusable foundation for automated measurements, while Circuit Check brings test planning, sequencing and customized reporting into the overall solution.
At the highest level of test maturity, the question changes.
It is no longer simply whether a component works or meets its specifications. The question becomes:
Will the system behave correctly in the conditions it will encounter during the mission?
HIL testing combines real hardware and real I/O with real-time models in a closed-loop environment. Engineers can introduce faults and test off-nominal scenarios that would be impractical—or impossible—to reproduce during an actual mission.
NI technologies such as VeriStand, PXI FPGA I/O, SLSC and RMX power and loads can provide the real-time test infrastructure, while Circuit Check can provide capabilities including security, optical and high-density switching and communications.
The goal is to increase fidelity and confidence while reducing the cost of finding defects late in the development cycle.
Another major theme of the presentation was digital engineering.
A digital thread isn't simply a collection of connected software tools. Its real value comes from maintaining an unbroken chain of traceability throughout the product lifecycle.
That thread connects:
Requirements → Models → Test Procedures → Test Results → Flight Anomalies
When a requirement changes, the impact should be visible throughout the development and verification process.
Which test procedures need to change? Which models are affected? Which results need to be reevaluated? What documentation needs to be updated?
The strength of a digital thread isn't how many tools it connects.
It's how quickly a change reaches everything it should—and how confidently an engineering team can prove it.
The presentation also explored how the same modular test platform can support an organization's entire integration and test campaign.
Rather than developing completely separate test architectures for each stage of development, a modular platform allows teams to reuse hardware and measurement IP as they move from functional testing to automated characterization and ultimately system-level HIL validation.
NI's PXI-based ecosystem provides a modular foundation for instrumentation, FPGA processing, switching, power and loads. Software such as LabVIEW, TestStand, VeriStand and SystemLink can provide programming, test execution, real-time modeling and data/system management.
Circuit Check adds system integration, automation, custom test solutions, fixtures, switching and interfaces needed to turn those technologies into complete test systems.
This approach can help organizations scale their test capabilities as the product moves through its development lifecycle—without starting over at every stage.
These concepts are being applied across multiple aerospace test systems, all built around an NI PXI-based architecture. FPGA cards play a particularly important role, primarily supporting proprietary, high-speed serial communication protocols. While each system uses the FPGAs differently, using the same card type enables code reuse and helps streamline development.
The systems also incorporate standard and industrial digital I/O, including 6509/6515 modules, for DUT signaling and system control. Programmable variable resistors are used in some systems to simulate thermistors, while DMM combinations provide measurement of various signals. Other applications use simultaneous-sampling DAQ technology to measure phase voltages across motor loads.
One of the most interesting aspects of this architecture is the decision to leverage commercial off-the-shelf (COTS) hardware rather than develop custom hardware, even when the number of required I/O lines is significant. That decision was driven by lead time and software support, along with the desire to leverage proven COTS technology.
Those same advantages remain relevant today. By using modular, commercially available hardware, aerospace test teams can achieve the performance and flexibility they need while reducing development time and creating opportunities for greater hardware and software reuse.
As space systems continue to become more complex, organizations need a testing strategy that evolves with them.
That means asking the right questions early:
The answers don't come from a single instrument, software package or test station.
They come from designing a connected test strategy that brings together hardware, software, automation, simulation, data and engineering expertise.
For today's aerospace programs, the ultimate goal isn't simply to prove that a piece of hardware works.
It's to build enough confidence—before launch—to know that the system will perform when it matters most.
From prototype to mission, better testing means greater confidence in mission success.