The Test Like You Fly and Test What You Fly Approach for the Artemis Human Spaceflight Paradigm

The principles of Test Like You Fly (TLYF) and Test What You Fly (TWYF) seem self-explanatory—the more closely ground testing can replicate flight conditions and mission operations, the less risk of unexpected issues during execution of the mission. However, for every spaceflight program, a multitude of factors dictate the extent to which that principle can be followed. Therefore, the TLYF process involves a continual assessment to maximize the effectiveness of ground testing, given the limitations, and to characterize the remaining risk to mission success.

An effective TLYF approach relies on test configurations that represent the actual mission configurations with sufficient fidelity, including the vehicle configurations and the operational environment. This paper will discuss the TLYF assessment, exception evaluation, and risk acceptance process as it applies to integrated testing between multiple elements whose size and complexity may preclude the possibility of validating their interfaces on the ground in their final flight configurations.

In the Artemis paradigm, starting with the Artemis III mission, there will be separate government launched elements including Orion and Lunar Gateway elements, and commercially launched elements including lunar landers, surface elements such as rovers and habitats, and other Gateway elements. Additionally, there will be spacesuits, logistics, and utilization elements which may be launched on a variety of vehicles. Because of this complex architecture of distributed manufacture, test, and launch, where elements would not otherwise come together pre-flight, opportunities to test hardware together pre-flight must be purposefully driven.

This paper will address the TLYF approach based on case studies of past implementation and outcomes. It will then recommend a standardized process across the Artemis campaign, using a general rubric for scoring exceptions and their importance. To address the importance of TLYF as a process, this paper will conclude with a detailed presentation of a consistent process for assessing both TLYF and TWYF aspects to devise test campaigns that make best effort toward the highest fidelity options as a default. As the Artemis programs implement this process, the expectation is that needs and opportunities for testing are identified in time to be value-added and a better understanding of the residual risk posture is achieved for the campaign.