Preparing the Dream Chaser® Spaceplane for Launch.

Combs begins by outlining how the collaboration between Sierra Space and ARS emerged from immediate scheduling challenges rather than long-term program intent.

“Sierra Space initially planned to conduct the Vulcan proto-qualification launch acoustic test for the Dream Chaser® spaceplane at NASA’s reverberant test chamber, located at the Armstrong Test Facility in Sandusky, Ohio. However, as the scheduled test dates approached, conflicts with other high-profile government programs created constraints with test chamber availability.”

With traditional test facilities no longer available on the required timeline, the Sierra Space team was faced with a critical decision: either accept program delays or identify an alternative path that could still deliver representative launch acoustics. Combs explains that this moment became the catalyst for reassessing how acoustic qualification could be achieved outside the reverberant chamber.

“To ensure the program remained on track, Sierra Space began evaluating alternative Direct Field Acoustic Noise (DFAN) testing options to eliminate dependance of the reverberant test chamber. After an extensive review, Sierra Space selected ARS as the preferred vendor for these critical tests.”

As Combs goes on to explain, the decision was not simply about availability. It was driven by the need to match the testing method to the unique physical characteristics of the Dream Chaser vehicle and to ensure the acoustic environment remained well controlled.

“The Neutron™ system from ARS stood out for its ability to deliver a full range of output and generate homogeneous, high-intensity sound fields, a key differentiator for the unique needs of the Dream Chaser spaceplane.”

Combs goes on to explain why that capability mattered in practice, particularly given the Dream Chaser’s geometry and the sensitivity of acoustic field uniformity when testing a non-traditional vehicle shape.

“Given the specialized geometry of the Dream Chaser, avoiding standing waves and hot or cold acoustic spots was essential to achieving accurate and reliable test results. The ARS solution met these requirements, ensuring precise simulation of the acoustic environments the vehicle will encounter during launch.”

Early Campaigns and First-of-Their-Kind Testing

With the testing approach defined, Combs turns to the first acoustic qualification campaigns and the practical considerations that shaped how those tests were executed. He notes that the physical configuration of the Dream Chaser stack directly influenced the test strategy.

“Due to the overall height of the Dream Chaser® spaceplane when stacked atop its Cargo Module, Sierra Space needed to separate the acoustic test events for our vehicles.”

The Cargo Module campaign became the first major test effort conducted by ARS, establishing a working model for how the teams would coordinate planning, execution, and data validation.

“The Cargo Module launch acoustic test marked the first major test operation with ARS, and the results exceeded expectations. ARS proved to be collaborative throughout the process, working closely with Sierra Space to achieve this milestone.”

Combs further elaborates on how this collaboration enabled a first-of-its-kind application of DFAN within a NASA facility.

“For the first time, a Direct Field Acoustic Noise (DFAN) test was performed in NASA’s Space Systems Processing Facility. Together, Sierra Space and ARS developed compelling rationale to assure NASA that the testing posed no risk to their facility.”

Beyond the technical milestone, Combs explains that this approach delivered meaningful program-level benefits.

“This collaboration unlocked significant cost and schedule savings for the campaign, enabling Sierra Space to move forward efficiently.”

He goes on to unpack the level of coordination required to execute the campaign successfully and consistently.

“The combined team meticulously planned and executed integrated operations with precision. ARS’s full-service test support played a critical role in the success of the test, from providing supplemental instrumentation where needed to ensuring a consistent acoustic environment during test runs and performing thorough post-processing of test data.”

Combs notes that this level of coordination and execution was essential to achieving a test outcome that could confidently support qualification decisions.

“The result was an extremely successful DFAN campaign, qualifying the Cargo Module to ride atop a Vulcan rocket to orbit. This achievement underscores the strength of Sierra Space’s collaboration with ARS and marks another key step forward in preparing the Dream Chaser spaceplane for its upcoming missions.”

Reducing Risk Through Integrated Test Configurations

Building on those early successes, Combs shifts the discussion toward how future test campaigns can benefit from integrating multiple dynamic test objectives within a single configuration.

“The ability to satisfy multiple test requirements within a single setup delivers significant cost and schedule savings, an essential advantage in the competitive commercial space industry.”

He then expands on the operational value of minimizing hardware movement and reconfiguration across test events.

“Equally important is the reduction in risk associated with minimizing the movement and reconfiguration of spaceflight hardware for multiple test events. Fewer test setups mean fewer opportunities for errors or damage, ensuring safer and more reliable operations throughout the testing process.”

The Importance of Adaptable Testing Collaboration

As Sierra Space’s portfolio continues to expand, Combs emphasizes that adaptability has become a defining requirement when selecting testing supplier.

“As Sierra Space continues to evolve and expand its business, having flexible and adaptable parties in the testing space is more important than ever.”

He points to system scalability as a critical enabler of that adaptability.

“The scalability of the Neutron™ System is a critical asset, enabling acoustic testing across a wide range of applications, from individual components to large-scale spacecraft like the Dream Chaser®.”

Combs goes on to connect that scalability to the broader demands of Sierra Space’s expanding range of programs.

“This versatility ensures that Sierra Space can meet the rigorous demands of its growing portfolio while maintaining efficiency and precision in its testing processes.”

Establishing a Framework for Mobile Acoustic Testing

Turning to the practical realities of mobile acoustic testing, Combs describes how success depended on close coordination across both organizations. He notes that establishing a repeatable framework required careful attention to both technical execution and logistics.

“Together with ARS, we meticulously planned both the technical aspects of the environmental test as well as the detailed logistics necessary to integrate the Dream Chaser® vehicles and the ARS Neutron™ system into a singular test configuration.”

With that framework in place, Combs reflects on what ultimately enabled the campaign to succeed and why the experience continues to shape Sierra Space’s approach to testing.

“The flexibility and expertise of the ARS team, combined with the scalability of the Neutron™ system, have been instrumental in the success of our acoustic testing efforts.”

Combs then reflects on how those technical and operational strengths translate into longer-term confidence in the relationship.

“This collaboration has not only delivered outstanding results but has also opened the door for future collaborations. We are excited to explore opportunities to work with ARS across other areas of our business.”

Taken together, Combs’ reflections illustrate how modern acoustic test programs are increasingly defined by adaptability, integration, and disciplined execution. For Sierra Space, the Dream Chaser campaigns demonstrate how aligning testing capability with real program constraints can deliver reliable qualification data while preserving schedule and reducing risk.

As launch timelines continue to accelerate and testing environments grow more complex, approaches that prioritize flexibility and collaboration will remain essential. In that context, the experience described here offers a clear example of how thoughtful acoustic test planning supports readiness long before ignition.