Flying an autonomous aircraft at Mach 5 and above demands more than propulsion and flight software. What does building a repeatable hypersonic test operation actually involve? At the 20th Annual UAS Summit, Zachary Krevor, President and CEO of Stratolaunch, shared lessons from operating multiple hypersonic UAS with different carrier aircraft and at different test locations. His central message was that expanding access to hypersonic flight testing requires teams to treat operational preparation as seriously as aircraft performance. Despite extensive preparation, he said, “we ultimately learn something every time.” Read on for the lessons learned.
Talon-A Targets the Hypersonic Flight-Test Bottleneck
Krevor framed Stratolaunch’s mission around the persistent constraint of limited access to UAS flight-test infrastructure. Wind tunnels remain useful, but scheduling constraints and the uncertainties that remain without actual flight data can slow development. Stratolaunch operates the only autonomous, reusable, air-launched hypersonic flight test platform in the U.S., called Talon-A,to carry technologies into the hypersonic environment, collect data and return customer payloads for examination.
During a typical mission, a carrier aircraft takes off with Talon-A attached and releases it at conventional airliner speeds and altitudes. Talon-A ignites its engine, accelerates to Mach 5 or above, performs maneuvers and technology demonstrations, then autonomously lands on a standard runway.
Customers can fly sensors, instrumentation and materials at different locations on the aircraft. Onboard data storage and recovery allow them to analyze both recorded performance and the payloads themselves.“We can return the payloads in a very prompt manner,” Krevor said, emphasizing the importance of keeping customers’ development programs moving.
Stratolaunch has operated two Talon-A aircraft, a third in production and completed more than 10 hypersonic flights. Krevor described the company’s ambition to reach the goal of two, three or even four hypersonic flights per month.
Five Lessons for Deploying Hypersonic UAS
Krevor’s presentation highlighted five practical lessons for turning individual flight successes into a repeatable operation.
1. Test Communications and Safety Systems as They Will Fly
Ground preparation does not reveal every issue that emerges when aircraft, communications links and flight termination systems operate together in flight.
Krevor said Stratolaunch continues to learn from airborne telemetry exchanges and flight termination system signals. The company now works backward from mission dates to accommodate captive-carry testing, with Talon-A remaining attached to its carrier aircraft.
“It’s imperative now that we’re doing that integrated test sequence, just like how it would happen on mission day,” he said.
The lesson here centers on integration: validating individual components cannot substitute for exercising the complete mission configuration.
2. Scout Test Sites and Account for Environmental Differences
Maps cannot replace an advance visit. Krevor stressed the value of understanding actual distances, sight lines and vendor availability before deploying.
Environmental differences also exposed assumptions that had worked at Stratolaunch’s Mojave, California, base but did not hold elsewhere. In one example, the team did not consistently operate the carrier aircraft’s auxiliary power unit during mission preparations. In a hot, humid environment, that approach left components without cooling they needed inside the Boeing 747. “We ended up frying a variety of components,” Krevor said.
The experience prompted the company to examine environmental differences systematically before subsequent deployments.
3. Rehearse Aircraft Turnarounds With Deployment Equipment Only
To test its deployment readiness, Stratolaunch created a “home away from home” equipment cage inside its Mojave hangar.
Teams had to turn around a Talon-A using only the equipment in that designated inventory. If they discovered something missing, they had 24 hours to find a solution using what they already had. If they could not, the missing item went onto the deployment list and into the kit. The exercise exposed gaps while the team still had access to its home facilities, rather than after it reached a distant operating location. Krevor said the rehearsal helped avoid “trying to travel to and from Mojave at great distances” while working toward a scheduled flight.
4. Start Range Safety and Regulatory Coordination Early
Stratolaunch conducts quantitative flight safety analyses to estimate mission risks, alongside qualitative hazard analyses. Krevor emphasized that those hazards change with the operating location and environment.
Some ranges had not previously supported missions like Stratolaunch’s autonomous hypersonic flights. That made early coordination with the people authorized to approve operations particularly important. “Understanding that full process, what kind of analyses and risks they need to see,” became a key part of preparing for each location, he said.
Krevor also described starting with less demanding missions when appropriate, then working with regulators to expand the flight envelope as familiarity and confidence grew.
5. Plan for Emergencies Beyond the Aircraft
A Category 5 typhoon tested Stratolaunch’s emergency planning during one mission series.
The team moved its 747 carrier aircraft, Spirit of Mojave, out before the storm arrived. It also had to assess hangar protection, possible localized flooding, ways to elevate the hypersonic aircraft and which personnel needed to remain.
Krevor said the Talon-A aircraft subsequently returned to flight, but acknowledged gaps in the company’s advance preparation. “We could have certainly done a better job on our own knowing that ahead of time,” he said.
His advice extended beyond tropical weather. Teams should consider natural hazards and emergencies arising from their own operations, even when those scenarios appear unlikely.
Multiple Carrier Aircraft Support Hypersonic Test Expansion
Stratolaunch’s fleet strategy supports its push toward more frequent and geographically distributed testing.
The company currently operates three carrier aircraft, including Roc, the Spirit of Mojave, and its newly acquired Boeing 777 aircraft. The 777 is undergoing heavy maintenance and modification work in Mojave, CA before completion in 2027.
The additional aircraft would help Stratolaunch reach more locations and conduct simultaneous missions, as well as expected to increase the company’s overall flight capacity by about 35%. Those capabilities, however, depend on more than fleet size. Each deployment also requires suitable equipment, integrated testing, local approvals and emergency arrangements.
SkyRange Testing Will Put Deployment Lessons to Work
Krevor closed by announcing plans to return with the 747 and Talon-A for integrated captive-carry testing with SkyRange, working with GrandSKY and the surrounding North Dakota community during the following calendar year. “We’ll be here doing a variety of test series and look forward to seeing you out there,” he said.
That planned work connects Stratolaunch’s flight-test ambitions to the operational discipline Krevor emphasized throughout his presentation, to rehearse the complete mission, understand the location and resolve deployment weaknesses before they jeopardize a flight.