US hypersonic test vehicle pierces Norway sky at 7 times the speed of sound

US Air Force’s hypersonic test vehicle BOLT-1B has conducted its successful flight. The flight was conducted over Norway on September 2.

The test vehicle lifted off from the Andøya Space Sub-Orbital launch site at 11:41:01 local time and reached an apogee of 157 miles (254 kilometers) before safely splashing down inside the impact and dispersion area.

BOLT-1B completed all test objectives, and the launch team now has a lot of data to analyze in the months ahead, according to reports. The experimental vehicle traveled over the Norwegian Sea at Mach 7.2 and provided a stream of important data on the physics of airflow at hypersonic speeds.

The project is coordinated by the Air Force Office Scientific Research from United States and is carried out by Johns Hopkins Applied Physics Laboratory (APL), the Air Force Research Laboratory Aerospace Systems Directorate (AFRL/RQ), and the German Aerospace Center (DLR).

Data gathered from flight experiment

“The data we gathered from the flight experiment will be critical for improving methods for designing future hypersonic vehicles, so we can reduce modeling uncertainties and optimize their performance,” said APL’s Brad Wheaton, chief scientist with the Vehicle Design and Technologies Group in APL’s Force Projection Sector and the project’s principal investigator.

The project aims to study a phenomenon called boundary layer transition (the flow of air around the skin of a hypersonic vehicle), which increases hypersonic vehicle drag and aerodynamic heating.

The scientific data collected from the test will be used by researchers to validate new and more accurate modeling and prediction methods during the design of hypersonic vehicles, according to Johns Hopkins.

Experiment was loaded with instruments to take measurements

Designed and built by APL, the experiment was loaded with instruments to take more than 400 measurements, with locations on the vehicle determined by an extensive research effort to better understand the physics of boundary layer transition on the BOLT vehicle’s geometry.

As planned, the test concluded with BOLT-1B impacting the ocean approximately 115 miles (185 kilometers) offshore.

“Andøya Space Sub-Orbital is proud to have supported the BOLT-1B launch campaign,” said Thomas Gansmoe, Director of Sounding rockets and Engineering services at Andøya Space Sub-Orbital.

Data gathered will help engineers design future hypersonic vehicles

“We wish to congratulate the entire team with a highly successful and important test campaign. The effects of boundary layer transition are some of the greatest uncertainty sources for designing a hypersonic vehicle. The data gathered from this flight will help engineers design future hypersonic vehicles,” explained Gansmoe.

Hypersonic vehicles are those that move faster than five times the speed of sound, or Mach 5. The flow of the air has always been a key aspect for hypersonic vehicle’s flight.

Being able to pinpoint whether the air is laminar (moving in a smooth, straight line) or has transitioned to turbulent (swirling in eddies, with up to eight times the heat transfer) is critical for determining what materials to use when designing hypersonic aircraft and missiles, according to a brief explanation by Johns Hopkins University.