NASA Steps Up Civil Hypersonic Studies With Aerion, GE

AS2
Aerion is developing the AS2 supersonic business jet.
Credit: Aerion Supersonic

NASA is transitioning long-running hypersonic technology studies increasingly toward potential commercial applications and has awarded two new contracts supporting high speed design and propulsion work to Aerion Supersonic and GE Aviation respectively.

The work with Aerion, which is developing the Mach 1.4 AS2 supersonic business jet, builds on two previous collaborative study contracts and focuses on propulsion and thermal management technologies for aircraft flying in the sub-hypersonic Mach 3-5 speed range. 

The contract with GE Aviation targets high-temperature ceramic components and turbine-based combined cycle (TBCC) research for high-Mach vehicles, and is based on studies of an F101 engine.

Awarded as part of NASA’s Hypersonic Technology Project (HTP), the Aerion contract particularly reflects the agency’s ongoing pivot toward commercial high-speed flight research.  Although NASA traditionally has supported fundamental U.S. defense research work aimed at enabling routine, reusable, airbreathing hypersonic flight, this has changed in recent times. 

“There has been some push to get into looking a little closer at commercial hypersonics,” said Lori Ozoroski, project manager of NASA commercial supersonics technology at the agency’s Langley Research Center in Virginia.

Commenting at an AFWERX Vector/Supersonic Prime “Ask Me Anything” industry engagement webinar on Jan. 22, Ozoroski added that NASA’s move to examine the emerging civil high-speed flight sector came after “a year of due diligence.” This has included reviews of industry input and “multiple studies to provide insight on what are the key questions for hypersonics,” she said. “Is there a market? What are the enabling technologies? What kind of performance requirements are there for vehicles in that realm? And really trying to understand that design space,” Ozoroski said in summing up the approach.

Under the Space Act Agreement with NASA, Aerion said the collaboration will “evaluate the parametric suitability of propulsion and thermal management technologies. Through a joint assessment, the impact of Mach 3+ speed regimes will be explored to also establish solutions for enabling technologies in respect of integrated power generation and cabin systems.”

The company, which plans to start assembly of the first AS2 at its new Melbourne, Florida, facility in 2023, also aims to use its in-house developed aerodynamic optimization tools as part of the study. The tools will be used to “conduct technology assessments on future concepts and aid a transition to the faster aircraft of tomorrow,” Aerion added.

Aerion president and CEO Tom Vice said the collaboration with NASA will “significantly add to the work our company is doing on our next generation AS3 passenger jet.” Few details of the proposed follow-on to the AS2 business jet have been disclosed, though the project is known to be generically aiming at higher speeds for a larger, low-boom-capable airliner concept.

The agreement with Aerion follows a similar high-speed transport study contract announced last May between NASA and Virgin Galactic sister firm The Spaceship Company. The research work with NASA included collaboration on vehicle thermal management and propulsion system options in the Mach 3-5 regime. The studies on technologies up to the threshold of hypersonic conditions dovetails with Virgin’s long-running plans to develop an “SS3” high speed transport derivative follow-on to the company’s Mach 3 SS2 spaceplane.

NASA’s five-year contract with GE covers work for both the HTP and DARPA’s hypersonic vehicles research areas and supports materials technology development for high-speed aircraft structures as well as air-breathing engine technologies. In particular, the materials research will involve joint development of high-temperature resistant, lightweight ceramic composites made from silicon carbide/silicon carbide (Sic/Sic), and carbon/silicon carbide (C/Sic). The Sic/Sic material is targeted at advanced turbines for high-speed environments, while the C/Sic is aimed primarily at thermally resistant structures for high-speed hypersonic and space access vehicles.

GE’s knowledge, experience and control system analysis capabilities with the F101 will be used to assess the viability of the Mach 2-plus turbine engine to operate in a TBCC propulsion system for a hypersonic concept vehicle dubbed Aether, which has been developed under NASA’s HTP effort. 

The engine, originally designed for the B-1A bomber and subsequently used in the core of the CFM56 turbofan, is the only powerplant of its type with a fan bypass ratio of 2.0, which NASA believes will be required for accelerating the Aether vehicle to the point in the combined cycle operation in which the ramjet will take over. The F101’s relatively high bypass ratio will allow most of the flow to bypass the core when it is throttled down to avoid exceeding the core’s compressor and turbine flow temperature limits.

Guy Norris

Guy is a Senior Editor for Aviation Week, based in Los Angeles. Before joining Aviation Week in 2007, Guy was with Flight International, first as technical editor based in the U.K. and most recently as U.S. West Coast editor. Before joining Flight, he was London correspondent for Interavia, part of Jane's Information Group.