hypersonics
“We’re very much in the era of
hypersonics already, but we aren’t in the
era of where they are replacing more
traditional systems on a large scale”
1 // High-speed
photography captures
spectacular imagery of a
hypersonic projectile during
gas-gun research
2 // The large, two-stage
light gas gun (Photos: SwRI)
1
instrumentation to gather data in flight,” says Hellman.
Reaching and sustaining hypersonic speed has
always been a major challenge. Although Hellman is
confident of the X-60A’s predicted performance, he says,
“Instrumenting hypersonic payloads is also a difficult
challenge due to factors including the extreme heating.
“The X-60A will transmit data from its flight systems
and payload. Each payload will require a different set of
instrumentation corresponding to the technology tested,
while photography will be used during the initial release
and drop from the launch aircraft.”
Easy though it is to assume the X-60A is a weapons
research platform, Hellman says it is being designed, “as
a common vehicle for many different hypersonic
technologies, to avoid the need for a custom vehicle
designed for each flight”.
In so far as hypersonics can ever be explored at
minimum cost, it seems the X-60A has been conceived as
a versatile, cost-effective platform for multiple trials.
Even the need for an expensive mothership has been
32 MARCH 2020 \\ AEROSPACETESTINGINTERNATIONAL.COM
addressed. Hellman says, “The
X-60A will initially be air-dropped
from a modified, commercially
provided Gulfstream III. It will fly
under an FAA commercial launch
license with additional Air Force
airworthiness and safety oversight.
Future flights are expected to
operate in a similar manner to help
keep them affordable.”
The X-60A’s first hypersonic flight is expected later
this year, with a second a few months later. The aircraft
has been designed using existing components and
technologies. The team’s major challenge has come from
integrating these into a single vehicle. Ground trials,
including integrated stage propulsion tests conducted in
2018 and 2019, have helped overcome these challenges.
The 2019 test at Cecil Spaceport, Jacksonville, Florida,
involved flight-like propellant tanks, propellant
feed lines, avionics, and software,
integrated with the vehicle’s Hadley
rocket engine.
The X-60A SBIR enables
contracting flexibility funding to
mature the capability. While
acknowledging that the X-15
provided foundational
knowledge for hypersonic
flight, Hellman says that
once the initial period of
system trials concludes, “more routine
flights at hypersonic speeds will allow us
to learn what we don’t currently know”.
KINZHAL
Among other systems, Lockheed Martin
has been contracted to develop the B-52
launched Hypersonic Conventional Strike
Weapon (HCSW) under what the
company describes as a hypersonic boost
glide development and test program.
Stratofortresses released Mach-3.3
Lockheed D-21 drones during the
Vietnam War and the manufacturer is no
stranger to high-speed programs, yet
decades have passed without a similarly
fast aircraft being developed.
15,700 mph (mach 21)
Maximum speed SwRI can launch
projectiles using its gas gun
3 // An X-60A hot fire
test, conducted at Cecil
Spaceport in
Jacksonville, Florida
(Photo: US Air Force)
4 // The Southwest
Research Institute’s
San, Antonio,
Texas campus
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