Interview: Julie Kramer White z
AEROSPACETESTINGINTERNATIONAL.COMAPRIL 2015 |^17
so we had to build a special test
facility, as there was no facility in the
USA that could test to the level we
wanted. There was some similar testing
done at Johnson Space Center for Apollo
and it was done in our vibro-acoustic
chambers here, but they could only go
up to about 160dB. So we are going to
do our vibro-acoustic testing at
Plumbrook, outside of Cleveland
[Ohio], so we can get to higher levels
than we can here. The plan is to take
a castle up there and to carry out what
we would call a ‘stub’ test, meaning the
very top is cut off because it’s so tall that
it will not fit in the generator.
“We will take it up to the maximum
facility vibration and acoustics, and then
they’ll take the ‘O’ drive off and submit
the capsule to those environments, so
we’ll get a very good understanding of
how those acoustic and vibration
environments are transmitted through
the ‘O’ drive and into the castle. I believe
that the test is actually scheduled for
facility at Kennedy Space Center where
it’s built, and they did multipoint
random vibration testing with the stingers
installed on the flight hardware that
drove the whole spacecraft. They were
able to get the dynamic responses of
the spacecraft to see that everything
was responding as we would have
anticipated it to, and to help us with
model correlation. It’s a little bit nerve-
wracking to hear the whole thing start
rattling, but it was great; it really
proved how well the system was built
and how well the models were
correlated. So we do all kinds of
different testing before we attempt toRIGHT: NASA’s
Orion spacecraft
is seen from an
unpiloted aircraft
as it descends
under three
massive red
and white main
parachutes at
20mphBELOW: NASA’s
Orion spacecraft
floats in the Pacific
Ocean after
splashdown from
its first flight test
in Earth orbitPARACHUTE TRIALS
Engineers in Arizona have
been testing subscale
parachutes for NASA’s Orion
spacecraft to help improve
the safety and reliability of
the Orion’s landing by
investigating ways to make
its main parachutes more
aerodynamically stable
while maintaining drag
performance, in preparation
for its next mission –
Exploration Mission-1.
In January 2015, a
team from NASA, Jacobs
Engineering, Airborne
Systems, and the National
Full-Scale Aerodynamics
Complex, tested 13 differentparachute configurations in
one of the complex’s wind
tunnels in California.
During the testing, a
tether system was used
to hold the parachute and
measure aerodynamic forces
to help determine which
parachute configuration
provided the best
performance. The parachute
was also allowed to fly freely
in the tunnel. During these
free-flights, data was
gathered using
photogrammetry, a method
of taking measurements
using photography. Kramer
says, “I would characterizethe tests by saying it was a
‘C’ pass. It’s a parachute
system for Orion and it has
been a very successful
program. All complicated
testing like that has its
issues, and even getting
set up for a parachute test
and getting it off in the right
conditions is extremely
complicated; clearly there
were some details that
weren’t quite right. We had
to rebuild the test vehicle
and we’ve been in a series
of successful tests and
obviously the parachutes
performed beautifully on
EF T-1.”2018 right now; that’s the final
configuration with the final castle.
“We did what we call the multipoint
random vibration tests on the EFT-
capsule because we wanted to get some
dynamic characterization of the system.
But EFT-1 was never intended to go
through abort load; it was just going to
go through normal asset loads and they’re
quite a bit lower. So we were able to
subject the airframe and all the systems
that had been installed at that point –
the propulsion systems, the acid thermal
control systems, all the harnesses,
everything had been installed. We
actually sent a team down to the