Composite Materials for Cryogenic Fuel Tanks

Use of composite material, rather than aluminum, for the hydrogen and oxygen tanks for the reference mission spacecraft gives us a very significant weight reduction.

In the NASA news release below, they report that composite tanks being developed for the DC-XA rocket are 37% lighter than their aluminum counterparts for the same strength of materials. Since this is the state of the art in early 1996, we can assume that by the time we build the Artemis spacecraft composite tanks will be off-the-shelf technology.

Jim Cast
Headquarters, Washington, DC                 January 25, 1996
(Phone:  202/358-1779)
Dom Amatore
Marshall Space Flight Center, Huntsville, AL
(Phone:  205/544-0031)
RELEASE:  96-13

COMPOSITE HYDROGEN TANK TEST COMPLETED FOR DC-XA

    A new lightweight composite hydrogen tank for the Delta
Clipper-Experimental Advanced (DC-XA) vehicle, an unpiloted,
single-stage rocket being developed by NASA and McDonnell
Douglas Aerospace, has successfully completed testing at the
Marshall Space Flight Center, Huntsville, AL.
    "This is really quite a breakthrough," said NASA's DC-XA
project manager Dan Dumbacher.  "This is the largest composite
hydrogen tank ever to successfully survive flight operating
conditions.  It demonstrates that composite tanks can be used
for other reusable launch vehicles in the future."
    Permeability of composite materials has been a concern for
engineers, but this tank withstood pressure testing at
cryogenic temperatures that simulated the DC-XA flight
environment without leaking hydrogen.  Composite materials are
formed by blending epoxies and various filaments to form
strong structures with a variety of aerospace uses.  NASA has
been conducting intensive research and development on
composites since the 1970s.
    The DC-XA is a flying experimental testbed that is
demonstrating technologies for NASA's Reusable Launch Vehicle
Program.  Knowledge gained in developing and test flying the
DC-XA will be used in development of the X-33 advanced
technology demonstrator and ultimately in a full-scale
reusable launch vehicle.
    The ability to use composites is important to the
development of a single-stage-to-orbit reusable launch vehicle
because of the weight reduction they provide.  Getting the
weight down is a key factor in launching a payload to orbit in
a single stage rocket.  DC-XA's 16-foot-tall hydrogen tank,
eight feet in diameter, is made of graphite composites and
weighs 2,020 pounds -- 1,200 pounds lighter than the tank used
in its predecessor, the DC-X.  Yet the composite tank provides
the same strength that an aluminum tank would.
    The successful on-time completion of this test is a big
step forward for the DC-XA, Dumbacher said.
    "It's a major milestone in the DC-XA program," Dumbacher
said .  "It keeps us on track to flight test the vehicle in
May.  We've shipped the tank to McDonnell Douglas Aerospace in
Huntington Beach, CA, where they will build the flight vehicle
around it."
    "This will be the first graphite epoxy cryogenic fuel tank
to undergo flight testing," said Dave Schweikle, McDonnell
Douglas DC-XA program manager.  "The tank was designed and
fabricated by McDonnell Douglas to hold liquid hydrogen at
minus 423 degrees Fahrenheit and to serve as an integral part
of the DC-XA's structure."