AAWSAP DIRD, Positron Aerospace Propulsion, March 2010

Text

This text came with the file. It may have mistakes. When the text and the image disagree, the image is right.

UNCLASSIFIED/fFOA 8FFl&IAl l48l: 8HL'I
Positron Aerospace Propulsion
Introduction
Antimatter is considered an extremely attractive fuel for aerospace propulsion
because of its enormous advantage in energy density over all other known
sources of energy. However, because antimatter does not occur naturally and
is unstable in the presence of matter, no vehicles have ever flown using it.
After a short overview of the various aerospace applications of antimatter, this
paper provides a detailed analysis of air-breathing turbojets and turbo-ramjet
missiles, as well as rockets for manned interplanetary missions. It discusses
new methods of producing and storing large numbers of antielectrons, or
positrons, and compares their costs with those of antiprotons. Finally, the
paper considers the prospects for the first, modest demonstration of positron
propulsive flight within the next 10 years. Interplanetary missions on
positron-propelled spaceships are described in detail, with estimates of
positron requirements for each mission. Standalone positron power systems
are described briefly.
Studies of positrons as a fuel for aerospace propulsion applications have been
sponsored by the Air Force Research Laboratory, Eglin Air Force Base, Florida,
and the NASA Institute for Advanced Concepts, Atlanta, Georgia. This paper is
an anthology of that work and not a general review of antimatter propulsion.
The positron was predicted by Dirac in 19291 and discovered by Anderson in
1932.2 Along with the antiproton, which was discovered in 1954,3 the positron
has the largest specific energy of any known material. Because aerospace
propulsion performance is ultimately limited by specific power, this advantage
was immediately appreciated. However, compared with chemical sources of
energy, positrons presented new and serious production and storage
challenges.
Antimatter has a long history of appearing in science fiction literature, dating
to a 1942 short story in Astounding Science Fiction and the 1949 book Seetee.
It later appeared in the Star Trek television and film series and continues to be
an appealing subject for contemporary books and films, such as Angels and
Demons.
Positron aerospace propulsion is now entering a critical period owing to new
technologies that bear on production and storage issues. To their advantage,
positrons, unlike nuclear fission and antiprotons, present no radiation or
environmental safety problems.
UNCLASSIFIED//FAR AEEICllk Wlili 8Nl¥
V