24 August 2019 | New Scientist | 15Biofuel Military technology
Alice Klein David Hambling
A POWERFUL military jet fuel
normally made from coal tar can
be made more cheaply from plants.
A team led by Guangyi Li at the
Dalian Institute of Chemical Physics
in China have come up with a way of
producing the JP-10 superfuel from
a chemical called furfuryl alcohol
that is extracted from plant waste
such as cotton stalks, forestry
offcuts and sugar cane residue.
The process to convert furfuryl
alcohol into the fuel uses catalysts
and temperatures of up to 250°C.
JP-10 is prized because it is
stable at a range of temperatures
and has a low freezing point. It also
has a high energy density, which
means a small volume can propel
an aircraft a long distance.
The downside is that it costs
about $7000 per tonne, more
than 10 times as much as ordinary
jet fuel. This limits its use to
missiles and high-performance
military aircraft.
The new way of making JP-
brings the cost down to below
$5600 per tonne. It could drop to
half that again as it becomes easier
to extract furfuryl alcohol from
plant matter, the researchers write
(Angewandte Chemie International
Edition, doi. org/c9k9).
This would still mean it was
about four times as expensive as
commercial jet fuel. But the reduced
cost could expand its military uses.
Making JP-10 from green waste
should be more environmentally
friendly than the usual way of
producing it from coal tar, says Ian
O’Hara at the Queensland University
of Technology in Australia. “Fuels
from bio-based sources tend
to have significant greenhouse
gas reductions compared with
conventional fossil fuels,” he says.
There is mounting interest
in using biofuels to cut aviation
emissions, says O’Hara. That is
largely because, in contrast to cars,
it is hard to make planes electric. ❚
Jet fuel made
cheaply from plant
waste, not coal
ARTIFICIAL intelligence may
soon decide who lives or dies.
The US Army wants to build
cannon-fired missiles that will
use AI to hunt their targets, out
of reach of human oversight.
The project has raised concerns
that the missiles will be a form
of lethal autonomous weapon.
The project is called Cannon-
Delivered Area Effects Munition(C-DAEM). Companies will bid for
the contract to build the weapon,
and prototype demonstrations
are due to take place in 2021.
Requirements state that it
should be able to hit “moving
and imprecisely located
armoured targets” whose “exact
position has high uncertainty”.
Unlike laser-guided weapons,
which strike a target highlighted
by a human operator, C-DAEM
will find targets for itself. To
achieve this, a parallel project
will aim to develop algorithms
for the weapons. These will
be similar to face-recognition
algorithms, but will use
infrared cameras instead of
traditional ones as they are
more accurate at identifying
targets, such as tanks.
The weapons will have a range
of up to 60 kilometres, taking
more than a minute to arrive,
and will be able to search an
area of more than 28 square
kilometres for targets. They will
have a way to slow down, such
as a parachute or small wings,
which will be used while
scanning objects below.
The weapons will hunt for
targets autonomously, deciding
when they have found one and
attacking without humanintervention, says Mark Gubrud
at the University of North
Carolina. They are effectively
killer robots, he says.
“It moves us from the current
situation, in which a human
operator needs to be reasonably
sure that the target is legitimate,
to one in which the human
operator need only have a vague
intuition that somewhere in a
10-square-mile area there might
be a bad person,” says Stuart
Russell at the University of
California, Berkeley.
The new weapon is meant to
replace cluster warheads, which
scatter dozens of grenades over
a wide area. These are effective
against armoured vehicles, but
have a high dud rate, meaning
that dangerous, unexploded
grenades remain after an attack.
Smart weapons ought to
be safer than indiscriminate
bombs, but Russell says that
may not be the case. “It seems
likely that less care would be
taken in target selection by
the operator and attacks wouldtake place with less reliable
intelligence,” he says.
Some may see this as an
autonomous weapon, but
it would technically comply
with the US Army’s rule that
a human operator must select
each target. “The word ‘select’,
as it is used in the US policy,
is very slippery,” says Gubrud.
“A human can ‘select’ a target
before it has even been seen.”
Select may just mean providing
a description of the target and
its general area, he says.
The US Army said by email:
“This is not an autonomous
weapon, nor is it intended to be.
We seek an advanced capability
for a round – once fired – to
continue pursuing a target
despite the types of interference
that might cause it to pursue
something else. This would
improve our capabilities to
avoid collateral damage.” ❚US Army wants AI missiles
that find their own targets
CAPT. BRIAN HARRIS, 16TH COMBAT AVIATION BRIGADENew autonomous rounds
are being developed for
155 mm guns like this“ The weapons will
attack without human
intervention. These are
effectively killer robots”