10 | New Scientist | 10 August 2019
THE Royal Navy wants to use
artificial intelligence to guide a
fleet of robot submarines to find
and destroy underwater mines.
Mines usually lurk in shallow
water until a vessel passes and
triggers a sensor, setting off an
explosion. Making sure waterways
are safe requires regular sweeps.
At present, the UK searches for
mines in the Persian Gulf using
crewed vessels. Tension with Iran
has once more highlighted the
vulnerability of shipping routes
in this region. From 2020,
searches there will also be made
using uncrewed boats and small
robot submarines.
Planning minesweeping routes
is difficult because there are so
many interacting variables. Tides
and currents, the weather, seabed
contours and the number of
wrecks and other metallic objects
that may confuse the search all
influence how long it will take to
survey a given area.
So, the Royal Navy and data
analytics firm Envitia are
developing a system called Route
Survey Tasking & Analytics (RSTA)
to help minehunting vesselssearch more efficiently. RSTA will
use artificial intelligence to take
all the variables into account and
generate search plans rapidly
without human intervention.
While current systems just
record possible mines as dots,
with RSTA the entire area will be
mapped with high-resolution
sonar. This means it will be easy
to tell from a distance if an areacontains a new and potentially
dangerous object.
The Royal Navy is already
testing robotic submarines
including the Remus 600. These
are torpedo-like craft that are
3 metres long and able to operate
independently for up to 24 hours
on battery power, locating mines
with sonar. Each one can search
several square kilometres a day,
depending on the conditions.
Once a mine is found, these
submarines can destroy it using
an explosive charge. Mines mayalso be opened up and inspected.
RSTA will attempt to find the
most efficient minesweeping
routes, bypassing difficult areas so
that a clear channel can be foundquickly to ensure shipping isn’t
interrupted. Each mine-clearing
trip will be fed back into the
system, allowing it to constantly
improve via machine learning.
Progress in AI is making it
possible to control large numbers
of vehicles and quickly detect
mines, says Sidharth Kaushal at
London’s Royal United Services
Institute, a defence think tank.
RSTA should be in service by- The project is part of the UK
Ministry of Defence’s “human-
machine teaming” plans, in which
increasing amounts of reasoning
will be carried out by machines.
The next application is likely to
be in anti-submarine warfare, says
Mark Atkinson of the Royal Navy,
but it may spread to other areas. ❚
Military technologyDavid HamblingJOHN WILLIAMS/DOD OFFICE OF NAVAL RESEARCHNews
Remus 600 underwater
craft could autonomously
search for minesAI-guided submarines
UK to use robots to find and destroy mines in the Gulf
AstronomyEarth’s atmosphere
could be a giant lens
for a space telescopeTO TAKE better pictures of
exoplanets and seek signs of life,
we need to harvest as much light
as possible from distant objects.
Enter the terrascope.
This space telescope would
use Earth as a kind of lens, taking
advantage of the way light changes
direction as it passes through
the planet’s atmosphere. “This
deflection means that distant light
sources behind the Earth will havetheir rays converge towards a focus
point, and that’s where we place our
detector,” says David Kipping at
Columbia University in New York.
Rays of light travelling at higher
altitudes deflect less, so they would
meet further away from Earth. The
different meeting points create a
focal line where detectors might go.
The closest a detector could be
is about 325,000 kilometres away.
“But a better choice is at the Earth’s
Hill sphere,” says Kipping. The Hill
sphere is the region where Earth’s
gravity, rather than the sun’s, is
the dominant force, extending to
around 1.5 million kilometres away.Kipping says light rays that meet
at the edge of the Hill sphere would
get no closer to Earth’s surface than
14 kilometres, avoiding mountains,
clouds and most of the degrading
effects of the lower atmosphere.
He estimates a 1-metre detector
there would be akin to a 150-metre
optical or infrared telescope on
Earth (arxiv.org/abs/1908.00490),
more than 14 times the size of the
biggest optical ground telescope.There are technical challenges.
The terrascope would need a device
called a coronagraph to block light
from Earth. “Space coronagraphs
are expensive and fiddly,” says
Benjamin Pope at New York
University. He says brief observation
periods while objects pass behind
Earth might also be an issue.
Erika Hamden at the University
of Arizona says the terrascope
would also be mostly limited to
detecting infrared signals and
possibly part of the visible spectrum.
UV imaging wouldn’t be possible
because of light from the sun. ❚
Abigail Beall“Each mine-clearing trip
will be fed back into the
system, allowing it to
constantly improve”325,
Distance in kilometres from Earth to
the closest feasible terrascope detector