Germans develop submarine-launched UAV

[theregister.co.uk] You have to do something special these days to make
your flying robot stand out from the swarm – but remorselessly
efficient German designers have done just that. They plan to offer
small unmanned air vehicles (UAVs) which can be launched and controlled
from a submerged submarine.

The UAV in question is called VOLANS (coVert OpticaL Airborne
reconnaissance Naval adapted System), and is based on the existing
German Aladin
drone, a hand-launched job which has already seen service in
Afghanistan. "At least three" small folding VOLANS machines can be
packed in a pressure-tight tank along with a folding catapult launcher,
and the whole thing is mounted on a telescoping submarine mast which
works in the same way as a periscope. The multi-purpose mast system,
which can alternatively be fitted with a remote-operated heavy machine
gun or electronics packages, is called "Triple M".

In order to launch a VOLANS, the sub comes to periscope depth, pops
up the Triple M mast above the surface, and fires off an aircraft. The
launcher mast can then seal up and slip back below the waves, though if
the submarine is to receive any data from the UAV (or change its
pre-programmed flight plan) it needs to put up an antenna. Video
recorded aboard the drone can be downloaded to the sub later at a
prearranged time, however, so there’s no need to stay at periscope
depth with comms mast up throughout the flight.

If the VOLANS‘ performance is comparable to the ordinary Aladin, it
will be able to stay airborne for up to an hour before its battery runs
flat. The only way for the sub to recover drones would be to surface,
so realistically the system will mostly be for one-shot use. The drones
have a speed of "45 to 90" km/hour, so they could range quite far from
their mother ship, though they will only be able to communicate with it
from within line of sight – 30km or so.

This sort of thing could be quite handy for submarines, whose great
Achilles heel is their lack of sensor range when submerged. Normally a
submarine – especially a non-nuclear one, slowed to a crawl when
underwater – finds it extremely difficult to find or intercept a target
at sea while remaining submerged, unless it is receiving information
from elsewhere. Drone reconnaissance could change all that, going some
way perhaps towards making conventional subs the terrible threat that
former Cold War subhunter navies like to paint them as.

Even if VOLANS doesn’t get picked up on radar, however, its C-band
video download transmission will localise its mother sub to within a
fairly small area of sea. Modern sub-hunting helicopters are said to be
able to sweep such areas almost at once* using their new dipping
sonars, so a sub skipper launching a VOLANS when up against
first-division opposition would probably be signing his own death
warrant.

The system’s makers say they see it more as a thing for everyday
modern missions rather than full-scale maritime combat against big
navies. They reckon it might be useful, for instance, to give a
special-forces team deploying by submarine a look at their landing area
or target before disembarkation.

Source: http://www.theregister.co.uk/2008/07/10/german_submarine_uav/