Astronomy

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equipment to deploy a hot

water drill. How can a

miniaturized cryobot

pack enough power?

Stone proposes using a

5,000-watt industrial

laser as a power source.

Engineers envision a laser

on the lander that powers a microprobe,

with the probe itself spooling fiber

behind it. Other designs, like the

VALKYRIE, would carry a nuclear

power system on board. The laser power

comes through an armored fiber optic

cable. Designers have been able to fabri-

cate a 12.5-mile-long (20 km) fiber spool

that fits in a 1-quart bottle. Proof of con-

cept was carried out by Stone Aerospace’s

Artemis probe, which utilized a 9.3-mile

(15 km) fiber optic spool.

Once the cruise through the ice is

underway, the probe must avoid hazards

and buried obstacles too small to see by

orbiters with ground-penetrating radar.

The VALKYRIE test bed carried an

onboard ice-penetrating radar that could,

within a range of about 330 feet (100 m),

detect objects as small as 4 inches

(10 centimeters) across. Tests carried

out in Alaska in 2015 proved that the

probe could look ahead with enough

warning to avoid a collision.

This is critical to mission success,

says Stone. “We don’t want to risk a

$4 billion mission on something like a

trash can-sized piece of rock and then

you’re done.” With a tunable laser

system, the pathway of the probe

through the ice can be changed as the

laser shifts its focus to one side.

Sailing the

alien seas

Once deployed in the ocean, the robot

would map the seaf loor, chart currents

and chemical streams, and look for life.

The cryobot could even be programmed

to search for sources that may support

living organisms.

For example, a plume with a higher

sulfur content might indicate hydrother-

mal vents, so the probe would try to fol-

low the sulfur trail back to its source.

The next step would be to maneuver to

that site, and look for changes in the

background that would suggest the pres-

ence of microbial communities (such as

mats or changing colors). The cryobot

would then take close-up, high-definition

video. Finally, a sample would be pulled

into a microscope for confirmation and

characterization of living systems.

With the remoteness of Jupiter’s sys-

tem, the robot must think for itself. But

how do we train it to recognize life? One

possibility is to load a digital library of

Earth’s microbial life architectures into

its memory for comparison. Anything

that moves within the probe’s field of

view is then compared to various micro-

bial structures and patterns. Because

form follows function, microbes of other

worlds should have some characteristics

similar to those seen in the animal king-

dom on Earth.

Getting around

In addition to studying propellers, engi-

neers have been creating propulsion sys-

tems based on life-forms in Earth’s seas.

These biomimetic designs emulate the

agility and mobility of biological forms.

The ocean’s inhabitants exhibit high-

endurance swimming that out-

paces current underwater propulsion

systems for stealth, f lexibility, and speed.

For example, the glass knifefish (or

“glassfish”) uses a single ventral fin,

which runs the length of its entire body,

to change direction or hover in place.

Designers at the University of Edinburgh

are working on SquidROV, a biomimetic

submarine propulsion system that uti-

lizes a glassfish-style fin to maneuver.

Some engineers suggest that such a pro-

pulsion system is more efficient than a

One of the most efficient ways

to cut through the ice in a place like

Earth’s polar caps is a hot water jet.

An underwater
explorer could be
designed to collect
exotic samples
from the oceans
of other worlds for
onboard analysis.
Or it could simply
return the samples
to a more functional
laboratory nearby.
MICHAEL CARROLL