ROOM
19
Special Report
compact radioisotope power system, deep space
nanosats heading out to Jupiter and beyond
will have to rely on their host spacecraft to get
to their destination, run on energy stored in
batteries after their release from their storage/
hibernation container, and relay data back to
Earth through the primary spacecraft.
It is common enough for deep space missions to
use a gravity assist manoeuvre at Venus to provide
a boost in velocity to propel them on their way
to their primary mission target. NASA missions
that have used this slingshot effect include Galileo
(Jupiter), MESSENGER (Mercury), Cassini (Saturn),
and Parker Solar Probe (the Sun). Now, imagine that
every time a mission executes a gravity assist at
Venus, it drops off a small nanosat probe that could
sample and analyse part of Venus’ atmosphere,
relaying the data back to Earth via the vehicle
that dropped it off, or be captured into a stable
orbit that allows longer-term study of our nearest
neighbour. Straight shot, independent trajectories
to Venus are also possible for nanosats.
The Moon is an attractive destination
for nanosats, since it is so close to home,
N
ASA’s Curiosity rover, currently exploring
the Gale crater on Mars, weighs in at
899 kg and the Europa Clipper
spacecraft will probably tip the scales at
over three tonnes. Mass generally drives the cost
of each mission – so bigger spacecraft usually
cost significantly more than smaller ones.
At the other end of the scale in both size and
cost, cubesats and nanosats could, in theory,
fly more missions for the same budget. But
could smaller spacecraft deliver in the space
science arena? The answer, as suggested by a
recent National Academy of Sciences report is a
qualified ‘yes’: small spacecraft such as cubesats
can take on unique science missions but are not
a substitute for the larger ‘flagship’ missions like
Curiosity or Europa Clipper.
Destinations
So where can we reasonably expect to explore
in our Solar System with smaller spacecraft?
The Sun is an obvious target, since we can
cost-effectively send cubesats and nanosats
to places that provide a unique vantage point
to view solar phenomena. The inner solar
system is fairly easy to reach, being accessible
to both free-flying and ‘hitch-hiker’ cubesats/
nanosats, while the outer solar system is
currently compatible with just hitching a ride
on a larger spacecraft. Without a suitable,
Exploring our Solar
System with cubesats
and nanosats.
The ‘cubesat kitchen cabinet’ has helped to
conceive some new, exciting science missions
using deep space cubesats and nanosats
NASA/JPL
