ROOM
72
Astronautics
evaporated liquids, including cryogenic ones
- such as oxygen, hydrogen, chloride, fluoride
and some hydrocarbons - with relative ease. In
this instance, polyethylene tubes can be used as
containers for such liquids.
A further option to consider when developing
cargo delivery technology for hard-landings on
the Moon, is the use of regolith-filled shells. The
shells would also have a closable hatch, so that the
entrance port is closed and the gases contained.
Such ‘collectors’ offer added improvements
including ease of material retrieval and ease of
preparation of next cargo delivery, as well as the
potential use of generated heat.
A lasting impact
The part of a collector that could be delivered
from Earth, such as the container, can be made of
highly durable materials such as aramid, instead
of metal. The container would be tube-shaped,
with both ends sealed off and would be mounted
on a sledding mechanism or on landing wheels, or
a similar mechanism with a low materials-output
ratio. It would have a volume of 80 cubic meters
and a total mass (when empty) of 1 tonne. Taking
into account the mass of the cargo catcher and
density of the regolith only the 1 tonne container
has to be delivered from Earth.
Preliminary assessment shows that up to 100
kg of materials can be thrown into one such
catcher trap during a single mission. The rod-
shaped cargo enters the trap through one of the
container sides (the rod itself contains cryogenic
liquids). The rod breaks the membrane or the net
cargo portions, similar to ‘Rods from God’ high-
precision space weaponry. Objects of this shape
act like a cumulative charge spray when faced with
a barrier. Upon hitting the ground, the arrow-
shaped parts of the cargo, provided that the mass,
form, speed and material of the cargo were chosen
correctly, should enter the ground at such a depth
that their partial explosive evaporation will take the
form of a ‘closed-cavern camouflet’, without the
outside dispersement of the main material mass. A
camouflet, in military science, is an artificial cavern
created by an explosion. If the explosion reaches
the surface it is then termed a crater.
This method can be conveniently used to deliver
various metals to the location of the future base
construction. Other, easily sublimated materials
pose a difficulty however as any gases, for
example, will escape the camouflet through the
entry hole.
The second method of hard-landing cargo
delivery is based on the creation of hermetically
sealed camouflets in the ground. This is possible
if the target is hit precisely, with an error margin
that does not exceed 1-2 m. In this case, a
hermetic ring is built on the ground or on a side
of a hill, that is embedded into the ground and has
a diameter of 2-4 m. The ring covers the potential
landing area for the cargo and has a closable
hatch that remains open until the cargo lands in
the trapping ring. After the cargo has entered the
ground, the ring hatch is closed, thus hermetically
sealing the entrance to the camouflet.
This method has the advantage of being able to
deliver materials such as water and other easily
Implementing
and controlling
a hard landing
is not that easy
In coming years,
government-sponsored
and private-sector
spacecraft will land on the
Moon. This image shows a
resource prospector
carrying a Regolith and
Environment Science and
Oxygen and Lunar Volatile
Extraction (RESOLVE)
experiment, intended to
find, characterise and
map ice and other
substances in almost
permanently shadowed
areas.
NASA
