So far, ILC has managed to reduce the weight of the planetary suit
from the 107 pounds of the Space
Shuttle EMU to just 65 pounds.
During the last of the
Moon landings, Apollo astronauts performed maintenance
on seals and zippers of their
space suits. Maintenance on
the planetary suits will be
different. Instead of regularly
applying lubricants to bearing
surfaces, the bearings in these
surfaces will be treated with low
Planetary suits will be made
ready for different sized astronauts quickly and with less work.
The use of sizing rings and
lacing allows astronauts to
customize the fit of a planetary suit for themselves. Before joining parts like the
waist and legs, the proper
sized sizing rings are first
snapped into the suit. Now the suit
elements can be joined to make a perfectly fitting planetary suit. Lacing in
the arms can be loosened or tightened
to change the length of the arms.
The planetary suits are just
experiments, so they’re not ready yet.
More tests, like the number and
position of rotating bearing surfaces,
still need to be finalized. Also, the
ability of new materials used in the
suits to stand up to the expected
environmental conditions found
on the Moon and Mars still
needs to be tested.
Electronics and logic will
certainly play a larger role in the
operation of the planetary suit.
Control switches sewn into
the suit will allow astronauts to
control suit functions like
temperature and lighting. With
embedded microcontrollers, astronauts may not have to even use
switches; instead they may speak
or gesture to enable suit functions.
It sounds like NASA will be looking
for those with microcontroller
experience to help design their
future planetary suits. If I were you,
I’d begin designing and programming
with microcontrollers now! ■
November 2005 NUTS & VOLTS 75
Therefore, work is being done to design sizing rings for the I
spacesuits. The rings are designed to fit between suit joints, su
as between the arms and gloves, and extend the length of spaces
elements. Sizing rings are made from aluminum and come in seve
lengths. With sizing rings, astronauts can modify spacesuits to fit wh
they work on ISS.
THE NEW PLANETARY SUIT
We’ve seen some of the changes made in American spacesu
as they evolved from Project Mercury’s emergency-only spacesuits
the Apollo and Space Shuttle working spacesuits. The new planeta
suits will build on this history to create suits that are lighter in weig
and easier to work in and maintain.
REDUCING BENDING EFFORT
To allow an astronaut to bend his or her arms without reduci
the interior volume of the suit, rotating bearings will probably be add
to planetary suits. So, instead of flexing the fabric in the arm of a pla
etary suit, an astronaut will instead rotate his or her arm up and do
through the bearing surface in the shoulder. This reduces the degr
of rotational freedom in the shoulders and “programs” the moveme
of the astronaut. However, they will easily learn how they must mo
their arms and they will grow accustomed to it.
Restraint layers (linknet) are being made from more advanc
fibers than the spectra currently used in modern EMUs. By usi
stronger materials that stretch less in the linknet layer, a thinner linkn
layer can be used. And the thinner this layer, the less torque requir
to bend the layer.
Some stretch in the planetary suit fabric can be desirable. In t
right place, stretch can prevent the build-up of stress points in the s
As a result, the fabric of the planetary suit in that location doesn’t ha
to be as strong or as thick. Stretching also reduces the chances
material failure from over stressing.
To reduce planetary suit weight, ILC is replacing the old Spa
Shuttle EMU HUT with a soft upper torso made from fabric. Points
the suit where parts are connected together are being replaced w
machined titanium. The titanium creates lighter weight attachme
points with the same strength as the old steel swivels and bracke
used in current spacesuits.
Aluminum has replaced steel as the material in the bearing rin
that seal together elements of the suit. However, some bearings — l
those in the shoulder — are being replaced with experimental graph
epoxy rings that save a pound of weight over the aluminum rin
Further weight savings may occur by using materials that provi
multiple functions. As an example, a single layer of new material m
be able to replace two layers, such as a pressure-retaining layer a
a thermal layer.
■ US Space Gear, Lillian D. Kozloski, 1994
■ The Space Shuttle Extravehicular Mobility Unit (EMU ), NASA
■ The Right Stuff, Design Magazine, vol. 59, no. 12, 09.13.04
■ The ILC Dover website, www.ilcdover.com/