From the archive, originally posted by: [ spectre ]

http://spacelogistics.mit.edu/
http://www.marsonearth.org/

SPACE-NET
http://web.mit.edu/newsoffice/2007/spacenet.html

Engineers create SpaceNet–the supply chain
Network of nodes could ensure delivery to moon

Deborah Halber, News Office Correspondent
March 19, 2007

If you think shipping freight from Cincinnati to El Paso is
challenging, imagine trying to deliver an oxygen generation unit from
the Earth to a remote location on the moon.

By 2020, NASA plans to establish a long-term human presence on the
moon, potentially centered on an outpost to be built at the rim of the
Shackleton crater near the lunar South Pole.

To make such a scenario possible, a reliable stream of consumables
such as fuel, food and oxygen, spare parts and exploration equipment
would have to make its way from the Earth to the moon as predictably
as any Earth-based delivery system. Or more predictably: One missed
shipment could have devastating consequences when you can’t easily
replenish essential supplies.

To figure out how to do that, MIT researchers Olivier L. de Weck,
associate professor of aeronautics and astronautics and engineering
systems, and David Simchi-Levi, professor of engineering systems and
civil and environmental engineering, created SpaceNet, a software tool
for modeling interplanetary supply chains. The latest version,
SpaceNet 1.3, was released this month.

The system is based on a network of nodes on planetary surfaces, in
stable orbits around the Earth, the moon or Mars, or at well-defined
points in space where the gravitational force between the two bodies
(in this case, the Earth and the moon) cancel each other out. These
nodes act as a source, point of consumption or transfer point for
space exploration logistics.

“Increasingly, there is a realization that crewed space missions such
as the International Space Station or the buildup of a lunar outpost
should not be treated as isolated missions, but rather as an
integrated supply chain,” said de Weck. The International Space
Station already relies on periodic visits by the space shuttle and
automated, unpiloted Russian Progress re-supply vehicles.

While “supply chain” usually refers to the flow of goods and materials
in and out of manufacturing facilities, distribution centers and
retail stores, de Weck said that a well-designed interplanetary supply
chain would operate on much the same principles, with certain
complicating factors. Transportation delays could be significant–as
much as six to nine months in the case of Mars–and shipping capacity
will be very limited. This will require mission planners to make
difficult trade-offs between competing demands for different types of
supplies.

A reliable supply chain will “improve exploration capability and the
quality of scientific results from the missions while minimizing
transportation costs and reducing risks” to crew members, de Weck
said.

SpaceNet evaluates the capability of vehicles to carry pressurized and
unpressurized cargo; it simulates the flow of vehicles, crew and
supply items through the trajectories of a space supply network,
taking into account how much fuel and time are needed for single-
sortie missions as well as multiyear campaigns in which an element or
cargo shipment might have to be prepositioned by one set of vehicles
or crew members while being used by another.

In addition to determining a logical route, SpaceNet also allows
mission architects, planners, systems engineers and logisticians to
focus on what will be needed to support crewed exploration missions.

Mars on Earth

To experience an environment as close as possible to harsh planetary
conditions, MIT conducted an expedition to Devon Island in the
Canadian arctic in 2005. The researchers established a semi-permanent
shelter at the existing NASA-sponsored Haughton-Mars Research Station

(www.marsonearth.org) and compiled an inventory of materials at the
base, including key items such as food, fuel, tools and scientific
equipment, while carefully tracking inbound and outbound flights.

They also experimented with modern logistics technologies, such as
radio frequency identification, that autonomously manage and track
assets with the goal of creating a “smart exploration base” that could
increase safety and save astronauts and explorers precious time.

SpaceNet 1.3 is written in MATLAB, a high-level technical computing
language and interactive environment for algorithm development, data
visualization, data analysis and numerical computation.

The SpaceNet development team includes MIT graduate students,
postdoctoral associates and research staff led by de Weck and Simchi-
Levi, aided by partners at Caltech’s Jet Propulsion Laboratory;
Payload Systems Inc., which provides science and engineering services
for spaceflight applications; and NASA industry partner United Space
Alliance.

For more information on SpaceNet 1.3, go to spacelogistics.mit.edu.

This work was funded by NASA.

A version of this article appeared in MIT Tech Talk on March 21, 2007