Space Elevators with Mr. Ben Shelef - founder of the Spaceward
Foundation which is a public-funds non-profit organization
dedicated to furthering space science and technology in the public
mindshare and in educational curriculums.
is Space Elevator and what is its purpose?
Space Elevator is a revolutionary space access technology, capable
of delivering staggering amounts of payloads to space in a safe
and benign manner, without any of the problems that plague rocket
based travel. The overview below considers a
concrete design for a 20-ton capacity Space Elevator, but Space
Elevators are infinitely scalable one can just as easily construct
them ten times or one hundred times larger.
Space Elevator structure is a tether, about 1/4" (0.6 cm) in
about 60,000 miles long, one end attached to the ground (or more
precisely, to a ship on the equator) and the other end attached to
a counterweight in space. The structure (tether and counterweight)
spins in unison with earth, completing one revolution every 24
hours, and this rotation keeps the tether taught by the pull of
the counterweight. For an earth-bound observer, the tether seems
to simply stretch straight up into space, with the counterweight
pulling up on it as if by magic. Were the tether to be released
from the anchor, it would fly upwards into space, following the
counterweight. For various reasons, outside of the atmosphere, the
tether is spread out to be very wide and very thin (keeping the
same cross sectional area) making it look more like Saran Wrap
than like a round tether. In such a configuration, it is referred
to as a ribbon.
order to access space, vehicles called climbers,
travel up the ribbon using mechanical traction wheels, powered by
electric motors and a photo-voltaic array. The climbers move at
about 200 km/h (about 120 mph), and the ride to GEO takes 4 days. Since solar light
is not powerful enough to drive the climbers straight up the
ribbon, the design has the photo-voltaic array placed at the
underside of the climbers, and a strong beam of light projected
from the ground and providing the source of power. Since the power
source is left on the ground, a climber can be 25% structure and
75% payload in contrast to the 1-5% payload numbers that are
common with rocket based launch systems.
ride in the Space Elevator is comparable to a ride in a ship there
are no strong accelerations, vibrations, or risk of explosion.
Payloads can be launched fully deployed (there is no practical
limit on the size of the cargo), and can be switched on while
still attached to the climber. If testing shows a problem, the
payload can be brought back down again.
addition to its earth-to-orbit capabilities, the Space Elevator
can use its rotation to sling payloads to earth escape
trajectories, again without the use of any propellant. If
dedicated to Mars exploration, for example, the Space Elevator can
place 10 ton payloads on the surface of Mars at an average rate of
one per day.
this 20 ton capacity design, the tether weighs about 1000 tons,
and the counterweight weighs another 600 tons. For a sense of
scale, the international space station weighs about 500 tons, and
a Space Shuttle weighs about 2000 tons at liftoff, and can carry
about 20 tons to space.
How will you
further space science and technology in the public mindshare and
in educational curriculums?
designed to address the "social engineering" of the
Space Elevator. Its
goals are to advocate the concept to the general public, and
capture mindshare in the science and technology community.
order to achieve these goals, we are following two parallel tracks
a competitive track aimed at academia and private industry, and an
outreach track aimed at K-12 and the general public.
the days of airships, the advocates of airplanes devised a new way
to promote their (obviously impractical...) inventions. It was
called an "air show", and it had a dual purpose:
First, these pioneers knew that they could explain
airplanes all they wanted using equations and diagrams; it was not
until they showed them flying that they really got their message
Second, they recognized the power of competition -
by bringing together airplane enthusiasts in a competitive
environment, they were able to accelerate the rate of development
beyond what was likely in the isolated confines of their shops.
We plan to follow
in their footsteps. Our Space Elevator competitions will
demonstrate to the public what it is that we're advocating, and
draw engineering and scientific talent to work on the
What is the Space Elevator Roving Showcase?
The Space Elevator Roving Showcase (SERS) is a mobile
demonstration of the Space Elevator. SERS will tour the country,
setting up shop in all major airshows and science fairs, as well
as schools, universities, and as a visiting exhibit at tech
museums and other places of interest.
Operated by a crew of two
(narrator and operator) and featuring a working 100-foot tall
beam-powered climber display, an A/V tent, and several additional
displays, SERS is a miniature mobile space science museum, capable
of going to where the crowds already are - truly a public outreach
Tallying the attendance figures
of all the events and destinations SERS can reach, SERS will bring
a first-hand Space Elevator experience to easily two million
people per year.
SERS was conceived during
International Space Conference 2005 (ISDC) in May 2005, after
breaking our knuckles in the conference parking lot for 3 days
(most of the parts arrived in DC direct from the machine shop - we
brought the mockup from concept to hardware in less than 2 weeks).
The result was both satisfying and tantalizing - it was very clear
that we should have this display boxed and packaged, and take it
on the road.
SERS will be much grander than
the ISDC mockup, but we intend to grow the fully functional SERS
from the mock-up in a gradual manner. Our first appearance, with a
rental truck, a 100 foot boom, a slide projector and a re-vamped
version of the Washington DC climber mock-up will probably occur
in the middle of June 2005.
This appearance will validate the
concept, and will give our sponsors some more images to chew on.
Following a successful appearance, we will continue to develop the
display, adding signage, a working climber, an outdoor theater and
more A/V content.
More details are available on our web site, http://www.elevator2010.org
How are the projects finanaced and how can people
sponsorship based. Our
current partners are very excited about SERS, since they can
easily see the exposure potential. We are now looking for more
sponsorship - SERS will not come for free, and will have
significant construction and operating expenses. We intend to create a lot of buzz around
the Space Elevator, have high-attendance (100,000 visitor) events,
and get corporate sponsors.
Ben, thank you for talking to ASG
via email (May 29, 2005).
Read about the
Space Elevator Games. 2006 Space Elevator Competition.
The Space Elevator: A Revolutionary
Earth-to-Space Transportation System
Bradley C. Edwards, Eric A. Westling
of Future Space Transportation
Tim McElyea, David Brin
Any comments or suggestions on Space
Elevators page, click on