■ FIGURE 9. The Centaurus
Aerospace dish antenna and
rectenna. Their rectenna —
visible against the wall —
consists of printed circuit boards
and surface mounted diodes. It’s
very thin and flexible.
USST’s third generation design
was fantastic. Very sleek and
lightweight, its power source is a laser.
The USST laser transmitter is a 9 kW
bank of infrared laser diodes and the
receiver on their climber is an array of
gallium arsenide (GaAs) solar cells.
Calculations indicate that their design
is capable of carrying 115 kg at a
speed of 2 m/s. Team USST’s 2006
entry to the Spaceward Games was
the fastest, most capable design.
However, it failed to win the prize
purse by a mere 0.04 m/s. This year’s
entry weighed 25 kg, or 33 pounds.
UNIVERSITY OF BRITISH
The University of Columbia’s entry,
UBC Snowstar, weighed 12. 5 kg
because of its Kevlar, balsa, and carbon
fiber kite tube construction. This was
UBC’s third year at the games.
Unfortunately, we didn’t get a chance to
talk to this team before we had to leave.
Hopper, is substantially different in
design than the other entries. Its narrow
shape means that in high wind
conditions, Sky Hopper won’t impart a
lot of lateral force or motion on the
ribbon. Uniquely, its photovoltaic array
is internal to the climber’s body. The
shape of the reflective surface inside
the climber traps light shining into it,
boosting the efficiency of its solar
cells by 18.5%. An infrared blocking
filter protects the photovoltaic array
inside the climber from the heat of its
concentrated sunlight (which is 40
times more intense than sunlight).
Sky Hopper’s climbing motor is
an 18 volt cordless drill motor
operating at 24 volts. With a current
draw of 110 amps, Sky Hopper is
expected to climb at a speed of 2 m/s
with its 95-100 pound payload.
THIS YEAR’S RESULTS
Unfortunately, due to work, we
couldn’t arrive early enough or stay
late enough to see the entire
climber competition, but thanks to
information from Spaceward’s Ted
Semon, here’s what happened.
■ FIGURE 10. The University of
Saskatchewan Space Development
Team’s laser driven climber. Because
of the coherence of laser radiation, their
power array is very small.
Eight climber teams arrived to the
games and qualified indoors: University
of Saskatchewan, LaserMotive,
University of British Columbia, Kansas
City Space Pirates, Technology
Tycoons, Earth Track Controllers, McGill
University, and Centaurus Aerospace.
Two teams — Andromeda Connection
and Team Zero-G — only brought
displays to show and did not compete.
The second qualification round
took place outdoors on a short
ribbon, only 100 feet tall. The Kansas
City Pirates (KCSP) entry was spectacular; it climbed the ribbon at an
average speed of 3. 5 m/s on Monday.
Because of uncooperative weather,
University of British Columbia
Snowstar, Technology Tycoons, and
University of Saskatchewan USST
couldn’t qualify until Wednesday.
As you’ve already read, Saturday’s
weather prevented climbers from
running until Sunday. We briefly saw
■ FIGURE 12. Andromeda Connection.
The last two climbers
we visited were the
Andromeda Connection and
Team Zero-G. Andromeda
Connection’s climber, Sky
■ FIGURE 11. The University
of British Columbia’s entry
on the ribbon. The mirror at
the bottom of the ribbon
directs the light from two
very large mirrors to the
bottom of their climber.
March 2008 87