The Ravenna Ultra-Low-Altitude Vehicle is a backyard rocketship
treehouse nestled in the Seattle neighborhood of Ravenna.
The best way
to describe it is to show you a flight!

Rarely does building a treehouse require welding, grinding, painting,
riveting, bending, crimping, plumbing, brazing, laser cutting,
sound design, printed circuit board fabrication, thousands of
lines of C code, distributed network protocols, sewing and embroidery.

Ours did.

The RULAV is a hexagonal capsule, 7.5 feet (2.3 meters) high, atop a tripod
7.5 feet (2.3 meters) high, for an overall height of about 15 feet
(4.6 meters). It is about 6.5 feet (2 meters) across at its widest point.
The frame is welded mild steel with
riveted aluminum skin. It contains nearly 800 LEDs forming dozens of
numeric displays spread across 14 control panels, each with an
acrylic face laser-cut
and etched with labels such as “Lunar Distance” and “Hydraulic Pressure”.
The pilot controls the rocket using
a joystick
and panels full of working switches, knobs and buttons.
Underneath the capsule are three “thrusters” that shoot plumes of
water and compressed air under the
control of the pilot’s joystick, simulating real positioning thrusters.
Takeoff and docking sequences are augmented by a paint-shaker that
simulates the vibration of a rocket engine. Sound effects complete the
illusion, with a powered subwoofer that gives the rocket a satisfying rumble.

Behind the scenes, rocket operations are
controlled by
three Atmega328 microprocessors
on custom-fabricated printed circuit boards,
running a small operating system, RULOS, that we
built just for this project.
The processors communicate using an in-rocket TWI network
and will eventually talk back to the house over a serial port.
A trench running from the house to the rocket carries
12VDC power for the lighting and electronics,
water for the thrusters,
compressed air,
and several data signals.

The RULAV was built in 2009-2010 by
Jon Howell
Jeremy Elson,
with lots of help from other people.
This site describes the rocket’s
design and construction in detail,
along with dozens of photos and videos.

And, if you’re ever in the Seattle area, stop
by and visit
… you are go for launch!

Read More