August
2005, Issue 181
Flight
Computer for High-Power Rocketry
ZSAT
II TEST
I
selected a J468R for ZSAT II’s shakedown flight on Bootstrap
Bill. I built this reload in the afternoon and loaded
it into Bootstrap Bill. I then prepped ZSAT II, which
also has provisions to trigger two electronic matches
that can be used to release the parachute system or
timing control for a multiple-stage rocket.
Two
other systems came into play at this point. One was
a new RF module that plugs into a Palm OS device for
long-range RF control. On the launch pad, I still had
my IrDA port, which has become a standard addition to
all of my products. But as the rocket cleared the pad,
the IrDA port didn’t work. I could then switch over
to this Palm-based RF handheld system.
I
developed a central command station that enables people
back at base camp to monitor the rocket (see Photo 5).
On this mission, I loaded Bootstrap Bill on the launch
pad and radioed to central command to power up the on-board
camera for a video test (see Photo 6). A command sent
over the RF link turned on the camera. A clear video
signal was seen on the TV monitor at our base camp.
Cool! There was a lot going on at this point with the
system.
|
(Click
here to enlarge)
|
Photo
5—I used this central command station at our base
camp. It includes an eZ80 MCU, a 240 × 320 graphic
LCD, a MaxStream 900-MHz RF module (mounted on back),
and a video camera that records the downlink video
from ZSAT II. The rocket’s status and
its commands can be controlled from this
station. |
|
(Click
here to enlarge)
|
Photo
6—Bootstrap Bill’s payload bay has a video camera.
I used my Palm OS cell phone to beam commands into
the payload bay using the IrDA transceiver. The
IrDA window input is shown on the right side of
the payload bay. The “Remove Before Flight” safety
flag removes power from the flight computer when
it’s installed. |
Bootstrap
Bill flew like an eagle. In all the excitement, I radioed
back to base camp for an update on the video.
“We
got it! We got it!” was the enthusiastic response.
As
I moved out to recover Bootstrap Bill, I asked for an
update on the video but was given the order to keep
recording. Extremely bad orders! By doing this, I taped
over the good stuff. Well, I’m still happy that I recovered
the system. It definitely works.
