NearSys UltraLight Flight Computer

The first NearSys flight computer is now ready for purchase. The flight computer is programmed in BASIC and centered around the PICAXE-28X. The UltraLight has four analog channels, three digtal channels, two servo ports, and two camera ports. This means the UltraLight can record the analog values of four sensors, operate three digital devices including Geiger counters, control two servos, and operate two cameras. The flight computer has 32k of memory for storing mission data.

After building the UltraLight kit, you just ned to plug in a GPS receiver to be ready for flight. The flight computer contains a transmitter, TinyTrak based TNC, and a SMA antenna connector (the kit includes the cable and wire to make an antenna).

The UltraLight also includes a control panel that mounts to the near spacecraft airframe. The control panel permits the flight computer to be programmed without opening the airframe. The control panel has three power switches for main power, servo power, and audio beacon. The third switch powers up the audio beacon. the 90n dB piezo buzzer helps recovery crews locate the near spacecraft when it lands in tall grass of trees. Using a seperate battery pack for the servos insures that a bad servo can't ruin the science mission. The control panel also includes a Commit Pin that allows you to power up the near spacecraft long before launch without wasting memory recording data on the ground.

Additional information will appear on the NearSys website shortly (Nearsys.com/catalog).

Astrophotogaphy with a Digital Camera

I've been using a FinePix S7000 to make astronomic images from Topeka. Most of my images are of Jupiter and its four major satellites for an astronomy/physics lab I'd like to write (I hope to create an activity book of astronomy with this and other lab exercises). Last night, after photographing Jupiter, I used my planetarium program to identify the satellites in the image. I found out that the planet Uranus was just above Jupiter and upon checking my image, i realize I recorded the planet.

The picture was five seconds long with a zoom of six power (optical zoom, not digital). I'll keep photographing the planets to monitor the motions between them and the fixed stars.

BalloonSat Extreme

NearSys introduces the BalloonSat Extreme. This is one of the largest BalloonSat flight computers. At its heart is the BASIC Stamp 2 (the BS2pe is recommended), so it is powerful and easy to program.

The flight computer has an eight-channel analog port with 12-bits of resolution for sensors like weather stations. There is a five-channel digital port with connections directly to the BS2 for sensors like Geiger counters. Unlike other BalloonSat flight computers, the BalloonSat Extreme has a GPS Port to allow your BalloonSat to monitor and record GPS reports (like altitude and time). The flight computer can operate three cameras. The cameras can ones with modified shutter buttons or be Canon cameras running the CHDK USB remote program. The flight computer can also control three servos. The servos have a seperate power supply to prevent a bad servo from draining the main power supply.

Part of the BalloonSat Extreme kit is its Control Panel, a seperate printed circuit board. The Control Panel allows you to power up the flight computer without opening the BalloonSat. Two LEDs indicate power is available for the flight computer and the servos. Finally, there is a Commit Pin that allows the BalloonSat to be powered up long before launch. When ready for lift-off, pull the Commit Pin and the flight computer will begin recording data.

The entire kit is only $48. Check it out and its directions and sample code at, http://nearsys.com/catalog/balloonsat/extreme.htm

I'v spent a couple of months perfecting a hovercraft-based robot. My initial goal was to develop a line of robots that behaved like satellites in a weightless environment. They would not move around on wheels (what good are wheels in space?) but navigate around on jets of air (safer than hot rocket exhaust). I discovered though, that air hockey tables can't generate sufficient air flow to lift the robot base. After another year and a half of thinking, I decided to use a hovercraft base in place of the air table. The design I came up with was made possible my resources on the Internet. The toy hovercraft described where just the thing to help me develop the NearSys HoverBot. Unlike traditional robots, the HoverBot accelerates when it drives. Most robots travel at a fixed speed that makes it easier to program navigation goals. The HoverBot roboticist must think about time, acceleration, velocity, and displacement when navigating. Here's an introductory video. You can learn more in my Servo magazine article and can soon purchase a kit from my website, NearSys.com/catalog.

The NearSys HoverBot

I'v spent a couple of months perfecting a hovercraft-based robot. My initial goal was to develop a line of robots that behaved like satellites in a weightless environment. They would not move around on wheels (what good are wheels in space?) but navigate around on jets of air (safer than hot rocket exhaust). I discovered though, that air hockey tables can't generate sufficient air flow to lift the robot base.

After another year and a half of thinking, I decided to use a hovercraft base in place of the air table. The design I came up with was made possible my resources on the Internet. The toy hovercraft described where just the thing to help me develop the NearSys HoverBot.

Unlike traditional robots, the HoverBot accelerates when it drives. Most robots travel at a fixed speed that makes it easier to program navigation goals. The HoverBot roboticist must think about time, acceleration, velocity, and displacement when navigating.

Here's an introductory video. You can learn more in my Servo magazine article and can soon purchase a kit from my website, NearSys.com/catalog.

Test of Geiger Counters

Last week I launched two geiger counters into near space. The mission was for KU aerospace engineering students and I got to send my experiments along in the tracking capsule.

The first geiger counter is the reliable Aware Electronics RM-60. I've flown this geiger counter dozens of times and really love it. It measures everything, alphas, betas, and gammas. Aware has a range of geiger counter products that you'll love. See them at http://www.aw-el.com/

The second geiger counter was built from a kit that's available from Electronics Goldmine. The tube is Russian built and does not include a mica window for alpha particles. Here's the webpage for this product. http://www.goldmine-elec-products.com/prodinfo.asp?number=c6979

The Russian tube is suppose to be pretty sensitive. In my tests, it detects more background radiation. However, I don't have a calibrated source that I can verify that it's actually detecting properly. I have s short video on a test that you can watch on my YouTube channel, www.youtube.com/nearsys.

Below is a chart I produced with data from NearSys-10A. Note how much more radiation the Goldmine geiger counter is detecting.

Normally the RM-60 shows a drop off at 62,000 feet. The driop off doesn't happen until closer to 70,000 feet and it doesn't show up well at all for the Goldmine detector.

So much more to learn!

HoverBot

I finally got the Hoverbot set up with a relay H-Bridge. Unfortunately, one of the relays died. But that still gives me enough to demonstrate this proof of concept.

As you can see, the Hoverbot picks up quite a bit of speed when the drive fans are operating. In this video clip, the fans are on for three seconds and off for one. I've since reduced the lift fan's voltage to 4.5V (from 6V) and reduced the drive fans' voltages to 4.5 volts.

There are two problems to addess. The first is that the Hoverbot has a tendency to steer to the left. Experiments indicate it is due to the counter-clockwise spin of the lift fan. I may have to double up lift fans in a future design.

The second problem is that once the Hoverbot gets into a wobble, it won't come out. In fact, the drive fans are no longer effective in wobble. The HoverBot is going to have to detect this and correct it. Either an extendable foot or being able to shut down the lift fan is going to be required.

Enjoy the video