HASIP Voyage

Update:

The idea behind HASIP (High Altitude Space Imaging Platform) is to develop a stable, light weight, high altitude image platform capable of carry small telescopes or large cameras into near space that would allow scientific teams and the academic community more opportunities to perform stellar research where atmospheric disturbances is reduced by 99%. HASIP’s initial mission will be solar photography at or above 100,000 feet above sea level. The telescope will be controlled by 3 axis sensors to maintain a fixed position on the sun. The platform will be equipped with a 2 way communication system which will provide extended reach Command and Control capabilities such as real time position reporting, ballast control, and cut-down.

After a long period of absence I have started working on this flight again.  I have nearly completed the new 3-axes camera platform and will start testing it this week.  I had to engineer a rotating base that could spin freely in either direction continuously while supplying power and control signals to the other servos and sensors.

I ended up developing a 7 contact circular electrical system as the base plate.  This system permits the pitch and roll servos to operate within their designed parameters while allowing full yaw rotation of the base in a clockwise or counterclockwise direction.  By combining power and ground and designing a special breakout PCB for the top of the plate I was able to minimize the number of contract circle required and us a base that is 6” in diameter.

Contact Plate Pieces Contact Housing Assembled

After some fine tune alignment procedures I have the contacts lined up with the circles. I wrote a small demo program to test it. I still need to incorpate the 3-axes digital compass I received from PNI corporation then I can start writing the tracking code. The movement is a little jerky in the video because I am hand holding the platform and playing around with varying the speed of the servos.

More to come ...

Current code: iStabilizer
Supporting objects: H48C

MultiProcessor Flight Computer (MPFC)

This flight will continue to use the Propeller as the main processor. In addition to previous functions the Prop will control video camera positioning via received data from the TCM-5 and a 2-axis gyroscope.  The TCM-5 will compensate for capsule pitch, roll and direction during the ascent phase of the mission.  The 2-axis gyroscope will adjust the speed of the positioning and tracking motors based on the angular rate of the change of the capsules pitch and roll. 

Telemetry System

This launch will use 2 telemetry systems. The primary unit is the same from previous flights without any modifications. The secondary unit is the HAPBTracker2 (HT2). It will be carried onboard all future flights and will use 144.39MHz, same as the primary, except the interval will be longer between broadcast and staggered. I also have the option of changing frequencies on the HT2 by using the 4-bit switch I installed.

The HT2 is designed to be a stand-alone unit or integrated into the existing flight systems. This will be give some leverage of weight control and how I use the system. When connected to the flight system it weighs 1 oz, would be powered by the capsule power supply, recieve GPS data from the GPS18, and positioned in one of the Hitchhiker slots. As a stand-alone unit it weighs ~7 oz with its own power supply, gps, and antenna. This configuration will enable the unit to be placed inside a second payload for future flights.
Position Frequency Position Frequency
0000
144.3900
1000
144.6400
0001
144.7900
1001
147.5000
0010
144.9900
1010
147.7000
0011
144.3500
1011
144.0000
0100
144.8000
1100
145.0075
0101
145.1750
1101
146.0050
0110
144.5750
1110
147.0025
0111
144.9300
1111
148.0000
Switch Position vs. Frequency
Equipment Price Weight
Garmin GPS-18LVC OEM $75.00 2.625 oz
SMT Opentracker+ $39.00 ~0.4 oz
SMT MX146 Transmitter $75.00 ~0.4 oz
Radio Antenna $10.00 ~0.25 oz
(6)1.5 Lithium Batteries   $15.00 3.625 oz

The equipment used is listed in the table along with the links to the respective websites. The schematic and PCB layouts are also available for download in jpeg and ExpressPCB format.

JPEG format: Schematic, PCB
ExpressPCB format: Schematic, PCB

 
Garmin had discontinued the GPS18 and replaced it with the GPS18x. However, the ballooning community found out the GPS18x had an altitude problem above 60,000 feet and reported it to Garmin.  Garmin was able to reproduce the problem and has put the GPS18 place back on the list of available units that can be purchased.

System Testing

I completed the wing assemblies.They are made from balsa wood wrapped with Monokote. Carbon graphic tubes will be used to attach the wings to the capsule. I recorded the capsule swinging from a rope without the wings and with the wings in 2 different configurations. Testing indicates that the wings in a rudder position seem to help stabilize the capsule or at least keep the capsule camera pointing into the wind. You will notice that I had to stop the third configuration from swinging.I believe that maintaining relative camera position is better then the camera spinning in circles.


I have completed fabricating my dual axis video camera holder.  I used a 1”x 1/8” aluminum flat bar I bought from the local hardware store as the main support.  A Dremel tool works nicely for cutting out the rectangle hole for the servo.  I used the edge of my workbench to bend the flat bar into the proper shape and got a nice clean bend.  Finally, drilled and tapped 4/40 holes to mount the servos.

I am using HiTec 645MG servos to maintain the camera position.  I chose them because of their response time, torque capabilities, and price.  The total weight of the new platform is 13 ¼ oz (378 g) of which 5 ½ oz (156 g) is the camera.

I changed the procedure I was using which seems to have taken care of the jerkiness. I was using Servo32v2 object which worked good when only one servo was active, however, as soon as I enabled another servo they both became jerky and would not stay level even when there was no movement. I tried using different zones for the 2 servos. This smoothed out the jerkiness a little but the camera would not stay still. I also tried enabling 2 instances of the object with different names but I saw the same results. I finally decided to keep it simple by using the propeller clock to do my PWM control.  The problem with this method is that I can not run the servos in parallel because there is only one system.  I might be able to introduce some variables that monitor the system clock and use that instance for the second servo.  I will know more after I do some testing.


Launch Day (Pending)

Damage Assessment (Pending)

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