About OLHZN-5 :: Continuity
OLHZN-5 is the fifth planned high altitude weather balloon flight for Overlook Horizon High Altitude Balloons. This flight is currently scheduled for March 26, 2017 and will feature some tech changes to our tracking apparatus to try to resolve our radio tracking issues that we experienced on OLHZN-3 and OLHZN-4. This flight will debut our newly designed custom circuit boards for better reliability and to help eliminate possible problems on launch day. The following design modifications were made on our new custom circuit boards:
- Voltage divider resistor values increased by 100x to reduce current draw on voltage measurements
- Now using rechargeable 3.7v 18650 Lithium-Ion batteries for both main and camera power.
- 3rd camera circuit added for a upward (balloon) facing burst camera. This will not be used on OLHZN-5, but will likely make its debut on OLHZN-6.
- 3 Adafruit Powerboosters added to reduce battery weight by converting a single 3.7v battery to 5v for cameras this also allows us to switch on/off the cameras with a low amperage (500mA) switch instead of requiring a more robust 6A switch.
- Internal temperature sensor changed from a weatherproof wired component to an onboard DS18B20 to eliminate the extra internal wire.
- Added master switch for main power (SPDT) to make it easier to prepare for launch.
- Moved power outage alarm off the raw 5V feed to a digital output feed so that the alarm can be triggered for other instances in addition to power outages.
- External components (camera power, power outage alarm, landing alarm, outside temperature) are now connected via 2.5mm DC barrel plugs for easy connectivity and launch day assembly.
This flight will feature our newly designed custom circuit boards to streamline our operations. The new circuit board design eliminates nearly all the wires that were used in previous flights which were prone to accidental shorts, wear, breakage, bad soldering, incorrect placement and just a general mess. The new printed circuit boards (PCBs) are cleaner and condense everything into one board that is pre-traced with all the necessary electrical connections to eliminate human error and the mess! Additionally, we’ll be switching to 18650 Li-Ion batteries and using Adafruit Powerboosters to generate power with less payload weight.
This flight will feature at least two packaging changes based on our testing and analysis from OLHZN-4. First, our cameras will be wrapped in copper tape to establish electromagnetic shielding, i.e. a Faraday cage. Previously, the cameras were causing interference with our GPS signals on both our main tracking unit and our backup tracking unit. We hope that this shielding will reduce, if not completely eliminate the interference. Secondly, we will be utilizing a new payload box for this flight in a further attempt to reduce interference from the cameras. The box shape is still to be determined, but will contain sufficient spacing between the cameras and the GPS units as our previous tests indicated that interference was only noticeable when the cameras were in very close proximity as they were for OLHZN-3 and OLHZN-4.
For this flight we will be utilizing Baofeng BF-F8+ amateur radios with extended antennas to perform team coordination operations via radio communication. Amateur radio operators can listen in to our team coordination on the designated frequency which will be announced closer to launch day. Callsign: KD2KPZ.
We’ve implemented some automated tracking via our Twitter Bot, @OLHZN. Follow our automated bot on Twitter to see updates anytime tests are performed or while flights are in progress.
All of our flights to-date have been exempt from FAA Pre-Launch notifications per FAR 101.1(a)(4). This flight will not be any different, however, out of an abundance of caution, we’ve decided to begin filing an official HiBal Pre-Launch Notification with the FAA even for flights that technically meet the reporting exemption criteria.
Major Flight Prediction Shift
Starting on Wednesday, March 22nd, a major flight prediction shift occurred in the wind patterns that were deeply concerning for this upcoming high altitude balloon (weather balloon) flight. Our flight date is set to March 26th and has been shifting around. These predictions can still change a little, but the closer we get to our planned launch date, the less likely those changes are. The predictions will only increase in reliability as the launch date approaches. Currently, our prediction now points to a landing in the Cato, NY area which is a good landing zone. We have a concern regarding precipitation at launch time on launch day that may slightly delay or adjust our launch time, but it appears we should get at least a small dry period to launch. We’ll be watching and updating our wind predictions daily as the launch day approaches as well as carefully monitoring the ground weather conditions for launch time. At this time, chance of launch is set at 85% and things are looking better!
Live Flight Tracking Map
Launch Day Wind Forecasts
Estimated Ascent Rate: 4.00 m/s
Estimated Burst Altitude: 96.646 ft.
Time to Burst: 123 minutes
Estimated Helium Volume: 108.3 cu ft.
Payload Mass: 1596g (3.52 lbs)
Neck Positive Lift: 754g
Estimated Landing Speed: 6.2 m/s (13.84 mph)
Estimated Descent Time: 37 minutes