Information Regarding SHARP High Altitude Balloon Flights
The SHARP 3.1 high altitude balloon has a surface of the Earth volume of roughly 230 cubic feet or 6.4 m3. Its flight is therefore dependant on the receipt of a Special Flight Operations Certificate issued by Transport Canada. The flight of SHARP 3.1 falls under section 602.42 of Canadian Flight Regulations more specifically:
Large Unoccupied Free Balloons
602.42 No person shall release an unoccupied free balloon having a gas-carrying capacity of more than 115 cubic feet (3.256 m3) except in accordance with an authorization issued by the Minister pursuant to section 602.44. (1200 gram balloons are the limit here -113 cu. ft. A 3000 gram balloon has a release volume of about 4.97 cubic meters or 176 cubic feet and requires a Minister's permit.)
and
Authorization by the Minister
602.44 The Minister may issue an authorization referred to in section 602.42 or 602.43 where the release of the balloon or the launch of the rocket is in the public interest and is not likely to affect aviation safety.
October 2013
Helium
DESCRIPTION
|
HELIUM T Type Cylinder |
Purity (%) |
Volume (Cu. Ft) |
Pressure (PSIG) | |
|---|---|---|---|---|
 HE T |
99.995 |
291
= 8.24 m3
= 8240 L |
2640
= 180 atm
= 18 200 kPa
|
Flight Day
On flight days the public will be able to follow the SHARP payload's progress in real time using the two web sites below. Look for the balloon (APRS) and boot track (SPOT) icons on the Google Earth maps. The other web sites contain useful flight planning information.
APRS.fi
This APRS web server in Finland will display a GoogleEarth map showing automatic packet reporting system transmitters in your area. Move around the map to locate a SHARP APRS transmitter such as the SHARP 3.1 payload. SHARP payload icons are small balloons and will have the VE4SHS amateur radio callsign attached to it. See the image below. If the launch is from western Manitoba, you may have to move to western Manitoba to view the launch area. You can also use the search pane on the right side of the map to search for VE4SHS-9. Clicking on the balloon or waypoint dots will give you the latitude longitude, altitude and airspeed of the payload on the balloon. The SHARP APRS transmitter is programmed to transmit packets every 30 seconds.
SPOT Messenger
SHARP payloads use a SPOT Satellite Messenger as a backup to locate downed payloads. The web address for the SHARP SPOT Tracker is linked to the picture of the SPOT Satellite Messenger below. If the SPOT is turned on, you will be able to see where the SHARP payload is throughout the flight. The SPOT transmits every 10 minutes.
Flight Prediction Tools
Jet Stream (SFSU)
NOAA HYSPLIT
Accuweather Forecast
Weather Radar
Nav Canada Aviation Weather
Moon Phase Calendar
UK High Altitude Society
GPS Visualizer
UTC/GMT
The Basics of High Altitude Balloons (HAB's)
The heavier a payload, the greater the volume of gas needed to lift it. For a fixed payload, increasing the volume of gas increases the ascent rate. However, increasing the volume of gas also reduces the balloon's burst altitude; the altitude at which the balloon becomes so large (due to reduced atmospheric pressure) that the balloon explodes. A commonly used ascent rate is 1000 feet per minute or about 5 metres per second. With a fixed payload and ascent rate, the burst altitude can be determined for a particular balloon type. The Habhub web site (thanks Cambridge University students!) provides an easy to use HAB burst calculator.
Greater altitudes are achieved by minimizing the volume of gas in the balloon. Reducing the volume of gas reduces the ascent rate. If the ascent rate becomes too low, it may be necessary to reduce the mass of the payload. For high altitude flights, we try to release the payload from the HAB well below the burst altitude using a cut-down circuit. If the cut-down circuit fails to release the payload, the balloon will likely burst is short order. When this happens the payload and parachute stays attached to what remains of the balloon; the lower hemisphere of now shredded latex. The balloon and balloon line can snarl parachute lines and the APRS radio antenna. At burst altitude, a 3000 gram balloon is about 13 metres in diameter making it roughly the size of a small house. SHARP-2 was easily observed by the chase team at an altitude of 38 km and a straight line distance of over 40 kilometres. The balloon line should not be made too short to prevent a burst from being close to the payload. The SHARP-2 Byonics APRS transmitter was knocked out for over 10 minutes after a burst. The SHARP balloon line which connects a 3000 gram balloon to the top of the parachute are 6 to 10 metres long.
If extreme flight distances are the goal then the balloon should have as small a volume of gas loaded as possible. By using large balloons, small volumes of gas and very small payloads (low ascent rates), very long distance flights can be achieved. The HAB must be filled with very good accuracy. Measuring lift with gram precision requires a precision scale and filling indoors to prevent wind force on the balloon. Long distance flights also result in a relatively long time aloft (days to Europe). Most balloons are degraded rapidly by conditions in the stratosphere particularly ultraviolet radiation. UV exposure can be reduced to some degree by flying at night. Manitoba latitudes produce long winter nights but also very cold temperatures for the crew assembling the balloon. California Near Space have had two transcontinental, trans-Atlantic flights to date. The California Near Space Project web site has a lot of interesting information on long distance HAB flights. Another HAB group striving for long distance flight is FAST. This group uses a gas mass flow meter to precisely fill the balloon to achieve neutral buoyancy.
Zero Pressure and Super Pressure Balloons
Whitestar Project Super Pressure
December 2013
Other Long Distance/Duration Information
Leo Bodnar (Silverstone, UK)
PICO SPACE (Melbourne, Australia)
AVA (Anthony Stirk, UK)
Dave Akerman (Pi In The Sky)
August 2014