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Non-Commercial Use Only. Please read the 'About' page.
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Cambridge University Spaceflight Landing Predictor - Leaflet Version (github)

A tool to predict the flight path and landing location of latex sounding balloons.

Written by Jon Sowman, Adam Greig and Daniel Richman for CUSF. Credit also to Rich Wareham for work on the predictor. Some parts of code taken from old landing prediction software, credit to Rob Anderson, Fergus Noble and Ed Moore.

Work to switch to Leaflet mapping and to use the Tawhiri API by Mark Jessop, for the SondeHub project. The Sondehub instance of the Tawhiri API is available for use in non-commercial applications.

This predictor uses data from the NOAA GFS models.

No guarantee is given for the accuracy, precision or reliability of the data produced by this software, and you use it entirely at your own risk. For more information, see #highaltitude on

This predictor is intended for non-commercial use only. If you are using this predictor in a commercial setting, please read this page.

Copyright 2013 Cambridge University Space Flight

Burst Calculator

Burst Calculator Web Page


This calculator is designed to help you find how much gas to put into a high altitude balloon to achieve a desired burst altitude or ascent rate. You have to know the payload mass (including parachute) and balloon mass.

Usage is very straightforward: enter the payload mass into the first box, select the balloon mass from the second box, and type in either a desired burst altitude in meters or ascent rate in meters per second in the relevent box. Pressing enter or clicking away from the box you are typing into will run the calculations, displaying the results in the box at the bottom.

The 'Constants' box can be used to adjust constants used by the calculator. These include selecting a type of gas (or entering a custom gas density), adjusting modelling parameters or entering a custom burst diameter or drag coefficient for your balloon. Click the tick box next to the burst diameter or drag coefficient boxes to use a custom value, otherwise the appropriate value for your selected balloon will be used.


Written by Adam Greig for CUSF in March 2010. Maths derived from `burst1a` spreadsheet by Steve Randall. Balloon information from Kaymont Totex sounding balloon data.

No guarantee is given for the accuracy of any data included or produced by this program, use at your own risk.

Copyright 2010 Cambridge University Space Flight

Burst Calculator
Payload Mass (g) AND Balloon Mass (g)
Target Burst Altitude (m) OR Target Ascent Rate (m/s)
Burst Altitude: 33000 m Ascent Rate: 2.33 m/s
Time to Burst: 238 min Neck Lift: 1733 g
Launch Volume: 2.66 m3 2660 L 93.9 ft3


For advanced use only! You can probably leave these alone.

Advanced NOTAM & Airspace Settings

NB This is not yet functional !!!

NOTAM details
Airspace Details
Show Default airspace
Show class A airspace
Show class D airspace
Show class E airspace
Show class G airspace
Show prohibited airspace
Show restricted airspace
Show MATZs
Show danger areas
Show offshore/NOTAMed danger areas
Show hazards (HIRTA/AIAA etc)
Launch Site: Custom
Latitude/Longitude:  / 
Set With Map Save Location
Launch altitude (m):
Launch Time (UTC): :
Launch Date:
Ascent Rate (m/s):
Burst/Float Altitude (m):
Flight Profile:
Use Burst Calculator
Descent Rate (m/s):
Prediction Type (info):