The minimum size a launch site should be is at least?

• A. 1000 ft for every 1 knot of wind
• B. 2000 ft for every 1 knot of wind
• C. 1000 ft for every 5 knots of wind
• D. 500 ft for every knot of wind

Answer: (A)

Wind speed directly affects how far a balloon will drift during takeoff, so the launch field must be large enough to keep the balloon and crew clear of obstacles as it rises. The rule of thumb is to plan a minimum of 1,000 feet of field length for every 1 knot of wind. This scaling gives you sufficient room to inflate, begin lift-off, and drift safely to a safe altitude without hitting trees, power lines, or spectators. For example, with 5 knots of wind, you’d want at least 5,000 feet of clear space. If there are obstacles or higher winds, you’d choose an even larger field to maintain a safe margin. The other options either underestimate or overestimate the required space and don’t align with the practical safety buffer used in launch planning.