1. a rocket launched from a balloon at high altitude
Usage: aerospace; technical

Examples

• The scientists used a rockoon to study the upper atmosphere.
• A rockoon combines the advantages of both balloons and rockets.
• The balloon carried the rocket to 100,000 feet before the rockoon was fired.
• Early space research relied heavily on rockoon technology.
• The rockoon reached altitudes that neither balloons nor ground-launched rockets could achieve alone.