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National Aeronautics and Space Administration

Goddard Space Flight Center

Scientific Ballooning.

Balloon Program Office

Ground Model Testing

Test flights previous to 2007 encountered issues with full deployment at float. It is difficult to replicate flight and deployment conditions on the ground, but a series of scaled model balloon tests were completed to explore the deployment trade space. These tests were intended to try to replicate the issues seen during the actual test flights, and then to explore the potential solutions to the deployment issues through various techniques. These tests were intended to help better understand the impact of the design on the eventual deployment path, and to try to characterize the likelihood of full balloon deployment. These scaled indoor model tests were also designed to further the understanding of the performance of these types of structures through stepped pressurization and measurements of the balloon during all stages of the test. This understanding has been key to understanding the capabilities and limits of the balloon materials.

Tests were completed on 4 m, 8.5 m, 27 m and 30 m diameter balloons. The model balloons increased incrementally in size and complexity. This stepwise approach allowed for exploration of the design trade space through changing only one or two key variables at a time. These tests increased knowledge in other areas related to balloon production, repairs/reinforcements, and balloon fabrication that have improved the processes and techniques used for flight balloon production. These tests helped establish a guide in assessing the potential for the balloon to initially deploy, a challenge faced by all of these pumpkin shaped Super Pressure Balloons.

Indoor model test of a ~27 m diameter balloon designed to replicate the "S" cleft deployment issue seen in flight
Indoor model test of a ~27 m diameter balloon


Indoor model testing to replicate flight deployment issue
Indoor model testing to replicate flight deployment issue


Inside views of the model balloon and the flight balloon showing a section of undeployed balloon. The ground model almost exactly matches the flight balloon.
Inside views of the model balloon and the flight balloon


Comparison of initial deployments for three different ~27 m balloon designs with design improvements to prevent clefting
Comparison of initial deployments for three different ~27 m balloon designs


Indoor model testing to explore balloon deployment and design strength
Indoor Model Strength Test


NASA Code 820

Scientific Balloon Update

Report back for the latest update from NASA's Balloon Program Office.