Sunday’s Red Bull Stratos jump was made possible, in part, by two Massachusetts companies: Waltham-based SolidWorks, which helped simulate the record-breaking fall and perfect the helmet that helped Felix Baumgartner land in one piece, and Worcester-based David Clark Co., which actually helped build the helmet.

A few months back, upon hearing about the Stratos jump, Stephen Endersby, product design manager at SolidWorks, started running his own simulations of the jump, even as the Stratos team was using SolidWorks to ensure the record-breaking fall would go off without a hitch.

“At the time, I didn’t even know that,’’ said Endersby, who eventually blogged his own simulations of the physics behind the fall.“I’m a curious engineer, so when things happen, I wonder what caused that? Physics dominate everything.’’


It was only after Endersby started playing with the numbers that mechanical engineer Brandon Arroyo tipped him off that the Stratos team has used SolidWorks for their own simulations to run virtual tests on how well the helmet and craft Baumgartner used would hold up.

’’In these sorts of situations you want to make sure it’s going to work, because the cost of failure is high,’’ said Endersby. “Lots of our customers in medical or telecommunications or even machine design, they want to make sure it’s going to last a long time.’’

In Baumgartner’s case, the helmet had to survive about 11 very intense minutes of falling, and was subject to some extra intense pressures.

“The helmet would have seen a higher velocity around it purely because of its shape,’’ Endersby said. “His chest and arms are very flat subjects. The helmet, if it was a perfect sphere, the wake at the back of it would shake it about because that’s what happens when you deal with spheres.’’

Thus all the attention paid by the Stratos team to head stabilization.

“When you want to actually physically test what these guys did, it’s nigh impossible,’’ Endersby said. “Maybe NASA has a wind tunnel where you can drop pressure down to those levels, but for the average, and indeed even large companies, this type of stuff is impossible without some sort of simulation company. Modern software gives people access to tools that 10, 15 years ago were in the realm of high end scientists.’’


He noted that today, if someone else wanted to break the land speed record with a motorbike, for example, he could design and test that physically with readily available tools. He would, however, still need to find a sponsor with deep enough pockets to fund the feet.

“That’s another task entirely,’’ Endersby said.