'Stratospheric jump lacked scientific value'

The successful jump on Sunday by an Austrian stuntman from a balloon 39 kilometers above Earth was equivalent to the first successful climb of Mount Everest, but it did not contribute to scientific knowledge, according to Hebrew University astrophysicist Prof. Nir Shaviv.

“It was the highest-ever jump from the stratosphere,” he told The Jerusalem Post on Monday, “but it has been done before from about 30 kms. high,” he explained.

The , 43-year-old Felix Baumgartner, landed in New Mexico by parachute and on his own two feet at the end of the skydive, during which he broke the sound barrier by reaching a speed of 1,342 kilometers per hour.

“It’s certainly possible to fall at a speed faster than the sound barrier and survive if the jumper doesn’t get dizzy, lose his orientation and is unable to open his parachute,” said Shaviv, who admitted that he had not known about the achievement until his 13-year-old son told him about it.

“My wife has parachuted from a plane, but I would not do it,” said the expert at HU’s Rakah Institute of Physics and expert in astrophysics, space and cosmology who usually spends his time studying the makeup of stars and black holes.

This is a height with particles dense enough that the temperatures surrounding him would not burn him up as long as he is in a protective suit, said Shaviv. “An ordinary plane could not reach such heights, but a large balloon could. Nevertheless, if he were higher – at about 100 kilometers from Earth – his speed while falling would have been so fast that as a result of shock waves, the lower density of particles and the temperature, he would have been consumed by fire.”

Space vehicles that fall back to earth are protected from burning up by thick ceramic plates.

Shaviv did not think astronauts would gain any knowledge from the audacious stunt, as they do not abandon their spacecraft at such a height. “But like the first conquest of Mount Everest – in stretching human boundaries and following human curiosity – his courageous act has importance on its own,” Shaviv added.

It took Baumgarten some 2.5 hours to reach the point where he jumped from the small fiberglass and acrylic capsule that propelled him into the stratosphere.

“As he rose, the temperature had to get colder, even to -60 degrees celsius, until he reached 10 kms. to 15 kms.

away, but then the ultraviolet light warmed him before he fell rapidly, and it was warm again. His astronaut-like suit protected him,” suggested the HU scientist. “He broke the sound barrier, but wouldn’t have heard anything inside anyway. Theoretically, it he had gone higher, he would have needed a much larger balloon.”

Dr. Noah Brosch of the astronomy and astrophysics department and the Wise Observatory of Tel Aviv University speculated that “there might be something to be learned about astronauts jumping off a space capsule in trouble, but I do not know enough about this. The suit worked at mach one, but I am not sure it would be effective at a higher speed.”