This morning in Roswell, New Mexico, a spacesuit-clad 57-year-old Google executive, Alan Eustace, strapped into a harness beneath a giant helium balloon and lifted off to new heights in the upper stratosphere. After reaching an altitude of 135,908 feet—more than 25 miles high, with a black sky overhead and a visibly-round planet beneath—Eustace severed his connection to the balloon with a small explosive charge, and fell to Earth.

As first reported by John Markoff in the New York Times, during his descent Eustace broke the world record for highest-altitude jump, soaring more than a mile higher than the previous record-holder, Austria’s Felix Baumgartner, who ascended to 128,100 feet in October 2012. In his descent Eustace broke the sound barrier, reaching a top speed of more than 800 miles per hour. He safely touched down via parachute about 15 minutes after leaving his balloon.

Whereas Baumgartner’s plunge was a heavily promoted public extravaganza sponsored by energy-drink company Red Bull, Eustace’s attempt was pure Silicon Valley: shrouded in secrecy until today, and apparently largely self-funded. That minimalist, low-key approach may have contributed to Eustace’s decision to ascend dangling free beneath his balloon, rather than riding in a more complex and costly pressurized capsule as Baumgartner did.

Eustace had worked with a cadre of experts in aeronautics and life-support systems to perfect his crucial pressure suit, design the parachute, and conceive the mission profile. “What if you could design a system that would allow humans to explore the stratosphere as easily and safely as they do the ocean,” he said in a statement. “With the help of the world-class StratEx team, I hope we’ve encouraged others to explore this part of the world about which we still know so little.”

The “StratEx” Eustace mentioned is short for “Stratospheric Explorer,” according to the prime contractor he partnered with for his stunt, Paragon Space Development Corporation. The company’s website states that the StratEx system has, among other uses, “wide-ranging applications for the study of the science of the stratosphere,” and encourages potential customers to get in touch. Eustace, it seems, is hoped to be only the first of many future daredevils ascending to lofty heights.

Do not be fooled. For a part of the world “about which we still know so little,” the stratosphere is a crowded, busy place, filled with tens of thousands of commercial airline flights each day and monitored by fleets of weather balloons, sounding rockets, and orbital satellites. And although the overlooked upper stratosphere and the mesosphere above it have been dubbed the “ignorosphere,” truth is, the case for sending human “explorers” there is as thin as its air.

Eustace’s audacious project is a spectacular feat of engineering and a heroic achievement worthy of celebration. It’s also an astounding testament to the growing power of extremely wealthy individuals to perform feats that were previously the purview of advanced nation-states. But it is not science – it is, in the words of Alan Stern, a prominent space scientist on the Paragon board, “engineering space tourism.”