A singer brings the wine glass to his lips. Unleashing a sustained note directly into the side of the glass, the goblet’s walls begin shaking. If the tone is just right, it can trigger vibrations in the brittle material that eventually causes the glass to shatter.
The phenomenon is called resonance, when a transmitted sound wave’s frequency matches the natural frequency of a receiving material and causes it to oscillate.
Now picture a rocket lighting up. It turns out that the same acoustic phenomenon can happen inside the liquid-fueled engine as combustion occurs. The results, as one might imagine, are not good.
“The flame is the singer that can excite a tone, and combustion can couple with the acoustics of the rocket chamber,” says John Bennewitz, a University of Alabama in Huntsville (UAH) graduate student and Von Braun Propulsion Fellow. “The tone can eventually rip the whole engine apart.”
In a former Boeing 747 assembly plant within shouting distance of the Los Angeles International Airport, Space Exploration Technologies, or SpaceX, is building a revolution.
Since the dawn of space flight, the industry has been dominated by large firms essentially writing their own paychecks. Only the biggest communications companies and national governments could afford launches costing hundreds of millions of dollars. That’s changing now, in large part because of SpaceX.
Among the fields in which moving even a small distance in the wrong direction can lead to disaster: surgery and robotic operations. With recent innovations like the da Vinci Surgical System, the latter is being deployed more and more to improve accuracy in the operating room.
And now, surgeons are starting to get a bit of robotic help from above—way above. The Canadian Space Agency’s robotic Canadarm boom and manipulator has been used for decades to snatch satellites and move astronauts around during spacewalks. Some of that same technology is now being applied for surgeries on Earth.
The intrepid traveler never feels farther from home than when a holiday meal is missed. That distance can’t seem more extreme than for how it must feel to the American astronauts on the International Space Station as Thanksgiving approaches.
That’s why NASA knows that planning meals isn’t just important for sustenance, but also to nourish the psyche of astronauts floating 260 miles above Earth in isolated, stressful conditions.
"We have what’s considered traditional items for Thanksgiving," says NASA food scientist Vickie Kloeris. "The psychology of the food system, especially for long duration astronauts like those aboard the space station, is very important."