NASA Astronaut Pettit Visits Aerospace Engineering Sciences Department

 “There are frontiers everywhere,” said NASA Astronaut Don Pettit (Ph.D) in his opening remarks at a March 6 seminar at the University of Colorado. “Whether it be going to space, exploring the depths of the oceans, or discovering something new in a laboratory, frontiers are the places that challenge us because the answers are not in the back of the book.”  Pettit then guided the audience of CU faculty, staff, and students through the story of his time in space and the perspectives he gained from living in orbit around Earth. 

In just over a year spent in space, Pettit has gained popularity for his do-it-yourself style experiments, some of which he described during the seminar. In one experiment, using only water, knitting needles, and fur from Russian clothing, Pettit created an electrostatic force on water that caused droplets to orbit around the needle. In another experiment, he used the example of a candle flame to describe how combustion works in space – in the absence of gravity, combustion is dominated by particle motion rather than convection, leading to spherical flames and strange new phenomena like cold combustion. In yet another experiment, Pettit explains the difference between hydrophilic (attracts water) and hydrophobic (repels water) molecules by removing the hydrophobic wax on the tip and sides of candy corn, then inserting each piece into a sphere of water. When there is no room to add additional candy corn, the critical micelle concentration (or “the critical candy corn concentration”) is reached. This, Pettit explained, is like placing the keystone of a Roman arch—it demonstrates the strength of surface tension when gravity is taken out of the equation.

To illustrate further the power of surface tension, Pettit built a spill-proof, open-faced “mug” that astronauts can use to drink coffee rather than slurp it out of a bag. “I may not be remembered in a hundred or two hundred years, but I’d venture to say that people who travel to space in the future will be drinking out of cups that follow my design,” Pettit joked.

When not working or experimenting, Pettit enjoys taking unique photos of the Earth and sky from orbit when traveling at nearly 5 miles a second (or approximately 8 km/s), 230 miles (370 km) overhead, like this one below.

Pettit closed by advising his audience, “Find whatever frontier you are passionate about, find the answers to problems that have not been solved, and find new questions that have never been asked before.”

More on Don Pettit can be found in the following links: