Sailing on sunlight

Particles of light bouncing off a shiny surface cause a small momentum. When sunlight rebounds from a large, glossy area, the momentum can propel a spacecraft.

Engineers at the Planetary Society, a nonprofit space exploration organization, are developing a spacecraft that can glide through space propelled by solar energy. Solar sails save the weight and expense of transporting fuel. “The idea, ultimately, is to be able to tack like a sailboat on each orbit,” Bill Nye, chief executive of the Planetary Society, told The New York Times.

Engineers plan to test the LightSail, a solar sail spacecraft that will be about the size of a loaf of bread when launched, this May. In orbit, the LightSail will extend four 13-foot-long booms and unfurl four triangular pieces of Mylar, forming a square sail spanning almost 345 square feet. Next year the company will launch a second LightSail to orbit around the Earth. NASA has successfully tested its own miniaturized solar sail satellite, NanoSail-D, which may be used to nudge decommissioned satellites back into the atmosphere instead of orbiting as space junk.

In 2010 Japan launched the Ikaros, a solar sail spacecraft which passed by Venus later that year.

Future spacecraft may sail between Earth and Mars, taking supplies to astronauts on the red planet. Solar sails may even go to the stars someday, the researchers said. Although sunlight would be too weak for such a trip, a giant laser aimed at a gigantic sail could provide the propulsion.

Pill warning

Women using hormonal contraceptives for more than five years have nearly double the risk of developing a glioma, the most common type of brain tumor, according to a new study in Denmark. Even women who use hormonal contraceptives for less than five years have a 50 percent increased risk.

Ten years ago the World Health Organization placed combined estrogen- progestin oral contraceptives, the type most commonly prescribed, in the highest classification of carcinogens. Risks have usually been associated with estrogen, but this study showed a slightly higher risk with progestin- only contraception.

“The conclusion is that there really are not any safe birth control pills,” Jim Sedlak, vice president of the American Life League, told LifeSiteNews. But some researchers argue that even with the heightened incidence the study revealed, brain tumors remain rare. —J.B.

Unboiling an egg

A team of chemists from the University of California Irvine (UCI) and Australia have developed a method to unboil an egg. The new process could mean substantial savings for cancer treatment, food production, and a variety of manufacturing and research applications.

Gregory Weiss, UCI professor of chemistry and molecular biology & biochemistry, described “a device for pulling apart tangled proteins and allowing them to refold. We start with egg whites boiled for 20 minutes at 90 degrees Celsius and return a key protein in the egg to working order.”

Proteins frequently mis-fold, during laboratory processes, into shapes that render them useless. Older unfolding methods are expensive and time consuming, often taking up to four days. The new process takes minutes. The researchers (including undergrad assistant Steve Kudlacek) first added a chemical substance that liquefies the solid material but leaves bits of protein molecules still balled into unusable masses; then they spin the material at high speeds to untangle the molecules.

The technique “is a low energy, inexpensive process and can be readily implemented for relatively low cost in conventional biochemistry laboratories,” the researchers said in ChemBioChem. —J.B.