The electromagnetic radiation carried by solar wind exerts pressure on surfaces that absorb or reflect it. Though small, this force can be harnessed and used as a form of space propulsion requiring no fuel. Solar sails are lightweight, highly reflective devices that harness this force and, when attached to spacecrafts, may be used to modify their orbits, perform fine trajectory corrections, and even drive interplanetary flights. Has a working solar sail ever been successfully tested?
W. Somerset Maugham
Back in the day
The Pledge of Allegiance is an oath of loyalty to the United States. It first appeared in the September 8, 1892, issue of The Youth's Companion, and its authorship has been ascribed to magazine staff member Francis Bellamy. Officially recognized by the government in 1942, the pledge became compulsory in some public schools, but the following year the Supreme Court ruled that recitation could not be required of any individual. What two words were inserted into the pledge in 1954?
Born on a day like today
The patron saint of Scandinavia, Ansgar was a missionary and the first archbishop of Hamburg. He was sent by Louis I to help King Harald Christianize Denmark and King Bjorn Christianize Sweden. He initiated a mission to all Scandinavians and Slavs and was appointed archbishop of Hamburg in 832. When Sweden and Denmark returned to paganism by 845, Ansgar thwarted the pagan rebellion. He was recognized as a saint soon after his death. Ansgar is often called the Apostle of what?