Two Chinese Astronauts Leave Space Lab

Two Chinese astronauts expect to leave their space lab this week, after a month-long stay that is a first for their nation.
China has poured billions of dollars into its space program, aiming to rival the United States and Russia in reaching Mars.
Such programs are enormous drivers of technological innovation. So it might come as a surprise to know that space communications rely on an old standby: radio waves.
Speech from an astronaut, video from cameras and data from sensors flow into a transmitter, which emits radio waves picked up by a terrestrial receiver. Terrestrial transmitters reverse the favor. The same basic technology sends music to your radio, YouTube videos to your cellphone and photos from Pluto.
There really isn’t an alternative until we figure out how to use lasers to convey data.
There has been a lot of fine-tuning of radio capabilities over the 125 years or so that scientists have been playing with electromagnetic radiation. We now have great antennas and efficient, secure encoding.
But the technology is also good for a simple call from home. Last week, China’s president, Xi Jinping, called the space lab.
“Everyone across China cares very much about both of you,” Mr. Xi said. One astronaut proudly said, “I will go forth, and successfully complete the mission.”
-Culled from The New York Times