Space travel can be exciting — and restless! NASA researchers are exploring ways to help astronauts enjoy a better night’s sleep on the space station … and beyond. Take the exploration of Mars, for example. On Mars, daylight is primarily yellowish-brown. On Earth, it’s blue-green. How will the human clock respond to the unearthly color of Martian skies? Some research indicates that it could make a difference. Melatonin production, for example, is suppressed more by some wavelengths of light than by others. Of more concern, perhaps, is the length of the Martian day: 24 hours and thirty-nine minutes. “That is significantly different than the period of the clock in humans,

Gravity hurts: you can feel it hoisting a loaded backpack or pushing a bike up a hill. But lack of gravity hurts, too: when astronauts return from long-term stints in space, they sometimes need to be carried away in stretchers. Gravity is not just a force, it’s also a signal — a signal that tells the body how to act. For one thing, it tells muscles and bones how strong they must be. In zero-G, muscles atrophy quickly, because the body perceives it does not need them. The muscles used to fight gravity –like those in the calves and spine, which maintain posture– can lose around 20 per cent of their mass if you don’t use them. Muscle mass can vanish at a rate as high as 5% a week.

When the space shuttle Atlantis returned to Earth this morning, it brought home some unusual cargo — seed pods grown in space. They’re the harvest of an 8-week-long commercial gardening experiment on board the International Space Station (ISS). Astronauts on the ISS have been tending a batch of fast-growing Arabidopsis plants (better known as “mustard weed”) to discover whether plants can complete their entire seed-to-seed life cycle in a weightless environment. If normal, healthy seeds were, the experiment will be a good sign that future astronauts can grow multiple generations of plants in space. Such self-perpetuating gardens will be a practical necessity for humans as they explore and colonize the solar system. Hardy space plants could provide fresh food, oxygen, and even clean water for explorers living for long stretches aboard orbiting outposts or on the Moon and Mars.

Centuries ago monitoring the stars and planets was a popular way to plan daily events. Some say it still is! But the scientific method has shown that astrology holds little, if any, predictive power. As a result the belief in astrology is now far less universal than it was in Titus’ day. Nevertheless there are certain endeavors that are absolutely dependent upon the positions of the planets. In fact, some of our civilization’s most advanced organizations, like NASA and its sister space agencies around the world, sometimes do nothing without first consulting the stars!

NASA’s Human Exploration and Development of Space enterprise tackles one of the toughest and most redeeming problems of all: sending humans into space. When Apollo astronauts were traveling to the Moon, they occasionally saw flashes of light inside their eyes. It was a sign that high-energy cosmic rays were coursing through their bodies. Fortunately, the dose of such radiation during a round trip to the Moon was not enough to cause health problems. No one was harmed. But the first astronauts couldn’t have known that’s how it would turn out. Blasting off for the Moon was a risky venture.