Landing humans on Mars will be hard, but keeping them alive will be even harder. NASA scientists are on the verge of designing some of the most innovative rockets and training the astronauts who will pilot them.
Orbits are the dynamics that drive the universe. From the smallest asteroid to the largest super-cluster, everything in the universe is in orbit. We owe our very existence to the stability of earth's orbit — it gave us life and keeps us safe. But we are the freaks. Everywhere else we look we find orbits are chaotic, unstable, and violent. Beyond our solar system we find planets that are blow-torched, stars that eat each other, and black holes that destroy everything in their path. Yet on the very largest scale, orbits are also a creative force. clashing galaxies give birth to new stars and new worlds. on the galactic scale orbits even construct the fabric of the universe itself.
With repeated triumphs and new challenges comes increasing risk, until loss breaks the pattern. The white-knuckle suspense thriller of Apollo 13's famous near-disaster is only a triumphant prelude to darker moments ahead. The launch of the space shuttle program promises routine trips to Earth orbit for many new astronauts. But just when that promise seems fulfilled, routine shuttle launches begin to bore the public. NASA responds by training a school-teacher to fly, in order to teach children lessons from space. Christa McAuliffe's life is tragically cut short as she and the rest of the crew perish aboard the shuttle Challenger. All missions are halted. Eventually the shuttle returns to orbit, for fifteen years of successful missions until disaster strikes again with the shocking loss of Columbia. It would be the beginning of the end for the shuttle.
The US efforts to colonize the Moon will follow the Lunar Exploration Roadmap, laid out with events taking place over decades. Other countries have plans as well. How will robots be deployed to work on the Moon? At what stage will people inhabit the environment? What minerals will be harvested?
Scientists are only now starting to unravel the secrets of comets. Often referred to as dirty snowballs, they contain ice and elements from the very start of the universe. Some theorize that a comet, crashing into our planet, brought with it the organic material that started life on Earth. Spacecraft continues to offer new information on their makeup, from bringing back samples from a comet's tail to direct contact when a NASA-launched craft slammed into the comet Tempel-1.