Astronauts and cosmonauts on deep space flights:
When Will Humans Visit Mars?
Today, humans fly in space only in what is known as low-Earth orbit.
They have flown higher and farther, of course — to the Moon, for instance, and they may go there again — but it's possible they may not fly beyond low-Earth orbit again until a manned mission to Mars sometime around the year 2020.
The exact date depends on what is found at the Red Planet during planned visits to Mars by robot probes.
Several robotic missions are there already and other unmanned Mars explorations — orbiters and landers — are planned over the next decade. Taken together, that fleet will be the most ambitious human space project since the Apollo flights to the Moon in the 1960s and early 1970s.
Sometime around 2014, a spacecraft will leave Earth for Mars, hopefully, to return three years later with a pound of Martian rock and soil. We might learn from that spacecraft that Mars has mysteries which require humans to go there to solve.
Men are from Mars . . .
The biggest Mars mystery is whether life ever did, or still does, exist on the Red Planet. The discovery on Earth of meteorites from Mars which seem to contain evidence of primitive life out there has raised many new questions about the origin of life in the Solar System.Answering such questions and unraveling mysteries would lead to an age of enlightenment on Earth. The answers undoubtedly would bring up even more profound questions.
- Could Mars have had simple forms of life before organic life appeared on Earth?
- Could a chunk of Mars have landed on Earth and seeded our planet? That's a far-out suggestion, but, if true, we would be the result three or four billion years later.
- Are we Martians? Some scientists find it a fascinating speculation that perhaps the home planet of the human race might actually be Mars.
- With one of Earth's nearest neighbors showing evidence of life, could life be far more prevalent in the galaxy than people have imagined?
Men are from Earth...
A human flight to the Red Planet may be possible in the period 2018-2025. NASA is planning for human crews to explore Mars sometime around then.
It takes time to design and carry out missions to planets. NASA says six years are required between a decision to send humans to Mars and blastoff. Thus, the data on Mars climate and geology collected by Pathfinder and its several followers will be essential for planning ahead.
Humans fly now only in the so-called "low-Earth orbit" around 200 miles above Earth. The only time human beings have flown farther from Earth was briefly during the Apollo Project era of Moon flights in the late 1960s and early 1970s. People won't fly farther again until a manned mission to Mars in the period 2018-2025. The actual blast-off date depends on what the coming visits by robot Mars probes find at the Red Planet.
When a probe returns to Earth from Mars, after a three year trip, with a pound of Martian rock and soil, we will learn whether Mars has mysteries that require humans to go there to solve.
