Education and
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at the Lunar and Planetary Institute
Space Exploration

Background Information

Also see background information for Health in Space.

Humans are exploring space. While our current human exploration is through the International Space Station and transportation to and from it, future activities could include missions to the Moon, Mars, and other locations in the Solar System. These require rockets to launch from the Earth or Moon or a space station, landing capsules, and some type of facilities or colony from which to explore the Moon and Mars.

Human space exploration needs to meet the requirements for healthy life and productivity: air, food, water, energy, communications, transportation, productivity areas and tools, and recreation.

Modules and Technology
A space station or space colony will need different sections:


A rocket essentially is a container propelled in one direction by exhaust going in the opposite direction. Rockets help spacecraft get into space, stay in space, and maneuver in space. The main parts of a rocket include the nose cone (the leading, tapered section that reduces aerodynamic drag), the body tube ( the central structure, which includes the engine, propellant tanks, and payload), and the fins (which guide the rocket).

Space Capsules

Space capsules are the compartments designed to support astronauts during their journey through space, and land people or instruments on the surface of Earth or another planet. They must contain the basic elements that astronauts need to live — air to breathe, water to drink, and food to eat. They also have to protect the astronauts from the cold of space and space radiation.

Space Stations

Space stations are platforms for long-term living and working in space that orbit Earth; in the future, they may orbit other planets or moons. Space stations can carry out scientific research in an environment not found on Earth; they allow scientists and engineers to test materials and designs for future space travel.

Space Colonies
Space colonies on the Moon, Mars, asteroids, other worlds and in orbit around the Earth have been suggested, designed and promoted since the 1950's. Space colonies can include laboratories for unique or risky experiments, factories, observatories, and mining stations. There may eventually be a permanent lunar base for scientific research and mining, which would be a stepping stone to Mars. A lunar outpost could provide valuable information on the long-term physiological and psychological effects on humans living for long periods in space. The Moon could serve as a source for the large quantities of oxygen needed to fuel a spacecraft to Mars and back. In the more distant future, there may be bases on Mars, such as a Mars habitat that could be launched into orbit, eventually being delivered to Mars nearly 26 months prior to the first crew's arrival.

Research in Space

On Earth, gravity influences the way crystals, plants, and animals grow. In contrast, space stations and space colonies offer an environment where there is very little gravity. Research can help understand how weightlessness influences growth and development. In microgravity nearly perfect crystals can be grown; it may be possible to use these to create new and more efficient drugs and microchips for computers. Research is learning how plants can be grown in space to provide food, and how weightlessness influences calcium and tissue loss in humans — and how this can be prevented. Perhaps the most important reason for living in space is to determine how to keep humans healthy for the length of time that will be required by journeys of exploration to Mars and other planets.
Other research includes monitoring our Earth's atmosphere, weather, climate, oceans, land, and resources: space stations offer “the best seat in the house” to make observations of Earth's environments.

History of Human Space Exploration

Humans in Space

Prior to human exploration of space, test flights involved animals, including dogs, monkeys, and mice. In 1957, Russian scientists sent the first dog into space to allow them to investigate the effects of space flight on a living organism This was followed by other missions involving animals, leading up to the successful 108 minute Earth orbit by Cosmonaut Yuri Gagarin on 12 April 1961. Astronaut Alan Shepard was the first American astronaut to travel into space; he was aboard the Mercury capsule. The Gemini capsule carried the second generation of astronauts into Earth orbit for longer periods of time. The Apollo capsule took astronauts to the Moon, and the Lunar Module landed astronauts on the surface. Dozens of Russian cosmonauts have orbited Earth in the Russian Soyuz capsule. The Space Shuttle served as a means of transport and support for astronauts as they move between Earth and the International Space Station. Unlike earlier capsules, the Space Shuttle was designed to be used for many flights.

Space capsules have not always been successful and the price for exploration is high when counted in human lives; one early Soyuz capsule lost three cosmonauts when it depressurized upon re-entry. Two Space Shuttles, the Challenger and the Columbia, and their crews, were tragically destroyed due to malfunctions. The Challenger failed during lift-off, when a seal malfunctioned in the solid-rocket booster, causing the craft to explode 73 seconds after launch. The Columbia was destroyed on February 1, 2003, during re-entry, when a catastrophic failure occurred due to damage caused by foam that fell and struck the panels on the underside of the wing during launch.

Past space stations include: