The Aerospace Product Line: Spacecraft
The term spacecraft applies only to the portion of a space vehicle that actually goes into space. The booster rockets that deliver it to orbit are known as the launch vehicle. Spacecraft are individually tailored to specific programs and objectives.
The nation's current Vision for Space Exploration has a goal of returning humans to the moon by the end of the next decade while preparing for future exploration to Mars. The National Aeronautics and Space Administration (NASA) is developing a next generation manned spacecraft that will replace the current shuttle. The Orion spacecraft and Ares I launch vehicle will use both new systems and legacy systems based on shuttle technology with a goal of landing humans on the moon by 2014, paving the way for eventual journeys to Mars and beyond. Several companies are also developing systems that will take supplies, and someday perhaps people, to the International Space Station.
Unmanned spacecraft are satellites when they operate in Earth orbit or probes when they are launched into deep space. Their functional equipment, whether scientific instruments for research or electronics for practical applications, is known as the payload.
There is no standard design or size for satellites. They range from a few pounds to the 12-ton Hubble Space Telescope and are built in many different configurations.
Global communication networks are the largest area of satellite activity. As of 2007, there are currently more than 500 operational satellites in orbit. Civil satellites help people communicate wherever they are in the world. Faxes, telephones, e-mail, Internet transmission, and television are all possible because of satellites.
Satellites are also critical to emergency and weather services, environmental observation and Earth monitoring. The military operates separate communications, weather, reconnaissance and scientific communication networks.
As we've seen in the current conflicts in the Middle East, satellites play an increasingly important role in enabling a network-centric environment where data and information is seamlessly connected in real time.