History of Space Exploration
Lunar Space Exploration and Mars Rovers
Lunar Space Exploration
The Soviets sent the unmanned Luna 1 past the Moon in January 1959.
The United States followed with Pioneer 4 two months later.
In September 1959 the Soviet Luna 2 became the first craft to strike the Moon’s surface, and the next month Luna 3 radioed back the first photograph ever of the Moon’s far side.
On February 3, 1966, the Soviet craft Luna 9 successfully soft-landed and televised the first pictures from the surface of another world.
On July 20, 1969, Apollo 11’s lunar module successfully landed on Mare Tranquillitatis (the “Sea” of Tranquillity), and Neil Armstrong and Buzz Aldrin became the first humans to set foot on the Moon.
Five more successful Apollo landings (Apollo 13 was unable to land) followed, each with two men landing while one remained in lunar orbit in the Apollo command module. The last such mission was Apollo 17, in December 1972.
The Soviets had no manned lunar missions. They did, however, succeed in returning samples from the surface three times during the period 1970 to 1976.
The Apollo astronauts brought back 842 pounds, as weighed on Earth, of lunar rocks and dust, which are still being studied today.
One finding is that the Moon is receding from Earth at the rate of 1.5 inches per year because of tidal interactions with Earth, which also gradually slow Earth’s rotation.
Since the 1970s there have been no manned missions to the Moon, and no unmanned missions were sent until Japan’s orbiter Hiten was launched in 1990.
"Moon." Britannica School. Encyclopædia Britannica, Inc., 2016. Web. 4 Mar. 2016. <http://school.eb.com/levels/middle/article/275930#274032.toc>.
Picture of Armstrong on the Moon
Earth rising over the Moon's horizon
First view of Earth from the Moon
Mars Rovers
Opportunity-
Launch: July 7, 2003
Launch Vehicle: Delta II H
Arrival: Jan. 24, 2004 PST
(Jan. 25. 2004 UTC)
Landing Site: Meridiani Planum
Mission Duration: Still roving!
Odometry: 25 miles (40 km)
Raw Images Returned: 187,000
Instruments: Panoramic camera, Miniature thermal emission spectrometer, Moessbauer spectrometer, Alpha particle X-ray spectrometer, Microscopic imager, Rock abrasion tool, Navigation camera, Hazard-avoidance cameras
Spirit-
Launch: June 10, 2003
Launch Vehicle: Delta II
Arrival: Jan. 3, 2004 PST
(Jan. 4. 2004 UTC)
Landing Site: Gusev Crater
Mission Duration: Ended March 2010
Odometry: 4.8 miles (8 km)
Raw Images Returned: 128,000
Instruments: Panoramic camera, Miniature thermal emission spectrometer, Moessbauer spectrometer, Alpha particle X-ray spectrometer, Microscopic imager, Rock abrasion tool, Navigation camera, Hazard-avoidance cameras
The modern Mars environment lent a hand, providing wind that removed some dust from Opportunity's solar panels after the Mars southern hemisphere's winter solstice on Jan. 2.
For several months starting in mid- to late October, the rover team plans to operate Opportunity on the southern side of the valley to take advantage of the sun-facing slope. The site is in Mars' southern hemisphere, so the sun is to the north during fall and winter days. Tilting the rover toward the sun increases power output from its solar panels. The shortest-daylight period of this seventh Martian winter for Opportunity will come in January 2016.
Brown, Dwayne. Nasa Mars Exploration. Accessed 3/10/16.
<http://mars.nasa.gov/news/whatsnew/index.cfmFuseAction=ShowNews&NewsID=188>
Mars Exploration Rover
Picture Taken by Opportunity
Picture Taken by Spirit
Space Stations
A space station is a spacecraft designed to revolve around Earth in a fixed orbit as a long-term base for scientific research. Astronauts can live on a space station for days or months at a time while making astronomical observations, studying Earth’s resources and environment, and performing experiments.
Research into space stations began during the “space race” between the United States and the Soviet Union. As the two countries worked feverishly toward a Moon landing during the 1960s, they also hatched plans for Earth-orbiting space stations. These stations were to be used both for scientific research and military surveillance.
By 1969, the year the United States won the race to the Moon, the Soviet Union had begun to shift its emphasis in human spaceflight to the development of space stations. The Soviets launched the world’s first space station, called Salyut 1, on April 19, 1971.
The first crew to occupy the station spent 23 days aboard carrying out scientific studies but died when their Soyuz spacecraft lost its air through a faulty valve while returning to Earth.
With similar goals for a long-term manned platform in space, the United States launched its first space station, called Skylab, on May 14, 1973.
Over a period of eight and a half months, three three-person crews using Apollo spacecraft for transport spent time aboard Skylab, with the final crew staying for 84 days.
Skylab was abandoned in February 1974 and reentered Earth’s atmosphere in July 1979, with some portions of the station surviving reentry and landing in Australia.
The Soviet Union orbited and successfully occupied five more Salyut stations in a program that continued through the mid-1980s. Two of these stations were used for military purposes, but the others were devoted to scientific studies, particularly biomedical research.
The Soviet Union also launched guest cosmonauts from allied countries for short stays aboard Salyut 6 and 7.
The Soviet Union followed its Salyut station series with the February 1986 launch of the core element of the Mir space station. Additional modules carrying scientific equipment and expanding the living space were attached to Mir in subsequent years.
"Space station." Britannica School. Encyclopædia Britannica, Inc., 2016. Web. 8 Mar. 2016. <http://school.eb.com/levels/middle/article/606725>.
International Space Station
Space Shuttles
- A space shuttle is designed to go into orbit around Earth, to transport people and cargo to and from orbiting spacecraft, and to glide to a runway landing on its return to Earth’s surface.
The first vehicle of this type was developed by NASA. Formally called the Space Transportation System, it lifted off into space for the first time on April 12, 1981, and for the last time on July 8, 2011.
The U.S. space shuttle consisted of three major components: a winged orbiter that carried both crew and cargo; an external tank containing liquid hydrogen (fuel) and liquid oxygen (oxidizer) for the orbiter’s three main rocket engines; and a pair of large, solid-propellant, strap-on booster rockets.
At liftoff the entire system weighed 4.4 million pounds and stood 184 feet high. During launch the boosters and the orbiter’s main engines fired together, producing about 7 million pounds of thrust.
On some missions it carried a European-built pressurized facility called Spacelab, in which shuttle crew members conducted biological and physical research in weightless conditions.
Designed to be re-flown as many as 100 times, the U.S. space shuttle originally had been expected to reduce the high cost of spaceflight into low Earth orbit.
After the system became operational, however, the vehicle’s operating costs and the time needed for refurbishment between flights proved to be significantly higher than early projections. Between 1981 and 1985 a fleet of four orbiters—Columbia, Challenger, Discovery, and Atlantis—was put into service.
On January 28, 1986, Challenger, carrying seven astronauts, exploded shortly after liftoff, killing all aboard including a private citizen, schoolteacher Christa McAuliffe.
In 1992 Endeavour flew its first mission.
Between 1995 and 1998, NASA conducted a series of shuttle missions to the orbiting Russian space station Mir to give the agency experience in station operations in anticipation of the construction of the modular International Space Station (ISS).
"Space shuttle." Britannica School. Encyclopædia Britannica, Inc., 2016. Web. 4 Mar. 2016. <http://school.eb.com/levels/middle/article/544800>.