Portal:Technology

Two Jet Propulsion Laboratory engineers stand with three vehicles, providing a size comparison of three generations of Mars rovers. Front and center is the flight spare for the first Mars rover, Sojourner, which landed on Mars in 1997 as part of the Mars Pathfinder Project. On the left is a Mars Exploration Rover test vehicle, a working sibling to Spirit and Opportunity, which landed on Mars in 2004. On the right is a test rover for the Mars Science Laboratory, which landed Curiosity on Mars in 2012.

A structural worker bolts beams on the framework during the construction of the Empire State Building in New York City. The 1,250-foot (380 m) building opened on May 1, 1931, at the time the tallest building in the world, overtaking the Chrysler Building (seen to the right), which had just been completed the year before. The addition of a pinnacle and antennas later increased its overall height to 1,472 feet (449 m).

The Commodore 64 is an 8-bit home computer introduced in 1982 by Commodore International. Its low retail price and easy availability led to the system becoming the market leader for three years. It remains the best-selling single personal computer model of all time.

Union Pacific 844 at Painted Rocks, Nevada, on a run from Elko to Sparks, on September 15, 2009. Built in 1944, it was the last steam locomotive delivered to Union Pacific and is the only steam locomotive never retired by a North American Class I railroad.

A test firing of twin linear XRS-2200 aerospike engines, originally built for the Lockheed Martin X-33, a next-generation, commercially operated reusable launch vehicle. The aerospike engine is a type of rocket engine that maintains its efficiency across a wide range of altitudes through the use of an aerospike nozzle. A vehicle with an aerospike engine uses 25-30% less fuel at low altitudes, where most missions have the greatest need for thrust.

The Australia Telescope Compact Array is a radio telescope operated by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) at the Paul Wild Observatory, 25 km (16 mi) west of the town of Narrabri in New South Wales, Australia. The telescope is an array of six identical dishes each 22 metres (72 ft) in diameter, which commonly operate in aperture synthesis mode to produce images from radio waves. Five of the dishes can be moved along a 3-kilometre (2 mi) railway track; the sixth is situated three kilometres west of the end of the main track. Each dish weighs about 270 tonnes (270 long tons; 300 short tons).

This photograph, showing five of the Australia Telescope Compact Array's dishes, was taken around 1984, in the late phase of the construction process. It is a long-exposure photograph taken in darkness in the late evening; during the exposure, the photographer, John Masterson, walked around the dishes firing off over 130 flashes using a hand-held flash gun.

The four-stroke cycle of an internal combustion engine is the cycle most commonly used for automotive and industrial purposes today, including cars, trucks, and generators.

The cycle was invented by Nikolaus Otto in 1876, and is also called the Otto cycle. The cycle is characterized by four strokes, or straight movements in a single direction, of the piston.

This photo of the International Space Station (ISS) was taken during STS-119, a Space Shuttle mission that delivered and assembled the fourth starboard Integrated Truss Segment, and the final set of solar arrays and batteries to the station. Construction of the ISS is still ongoing and is scheduled to complete in December 2011.

The semi-submersible oil platform P-51, operated by Brazilian energy company Petrobras, being positioned by tugboats. Semisubs sit on pontoons located under the ocean surface, with the operating deck atop columns, above the sea level. In this manner, they are relatively protected from wave action.

The Mazda RX-8 sports car is a front mid-engine, rear-wheel drive four-seat coupé manufactured by Mazda Motor Corporation. It is the successor to the RX-7 and, like its predecessors in the RX range, it is powered by a rotary engine. The RX-8 began North American sales in the 2004 model year.

"Big Pete" Ramagos, rigger at work on Douglas Dam, Tennessee, June 1942. A rigger is a person or company which specializes in the lifting and/or moving of extremely large and/or heavy objects. Riggers use equipment expressly designed for moving and lifting objects where ordinary material handling equipment cannot go.

George Washington Carver (1860s–1943) was an American agricultural scientist and inventor. Born into slavery in Diamond, Missouri, he was raised by his master Moses Carver after being emancipated, having been separated from his parents as an infant during a kidnapping incident. After college, Carver became a professor at Tuskegee Institute, where he developed techniques to improve soils depleted by repeated plantings of cotton. He wanted poor farmers to grow alternative crops, such as peanuts and sweet potatoes, as a source of their own food and to improve their quality of life. Carver spent years developing and promoting products made from peanuts, although none became commercially successful. Apart from his work to improve the lives of farmers, he was also a leader in promoting environmentalism. Carver received numerous honors for his work, including the NAACP's Spingarn Medal. In an era of very high racial polarization, his fame reached beyond the black community; he was widely recognized and praised in the white community for his many achievements and talents. In 1941, Time magazine dubbed Carver a "black Leonardo".

This picture of Carver was taken around 1910 and is in the collection of the Tuskegee University archives.

An Agusta A109 rescue helicopter leaves Mount Pilatus, near Lucerne, Switzerland, after recovering a patient. Later renamed AgustaWestland AW109, the A109 is a helicopter manufactured by Agusta (now AgustaWestland) of Italy. It is a light-weight, twin-engine, eight-seat multi-purpose craft.

This diagram of four pulley systems illustrates how increasing the number of pulleys increases the mechanical advantage, making the load easier to lift. MA is the factor by which a mechanism multiplies the force put into it. In this diagram, 100 newtons is required to lift the weight off the ground. Each additional pulley increases the MA such that the four-pulley system only needs 25 newtons to accomplish the same task, but the rope must be pulled four times as far.

Nine Marines from Mike Battery, 4th Battalion, 14th Marines operate the 155mm M198 howitzer in November 2004. The battery was based at Camp Fallujah, Iraq and was supporting Operation Phantom Fury. All nine members of the M198 crew are present.