Part 4: Exploration 1

Reaction Engine  An engine, such as a jet or rocket engine, that ejects gas at high velocity and develops its thrust from the resulting reaction  This movement follows Newton’s Third Law of Motion: every action produces an equal and opposite reaction  Thrust: a propulsive force produced by the fluid pressure or the change of momentum of the fluid in a jet engine, rocket engine, etc. World English Dictionary; dictionary.com  Reaction engines were first developed by the Chinese between the 11 th and 13 th centuries. 2 Remember: A fluid can be a liquid or a gas

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What Is a Rocket?  A rocket is a device that produces thrust by burning fuel. The usually hot gases that are produced push out of the back of the engine which pushes the rocket forward.  Unlike jet engines, rocket engines carry all the fuel they need to carry out the reactions that produce the propellant gas. NASA's Saturn V rocket carried humans to the moon. Image Credit: NASA 4

The Development of Space Rockets  In 1903, a Russian teacher named Konstantin Tsiolkovsky wrote a paper describing the idea of liquid-fuel rockets that would produce enough thrust to escape Earth’s gravity.  In 1926, American scientist Robert Goddard flew the first liquid-fuel rocket. It was fueled with a mixture of gasoline and liquid oxygen. Robert Goddard built the first liquid- fuel rocket. Image Credit: NASA 5

The Development of Space Rockets  The Germans continued to improve on rocket design and used them during WWII for bombing.  In 1957, the USSR used a rocket to launch the first satellite, and in 1961 sent the first man, Yuri Gagarin, into space.  Also in 1961, Alan Shepard became the first American in space.  In 1962, John Glenn became the first to orbit the Earth.  In 1969, a rocket carried Neil Armstrong and Buzz Aldrin to the moon and back.  Today rockets carry space probes to the far reaches of our solar system and beyond. 6

Escape Velocity  The velocity needed for a rocket to escape a planet’s gravity  Depends upon the mass of the planet and the distance of the rocket from the center of the planet  Requires fuel (liquid or solid) that can burn long enough to maintain thrust through the atmosphere. Escape Velocities ObjectVelocity in km/s Mercury4.2 Venus10.3 Earth11.2 Moon2.3 Mars5.0 Jupiter63.4 Saturn39.4 Uranus21.5 Neptune24.2 Sun616 7

Exploring Space Beyond the Moon  Mariner 2 – launched in 1962 to fly by Venus; 1 st successful mission to another planet  Mariner 4 – launched in 1964 to fly by Mars; 1 st close photos of Mars 8

Exploring Space Beyond the Moon  Pioneers 6, 7, 8, and 9 formed a ring of solar- weather stations, spaced approximately along Earth's orbit, whose measurements were used to predict solar storms. 9  Pioneer 6 returned the first data on the Sun's atmosphere and recorded passage of Comet Kohoutek's tail.

Exploring Space Beyond the Moon  1967 Mariner 5 to Venus  1969 Mariner 6 and 7 to Mars  1971 Mariner 9 to Mars– 1 st spacecraft to orbit another planet  1971 USSR Mars 3 was the first human- made object to perform a survivable landing on Mars, but contact was lost only 20 seconds after landing. 10 Mariner 9 Mars 3 Years are when launched.

Exploring Space Beyond the Moon  1972 – Pioneer 10 1 st to fly beyond Mars; photographed Jupiter and its moons  1973 – Pioneer 11 sent to explore Saturn  Both dormant probes are now headed out toward distant stars 11 Pioneer 10 Pioneer 11 Years are when launched.

Exploring Space Beyond the Moon Mariner 10 was the only mission to Mercury until NASA's MESSENGER mission more than 30 years later.  It was also the first spacecraft to reach one planet by using the gravity of another planet (in this case, Venus) to alter its speed and trajectory.  This has become an extremely important technique. 12 Mariner 10 Years are when launched.

Exploring Space Beyond the Moon  Voyager 2 – only spacecraft to study all four gas giants  1977 – Voyage 1 explored Jupiter and Saturn  Both then went on to explore the farthest reaches of the solar system. 13 Voyager space probes Years are when launched.

Exploring Space Beyond the Moon  1978 – Pioneer Venus 1 explored Venus, mapping it from orbit by radar for 14 years  1978 – Pioneer Venus 2 carried probes that gathered data as they descended to the surface 14 Pioneer Venus spacecraft Years are when launched. USSR’s Venera missions also explored Venus

Exploring Space Beyond the Moon  Viking 1 and 2 successfully landed on Mars and sent back data  1984 – Vega 1 and 2 sent to Venus and then on to the comet Halley.  1989 – Magellen – mapped 98% of Venus 15 Vega Magellen Years are when launched. Viking

Exploring Space Beyond the Moon  1989 – Galileo sent to study Jupiter and its moons from orbit  NEAR Shoemaker (Near Earth Asteroid Rendezvous) lands on asteroid Eros  1996 – Mars Global Surveyor 16 Galileo NEAR Shoemaker Years are when launched. Mars Global Surveyor

Exploring Space Beyond the Moon  2003: Spirit and Opportunity Mars Rovers  Cassini sent to explore Saturn, carrying the Huygens probe that landed on Titan  2004 – MESSENGER sent to study Mercury 17 Spirit/Opportunity Cassini Years are when launched. MESSENGER Huygens

Missions in Progress  2006 New Horizons – expected to arrive at Pluto in 2015  2007 Dawn - arrived at asteroid Vesta in 2011, will move on to Ceres in 2012  2011 Juno – expected to arrive at Jupiter in Years are when launched.

Missions in Progress  On August 6, 2012 Curiosity landed on Mars.  Has seventeen cameras and equipment to analyze soil samples  Looking for any evidence that Mars may have once supported life  Should function for 2 years 19