Mission Mans Legacy on space

The Exploration of Space

NASA has a long legacy of space exploration. In the

decades since its founding, the space agency has

landed rovers on Mars, sampled the atmosphere of

Jupiter, explored Saturn and Mercury - and even

landed humans on the moon - to name a few.

Some missions, like the Kepler planet-hunting

observatory, are relatively new, and only time will tell if

they join the ranks of NASA's finest flights.

Here's our subjective list of 10 NASA missions that

have already earned their spot in the space mission

hall of fame.

Pioneer

Pioneer 10 and Pioneer 11, launched in 1972 and 1973, respectively, were the first spacecraft to visit the solar system's most photogenic gas giants, Jupiter and Saturn. Pioneer 10 was the first probe to travel through the solar system's asteroid belt, a field of orbiting rocks between Mars and Jupiter. Then about a year-and-a-half after its launch, the spacecraft made the first flyby of the planet Jupiter. It took stunning up-close photos of the Great Red Spot and the wide swaths of red that band the planet. About a year later, Pioneer 11 flew by Jupiter, and then moved on to Saturn, where it discovered a couple of previously unknown small moons around the planet, and a new ring. Both probes have stopped sending data, and are continuing out on their one-way voyages beyond the solar system.

Voyager

Shortly after the Pioneers made their flybys, the Voyager 1 and Voyager 2 probes followed. They made many important discoveries about Jupiter and Saturn, including rings around Jupiter and the presence of volcanism on Jupiter's moon, Io. Voyager went on to make the first flybys of Uranus, where it discovered 10 new moons, and Neptune, where it found that Neptune actually weighs less than astronomers thought. Both Voyager crafts have enough power to keep transmitting radio signals until at least 2025, and are now exploring the very edge of the solar system and beginning of interstellar space. Voyager 2 is currently the farthest man-made object from Earth, at more than a hundred times the distance from the Earth to the sun, and more than twice as far as Pluto.

WMAP

The Wilkinson Microwave Anisotropy Probe (WMAP),

launched in 2001, may not be as well-known, but it

measures with unprecedented accuracy the

temperature of the radiation left over from the Big

Bang. By mapping out the fluctuations in the so-called

cosmic microwave background radiation, the

spacecraft has heralded a leap forward in

cosmological theories about the nature and origin of

the universe. Among other revelations, the data from

WMAP revealed a much more precise estimate for

the age of the universe ? 13.7 billion years ? and

confirmed that about 95 percent of it is composed of

poorly understood things called dark matter and dark

energy.

Spitzer

Another spacecraft with a profound effect on cosmology and astrophysics is the Spitzer Space Telescope, which observed the heavens through infrared light. This light, which has a longer wavelength than visual light, is mostly blocked by Earth's atmosphere. In addition to taking gorgeous photos of galaxies, nebulae and stars, the telescope has made numerous groundbreaking scientific discoveries. In 2005 Spitzer became the first telescope to detect light from extrasolar planets (most of these distant worlds are detected only through secondary, gravitational effects on their suns). In another observation, astronomers think the telescope may have even captured light from some of the first stars born in the universe.

Spirit & Opportunity

Intended for just a 90-day mission, these workhorse Mars rovers have far outdone themselves, and are still chugging away on the red planet more than five years after landing. Spirit and Opportunity, the twin Mars Exploration Rovers, landed on opposite sides of the planet in January 2004. Since then, they have been traveling all over the surface, poking into craters and roving over unexplored hills. Among their major finds is evidence that the surface of Mars once had liquid water. (A tip of the hat to Sojourner rover, which brought full-color close-ups of Mars in 1997, just as the Internet was becoming wildly popular, thereby earning a special place in the hearts of millions who enjoyed unprecedented access to NASA mission photos.)

Cassini-Huygens

This joint NASA/ESA spacecraft, launched in

1997, reached its destination, Saturn, in 2004.

Since then it has been in orbit around the ringed

world, taking one stunning snapshot after another

of the planets rings, moons and weather. The

Hugyens probe separated from Cassini and made

a special trip to the moon Titan, where it

descended through the atmosphere and landed

on solid ground in 2005. Though previous

spacecraft have visited Saturn, Cassini is the first

to orbit it and study the system in detail.

Chandra

Since 1999, the Chandra X-ray Observatory has been scanning the skies in X-ray light, looking at some of the most distant and bizarre astronomical events. Because Earth's pesky atmosphere blocks out most X-rays, astronomers couldn't view the universe in this high-energy, short-wavelength light until they sent Chandra up to space. The observatory has such high-resolution mirrors, it can see X-ray sources 100 times fainter than any previous X-ray telescope. Among other firsts, Chandra showed scientists the first glimpse of the crushed star left over after a supernova when it observed the remnant Cassiopeia A.

Viking

When NASA's Viking 1 probe touched-down on

Mars in July 1976, it was the first time a man-

made object had soft-landed on the red planet.

(Though the Soviet Mars 2 and 3 probes did land

on the surface, they failed upon landing). The

Viking 1 lander also holds the title of longest-

running Mars surface mission, with a total

duration of 6 years and 116 days. The spacecraft

also sent the first color pictures back from the

Martian surface, showing us what that mysterious

red dot looks like from the ground for the first

time.

Hubble

The most-loved of all NASA spacecraft, the

Hubble Space Telescope has name recognition

around the world. Its photos have changed the

way everyday people figure themselves into the

cosmos. The observatory has also radically

changed science, making breakthroughs on

astronomical issues too numerous to count. By

finally sending up an optical telescope to peer at

the sky from beyond Earth's turbulent

atmosphere, NASA developed a tool that could

reveal stars, planets, nebulae and galaxies in all

their fully-detailed glory.

Apollo

NASA's best space science mission? The one humans got to tag along on, of course! Not only was sending a man to the moon monumental for human history, but the Apollo trips were the first to bring celestial stuff back to Earth and greatly advanced our scientific understanding of the moon. Before Apollo, many people weren't even convinced the moon wasn't made out of cheese (well? non-scientists at least). By studying the moon up close and personal, and then carting? loads of moon rocks home, the Apollo astronauts gathered data that helped us learn how old the moon is, what it's made out of, and even how it might have begun.

History of Rocket

propulsion

the date reporting the first use of

true rockets was in 1232. At this time, the

Chinese and the Mongols were at war with each

other. During the battle of Kai-Keng, the Chinese

repelled the Mongol invaders by a barrage of

"arrows of flying fire." These fire-arrows were a

simple form of a solid-propellant rocket.

The first rockets that were

used in modern rocketry were

invented by Dr. Robert

Goddard. For this he is

known as the Father of

Modern Rocketry. He created

the first successful liquid fuel

rocket, adding the nozzle

design that is so common

today.

Rockets are now used for fireworks, weaponry, ejection seats, launch vehicles for artificial satellites, human spaceflight, and space exploration. Chemical rockets are the most common type of high power rocket, typically creating a high speed exhaust by the combustion of fuel with an oxidizer.The first rocket which could fly high enough to get into space was the V2 missile which was first launched by Germany in 1942. The first rocket which actually launched something into space was used to launch Sputnik, the first satellite, on October 4, 1957.

Hubble Space Telescope

the Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for astronomy. The space telescope was named the Hubble Space Telescope, after American astronomer Edwin Hubble, who showed that the fuzzy patches of light in the night sky were actually other galaxies, far distant from our own, and went on to prove that the universe was expanding.

Edwin Hubble