Space Exploration

Human beings are innately curious about the universe around them and this curiosity results in the need to investigate and develop an understanding of what we see. When it comes to space mankind has always been looking upwards towards the heavens, fascinated by this dark expanse that is sparkled with shinning lights. This fascination inspired people to develop techniques and technology that would allow them to better see and understand what is really out there and what is going on out beyond our own world. Space exploration is the investigation of physical conditions in space and on stars, planets, and other celestial bodies through the use of artificial satellites (spacecraft that orbit the earth), space probes (spacecraft that pass through the solar system and that may or may not orbit another celestial body), and spacecraft with human crews.

Important Individuals In Space Exploration

Sergei Korolev- Freed from imprisonment by Stalin to work on the development of ballistic missiles. Created the rocket which propelled the famous Sputnik space exploration.

Wernher Van Braun- Creator of the V-2 missile. Surrendered to U.S. and worked on ballistic missiles and the U.S. space program for the next 15 years contributing to a multitude of space exploration missions.

Kerim Kerimov- Was a Lt. in the Soviet Union Space Program as an Artillery officer. Headed up Soviet Union's efforts to dock a manned spacecraft in orbit.

Valentin Glushko- Revolutionary liquid propellent engine builder for the Soviet Space Program. Eventually appointed to Chief Designer of the Soviet Space Program.

Bob Gilruth- Director of NASA in Houston during the moon race and successfully led the Mercury, Apollo and Gemini missions during his time as Director.

Christopher C. Kraft, Jr.- Headed all Mercury missions and many Gemini missions before becoming Director of the Manned Spacecraft Center of NASA in Houston.

Maxime Faget- Recognized for his intricate role in the Mercury missions. Honored with the NASA Medal for Outstanding Leadership.

Targets of Space Exploration

Terrestrial Planets


As one of the planets visible with the unaided eye, Mercury has been known before recorded history. But until the development of the telescope, the exploration of the Mercury was only unaided eye observations. Early cultures like the Mayans and ancient Greeks were diligent astronomers, and calculated the motions and positions of Mercury with tremendous accuracy. Because Mercury is so small, and located so close to the Sun, astronomers weren’t able image features on its surface with any accuracy. It wasn’t until the 1960s, when Soviet scientists bounced radio signals off the surface of Mercury that astronomers got any sense of what its surface was like. But the best Mercury exploration happened when NASA’s Mariner 10 spacecraft first flew past Mercury in 1974. It revealed that Mercury’s surface is pockmarked with craters like the Earth’s moon. And like the Moon it has flat regions filled in with lava flows.(1)

Venus is the brightest body in our sky after the Sun and Moon. Observed at night through a telescope, Venus shines a slightly yellowish white. It wasn’t until the 1960s that exploration of Venus began. Powerful Earth-based radars pierced the clouds to provide us with our first topographical data on the planet’s size, surface relief and craters. Venus was the first planet to be visited by spacecraft, with the launch of the Mariner 2 probe in 1962. Between then and 1989, some 20 probes—including Mariner, Pioneer Venus, Venera and Vega—passed, orbited and even landed on the surface of Venus. Lava flows around Sif Mons volcano on the surface of Venus show it was once active. The Soviets made about 10 successful landings, gathering data and analyzing samples. In June 1985, a pair of balloons released by space probes Vega 1 and 2 drifted for 2 days through Venus’ atmosphere, taking numerous measurements. In 1989, the US probe Magellan took images of more than 90% of the planet’s surface, while its altimetry radar provided us with a series of relief maps. Cassini’s flyby of Venus in 1998 and 1999 aimed to observe lightning flashes in its atmosphere but detected nothing.(2)


Mars is the fourth planet from the Sun and is commonly referred to as the Red Planet. The rocks, soil and sky have a red or pink hue. The distinct red color was observed by stargazers throughout history. It was given its name by the Romans in honor of their god of war. Other civilizations have had similar names. The ancient Egyptians named the planet Her Descher meaning the red one. Before space exploration, Mars was considered the best candidate for harboring extraterrestrial life. Astronomers thought they saw straight lines crisscrossing its surface. This led to the popular belief that irrigation canals on the planet had been constructed by intelligent beings. In 1938, when Orson Welles broadcasted a radio drama based on the science fiction classic War of the Worlds by H.G. Wells, enough people believed in the tale of invading Martians to cause a near panic.(3)

Jovian Planets


Jupiter is the most massive planet in our solar system; with four large moons and many smaller moons it forms a kind of miniature solar system. In fact, Jupiter resembles a star in composition, and if it had been about 80 times more massive, it would have become a star rather than a planet. In 1610, using his primitive telescope, astronomer Galileo Galilei saw four small "stars" near Jupiter. He had discovered Jupiter's four largest moons, now called Io, Europa, Ganymede, and Callisto. These four moons are known today as the Galilean satellites. Newly discovered moons of Jupiter are reported by astronomers and acknowledged with a temporary designation by the International Astronomical Union; once their orbits are confirmed, they are included in Jupiter's large moon count. Not including the "temporary" moons, Jupiter has 50 total.(4)


Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first to gaze at Saturn through a telescope. To his surprise, he saw a pair of objects on either side of the planet. He sketched them as separate spheres, thinking that Saturn was triple-bodied. Continuing his observations over the next few years, Galileo drew the lateral bodies as arms or handles attached to Saturn. In 1659, Dutch astronomer Christiaan Huygens, using a more powerful telescope than Galileo's, proposed that Saturn was surrounded by a thin, flat ring. In 1675, Italian-born astronomer Jean-Dominique Cassini discovered a division between what are now called the A and B rings. It is now known that the gravitational influence of Saturn's moon Mimas is responsible for the Cassini Division, which is 4,800 km (3,000 miles) wide.(5)


Uranus, discovered in 1781 by astronomer William Herschel, was the first planet found with the aid of a telescope. As the seventh planet from the sun, Uranus takes 84 Earth years to complete one orbit. Voyager 2, the only spacecraft to visit Uranus, imaged a bland-looking sphere in 1986. When Voyager flew by, the south pole of Uranus pointed almost directly at the sun because Uranus was near its southern summer solstice, with the southern hemisphere bathed in continuous sunlight and the northern hemisphere radiating heat into the blackness of space.(6)


The ice giant Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. (Galileo had recorded it as a fixed star during observations with his small telescope in 1612 and 1613.) When Uranus didn't travel exactly as astronomers expected it to, a French mathematician, Urbain Joseph Le Verrier, proposed the position and mass of another as yet unknown planet that could cause the observed changes to Uranus' orbit. After being ignored by French astronomers, Le Verrier sent his predictions to Johann Gottfried Galle at the Berlin Observatory. Galle found Neptune on his first night of searching in 1846. Seventeen days later, its largest moon, Triton, was also discovered.(7)

Methods of Space Exploration

Manned Missions to Space

The first manned mission went up in 1961 on April 12, it was sent up by the U.S.S.R who sent Yuri Gagarin to be the first man in space. About a month later an American named Alan J. Shepard made a fifteen minute flight into space that was watched by over forty-five million viewers. Shortly after this President John F. Kennedy announced a plan to put a man on the moon and this was essentially the beginning of NASA's Gemini and Apollo missions.
Between 1961 and 1963, six manned spacecraft flew as part of the Mercury project. Mercury pilots rode in wingless capsules, which detached from their launch rocket and fell back to Earth. The small craft were designed to withstand the tremendous temperatures of reentering the planet's atmosphere and also survive a dramatic splashdown in the ocean. Yet Mercury had more to accomplish. In February 1962 John Glenn became the first American to orbit the Earth on the Friendship 7 mission. NASA's Gemini program was designed to refine spacecraft so that they could perform rendezvous, docking, and other advanced maneuvers that would be necessary to land an astronaut on the moon and return to Earth. As the missions of this era grew longer, astronauts became more adept at living within their spacecraft and even venturing outside it. Soviet cosmonaut Aleksei Leonov became the first person to exit an orbiting spacecraft in March 1965 (11). Over the last fifty years there have been numerous manned shuttle missions into space. After the fall of the Soviet Union there has been great cooperation between countries' space programs and it seems that space has been a very strong unifying factor. One example of this is the International Space Station. Although recently NASA has ended its shuttle missions into space for the time being other countries, especially China whose space
program is expanding, are

still sending manned missions into space and orbit around the Earth and private companies in a few years will begin sending transports into space around 2015 (12). There is also a debate that is occurring which asks whether unmanned missions into space are as or even better than manned missions. Despite this there is no end in sight for manned missions into space.
Space Probes

A space probe is an un-piloted and unmanned spacecraft that is used to make observations and
send information back to Earth regarding these observed objects. These probes carry sophisticated equipment, such as infrared sensors (to measure the temperature of an object), radars (to see planetary surfaces through clouds), ultraviolet sensors (to analyze atmospheric conditions), magnetometers (to measure magnetic fields), soil analyzers, spectrometers, and sensors to study wind velocities, or chemical compositions. They are various cameras, navigation, and communications systems. There also has to be a power supply and protection against heat, cold, and cosmic radiation. Exactly what equipment is on any deep space probe, of course, depends upon its mission (8). Space probes are launched with enough force to escape Earth's gravitational forces and explore throughout the solar system. Radio-transmitted commands and on-board computers provide the means for midcourse corrections in the space probe's trajectory; some advanced craft have executed complex maneuvers on command from earth when many millions of miles away in space. The data provided by a single space probe may require months or even years of analysis. Much has been learned from probes about the origins, composition, and structure of various bodies in the solar system. An example of how the use the information that is gathered is scientists trying to understand the earth's weather by constructing theoretical models of global weather systems make use of the knowledge that is gained concerning the atmospheres and meteorology of the planets. Because conditions on other planets are simpler than on earth, scientists can check each of their hypotheses separately in isolation from complicating factors (9). Various space agencies have launched probes to other planets, moons, asteroids and comets in the solar system. They include the United States, Europe, Russia, Japan, China and former Soviet Union. Probes have been sent on missions all over the Solar System (10).


Reflecting Telescope (
Reflecting Telescope (

Refracting Telescope (
Refracting Telescope (

Telescopes allow for objects that are at a distance to be seen easier and with more clarity than by the naked eye. They allow the users to observe the objects in space such as planets, comets and other non-planetary bodies. They do this by being able to collect light and focus that light to a point where an image is shown, the larger the lens the more light that can be collected and this increases the clarity and resolution. There are a variety of types of telescopes that are designed to see different frequencies and types of light, whether radio, visible, x-rays and others. For example, to see visible light a person would use a reflecting or a refracting telescope and in order to observe radio waves they would use a radio telescope.

Satellites man-made object launched into a temporary or permanent orbit around the Earth. Spacecraft of this type may be either manned or unmanned, the latter being the most common, and there are various types that each serve a different purpose. This idea of an artificial satellite being able to orbit the Earth was first proposed by Sir Isaac Newton(14). Satellites are extremely important today. All artificial satellites have certain features in common. They all include radar systems, sensors like optical devices in observation satellites and receivers and transmitters in communication satellites. Solar cells are used to generate power for the satellites and in some cases ,nuclear power is used. All satellites need altitude-control equipment to keep the satellite in the desired orbit.

The orbit of the satellite is achieved when it is given a horizontal velocity of 17,500 mph at sea level causing the Earth's surface to curve away and as fast as it curves away gravity pulls the object downward and at this point the satellite achieved orbit. As the altitude of the satellite increases, its velocity decreases and its period increases. The period of satellite is the time the satellite takes to make on revolution around the Earth. Satellites in later orbit are called synchronous satellites. If the satellite orbits in a equatorial plane, it is called geostationary which means it is always over the same place on earth at all times. This form of orbit is used in weather for reports of a certain area at all times (13). Satellites are very important Astronomical tools because they allow scientists to view the earth from space which provides them a different point of view and allows them to gather information that they would not have been able to gather otherwise. The other way that they can be used is to use them to explore the Solar System, these are known as Astronomy Satellites.


1. "Exploration of Mercury." Universe Today — Space and astronomy news. N.p., n.d. Web. 30 Nov. 2011. <>.
2. "Solar System Exploration: Planets: Venus: Overview." Solar System Exploration. N.p., n.d. Web. 30 Nov. 2011. <>.
3. "MARS - Exploration." Smithsonian National Air and Space Museum. N.p., n.d. Web. 30 Nov. 2011. <>.
4. "Solar System Exploration: Planets: Jupiter: Overview." Solar System Exploration. N.p., n.d. Web. 30 Nov. 2011. <>.
5. "Solar System Exploration: Planets: Saturn: Read More." Solar System Exploration. N.p., n.d. Web. 30 Nov. 2011. <>.
6. "Solar System Exploration: Planets: Uranus: Read More." Solar System Exploration. N.p., n.d. Web. 30 Nov. 2011. <>.
7. "Solar System Exploration: Planets: Neptune: Overview." Solar System Exploration. N.p., n.d. Web. 30 Nov. 2011. <>.
8. "Deep Space Probes." World Space Flight. (accessed December 2, 2011).
9. "Space Probe." Infoplease: All the knowledge you need. (accessed December 2, 2011).
10. "Space Probes: List of Popular Space Probes." Space Projects and Info. (accessed December 2, 2011).
11. "Early Manned Spaceflight." National Geographic. (accessed December 2, 2011).
12. "Can US Still Lead in Space Despite Shuttle's End?" Slashdot.
(accessed December 2, 2011)
13. James H. "Functions of a Satellite." (accessed December 2, 2011).
14. "Earth Satellite." Britannica: Academic Edition. (accessed December 2, 2011).
15. 1953, 1. April. "Sputnik Biographies--Sergei P. Korolev (1906-1966)." History Home. Web. 03 Dec. 2011. <>.
16."Lieutenant-General Kerim Kerimov - Telegraph." - Telegraph Online, Daily Telegraph and Sunday Telegraph - Telegraph. Web. 03 Dec. 2011. <>.
17."Glushko." Encyclopedia Astronautica. Web. 03 Dec. 2011. <>
18.Space), Rocket To. "Biography of Wernher Von Braun." MSFC History Office. Web. 03 Dec. 2011. <>.
19."Gilruth." Encyclopedia Astronautica. Web. 03 Dec. 2011. <>
20. "Kraft." Encyclopedia Astronautica. Web. 03 Dec. 2011. <>
21. "Dr. Maxime A. Faget." History Home. Web. 03 Dec. 2011. <>.