Space and its Exploration: How Space is Explored

Man, the Traditional Explorer

The exploration of space has always been filled with danger and peril but man and his tools have learned how to overcome and explore "the last, the
greatest, and the most dangerous frontier of all" (-National Geographic).

The story of the American manned space exploration starts with the Mercury rocket program. The rockets used were nothing more than ready-to-fly,
modified military missiles that had capsules instead of warheads. This method of early non-reusable rockets was costly and impractical, but it placed us
into the space race by putting astronaut Alan B. Shepard into space. The second leg of the manned space program was the Gemini rocket program. Its
purpose was to tackle the difficulties that a moon mission would start to supply such as docking in space and maneuvering a craft in zero gravity. The
other thing that they had to improve was the life support systems. All of the new developments on the capsule added weight and the old launch rockets
(mercury missiles) wouldn't do so they had to use a new intercontinental ballistic missile (ICBM). With the new launch vehicle, Titan, the Gemini program
was a success and making it possible to go to the moon.

The third stage of manned flight was the Apollo program. This program was the first and only program of the 20th century to bring men to the moon.
This time the rocket wasn't just a modified missile It was the "big daddy" of all missiles, it was the Saturn V rocket, larger than any functional rocket on the
face of the planet--standing 363 feet tall. When the time came, with Apollo 11, to take Neil Armstrong, Edwin "Buzz" Aldrin and Michael Collins to the
moon the world was ready. On July 16, 1969 the count down ended and the F-1 engines of the Saturn V rocket took to life guzzling 15 Tons of fuel each
second the first moon mission was under way. Four days later, a man was walking on the moon. Several other men went on the three moon missions
before the program was abandoned.

The fourth of the manned space programs started in April 1981 with the Space Shuttle. The Space shuttle is the answer to congress's demands for a less expensive alternative to the Saturn V rocket, to explore space with. What they got was just that the shuttle has three of the most efficient engines of there kind on its tail end and two of the largest reusable solid rocket boosters in the world. The shuttle carries 49 engines, 23 antennas, 5 computers up to 5 satellites and 2-7 people. There was only one major disaster for the space shuttle and that was the most famous of all the shuttle flights and that the Challenger mission. Seven astronauts were killed as a result of two faulty O-rings which had allowed the gasses in the main tank to catch fire, leading to a tragic explosion that shocked the world; an episode which set the manned space program back several years.
    Today, next phase of the manned space program is being entered with the development of VentureStar. This replacement for the Space Shuttle will reduce the price to one-tenth of today's current levels, by the use of a single-stage-to-orbit (SSTO) launch vehicle. The VentureStar requires no additional booster rockets an external fuel tanks, and launches simply by accelerating off a runway. Some of its advanced features include: linear aerospike engines for all altitude efficiency (see How Rockets Work), a lifting body design to aid in launching and re-entry, advanced composite materials for lighter structure and propellant tanks, an advanced thermal protection system. The X-33 will prelude the VentureStar as prototype employing the same (but downscaled) design and features.
    Man experienced his greatest glory of exploration in the twentieth century with the Apollo missions. What will be his next great endeavor into the twenty-first century? Missions to Mars are proposed but what next? The cold war competition with the former Soviet Union fueled nationalism and thwarted resources (money) into space program. What will fuel the next great stride, the mission to Mars suggests the question: "are we alone" (see Issues on Space Exploration). There is little doubt that man will begin to explore the interstellar universe in the distant future, but the rate at which we approach this is dependant on today when the fuels to manifest the "dream" to explore are smothered by an increasing conservative society.
    During the 1960's there was a race to beat the Russians to the moon. In the United States Americans were fueled in this space race by nationalism and eight million pound thrust rockets as we ushered into a new ear, the Space Age. America, so engulfed in cold war tensions and competition with the former Soviet Union, allowed for such great (and expensive) steps to taken early on.
    Man's conquering of the moon was a major triumph of technology and perseverance. After all, it required the largest, most expensive, and most powerful rocket ever to have left the planet earth. The Saturn V rocket, resulting from the impedus of millions of dollars and thousands of scientists, represents not only a means to propel three men to the moon, but it is the product of an age when man donned the crown of exploration.
    The Saturn V rocket begins its construction in the Vehicle Assembly Building (VAB), at the Kennedy Space Center. This building is 526 feet ( 160 meters ) tall and was designed to hold and assemble four Saturn V rockets at a time. This building is where all the components came together to form the finished rocket. All of the sections are stacked upon the Crawler, which is the worlds largest land vehicle. Once fully assembled, the doors are opened and the Saturn V heads towards its destiny. At a slow rate of 5mph, the Saturn V rolls towards its launch pad. There, after final checks and fueling, it awaits the count down. For when the clock strikes zero, 7.5 million pounds ( 3.5 million kg) of thrust is mustered to propel the rocket from its 365 foot tall launching structure. Twelve minutes later, after the first three stages have done their work, having lifted the final stages of this great giant into a three hour temporary orbit around earth. Then, after proper alignment, the 3rd engine roars to life accelerating the final two stages from 17,500 mph to 24,400 mph. Once this is completed the third stage is shut down and the capsule filled with the three astronauts inside continues its long journey towards the moon. Two days later, due to the force of gravity, the capsule slows to 2,300 mph deaccelerating at a rate of 460 miles per hour squared. Next, the ship enters the moons field of gravity and starts to accelerate again. The next day in the trip, the will pass behind the moon and start their burn to initiate moon orbit. This is a very scary and dangerous time because they are out of communication with earth (due to their location behind the moon). After successfully gaining moon orbit, they would launch the lunar lander. The lander is a small transport vehicle that ferried the astronauts and their equipment to the lunar surface and back to the moon orbiting return capsule (where one astronaut remained). The lander, after serving its purpose, was then discarded and left as space debris. The lander would spend several days on the surface of the moon while the crew collected samples and left experiments such as the reflectors that tell us accurately how far away the moon is and how fast it is moving away from the earth. When the lander then returns to the ship the crew will start there voyage home. After a long time in space the crew is quite tired and stressed due to the extreme isolation. This next step is the most dangerous due to the condition of the astronauts and the complexity of the maneuver. The ship will enter earth's the atmosphere at almost 25,000 mph (mach 35). The ship has its center of gravity offset so that they can adjust their angle of attack (entry). The ship skips in and out of the atmosphere twice before releasing its parachutes at 10,000 ft and splashing down into the ocean at a gentle 35 mph.
    Some of the most famous astronauts in this program are Neil Armstrong, Buzz Aldrin and Michael Collins just to name some of the 10 or so men who have walked upon the surface of the moon. [Return to How Space is Explored] [Return to Main]