| Space Exploration |
Article Index for Space |
Articles about Space Exploration |
Website Links For Space |
Information AboutSpace Exploration |
| CATEGORIES ABOUT SPACE EXPLORATION | |
| space explorationspace exploration | |
| space | |
| exploration | |
| futurology | |
|
It was given a boost by the launch of the USSR's '' Sputnik 1 '' on October 5 , 1957 , the first man-made object to Orbit the Earth , after which USA declared itself to be in Space Race with the Soviet Union . Two other famous achievements in the early days were putting the first man in space, Yuri Gagarin aboard '' Vostok 1 '' on April 12 , 1961 (again by the USSR), and the first people on the Moon , Neil Armstrong and Buzz Aldrin aboard '' Apollo 11 '' with Michael Collins on July 20 , 1969 (by the USA). After 30 years of competition focus has started shifting from competition to cooperation and from one-off flights to renewable hardware, such as the Space Shuttle , and to the International Space Station , to Space Tourism and most recently to the building of extra-terrestrial launch platforms, such as from a Space Station and possibly from the Moon. REACHING SPACE From a spaceflight perspective, the definition of space usually used is that space begins 100 km (62 miles) above Earth's surface. The United States sometimes uses a 50 mile definition. (See Boundary To Space .) One can distinguish the Sub-orbital Spaceflight and the Orbital Spaceflight (cf. Difference Between Sub-orbital And Orbital Spaceflights ). As for sub-orbital flights, on October 3 , 1942 German A4 rocket (a prototype for the next V2 Rocket used to bomb London), became the first successful launch of an object into space. The first Organisms launched into space were fruit flies and corn seeds aboard a U.S.-launched german V2 rocket in July, 1946 . Another milestone was achieved on May 17 , 2004 when Civilian Space EXploration Team launched the GoFast Rocket on a suborbital flight, the first amateur space flight. On June 21 , 2004 , SpaceShipOne became the first privately-funded manned Spacecraft . Achieving orbit is not essential for manned or unmanned interplanetary voyages. Early Russian space vehicles successfully achieved very high altitudes without even going into orbit. The early Apollo mission planning also considered using a Direct Ascent to the moon, but abandoned it later. Many unmanned space probes to the outer planets use direct ascent -- they do not orbit the earth before departing. However, plans for future manned exploration often include final vehicle assembly in earth orbit. Because suborbital flights are by definition short (less than 1.7 hours) then any longer mission requires orbital flight (with elliptical or circular trajectory), or superorbital flight (over parabolic or hyperbolic trajectory). Also, orbital flight requires much higher velocities than suborbital making it technologically challenging to achieve. That is why orbital flights are so tremendously essential for space exploration. FIRST ORBITAL FLIGHTS The first successful orbital launch was of the Soviet unmanned '' Sputnik I '' mission on October 4 , 1957 . The satellite weighed about 83 kg (184 pounds). It had two radio transmitters (20 and 40 MHz) "beeps" of which can be heard by any radio around the globe and is believed to have orbited Earth at a height of about 250 km (150 miles). Analysis of the radio signals was used to gather information about the electron density of the ionosphere. Temperature and pressure was encoded in the duration of radio beeps, indicating the satellite was not punctured by a meteorite. Sputnik 1 was launched by an R-7 rocket. It incinerated upon re-entry on January 3 , 1958 . This success led to an escalation of the American Space Program which had an unsuccessful orbital launch 2 months later and its first successful orbital launch 4 months after ''Sputnik''. In the meantime, Soviet dog Laika became the first animal in orbit on November 3 , 1957 . FIRST HUMAN IN SPACE First flight in space made by a human being was '' Vostok 1 '', carrying 27 year old Cosmonaut Yuri Gagarin on historic date of April 12 , 1961 , making one orbit around the globe, lasting about 1 h 48 min. Currently this milestone date is celebrated as Cosmonautics Day (Space Day). Gagarin's flight resonated around the globe not only showing superiority of Soviet Space Program but opening entirely new era in space exploration - manned space flights. The U.S. would launch its first man into space within a month of Gagarin's flight; however, it took the U.S. nearly a full year to place a man into orbit. THE KEY PEOPLE IN EARLY SPACE EXPLORATION The dream of stepping into the outer reaches of the Earth's atmosphere was driven by rocket technology. The German V2 was the first rocket to travel into space, overcoming the problems of thrust and material failure. During the final days of World War II this technology was obtained by both the Americans and Soviets as were its designers. The initial driving force was a weapons race for inter-continental ballistic missiles ICBM as long-range carriers for fast Nuclear Weapon delivery, but in 1961 when USSR launched first man into space, USA declared itself to be in the " Space Race " with Russia.
Other key people included:
CRITICISMS It is more expensive to perform certain tasks in space with humans rather than by Robot s or machines. Humans need large Spacecraft that contain provisions such as a Hermetic and temperature controlled cabin, production of breathable air, food and drink storage, waste disposal, voice- and other communication systems, and safety features such as crew escape systems, medical facilities, etc. There is also the question of the security of the spacecraft as whole; losing a robot is nowhere near as dramatic as human loss, so overall safety of non-human missions isn't as much of an issue. All of these extra expenses have to be weighed against the value of having humans aboard. Some critics argue that those few instances where human intervention is essential do not justify the enormous extra costs of having humans aboard. Other critics, such as the late , Laser s, etc. Some critics contend that in light of the huge distances in space, human space travel will never be able to do more than achieve an earth orbit or at best visit our closest neighbours in the Russia. From this point of view, the ISS was a justifiable cash outlay. Some people also have moral objections to the huge costs of space travel, and point out that even a fraction of the space travel budget would make a huge difference in fighting disease and hunger in the world. However, space exploration itself receives a very small percentage of total government spending (nearly always under 0.5%). Overall, the public remains largely supportive of both manned and unmanned space exploration. According to an Associated Press Poll conducted in July 2003 , 71% of US citizens agreed with the statement that the space program is "a good investment," compared to 21% who did not ( Pollingreport.com ). Some supporters of Space Explorations, such as Robert Zubrin , have criticized ideas about in orbit assemblies, and argues for a direct approach for human settlement of Mars called Mars Direct . TIMELINE OF SPACE EXPLORATION See Also: List of human spaceflights chronologically 1942-1975 1Project Vanguard was transferred from the NRL to NASA immediately before launch. post-1975 REUSABLE SPACECRAFT The first reusable spacecraft, the Space Shuttle , was launched by the USA on the 20th anniversary of Yuri Gagarin's flight, on April 12 , 1981 . During the Shuttle era, six orbiters were built, all of which have flown in the atmosphere and five of which have flown in space. The '' Enterprise '' was used only for approach and landing tests, launching from the back of a Boeing 747 and gliding to deadstick landings at Edwards AFB, California . The first Space Shuttle to fly into space was the '' Columbia '', followed by the '' Challenger '', '' Discovery '', '' Atlantis '', and '' Endeavour ''. The ''Endeavour'' was built to replace the ''Challenger'' when it was Lost in January 1986. The ''Columbia'' Broke Up during reentry in February 2003. The first (and so far only) automatic reusable spacecraft was the Buran (Snowstorm), launched by the USSR on November 15 , 1988 , although it made only one flight. This Spaceplane was designed for a crew and strongly resembled the U.S. Space Shuttle, although its drop-off boosters used liquid propellants and its main engines were located at the base of what would be the external tank in the American Shuttle. Lack of funding, complicated by the dissolution of the USSR, prevented any further flights of Buran. Per the Vision For Space Exploration , the Space Shuttle is due to be retired in 2010 . The orbiter Atlantis (Space Shuttle) may be retired as early as 2008 . The Shuttle's human transport role is to be replaced by the partially reusable Crew Exploration Vehicle (CEV) no later than 2014 . The Shuttle's heavy cargo transport role is to be replaced by expendable rockets such as the Evolved Expendable Launch Vehicle (EELV) or a Shuttle Derived Launch Vehicle . Scaled Composites SpaceShipOne was a reusable suborbital Spaceplane that carried pilots Mike Melvill and Brian Binnie on consecutive flights in 2004 to win the Ansari X Prize . The Spaceship Company will build its successor SpaceShipTwo . A fleet of SpaceShipTwos operated by Virgin Galactic should begin reusable Private Spaceflight carrying paying passengers in 2008 . SPACE AGENCIES While only the United States, Soviet Union/Russian and Chinese space programs have launched humans into orbit, a number of other countries have space agencies which design and launch satellites, conduct space research and coordinate national astronaut programs. In Europe, the European Space Agency serves several nations. Several nations have launched their own satellites including India, Japan and France. See also List Of Space Agencies SEE ALSO Unmanned missions Main article: Unmanned Space Mission
Animals in space Humans in space Main articles: Astronaut s and Human Spaceflight
Recent and future developments
Other
EXTERNAL LINKS
|
|
|