Space has always been one of the greatest mysteries to humankind. From the beginning of time, people have looked into the sky, and speculated about the vast array of possibilities that could exist. Before humans were able to explore space, many astronomers observed the stars, moon, and sun through telescopes and the naked eye. Astronomy is the oldest of the natural sciences. The first astronomers were able to differentiate between planets and stars, since star remained fixed over time while planets moved. Calendars were set by observations of the sun and the moon, being especially important to agrarian societies. Our current calendar is based on the Roman calendar (a lunar calendar) which was broken up by phases of the moon and divided into twelve nearly equal months, with varying amounts of days. Around 1543, Nicolaus Copernicus proposed a heliocentric system based on his observations and deductions. This revalation set the stage for further mathematical models and insights into space.
Kepler was the first to derive mathematical predictions related to celestial motion. Throughout his life, he discovered the three laws of planetary motion. These laws are as follows: The orbit of a planet is an ellipse with the Sun at one of the two foci. A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time. The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit. Using these laws, he expanded the existing heliocentric model.
Galileo Galilei was one of the first to observe the sky via telescope, after constructing a refractor telescope. He discovered moons of Jupiter, craters on our moon, sunspots, and bodies orbiting other bodies, nullifying the Ptolemaic model. Isaac Newton aided the development of our understanding of space through his law of universal gravitation and laws of motion. Many others came after and added more observations to improve our understanding of space. In the 19th century, forms of light invisible to the naked eye were discovered, having a major impact on astronomy. Other stars similar to our sun were discovered with varying masses and temperatures, and well as the existence of our galaxy by the 20th century. Soon after, the expansion of the universe was uncovered by the recession of most galaxies from our own.
The development of ballistic missile during World War II paved the way for launch vehicles that would spark the space race between the Soviet Union and the United States. Rockets were developed that were powerful enough to overcome gravity and real orbital velocities. During WWII, long distance rockets were developed because of their potential to be used a weapons, the first of these being V2 missiles. In 1957, the Soviets launched the first artificial satellite into space, followed by the first human orbit four years later. In 1958, the first US satellite flew into space. By 1961, Alan Shepherd became the first American in space, followed by John Glenn being the first American to orbit in 1962. Soon after in 1969, the US put the first man on the moon after years of unmanned space missions and practice manned missions in the Gemini and Apollo series.
The space race was followed by an era of space cooperation with the International Space Station. Around the same time, the first space station (Skylab) was conducting research with an internationally crewed space mission. Next, satellite communications were expanded to carry television programs. Satellites were able to discover an ozone hole, pinpoint forest fires, and find new stars and galaxies. In 1981, the space shuttle Columbia brought forward a period of reliance of reusable shuttles for space missions. The advantages of space systems developed since the 1980’s have aided in homeland defense, weather, communications, navigation, imaging, and remote sensing for disasters.
NASA continues to develop orbiters, landers, rovers, and other vehicles intended to increase of knowledge about the universe. In addition to NASA, private industries have taken an interest in space exploration. Currently, NASA is exploring Mars heavily, with the prospect of sending humans in the 2030’s. Humans will continue to develop technology to learn more about the universe, its origins, and future. Although there are still many uncertainties, significant progress has been made and will continue to be made for the betterment of mankind.
Economic and Societal Impacts:
Around the time of the Gemini and Apollo missions, the economic cost compared to the potential gain of space exploration was often questioned more than ever. Would going to the moon, after causing many deaths and millions of dollars, be worth the trouble? Would sending people into space be worth the money and time to get them there? At the time, these were hard questions to answer. However, man is now benefitting from space exploration more than ever. Despite the high costs of space activities, there is a tremendous return to the community in terms of scientific and technical knowledge, jobs, and space spin-offs. Man now has images of distant stars and galaxies from the Hubble telescope, experiments about biology and physics in a microgravity environment in the ISS, and countless other developments to benefit everyone.
Human space exploration helps address fundamental questions about our place in the universe and the history of it. Through the development of space equipment and vehicles, technology expanded, new industries were created, and international relations were aided. The creation of these jobs helped offset the costs the missions. In addition, the technology created can be continually used and expanded upon for current and future uses both in space in internally. We have the best weather tracking information available due to some of these developments in space, which has saved countless lives. For example, hurricane tracking allows for proper evacuations, preventing loss and life. Through these technologies, national defense is aided. There is great surveillance and monitoring available now that never would have existed before. Communications are increased, allowing internet and satellite television to exist, creating countless jobs and improving the overall human experience. Navigation has improved greatly, enabling the average person to have GPS anywhere they have cell phone service. This navigation can be expanded to the military applications. The ISS also sets an example of collaboration and peace between nations, working towards a common goal of human discovery and advancements.
Space programs also have the ability to protect earth from asteroids. Many large asteroids that can destroy the human race can now be tracked and monitored. Space exploration also allows us to look at gaining raw materials from other planets or asteroids. The Earth has a fixed amount of resources, so many private companies are looking into extracting resources from other bodies and bringing them back to Earth. This could have great economic and industrial implications. The exploration can also help humans determine if there exists life outside our planet. Therefore, it is clear that space exploration has had tremendous impacts on the economy and society.
Current and Future Challenges
Although there have always been severe challenges, space flight has prevailed. Technology has been developed through countless people of different countries, working towards the same goal. There are several factors that have caused challenges in the past and continue to cause challenges today and in the future, with scientists are working hard to remedy. One problem is the cost of takeoff. It requires about 25,000 mph to launch a vehicle from Earth, which can be costly. The Curiosity Rover cost nearly $200 million just to launch, which is a large portion of the mission’s overall budget. If this were expanded to send men to Mars, there would be significantly higher costs associated with weight needed to sustain life. This problem of budget can be remedied slightly by reusing shuttle, as done in the past, but takeoff will always be a serious cost consideration. Another problem we currently face is propulsion. The space vehicles have incredible mass, which makes them more difficult to propel. At current rates, going anywhere outside the solar system would take an entire life span. In addition, adding more fuel would add more mass, requiring more fuel to propel, and so on. The problem compounds itself. With current fuel masses, propulsion is a major concern. This could be remedied by using alternate fuel with lower mass in the future. The next problem we face is the accumulation of space debris. The amount of space junk already existing poses serious risks to future missions and current satellites. There are many systems in place (like the ISS) that could be compromised to failure because of collisions with space debris, causing major economic and social consequences. They pose risks to future vehicles that have to pass through all the debris around earth to reach beyond. This is a severe problem for current and future missions. Another problem is navigation. It is hard to go where no one has gone before, with little information about what is there. Transmission from earth to deep space take hours, which is too long for space exploration missions. Another problem is the radiation effects on humans. Going outside the Earth’s atmosphere can cause cancer, cataracts, and other health problems. This could be a problem in the future when a higher volume of people go on space missions, especially if there is still no cure to cancer. Similarly, the body experiences loss of bone mass and muscle wasting during the microgravity environment. This would be remedied if artificial gravity could be developed. Once you arrive near a planet, landing will be a significant problem, and if successful, sustaining life away from Earth. Knowing the best location to land on the new planet and landing successfully is still a significant challenge. And, if landing is successful, there will be a lack of resources. From beginning to end, there are significant challenges faced with exploring space and other planets. Some are easier to help than others.