Human space exploration has its roots in war. The Saturn rocket used to propel Neil Armstrong and Buzz Aldrin to the moon was based on the V2 rockets developed by Nazi Germany to pummel London during WWII. Furthermore, the space race was not a born out of a need to explore and expand human knowledge, but was more a technological showcase between the United States and Soviet Union during the cold war. However, we now live in more peaceful times. The cold war is over and it has been over forty years since a human being last walked on the Moon, and few scientists seriously believe we will be returning any time soon.
Manned space exploration
Manned space exploration is expensive, very expensive. NASA has a budget of over $17 billion a year, and the American Congress has agreed to fund the new Space Launch System (SLS), which is the most powerful rocket ever produced. While this is capable for the first time since the Apollo missions of sending humans beyond low-Earth orbit (where the International Space Station sits and where the Space Shuttle did all of its missions), this doesn't mean we will be sending humans back to the Moon or beyond anytime soon.
For the last forty years, manned space travel has involved relatively short hops into low Earth orbit, with the Space Shuttle, Russian Soyuz and European Ariane rockets used mainly for putting communication satellites into orbit. Of course, this has improved our technology dramatically. Without space travel, life would be very different on Earth, especially when it comes to communications and telecoms. Mobile phones, satellite TV and GPS are all technologies that are owed to the space race, and few of us could imagine life without a smart phone, sat nav and the other communication devices we have come to rely on. Furthermore, these telecom satellites have made long distance calls and global communication much cheaper and simpler, and have created a much smaller world. Because of these communication satellites, the internet has flourished, providing us with such things as Google Earth, something unconceivable forty years ago. However, as useful as telecom satellites and the big changes they have made to communications are, there has been very little space exploration by humans. In fact, since the last man walked on the moon in 1972, no human has left low Earth orbit, and it doesn't look like the future of space travel is going to involve humans doing much exploring at all.
Robot exploration
Setting foot on the Moon, Mars or other far off body, landing on the surface, and then returning home safely, costs far too much to be justifiable. However, that doesn't mean that space exploration is over. While sending humans to far off bodies such as the Moon or Mars is very expensive, sending robots is much, much cheaper. After all, robots don't need oxygen, food water and a comfortable temperature in order to survive. Furthermore, and perhaps more importantly, robots don't have to be brought home, and a one-way ticket to Mars is much cheaper and technologically easier to do than a return trip.
In addition, while human exploration is inspiring and romantic, it isn't that useful when it comes to scientific understanding. Advances in robotic technology means there are few things an astronaut can do in space that a robot can't. The Mars Curiosity Rover, for instance, is a complete laboratory that can sample, analyse, and study the rocks and soil of the Martian surface. Furthermore, with its array of cameras, you don't need human eyes on the surface to see the planet.
The stars and beyond
Even unmanned space exploration is still limited. While we can pretty much send a robot anywhere in the solar system, reaching to the stars is beyond our capabilities. The Voyager probes, for example, have been in space over 35 years, and yet are only just reaching the outer limits of our solar system. Travelling at 57,000 km/h, Voyager 1 is approximately 17 light hours from Earth, or put another way, in 35 years, Voyager 1 has travelled 0.2 light years. When you consider the nearest star, Alpha Proxima, is 4.2 light years way, it will be another 70,000 years before the satellite gets anywhere near.
However, travel to the stars is not beyond the realms of possible future technologies and is limited purely by propulsion. The problem is, the only method we have to propel a spacecraft at the moment is rocket power, and the big problem with that is how much fuel has to be carried for just a relatively short periods of propulsion (95% of Saturn 5 contained fuel, and 60% of this was burned in the first couple of minutes). However, if a propulsion system that is more economical is developed then travel to the stars within reasonable timescales, such as a couple of decades, is far more realistic, even considering the immense distance.
For example, the average family car has an acceleration force of 1 g. However, because of gravity, air pressure and friction, speed is limited on Earth. In space, none of these forces apply, so if an average family car could drive in space, it would keep on accelerating to immense speeds. In fact, if it had enough fuel, it would take less than three months for it to reach 50% of the speed of light, which would mean that Alpha Proxima was within reach within a decade of space flight (about the same amount of time as it currently tales a probe to reach Jupiter). Of course, no such propulsion system yet exists, but scientists believe they may not be that far away, which means in a few generations time, manmade robots could begin exploring planets in other solar systems, of which there are many, and return their signals within the lifetime of those that sent it.
Commercial space travel
Despite all this, humans will still have a place in the future of space travel, although it is going to be a much more local activity, and it probably won't be through large organisations such as NASA. Commercial space travel is now a reality. Projects such as Virgin Galactic are already preparing to take tourists into space. While these trips are sub orbital, the demand from rich celebrities and wealthy business people mean it won't be long before commercial enterprise starts to expand. Already, the cash strapped Russian Space Agency is preparing to take musical singer Sarah Brightman to the International Space Station, and more wealthy space tourists are bound to want to follow.
For the rest of us, space travel may seem like a dream. However, the same was said about the first jet airliners, but jumping on an airplane is something most people have done. While a visit to Mars, the Moon or planets beyond our solar system may never be a reality for us humans, in the future, a holiday in space may just become as common as flying abroad is today.
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Source: http://clubofamsterdam.blogspot.com/2013/01/joy-rides-and-robots-are-future-of.html
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