What is the near future of manned space travel?
NASA has aimed to replace its space shuttle with a new model, called Orion that closely resembles a larger version of the Apollo module which took men to the moon in 1972. Orion is scheduled to make its first manned flight in 2013 while NASA’s current shuttle is aiming to be taken out in four years time, leaving a three year gap in which the US will have no craft to service the International Space Station. Orion’s objective is to take people to Mars for the first ever time.
Unlike the shuttle which is able to land on a runway after completing its mission and then being reused dozens of times Orion will be a single use multi-stage rocket. The programme has an estimated cost of a staggering cost of 230 billion dollars and is hoping to rekindle public enthusiasm for space travel after the Columbia disaster of 2003.
Is space exploration a waste of money?
NASA scientists have lost contact with the latest unmanned spacecraft sent to Mars, the $165m Mars Polar Lander. In September, the $125m Mars Climate Orbiter mission also failed, after an embarrassing mix-up over metric and imperial measurements. The history of failed missions to Mars stretches back 40 years, so are they a waste of taxpayers' money?
However we should also bear in mind that the Voyager 1 probe sent out on the 5th September 1977 is still in regular contact with NASA and has provided them with immense data over its years active. Voyager 1 now holds the record to be the furthest artificial object from Earth at 9.3 billion miles away. It proved successful in its planned mission of observing Jupiter and Saturn and the went on to provide us with further data and will soon be able to tell us more about interstellar space, a region where the sun has no influence on other bodies. Voyager 1 is predicted to still be largely functional until 2020. So when we consider costs as well as many failed missions there are also some which have greatly outperformed their expectations such as Voyager 1.
Or should we in fact spend more on exploring space, to ensure greater success? Is exploring our universe an inspiring endeavour well worth the money? Do we have a duty to follow our curiosity and find out as much as possible about our place in the cosmos? There are many people on both sides of this argument some thinking money would be better spent on Earthly issues while other think more money should be spent on space travel to ensure its success. However, the general attitude seems to be, “The cheaper you do it the more likely it is to go wrong. Let’s try doing it slower and better instead.” () This could be a fair point but we don’t know who the person is who wrote this as a comment on the BBC website. They may have no background knowledge on space exploration at all and may have overseen and difficulties which at this point in time we cannot solve however much money and time we spend on it.
How can we benefit from manned space travel?
It is a common fact that the Human population is increasing at an alarming rate. What will we do when even intensive farming cannot cater our needs and there are simply too many people on the planet. Or what if tomorrow we detect a comet heading for a head on collision with us in less than five years. Manned space travel can help us discover other planet’s which could support human life in the event that we need to find it elsewhere than on Earth. Space travel can tech us new things that are discovered during space production or actually in space. A team of doctors have carried out the world's first "weightless" surgical operation in an aircraft diving steeply thousands of feet above France. The simple operation - the removal of a small tumour from the arm of a volunteer - was intended to prove that surgery could be used in space stations or long-distance space flights. If nothing else manned space travel could be the key to securing future human generation from many threats on Earth including Global warming. It is also possible that if suitable vehicles are made we would not have to arrive in Sydney after an uncomfortable 21 hour flight. With the right machine we could just jet out into sub-orbital space where atmospheric drag is much less and arrive in Australia just a few hours after we set off.
Manned space travel here to stay?
For the near future manned space travel has been confirmed to other planets such as Mars and also our moon. Now that space travel is getting cheaper and easier with rapidly advancing technologies, a new sector has emerged in manned space travel, tourism. Richard Branson’s Virgin Galactic is already set to launch tourists into sub-orbital space. Customers would go to training camp before the flight into space ant then experience a short amount of time in space experiencing zero gravity and a view of the Earth from space. Branson’s space cruiser has already been tested and been given the go ahead. Although for the time being it is only affordable for the wealthy the technology as always is getting cheaper and tourist space travel could be the normal for many of us in the not too distant future. This can only mean that if in no other form manned space travel will live on in the tourism industry with Richard Branson leading the war. (BBC Focus article, issue# 170) The reliability of this article is full as work and money has already started on the project and a working model of the galactic tour ship has been successfully tested on a number of occasions. It is almost definite that space tourism will continue to cause a spark in people’s minds so there is little doubt space tourism will stop anytime soon after it starts.
Is there an alternative to manned space exploration?
Some people think very much so, each shuttle launch costs around $1.3bn, but the most important exploration today is carried out by unmanned craft, costing far less per individual mission. Nasa's most productive programme is the Hubble Space Telescope, which has provided invaluable insights into fundamental problems of astrophysics- Hubble's Ultra Deep Field is the most sensitive astronomical optical image ever taken. Hubble is approaching the end of its life, but a "Next Generation Space Telescope" is due to be launched in 2010. The Mars Pathfinder and Mars Exploration Rovers have also been huge successes, continuing to send back important data about the red planet to scientists.
What are the problems with sending people into space?
Quite simply, space is an extremely hostile environment for humans. Everything we need - food, water, the air we breathe - must be taken with us. These factors limit the length of any mission, while the sheer weight of such basic items significantly reduces the useful payload of shuttle missions. Discovery and its surviving sisters, Atlantis and Endeavour, are hopelessly limited vehicles, capable of reaching only low earth orbit. For that reason, the International Space Station (ISS) which they service must fly in the same low and relatively unproductive orbit. And as the fate of Challenger in 1986 and Columbia in 2003 constantly remind, manned space travel is dangerous. Fourteen astronauts died in the two missions. There have also been countless other accidents taking place in space, a few which have resulted in casualties. During the Soyuz 11 mission (30 June 1971), the three-man Soyuz 11 crew – Georgi Dobrovolsky, Vladislav Volkov and Viktor Patsayev – died when pressure was lost inside the Soyuz descent module during their return to Earth. A faulty valve opened at the time of the orbital module’s separation, allowing the descent module’s atmosphere to leak into space.
What hazards will we face in space?
As mentioned above space is an extremely hostile environment for humans. Out in space we will face 5 main hazards inside and outside the space craft which a space suit or the space craft should protect us from. The first is lack of pressure. In space, there is almost no pressure. If the space suit is too elastic, it will expand like a balloon or even explode! The second is radiation. The Sun emits many forms of radiation, some which can be deadly to us. Cosmic radiation, the most deadly consists of high-energy protons and heavy ions which can greatly increase our chances of developing cancer or eye cataracts. Wallace Friedberg highlights other work suggesting that heavy nuclei in cosmic radiation cause "serious brain damage" leading to memory loss. "Heavy nuclei exposure must be a serious consideration for space missions such as a trip to Mars.” Since Wallace Friedberg works for the Civil Aerospace Medical Institute in Oklahoma City investigating radiation his information must be of some reliability as he is a scientist in the field. On Earth; we have the atmosphere to filter out most of the Sun’s harmful rays. In space, the atmosphere cannot protect us, so our space suit must. The third hazard is lack of oxygen. Humans need oxygen to breathe, and there is none in space, so the space suit must provide the astronaut with oxygen to breathe. The fourth hazard is the danger of micrometeoroids. These tiny pieces of rock and sand are travelling at extremely high rates of speed. The space suit must contain bullet-proof materials to protect the astronauts from these tiny projectiles. And finally, the fifth hazard is temperature extremes. In space, the difference between sun and shade can be hundreds of degrees Fahrenheit! The space suit must be able to keep the astronaut cool when they are in the sun, and warm when they are in the shade.
How does a space suit work?
A space suit is a complex system of , equipment and environmental systems designed to keep a person alive and comfortable in the harsh environment of outer space. This applies to (EVA) outside orbiting Earth and has applied to walking, and riding the , on the . Some of these requirements also apply to worn for other specialized tasks, such as high-altitude reconnaissance flight. Above (~63,000 ft/~19,000 m), pressurized suits are needed in the sparse atmosphere. Several things are needed for the space suit to function properly in space. It must provide:
A stable internal . This can be less than earth's atmosphere, as there is usually no need for the spacesuit to carry nitrogen. Lower pressure allows for greater mobility, but introduces the requirement of pre-breathing to avoid . Breathable . Circulation of cooled and purified oxygen is controlled by the . regulation. Heat can only be lost in space by , or with objects in physical contact with the space suit. Since heat is lost very slowly by radiation, temperature is regulated by a and heavy insulation on the hands and possibly feet. Shielding against harmful , shielding against . Protection against , provided by a , which is the outermost layer of the suit, a communication system, a means to recharge and discharge and and a means to manoeuvre, dock, release, and tether onto the space craft. A space suit should allow its user natural unencumbered movement. Nearly all designs try to maintain a constant volume no matter what movements the wearer makes. This is because is needed to change the volume of a constant pressure system. If flexing a joint changes the volume of the spacesuit, then the astronaut must do extra work every time he bends that joint, and he has to maintain a force to keep the joint bent. Even if this force is very small, it can be seriously fatiguing to constantly fight against your suit. It also makes delicate movements very difficult. The work required to bend a joint is dictated by the formula where Vi and Vf are respectively the initial and final volume of the joint, P is the pressure in the suit, and W is the resultant work. Because pressure is dictated by life support requirements, the only means of reducing work is to minimize the change in volume.All space suit designs try to minimize or eliminate this problem. The most common solution is to form the suit out of multiple layers. The bladder layer is a rubbery, airtight layer much like a balloon. The restraint layer goes outside the bladder, and provides a specific shape for the suit. Since the bladder layer is larger than the restraint layer, the restraint takes all of the stresses caused by the pressure inside the suit. Since the bladder is not under pressure, it will not "pop" like a balloon, even if punctured. The restraint layer is shaped in such a way that bending a joint causes pockets of fabric, called "gores", to open up on the outside of the joint. This makes up for the volume lost on the inside of the joint, and keeps the suit at a nearly constant volume. However, once the gores are opened all the way, the joint cannot be bent anymore without a considerable amount of work.
Are there any advantages?
The case for manned exploration boils down to the eternal argument over human versus artificial intelligence. Computer-controlled robotic missions can gather vast quantities of data. But they are less good at evaluating it. They cannot make the on-the-spot, creative judgements on which avenues should be pursued and which abandoned. Just like chess-playing computers, robots waste time and energy evaluating possibilities, when a human on the spot would instantly know whether a line of exploration was worthwhile. Furthermore, the publicity given to human space disasters masks the much higher failure rate of unmanned missions. Take unmanned probes to Mars; since 1960 roughly two out of three have failed. Challenger and Columbia notwithstanding, manned missions have had a 90 per cent success rate. And nothing gets people excited about space exploration - and makes them willing to pay for it - like dramatic human moments.
Should we pursue manned space exploration?
Yes...
- Our very survival as a species may depend on space travel "The survival of the human race is at risk as long as it is confined to a single planet," Professor Hawkings said last week, warning of the existential peril of a major asteroid collision. But if independent colonies can be established in space, mankind's future should be safe. Professor Hawking is thinking of another star, as there is nowhere like Earth in our solar system. But you have to start somewhere - and the moon and is the obvious place.
- When it comes to space exploration humans are just simply better at recognising what is of interest to us.
- We need men or women to make repairs in space, such as those which extended the useful life of the Hubble telescope and obviously cannot be done by computer controlled machines. This is one of the reasons unmanned space flights are much less successful than manned ones, there is nobody on board to fix the problems.
- We are and always have been naturally curious of space and watching men and women explore new worlds greatly fascinates us. Even ancient civilisations studied the stars and space, such as the Egyptians so why shouldn’t we?
- Pursuing manned space can help us look and judge planets and decide weather they could be habitable in the future. This would also support Hawkings theory that we would never be safe on Earth unless we knew w could live on another planet.
- Humans, unlike robots can make on-the-spot, creative judgements on which avenues should be pursued and which abandoned. This is one of the reasons that manned space flights provide us with large amounts of valuable information.
- Manned missions have a much higher success rate than unmanned ones. Two out of the three probes sent to Mars failed.
- However well you program a robot it will never be able to think or evaluate nearly as well as a human.
No...
- It can be argued that the costs of sending humans into space far exceed any benefits gained by employing them rather than machines.
- Unlike Manned missions, unmanned missions can travel through space for however long they want with few set backs such as old age and lack of supplies. Therefore unmanned space flights can go on for many years collecting data for us from great distances away where man can not go. One great example on the sustainability of unmanned space flights is the Voyager 1 probe which has now been flying for 30 years and holds the record for the furthest artificial object from Earth.
- There will always be an inherent risk in sending man into space and, as we all know, there can always be unforeseeable failures that can occur which cost us lives even with tried and tested systems such as the shuttle. Two great examples of this are in Challenger in 1986 and Columbia in 2003 where 14 people died in the two missions.
- Humans need so much in the way of supplies - oxygen, warmth, protection, etc - that the extra weight forbids going to most places.
- Space travel is intrinsically dangerous, and it better to lose machinery in the inevitable accidents than human lives.
- Robots and machinery do not make errors that humans inevitably make.
- Machines can work in much harsher conditions tirelessly without needs for breaks.
- At the moment the current technology can not take man very far away from Earth, anywhere quite close where we can go in the near future will be of no great help. The mission to Mars that NASA is planning for 2013 will cost 230 billion dollars and may not even tell us anything we don’t already know about the planet. And even if we do find out something new will the benefits outweigh the cost? Will the new information be worth $230 billion?
Conclusion
From looking at evidence from both sides of the argument we can straight away see there are many reasons why we should and shouldn’t pursue manned space. In the future the research carried out by manned space exploration can help save lives but at the moment it has also destroyed many lives. We must not doubt what we can do; space is out there waiting to be explored by us. The fascinating ideas that there may be life outside Earth drive us to carry on with manned space exploration. However, we must consider possible consequences of our actions as in the past things could go wrong again and result in deaths. At the same time technology is advancing at an alarming rate and with our own knowledge increasing manned space exploration is getting safer. But one could then ask, if technology is so advanced why can’t we just use robots to do the work for us. The advantages with this is that once airborne there is little chance of human life loss. This would also make the whole programme much cheaper. Robots make nearly no errors and are excellent at collecting data. The downside is that they will never be able to make decisions like a human brain and there are countless problems that can occur. With no man on board who would fix these? While robots can fix certain things they are still not yet advanced enough to out perform a human. There is also the fact that the success rate of manned space exploration clearly out performs unmanned space exploration.
In my opinion I think that manned space exploration should continue. With more money being spent and procedures being better organised so we can reduce the chance of human life loss.
Bibliography
Most of the information I used I obtained from the internet by conducting research. I also used an article from a BBC Focus magazine.
http://www.janes.com/aerospace/civil/news/jsd/jsd030203_3_n.shtm
BBC Focus Magazine Issue Number: 170
By Rohan Shah
