This article is about spaceship design and how space travel affects you. It has come to my attention. Many people have completely lost interest, and just devalue space travel. Mostly in America, our political parties are claiming The United States, economic woes as an excuse. Well I would like to point out at the near trillion dollars that the DOD has to make weapons, then look at NASA’s mere 18.7 billion. On the level of countries, especially the united states, you are looking at billions and trillions of dollars instead of what you are probably use to thinking of. The government looks at NASA and tells them to trying and save money, while they are blowing it left and right. Does that make since to you?
Rocket propulsion, is different from other methods of acceleration. The entire acceleration system is contained within the vessel. A runner makes use of the ground to accelerate.
“Human’s walking, is a series of controlled falls.”- Unknown Author
A car uses the road to accelerate creating friction, pushing the wheels against the asphalt. A jet uses the air to accelerate, pulling air through a turbine. A rocket accelerates, entirely by expelling its own mass backwards. A rocket does not need anything to push against or pull on. A sailor throwing cannonballs off the back of a ship is using the same principle. His boat will accelerate forward with each throw.
The most common form of propulsion is called chemical or conventional rocket propulsion. A chemical rocket relies on a highly explosive chemical reaction inside a tube to force fuel mass downward and the rocket up. NASA's Space Shuttle and the Saturn rockets used in the Apollo missions are all entirely chemical systems.The two most important characteristics of a rocket engine are its thrust and its specific impulse. Thrust is a measure of how much force the rocket can exert. Specific impulse can be thought of as a rocket's "gas mileage". It measures the amount of speed available from a unit mass of propellant. (Like gas) It is related to the speed of the rocket's exhaust.
Chemical rockets are useful for their extremely high thrust. For example, a single engine of the Saturn-V rocket has 6,800,000 Newtons of thrust. Currently, chemical rockets are the only propulsion technology that has been used to reach Earth orbit. However, electric thrusters have much greater specific impulse than conventional rockets, and can therefore propel a spacecraft to much greater speeds using much less propellant mass once the craft has reached Earth orbit. A solution would be to transport materials to space and build there. We are not at that stage quite yet, a moon base would help.
The Variable Specific Impulse Magnetoplasma Rocket (V.A.S.I.M.R.) is a new type of electric thruster with many advantages. In a VASIMR, gas such as argon, xenon, or typically hydrogen is injected into a tube surrounded by a magnet and a series of two radio wave (RF) antennas (called "couplers"). The couplers turn cold gas into superheated plasma and the expanding magnetic field at the end of the rocket (the magnetic nozzle) converts the plasma particles' thermal motion into directed flow for propulsion. With the use of this engine a trip to mars will take three months instead of three years. The engine can propel a craft up to 50,000 m/s (35 MPS). The temperature has presented significant problems. The top recorded heat was said to be about a million degrees Fahrenheit. They had to create a magnetic field to form a heat shield. Much like what the U.S. N.I.F. does with its fusion reaction. VASIMR is said to be capable of not just opening up mars to earth but our entire system.
With Humans making great leaps and strides into space we will need protection from several dangers as we leave the protection of our planet’s atmosphere. Among the most prominent dangers we have radiation. When the Sun flares, it produces x-rays, gamma-rays, and energetic particles. The energetic particles are the worst, but are delayed, so you have some warning that they are coming. This gives you time to get into a 'storm shelter', a well-shielded area that you can live in for a few days until the particles die down. A good place for a storm shelter would be in the center of the ship, surrounded by the water tanks. If you don't have a storm shelter (e.g. if you are out on an E.V.A. moonwalking in just your suit) a bad solar flare can kill you. However on longer missions the astronauts cannot live within shielded rooms, since such shielding would add significantly to the mass of the spacecraft, making them much more expensive and difficult to launch. It is also now known that the ‘drip-drip’ of even lower levels of radiation can be as dangerous as acute bursts from the sun. How do avoid radiation sickness? International teams of scientists lead by members from the Rutherford Appleton Laboratory have devised a way to create a miniature version of the Earth’s magnetosphere. In order to work, an artificial mini-magnetosphere on a space craft will need to utilize many cutting edge technologies, such as superconductors and the magnetic confinement techniques used in nuclear fusion.
The idea of the British and Portuguese scientists on the project appears to be inspired by Star Trek, a magnetic protection devise that weighs only several hundred kilos and uses approximately a kilowatt of energy. According to Bob Bingham:
“The idea is really like in ‘Star Trek’, when Scottie turns on a shield to protect the starship Enterprise from proton beams – it’s almost identical really.”
Research from the 60s estimated that a magnetic field would have to be hundreds of kilometers (miles) across, which would have made the equipment far too heavy to take into space. The simulation performed by Rutherford Appleton Laboratory, estimates that a bubble of several hundred meters (feet) would suffice, which makes the technology feasible.
After the difficulties of construction, propulsion, and radiation shielding are solved the problem of micrometeorites remains. Micrometeorites are a type of space debris that flies through space faster than a speeding bullet. Thousands of them hit the earth’s atmosphere every day and burn up on re-entry. Micrometeorites bombard the Moon’s surface as well. It is well known fact that they are responsible for the fine powder that cakes the regolith surface of the Moon. If just one hits a spaceship it can cause depressurization or damage the heat shield. Fortunately this has not happened yet. The chances of impact greatly increase on a long trip to say mars.
At the White Sands Test Facility in Las Cruces, New Mexico, NASA has built one of the world’s most powerful guns (pictured right after much trouble finding it). It is about 60 yards long, firing a projectile at a speed of 20,000 mph. A rifle bullet goes about 2,000 mph. It’s target? Spaceships. The gun is intended to test a ship’s hull for impact from micrometeorites. Its bullets are smaller than the end of an eraser. An example shot of one of its test fires though a ship’s hull displayed the awesome power they have to prevent. The round traveling at 16,000 mph ripped through three plates then broke apart and created a shotgun blast in the inner walls. NASA came up with a solution. The shielding ends up being a metal/foam/metal/foam/metal hull that looks like a triple stacked Pb & J sandwich. It wouldn’t seem like it but it does the job. This solution is simple cost effective and easily reproduced method that anyone could make. It works by absorbing the impact of the meteorite.
Being weightless is another plague of space travel. You lose bone density, and muscle mass. The saying use it or lose it comes to mind. Most experts think that working out does not work to stimulate the amount of bone growth you need. Scientist are trying to develop a way to simulate the effects of gravity on the body. Essentially creating our habit in space has proven very difficult task. Some scientists believe that centrifugal force will do the trick. Not an entire spinning spaceship, but just a spinning room. A spinning Space Station has been portrayed in the film “2001 a Space Odyssey.” (pictured below). It is not impossible but simply we are not at that level of space infrastructure.
A technology we need to survive working in space is the pressure suit. Here on earth you do not need one because earth’s atmosphere is pushing down on you with a force of about fifteen pounds, about the weight of the ordinary watermelon. If you were to be sucked out of a space station without a suit you would not explode but you would expand and get to a certain spot and turn into a goo or mush and then vaporize. Your blood, the air in your lungs would boil. You would die very quickly is the good news.
Currently our suits are inflated with oxygen and pressured. If you put a rubberband on your hand and just open and closed your hand about fifteen times you will soon realize what it’s like to work in our current generation of space suits. There is a battle of mobility and pressure that has been there since the 60s. Many experts think we need to have a robust pressure suit before we can even think about going to Mars. Scientist Dava Newman is perhaps the closest to developing our next generation pressure suits. The biggest difficulty is re-inventing it. She wants to ‘shrink wrap’ future astronauts. This ‘compression stocking’ gets the suit 2/3 of the way to the desired pressure. How can she get the rest? Dava looked for inspiration in the animal kingdom. She observed the giraffe eating grass on the Savanna, when they raise their head up to reach the tree about 5 meters they don’t faint. What about a giraffe’s physiology allows it to do this? They have special muscles in their blood vessels that constrict to create pressure. This blocks the blood from escaping out of its head creating an ‘eternal G-suit’ effect.
Dava then came up with the idea of reinforcing the suit with super strong red fibers that intersect up the suit for additional pressure. The hardest part to pressure on a suit is the joints. The complete project will have ‘smart wires’ running up the suit to monitor vital signs. A hard back plate will support the oxygen tanks on the back of the suit. The Helmet itself doesn’t change much; it remains a gas pressurized helmet. The suit makes you consume about 50% less oxygen then its counterpart.
You might think to yourself what can any of this do for me? Well with the Human population hitting seven billion in 2012, mankind will have to find a place to go and many of these things will help us move to space, the logical next step. Radiation protection techniques could also be employed by fusion reactors, nuclear plants, nuclear waste, and even radiation dangers. The moon rover improved many facets of automobiles in the 60’s. The use of robotic exploration could help us in hazardous areas to insure safety. Space exploration has been known to make unintentional purposes; they might even inspire something new. The world has many problems and space travel is helping to eliminate many of those year by year. Our astronauts are the explorers of our time just like Columbus of his. There are many things we do not yet know about space. Just like in Christopher Columbus’ time we didn’t know about the world. So be proud and show respect for our space and aeronautics organization. Thanks for reading this week’s article and stay tuned for the next.
"Is space exploration really desirable at a time when so much needs doing on Earth? It is an often-asked and serious question that requires a serious answer. One could present many arguments, from jobs and education to technology development and national security, for undertaking a robust space program. In an ideal world only one argument is necessary, though in the real world some would argue it is not sufficient. That argument is exploration, and that we should undertake it for the most basic of reasons -- our self-preservation as a creative, as opposed to a stagnating, society." -NASA
"Is space exploration really desirable at a time when so much needs doing on Earth? It is an often-asked and serious question that requires a serious answer. One could present many arguments, from jobs and education to technology development and national security, for undertaking a robust space program. In an ideal world only one argument is necessary, though in the real world some would argue it is not sufficient. That argument is exploration, and that we should undertake it for the most basic of reasons -- our self-preservation as a creative, as opposed to a stagnating, society." -NASA
