Think in terms of forces. What forces must we overcome to get a space ship (or any other object) into orbit ar
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The gravity from your mom (Mother Earth)
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One big adjustment is to once again get used to an environment that has gravity.  In the gravity free environment of space movement is unhindered by gravity.  Back on earth muscles have to readjust.
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Suppose you are taking a space walk near the space shuttle, and your safety line breaks. How would you get back to the shuttle? The thing to do would be to take one of the tools from your tool belt and throw it is hard as you can directly away from the shuttle. Then, with the help of Newton's second and third laws, you will accelerate back towards the shuttle. As you throw the tool, you push against it, causing it to accelerate. At the same time, by Newton's third law, the tool is pushing back against you in the opposite direction, which causes you to accelerate back towards the shuttle, as desired. This is the principle behind jet propulsion: a jet rocket expels fuel rapidly by ``pushing against it''. By the third law the fuel exerts an equal and opposite force against the rocket so the rocket accelerates in the opposite direction that the expelled fuel goes. Another example of the 3rd law is a book lying on a table. If the table were not there the book would fall under the force of gravity between the book and the earth. Why then doesn't the book move off the table, in accordance with the 2nd law? The table is exerting a force on the book that is just enough to cancel the gravitational force on the book. By Newton's third law, the book is also exerting an equal and opposite force on the table, and this is why the table feels the weight of the book. If the book were very heavy, its weight would cause the table to bend, or even break. This is illustrated in the following figure. \n\nThe answer to this question comes from the third law. Imagine the skateboard again. On the ground, the only part air plays in the motions of the rider and the skateboard is to slow them down. Moving through the air causes friction, or as scientists call it, drag. The surrounding air impedes the action-reaction. \n\nAs a result rockets actually work better in space than they do in air. As the exhaust gas leaves the rocket engine it must push away the surrounding air; this uses up some of the energy of the rocket. In space, the exhaust gases can escape freely.
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USE PRINCIPLE OF CONSERVATION OF linear MOMENTUM.\n\nearth gas lower KE because it has huge mass and huge inertia
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These answers "seem" correct. But Im not sure thats really the case. Within our solar system there is still gravity. What do you think is holding all the planets in place? Perhaps between systems that might be more true.\n\nThe problem is getting a large mass moving fast enough to really be productive. You still need loads of energy to get a real spaceship moving. We just dont have that tech yet. \n\nRight now scientists are working on a plasma engine. Check it out.
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All space garbage should be recycled and composted into an ecosystem. Thats the complicated set of chemistry questions that goes wtih that particular problem.\n\nUsing large enough diameters and centripetal force we can generate strong enough and stable enough pseudo\ngravity to compensate for that problem. A chemical problem with a civil engineering fix.
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Two objects will orbit one another indefinately unless disturbed.  The man made satellites that return to earth orbit to closely and are so small, atmospheric drag and solar wind eventually cause their orbits to decay.\n\nThe moon is large enough are far enough out, these factors don't come into play.  The primary force now is tidal friction, which causes the orbit to slow, and therefore expand, by a fractional amount each year.  \n\nDon't worry about losing the moon, though.  The sun will expand into a red giant, swallowing both earth and moon long before this happens.
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They're going to use the "Slingshot" method around Jupiter to give it that extra thrust that would be needed.  Since they calculated that there would be nothing in the path if they used that approach right now, it will be able to make it without outside influences (the gravity of the sun is already calculated in).
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It takes a lot of energy to break out of Earth orbit, and thus takes a lot of fuel.  Just to get to the moon, it took a giant, 3 stage, Saturn V rocket.\n\nThe space shuttle was specifically designed to be used in Earth orbit and thus could not carry near enough fuel to escape Earth's gravitational pull.
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Same way they do anywhere....\n\nJets take in air and spit it back out. A jet wouldn't work in space.\n\nRockets carry their fule with them, and so don't need to take anything in.\n\nThe mass and energy pushing away from the rocket will push just as hard in space as on Earth, and will do all the better since there is less gravity to worry about.
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The Space Shuttle can’t fly to the Moon—it only makes it about one five-hundredth of the way there, to low Earth orbit—because it doesn’t have the sheer thruster-power required to do so.\n\nIf you were to design a mission to the Moon, though, you’d need to use a carefully-calculated trajectory that takes into account the gravitational effects (and the mutual motions) of both Earth and the Moon.  The first step is to escape Earth’s gravity enough to head toward the Moon (and not just into a different orbit around Earth), so you fire your thrusters to change your velocity.  Then you need to aim for where the Moon will be (’cuz it’s constantly in motion around Earth, remember).  And then you have to enter orbit around the Moon, firing your thrusters again to position yourself properly in orbit.\n\nThat’s one way.\n\nESA’s SMART-1 spacecraft took a somewhat different approach.  It’s a lightweight ship that was launched with several other satellites into a geostationary orbit—about 50 times higher than the Shuttle flies.  Except that SMART-1 didn’t “circularize” its orbit like the other satellites; instead, it pushed itself into an orbit that took it very close to Earth then very far away.  Engineers timed the spacecraft’s most distant passes to take advantage of the Moon’s gravitational attraction, and eventually, SMART-1 nudged itself into orbit around the Moon.  In this case, very little thrust was used on the part of the spacecraft, so it could allow gravity to do most of the work.\n\nIn short, engineers tend to plan spacecraft trajectories very carefully, using a combination of thrust and gravity to get a ship exactly where they want it.\n\n\nRyan Wyatt\nRose Center for Earth & Space\nNew York, New York
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Very simple. start out asking yourself what information do i know about the problem. Anything from masses and forces to symmetries of the problem. Next Ask yourself what additional information you need to solve the problem, values, formulas, etc. from there it should all fall out with ease.
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The thrust of rocket engines are how ships are controlled in space.  Many of the forces that affect air ships (drag, lift, gravity) do not apply since you specified no air or gravity.\n\nTechnically, air ships don't go to space, so there's no real answer to this question.  Richard Branson's Space Ship One recently flew to the edge of space and then landed like a plane, but (as the name indicates) it was a space ship, not an air ship.\n\nAnd there are air and gravity in space.  Gravity holds galaxies, separated by millions of light years, together, so gravity will definitely act on space ships only 100 or 200 miles above the earth.  What causes weightlessness in orbit is not a lack of gravity, but free fall.  The atmoshere is very, very thin at the altitudes where satellites and the shuttle fly, but it is that thin air, causing frictional drag on satellites and the space station, that require constant reboosting to keep them in orbit.\n\nKey to effective flight and control is stabilization, so in addition to moving and turning a ship in space, thrusters also are used to keep it from spinning (reaction wheels also are used for this function).
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K so...I haven't done any Grav froces recently...but I'll try\n\nIm guessing use  Net force = ma\nThe net force is the Gravitational force, Gm1m2 / r^2 is = m2 4 (pie)^2 r/ T^2\n\nfor the 4 (pie)^2 r/ T^2    r is the distance form the planet's center, to the moon, for T, find how many second 40 days is.\n\nand the other r is the planet's radius\n\nm2 cancels\n\nsolve for m1, and yo uhave the mass of the planet.\n\nI guess plug in numbers after that, into the equaltion Fg = Gm1 m2  /  r^2\n\nm2 would be the 70 kg\n\nhope thats right
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Nope, takes much more than that to overcome the gravity power of the sun, because that is what keeps earth in orbit.
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Gravity is the force of attraction between massive particles. Weight is determined by the mass of an object and its location in a gravitational field. While a great deal is known about the properties of gravity, the ultimate cause of the gravitational force remains an open question. General relativity is the most successful theory of gravitation to date. It postulates that mass and energy curve space-time, resulting in the phenomenon known as gravity.\n\nGravity is acceleration.  means that (if the mass is unvarying) there must be a force that causes a mass to accelerate. For a rocket ship, that is the rocket engine. For the earth, it is the compression of the mass between something on the surface of the earth and the earth's center of mass. The acceleration is in relation to spacetime in that the weight one feels is one's resistance to deviating from one's path in spacetime. The same holds true in the rocket ship except that a rocket engine supplies the force to accelerate an occupant from his spacetime path. There is no difference between the weight he feels because of gravity or the rocket.
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Thatguy said:\n\n"because the moon is in orbit (read: freefall) everytime the moon tries to fall to the earth, the earth backs away from it and the cycle continues" \n\nwhich is complete nonsense. The earth "backs away"? orbit is the same thing as freefall? what?\n\nGravity is an attractive force that exists between each and every object that has mass. Think of it as being like magnetism.  The reason things orbit (eg the moon) is because the pull downwards towards the earth is almost exactly balanced by the pull away from Earth exerted by the centrifigal force of going around the earth & the gravitational pull of all that other stuff out there.  Orbits work because these forces are not exactly equal, so the tendency of something to fly off into space is just overcome by the attraction towards the large mass below, and the moon is, in fact, getting a little closer over time.  Eventually, like various pieces of space junk, the earth's gravitational pull will overcome the orbital force and the moon will crash into a field in Nebraska, where a farmer will claim an alien came out of it.\n\nclear as mud