why when space shuttle re-entry to atmospher have to be in highspeed which in turn burnt the shuttle itself?
117099
Space shuttle gains huge potential and kinetic energy as it goes up and orbits earth. This energy needs to be given out as it comes down. This happens in form of heat. Heat is generated in the process of slowing down the craft. \n\nIf we want to reduce the speed by means of spending energy, while it coes down we need to send up even larger amount of fuel to equilize gravity as it comes down. This will result in very bad design.\n\nMay be with nuclear powered plasma engines oe day we shall be able to bring the craft slowly. But that will not reduce the risk. The plasma wlll then be inside the vehicle, rather than outside of it. So we got to learn the art of handling super hot gases either way.
973904
I presume you mean the external fuel tank?\nIt is jettisoned just before the shuttle reaches orbit, and the tank lacking just a bit of speed to actually make it in orbit, it falls back and burns up in the atmosphere.
105847
The shuttle needs to reach a speed of 17,500 miles per hour to stay in orbit.
555677
You are using the term "power" incorrectly. Power is the rate of production of energy. A jet may have enough energy, but it does not have enough power. A fully fueled jet may be able to burn all it's fuel with oxygen from the surrounding atmosphere to generate enough energy to make it to orbit, but it takes many hours to do that, and all the time it is being slowed by friction with the atmosphere. The shuttle burns all it's fuel in 10 minutes, and it carries it's own oxygen in a tank so it can operate outside the atmosphere. So even though they may have similar energy, the shuttle has far more power.
880695
Think of a spacecraft flying in orbit like a swinging pendulum.  You need energy to get it started, but once it is oscillating, it will stay in that state for a long time.  If you wanted to increase or decrease the pendulum oscillation that would require energy too.  But once it is in a new oscillation cycle, it will tend to stay there.\n\nSimilarly, a spacecraft needs to burn a lot of fuel to get *into* or *out of* an orbit.  Staying in a particular orbit requires very Little energy.  If there were no momentum losses, then staying in orbit would require no energy.\n\nAn orbit is an ellipse with a massive body (like the Earth) at one focus.  Ellipses are like flattened circles.  The higher the eccentricity of the ellipse, the flatter it is.  The Earth's orbit around the Sun has a very low eccentricity and is therefore quite circular. \n\nSo long as a spacecraft is flying in an ellipse  shaped orbit then it needs almost no energy to stay there.  If it needs to maneuver (like the shuttle docking with the ISS) then it needs to fire its thrusters to slowly change its orbit to match the object it is trying to rendezvous with.\n\nSuppose you wanted to escape Earth's gravity.  You fire thrusters for 10 seconds.  Now your orbit is a flatter ellipse; your eccentricity just increased.  However, you are still in orbit around the Earth.  Part of your orbit may be far away from the Earth, but you are still under influence of Earth's gravity.  You will realize that there is a critical speed -- called the escape velocity -- which will allow you to go so fast that the Earth cannot pull you back.  This is like swinging a pendulum so fast that instead of rocking back and forth about a point, it just spins in circles.\n\nThe important concept here is that gravity does not stop pulling on you when you leave Earth's atmosphere.  All spacecraft in Earth orbit are feeling its gravitational pull.  However, they are all in a state of perpetual free fall.  They are falling towards the Earth, but at the same time they are moving around it fast enough that they keep 'missing'.  This is the same as if you took a ball on a string and spun it around in a circle.  The string has tension; the ball is accelerating toward you.  But its velocity is in the direction of travel (along the circumference) so it stays in a circular path.
611632
space shuttle burns hydrogen. imagine you're standing under it when it launches. endothermic or exothermic?\n\ncorrect reaction formula was already given.
914683
His and the other crewman's deaths taught NASA several painful lessons.  \n1. Not to use a pure oxygen in the cabin.   \n2. To have an emergency escape hatch on the inside of the rocket for the crew on the latch pad.  \n3. To have an escape chute available at the escape hatch\n4. To seal the electronic systems better.\n5. To have ground control from launch pad to orbit.
439960
According to the Bernelli principle it is because the ratio of high-speed wing over the TOP of the foil of the wing is not sufficient to generate lift.  Therefore gravity takes over and it falls back to earth.
78893
all the answers yet provided were all quite valid.\nhere's something else for y'all to consider though... and that is the amount of debris that our atmosphere shields us from.  you see, upon entering the atmosphere as high speeds, it creates friction, which begets heat, and that burns up the particle in question.\n\nso.. like.. uh..  the moon has no atmosphere.  that means any habitation is going to bear the full brunt of such debris...  it's not very pleasant at breakfast to have a meteor smash through your roof, especially when that roof was keeping all your oxygen inside......
1068651
White reflects light at *visible* wavelengths better.\n\nHowever, the designers were not trying to reflect visible light.  I would guess they designed the coating to emit thermal radiation as efficiently as possible - approaching 'black-body'.  The coating color would probably be secondary to that consideration.\n\n****\nSide Note\n*****\nDue to it's tremendous speed, the orbiter shock-heats air at it's leading surfaces during reentry. (the orbiter's underbelly is exposed directly to the 'wind stream', if you will, due to the orbiter's initial high-angle of attack)\n\nThe temperatures of the thermal protective surfaces rise primarily in response to thermal radiation from the incandescent shockwave.  NOT FROM FRICTION.
445480
If you are talking about the Mars Climate Orbiter, it is because the manufacturer specified the thrust of the attitude jets in pounds but the navigation team though the numbers were in metric units. This caused the navigation team to make incorrect calculations which resulted in the space craft arriving at Mars orbit insertion too low and entering the atmosphere instead of going into orbit.
61716
The air inside the vehicle is moving the same speed as the vehicle. To the fly it's still air, unless a window is open, then the fly may not be able to fly normally.
929210
You are exactly right. The energy given to the system when you hit them together was enough energy to break the bonds of the oxide layers on top. The thermal energy of the reaction elevated the electron energy states for a small amount of time, causing them to fall back down to their ground state and giving off some photons...hence the spark.
51283
Shuttles bring oxygen with them, because they have to burn their fuel to propel themselves through space.  It is because they carry liquid oxygen that they are so incredibly dangerous.\n\nBut really, fire is just an oxidation/reduction reaction.  All you really need are an oxidizer, a reducer, and heat.  Oxygen gas in the air serves as the oxidizer for most fires, and carbohydrates (lignin, cellulose, oil, petroleum, coal, etc) serve as the reducer in most fires you see.  But some rockets use nitrogen dioxide as the oxidizer instead of oxygen.  You could, theoretically, use hydrogen gas and chlorine gas to make a flame in the absense of oxygen--but oxygen is the only common and abundant oxidizer, since it is created as a byproduct of photosynthesis in plants and cyanobacteria.
979449
The rocket travels in a parabolic trajectory (we assume it has a zero burn duration). It is at the peak with 0 vertical velocity when it lands on the cliff edge at s=200 m height. Under 1g deceleration, it takes SQRT(2*s/g) = 6.387 sec to reach this height. The horizontal distance  traveled is 30 m in 6.387 sec for a velocity of 4.607 m/sec.\nI hope you realize that when you impaled the package with the rocket, all the blood plasma, propane and brandy were lost.\n\nEDIT: It would help if you said why it doesn't seem right. But if it isn't right, we must not be trying to get the payload up the cliff, just across the river. Which makes the cliff height another irrelevant parameter, along with the rocket and payload masses, and also means our rocket doen't travel the hypotenuse as you thought. We want a minimum-energy way to fling the stuff across the river (distance S = 30m), which means a 45-degree launch elevation (and still a parabolic trajectory). At launch, vertical velocity Vy = horizontal velocity Vx. To solve for velocity we use two definitions of flight time T: T = 2Vy/g (the time to ascend to peak height and then descend to the ground; of course T also = 2Vx/g), and T = S/Vx (hor. distance/hor. velocity). Then 2Vx^2 = Sg = 30m*9.80665m/s^2, so Vx=Vy=12.128 m/s, and the velocity magnitude = 17.152 m/s. This is the launch and impact velocity. \nOf course if the rocket has more energy than this minimum value, one must change the launch elevation to compensate and impact velocity will be greater. If it has less energy than the minimum, the explorer croaks.\nNow if this version doesn't seem right, maybe we're on top of the cliff and have to propel it downwards and across the river? I'll let you solve that one.\nP.S. Your problem statement is confusing. You say "... then fire the rocket at ground level toward the supplies." Do you mean toward the explorer?
146292
11.2 km/s with the following caveats:\n\n"Due to the atmosphere it is not useful and hardly possible to give an object near the surface of the Earth a speed of 11.2 km/s, as these speeds are too far in the hypersonic regime for most practical propulsion systems and would cause most objects to burn up due to atmospheric friction. For an actual escape orbit a spacecraft is first placed in low Earth orbit and then accelerated to the escape velocity at that altitude, which is a little less, ca. 10.9 km/s. The required extra velocity, however, is less because the spacecraft has already been accelerated to about 8 km/s."
47037
You've hinted on most of the problems related with travel at extreme speeds.  In my view it isn't possible with our current technological and scientific knowledge, here's why:\nWhen you drive a car at 30 mph you require a certain amount of enery to sustain that speed.  If you double your speed you more than double your energy requierements, because of friction between your car and the surrounding air as well as your tires and the road. Even if you had no tires (the equivalent of a perfect hipothetical electronagnetic propulsion) you'd still have wind drag.  The same happens in space, which is not completeley devoid of matter.  You would require enormous amounts of power to increase speed by small amounts once you really got going fast.  Actually, you would probably  require more energy than the energetic output of our entrier Solar System, depending on she size and acceleration of your vehicle, maybe even more than that of the entire galaxy.  The material out of which your spaceship is made would melt, burn or crack and other side effects like increased weight and dimensions (Einstein and Lorenz based) would have almost unforseable effects on the spaceship.  The only way of reducing this would be to travel in a circular or almost circular trajectory with modest accelerations, it would take almost a year for you to reach extreme velocities at a 1g acceleration.\nSumed up: you would require more energy than the planet can provide and the material of your spaceship would have to de made of a susbtance not yet researched.  Even solving these two (the solution of which could be centuries away - or maybe just decades, who knows, but it's not at hand) we'd have to deal with Einstein and Lorenz side effects on weight and dimensions, to attain 97%+ light speed (180,000 mps).