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I think this problem is known in the literature as 'soft landing'. A nice article which may interest you is (1) and the references therein. (1): Liu, Xing-Long, Guang-Ren Duan, and Kok-Lay Teo. "Optimal soft landing control for moon lander." Automatica 44.4 (2008): 1097-1103.

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I've heard that a spacecraft could never exceed the speed of light because it's (relativistic) mass quickly approaches infinity and therefore there could never create a big enough rocket to propel it faster and faster. In fact, the spacecraft could never even reach, much less exceed the speed of light. I think that you'll agree that the ...

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The problem is- The rocket is not 'fighting' with any force-field, it is 'fighting' with the very nature of space-time. So unless we have something of zero rest mass 'things' will tend to infinity. And yes the thrust will increase but space-time will distort( following Lorentz transformation, no GR effect here) in such a way that reaching 'c' 'tests' our ...

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At a very basic level for the computation of a circular orbit it is just enough to equate the centripetal and the gravitational force: $$F_g=F_c$$ $$G \frac{mM}{r^2} = m \frac{v^2}{r}$$ where $G$ is the gravitational constant, $m$ is the mass of the satellite, $M$ is the mass of the Earth, $v$ is the satellites tangential velocity and $r$ is the altitude of ...

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First of all it is a bit strange to say that scientists place satellites into orbit. Since a rocket does all the work, which in turn is build by engineers. But you might say that the people who control the rocket/satellite can be called scientists. I am not an expert on the planning of trajectories of satellites. However I do suspect that the trajectories ...

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Do you think anyone calculated the earth's speed to stay in orbit around the sun? As long as the speed is in the correct range the satellite will stay in orbit. For a satellite around the earth, the minimum speed is about 7 km/s. This is tangential speed, i.e. speed parallel to the earth's surface. Anything below 7 km/s, and the satellite will fall back. ...

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If it is a supercon magnet, it runs without losses until the field is deformed by a solar coronal mass ejection blasting by. It offers no protection against energetic photons. Consider a one tesla field filling a 200 m diameter bubble. How many joules is 4.2 million m^3 of one tesla field? (Suppose the field collapsed into a solenoid shorted by a ...

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Inflatable sphere component would give you most space

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This has a simple closed-form solution. Denoting $m_0,m_1$ as the initial and final person's mass, $v_r$ as the rice speed and $\delta=m_0/m_1$, if the bag is thrown in one single parcel, we have $$\Delta v_1=(\delta-1)v_r$$ By the rocket equation, if the rice is thrown continuously, we have $$\Delta v_2=v_r\text{Log}(\delta).$$ But $$\text{Log}(\delta)\leq ... 1 You need a model for how you throw the rice. The obvious one is that you can expel any mass at the same velocity v relative to you. Letting M be your mass (without the rice), V your velocity in the CM frame, if you throw it as one lump we have momentum conservation. You start with no momentum in the CM frame, so 10v=MV, V=\frac {10v}M. If you ... 0 Given a bag of rice of mass m_b that you can throw with a maximum acceleration \vec{a}_b, by Newton's second law, the most force \vec{F}_b you could exert on the rice is given by$$\vec{F}_b = m_b \vec{a}_b$$By Newton's third law, the reaction force (acting on you) \vec{F}_{you} is given by$$\vec{F}_{you} = - \vec{F}_b = - m_b \vec{a}_b Again ...

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