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3

For artificial gravity to work well, you need a really large station: if the station is too small, there are side effects that would make the experience very unpleasant. You need a diameter of 100-200 m. Current thinking is to achieve this by having two habitable modules with a truss or cable between them, and spinning the entire station. The simplest way ...


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The commercial CF6-80C2 engine has a mass of about 5T and a thrust of about 300kN, including intake and nozzle thrust at takeoff. As heavy commercial engines go, it’s about the best for this application. That thrust can provide 1g upward acceleration to about 15T total mass. Subtracting its mass and allowing a bit for fuel (at full thrust it burns 3kg a ...


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Orion is: expensive to operate. It's heavier, bigger, but primarily the development was done in ways that drove the costs up significantly. It is capable of flight to lunar orbit - and it's an overkill to ISS. Too expensive and too overengineered for that purpose. Dragon 2 and Starliner are simply far more cost-efficient solutions. significantly behind ...


0

Modern PHP runs on a Virtual Machine: A guaranteed environment that will exist regardless of underlying operating system or hardware. That is, core library functions that depend on features of an OS are not part of the VM, such as getting the PID of a child process after performing a pcntl_fork() in a Posix environment. Rather, language constructs like ...


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Developing software for space applications is quite different from "regular" software development, especially when we're considering human spaceflight. If you want to develop critical software (i.e. software that, in case of a failure, can lead to loss of life, mission, and/or facilities) for ESA, you need to comply with the applicable standards defined by ...


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Let's have a look on a 1998 paper on real time systems from CMU (Carnegy-Mellon Univeristy). Typical examples of real-time systems include Air Traffic Control Systems, Networked Multimedia Systems, Command Control Systems etc. In a Real-Time System the correctness of the system behavior depends not only on the logical results of the computations, but ...


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What exactly makes PHP CLI fundamentally unsuitable to power all the math on board a space craft? ... What, exactly, is it about this that is so "crazy"? You seem to be taking the unsuitability of PHP as a given premise here. Why is that? PHP has two major deficiencies that are relevant here. One is that it's not very performant; the ...


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Partial answer to the last part of the question: How can I know when it was last updated and on which basis? Compare the "revision date" in output header to the "Start (TDB)" date of last item in the table of ephemeris files: Output header: MRO around Mars: ******************************************************************************* Revised: Oct ...


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