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Warning: There is no way to decouple politics from this; I have tried to be objective. What ended as the ARM (Asteroid Redirect Mission) officially began in a speech by then-President Obama in April 2010 at Kennedy Space Center. This was the speech in which President Obama discussed the cancellation of the Constellation lunar landing program: "But I ...


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Halo orbit families exist near the L1, L2, and L3 librations points. This video focuses on the L1 and L2 halo families. There are northern and southern families at each of the libration points. The northern family is identical to the southern family but mirrored across the x-y plane. At each point, the family bifurcates from the planar Lyapunov family of ...


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A zillion years ago I was at a meeting where large projects were discussed and attempted to be justified. A slide was shown listing say five reasons why project such-and-such was absolutely vital and the speaker enthusiastically forwarded each reason in turn. The one response was "If you had one good reason you wouldn't need five. Ultimately it wasn't ...


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In fact, they are the preferred option among other staging orbits by analizing multiple factors: EARTH ACCESS: A study considering NASA SLS and Orion performances was carried out. Since SLS places Orion in a trans-lunar trajectory, Orion vehicle has to carried out orbital maneuvers to reach a orbit near the Moon, so the limiting factor will Orion's ...


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Making this a community wiki answer so others may add to it as they see fit: Advantages LEO assembly allows less mission risk if assembly does not go completely as planned. It's much easier to schedule and launch replacements or corrective hardware. LEO assembly allows for checkout and stress testing of hardware in a location where failure allows a safe ...


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I can maybe answer these questions, as someone that has worked on NextSTEP studies (HAB, PPE) and HLS Architecture and Lander Studies. In general, I thought a lot of the news articles were mostly shlock posted by people that have little clue about the architecture or Space in general (Yes, this comment is directed at you, Gerald Black - Let me know when ...


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Cislunar space is a large area: The region outside Earth's atmosphere and extending out to just beyond the Moon's orbit, including the Lagrangian points, is sometimes referred to as cis-lunar space. Earth orbits, Moon orbits and orbits around both (like Apollo 13's free return trajectory) can all be called cislunar orbits. LOP-G would use a halo orbit: ...


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Let's examine what Jim Bridenstine, current director of NASA and previous member of the Rocket Racing League (1, 2, 3) says. NASA Administrator Jim Bridenstine Explains the Lunar Gateway is a recording of director Bridenstine in YouTube, described as Published on Aug 7, 2018 NASA's new administrator spoke with reporters after a two-day trip to Kennedy Space ...


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The design of the Gateway is still in flux, but here's an illustration from a couple of years ago showing it next to the ISS (lower right corner). Source (in Spanish) This image compares Mir and ISS Source Historic Spacecraft


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The delta-v from LEO to NRHO is 3.95 km/s. The flight time is 5.33 days with an impulsive departure from LEO at 3.124 km/s and an NRHO capture impulse of 0.829 km/s. http://newpapyrusmagazine.blogspot.com/2018/06/cis-lunar-gateways-and-advantages-of.html


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No. The gateway is not bound to Earth, if we interpret "bound to Earth if the Moon disappears" as not drifting into interplanetary space regardless of what instance the Moon's gravitational influence is disregarded. There's a neat property of zero-gain flybys: At the point of closest approach, the velocity vector of the spacecraft is parallel to ...


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Your last sentence hits the major point. Other than Apollo, no humans have been outside of the Van Allen radiation belts. All of the astronauts on the nine space stations have been largely spared the radiation that they would be subject to for the months-long trip to Mars and back. The Apollo astronauts did get such an exposure, but their missions lasted ...


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How this is managed is a bit complex. The short answer is there may well be some clever ticks but weight constraints mean an effective radiation shield is not really a feasible option and apollo-style steel/aluminum capsules are near guaranteed, with the addressing being left to management things like returning crews near their limit of exposure. As for the ...


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LEO is a bit dangerous in my book. If anything goes wrong you may not have enough of a margin to fix things. Put the station in a little higher orbit and make your deliveries to LEO and use tug to push building blocks to the higher orbit. That way you have advantages of both. A big problem with LEO is the space junk. When you are done the higher orbit is ...


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Whether or not Jim Bridenstine said it, gateway won't literally go to L1 and L2. The current plan is to use a Southern L2 NRHO (Near Rectilinear Halo Orbit) which doesn't actually go near the L2 point. If it were a regular Halo Orbit, it would appear to orbit L2, and be closer to L2 than the Moon. A Near (read: Almost) Rectilinear orbit is offset from L2 so ...


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There are many ways to get to Gateway's destination NRHO. The transfer that a given spacecraft takes will likely depend on how quickly the vehicle needs to arrive. If it's a cargo vehicle, it can afford to take a long time for less fuel. If it's a crew vehicle, they probably have to go more direct. I can't really speak to the direct transfers, but I can ...


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Reading the linked questions, answers, and references (thanks @uhoh), particularly R. Whitley and R. Martinez, 2015, Options for Staging Orbits in Cis-Lunar Space and this figure: Leads me to believe that getting to a NRHO is much like an 'Apollo-style' lunar transfer (i.e., in plane, Hohmann-ish transfer orbit). The only difference comes in targeting the ...


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The question asks how long it would take. All "direct" trajectories to the Moon take about the same time -- 3 days. In principle you could shorten this by using quite large amounts of extra fuel (both to accelerate at the start and to enter lunar orbit when you arrive), but I don't think this has ever been done. You can also save a modest amount of fuel at ...


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First, note that Soyuz launcher and Soyuz spacecraft are two distinct entities. The launcher is based on soviet strategic R-7 rocket, and all of its modifications are definitely not powerful enough to put its namesake spacecraft anywhere near Moon orbit. Now, the Soyuz spacecraft is another matter. The Soyuz 7K-L1 spacecraft, in link with Proton launcher, ...


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