30

Unfortunately sending propellant ahead to pick up on route will not help. The same amount of propellant will be needed regardless if both are accelerated together or separately. Also if launched separately it adds to the complexity of the mission as a docking will be required. Any type of docking requires both ship and propellant store to be traveling on the ...


19

If you think less about fuel and more about the other amenities for a long distance mission, you are awfully close to the concept of a cycler. The basic idea is that you take a big vessel, on which astronauts can live for a long time and accelerate it on a trajectory that regularly passes by the places you want to travel in between. You do this without a ...


17

The real problem is that, in space travel, your speed determines your trajectory, and therefore two objects can't follow the same trajectory at different velocities. Precisely, a faster interplanetary trajectory will give you a more elliptic, elongated orbit around the sun, while a slower one will be more round (and I don't even consider the case of gravity ...


7

Rather than having fuel tanks you meet on the way the better way would be preposition fuel tankers at the start and end of the trip i.e Earth and Mars orbit. You put fuel tankers in Earth's orbit as its the easiest place to refuel (in this scenario) and means you can make use of small rocket launches (crew, ship, and fuel separately) instead of needing one ...


5

Welcome to Space stack exchange. This is a part of launch window analysis and I'd recommend using that as a search term. The simplest answer is "a bit more than 180 degrees". This is for the situation where the launch site is on the equator and the target satellite is geostationary rather than inclined geosynchronous orbit. Imagine that the ...


4

There is an answer about launch windows on Space Exploration Stack Exchange here. Basically, there was a launch window of a few minutes every two hours for optimum rendezvous with the Command Module, but in an emergency the LEM could just launch into lunar orbit at any time and then rely on the CSM (which had much larger fuel reserves) to perform orbital ...


4

As in the other answers, your ideas won't save fuel and time, but they may in the future vastly improve likelihood of mission success and crew safety, at the cost of more fuel and time. An unpeopled lander, or a sequence of unpeopled landers could, for instance, establish a fuel depot on Mars to allow for a lighter craft to land, and then refuel with the ...


4

The technical and organizational causes of the Gemini IV station-keeping failure are discussed in this conference paper. John Goodman, “A Cautionary Tale of a Secret, a Small Team, an Accelerated Schedule, and the Gemini IV Station-Keeping Failure,” 43rd Annual AAS Guidance and Control Conference, Breckenridge, CO, January 30 to February 5, 2020. paywalled ...


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