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Short answer: Space stations have been refueled on orbit, as well as some small demonstration missions. Long answer: There is only a limited number of objects that this is even an option. There are 3 types of docking which have generally happened. Those involving manned spacecraft but not a space station, those involving a space station, and those with ...


19

This is basically the approach being considered for getting all of the hardware to Mars for a crewed mission. However instead of refueling an upper stage that was used to get you to orbit, it is considered much easier with almost the same benefit to launch an entire fueled stage with engines instead of just the tanks with propellant. The only penalty is ...


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The ISS is periodically refueled by its cargo supply ships. NASA's Robotic Refueling Mission has experimented with refueling satellites. DARPA's Orbital Express demonstrated hydrazine refueling (among other autonomous orbital maintenance operations) between two satellites in 2007.


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ESA is working on such an engine. an ESA-led team has built and fired an electric thruster to ingest scarce air molecules from the top of the atmosphere for propellant, opening the way to satellites flying in very low orbits for years on end The molecules collected by the intake designed by QuinteScience in Poland are given electric charges so that ...


8

You can find most of the information you need on the picture below which comes from Reddit. Crucially, if you add up the relevant lines, delta-V from Mars to Earth-Mars transfer is about 5.92 km/s. Assuming they produce the vacuum raptor (not planned for the very first starship missions) Starship will have an $I_{sp}$ around 380s, so by the rocket equation,...


8

The reason for the acceleration is not so much to cause the transfer of the liquids, but to get the liquid to be at one end of the tank where the pump inlet is. Remember in zero-g, the liquid is not going to stay at one part of tank but will slosh all over and mix with "air" or whatever gas is in the tank along with the liquid fuel. Without a little bit of ...


7

There isn't much information publicly available, but the MEV appears to dock to the one component many satellites have in common: the rocket engine nozzle. An extensible probe from the MEV (on the left) enters the rocket nozzle and (presumably) expands its tip. Frame from a video on the Space Logistics website, annotation mine. A line in the fact sheet ...


7

No. (Unless it has been done as part of a secret mission.) NASA's Space Technology Mission Directorate had plans for just that called Cryogenic Propellant Storage & Transfer (CPST), which would have launched a mission to demonstrate both the transfer of cryogenic propellent, and its storage in space for a long period of time. Unfortunately it was ...


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This is a short answer but in KSP pumping fuel is totally costless, whereas in reality pumping fuel between stages is difficult even in the case where the stages are mated together on the ground. This is especially true when the propellants are cryogenic and therefore more akin to a thick slush than easily-pumped liquid. On the other hand, I have found a ...


6

I didn't see this referenced anywhere so I'm including it for completeness. Feel free to merge it in with another answer. STS-41G (launched October 5 1984) included a secondary payload called the Orbital Refueling System (ORS). Here's a description from the Press Kit ORBITAL REFUELING SYSTEM (ORS) The Orbital Refueling System experiment is a ...


5

Shuttle orbital manuevering / attitude system tankage used screens to ensure that fluid always remained at the tank exit. Sufficient fluid would cling to the screens to get the engines started. The screens are shown in this schematic of an Orbital Maneuvering System tank. In this case the screens are only at the aft because this system always provided ...


4

I think it’s because they want to use the same pipe work they use for tanking on the ground in orbit. I imagine the Starship will have an LOX inlet/outlet on one side and a Methane inlet/outlet on the other and all Starship will be built in the same way. If you back one Starship onto another with the heatshields pointing in the same direction the LOX pipe ...


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For the Salyut 6 space station, both Progress cargos and the station used bladder tanks. The tanks were pressurised using nitrogen. The nitrogen could be recovered once the operation was done (at least on the station side). To vent the pipes, they just let them open, exposed to vacuum for a week then purged with nitrogen. Source:The Story of Space Station ...


4

So long as the object you wish to slow is made of metal you can slow it by putting a ring of magnets around it. How fast this will work depends on the metals involved. I do not believe this can bring it to an actual stop, however--the slower it turns the less braking force. Edit: Yes, you can stop it--if your ring is spinning the velocity won't go to ...


4

Ullage (i.e. getting the fuel at the end the tank you want it to be at and the pressurant at the other end) for large rocket stages in free-fall is usually handled with small auxiliary thrusters. For small thrusters, it's practical to use bladder pressurization or some other solution; you use the small thrusters to slightly accelerate the large stage, and ...


3

For missions that require more fuel than the standard ACES stage contains, they propose to launch 2 rockets, one with the ACES stage and payload, one with extra LOX en LH. They also propose using the ACES stage and XEUS lander as space tugs, keeping them in space for a long time instead of having to launch a new one for every mission. That's what the '...


3

My reading of the Aviation Week article on this seemed to suggest that while Landsat-7 was not designed to be refueled, when they looked at its design, they found a fuel line, they could patch into that could be used to fill the tanks again. They need to cut away the insulation to get to the pipe, and then will probably use some variant of a vampire tap to ...


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The presentations Musk made at the IAC suggested 6 tankers to one spaceship, for a Mars mission. Two tankers to one spaceship for a lunar mission.


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There are multiple designs for rovers and robots which are designed to pick up regolith from the surface and transport it for water extraction. For example, in this video, a rover is shown which has dual drum-excavators and is picking up the surface material in the simulated martian environment. For such a rover to work, the water would need to be rather ...


3

Theoretically possible, but not planned. Refuelling in the sense of replacing expended fuel in the propulsion system is possible in theory. This answer provides a nice schematic of the propulsion system, and according to the legend at least there is a valve for filling up the propellant tanks. Presumably, you could "top it off" again once the fuels is ...


2

Making a drill rig mobile is easy; it simply gets mounted on a tracked or wheeled platform. Mineral exploration companies & water borers have used truck mounted drill rigs for decades. The technology can be adapted for use on other celestial bodies. As to ground stability issues, this would potentially be a major issue if drilling sub horizontal holes ...


2

First of all, let's look at what the delta V is for a fully loaded BFR upper stage in orbit. Given the Delta V tables shown, and assuming 150 tons, a delta V of 6.2 km/s is shown. 150 tons is assumed because that is the mass to LEO provided. As I understand it, these numbers come from a tanker orbiting Earth approaching the payload, and refueling it. It ...


2

An alternative would be to enclose the object in an air tight container and pump some air inside. Drag would slow down the craft. The main issues for the aerodynamic drag technique will still be the same as for the magnetic drag technique: maintain separation between the container and the spinning object de-spin the container as the rotating air transfers ...


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Of course everything about planned SpaceX Starship configurations and missions is still tentative and subject to change. However, there are a few points worth establishing: Despite the animation, one tanker on a refuelling mission can't come close to fully refuelling one starship. The Starship burns about 1100 tons of fuel to put 150 tons of payload (plus ...


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I believe the point is that the spacecraft itself only has to get out of Earth's gravity well once. Until ISRU propellant sources on the moon are up and running, propellant still needs to be brought up from Earth's surface, but regular bulk propellant-only launches to a fuel depot in LEO have different engineering requirements that may allow for cost ...


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