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### What can the KSP game actually teach about spaceflight and orbital mechanics, and what are its limitations?

I have seen at least several different users mention that they've found Kerbal Space Program helpful to understand issues of spaceflight and orbital mechanics. According to Wikipedia: While the game ...
5k views

### Are patched conics (and by induction, KSP) "useless" for simulating ion propulsion?

My previous KSP question What can the KSP game actually teach about spaceflight and orbital mechanics, and what are its limitations? resulted in some really productive discussions and under-the-hood ...
1k views

### Was the Apollo spacecraft always gravitationally bound to the Earth-Moon system?

When the Apollo spacecraft was en route to the Moon, was it an escape trajectory from the Earth-Moon system? If not for the burn(s) to enter lunar orbit, would it have continued in an independent ...
1k views

### By what methods can cubesats move from LEO to higher orbits?

If a cubesat is launched as secondary payload to LEO, what ways are there to put it in a higher orbit, for example outside of the van Allen belt to make a radiation experiment? The ISS launches ...
1k views

### Could a cubesat be self propelled to the moon from LEO?

Is it possible with current technologies to propel a cubesat, which is launched from Earth, to the moon? If current propulsion systems are able to do so, how do I continue the research in this topic ...
1k views

### Thrust and rotation strategy to circularize a standard GTO orbit using ion propulsion?

The previous question How much time does it take to circularize a GTO orbit using ion propulsion? has a good, quantitative answer based on a known delta-v. But I'm wondering how would you actually ...
859 views

### Have light gases like hydrogen or helium been explored for ion propulsion?

This answer and discussion in comments below this answer mention that for an ion of mass $m$ and charge $q$ accelerated by a voltage $V$ the momentum it receives (impulse) is p = \sqrt{2mqV} = \...
788 views

### How will the Lunar Gateway go to L2 and L1; how much delta-v is needed?

In a talk to the press which can be heard in the YouTube video NASA Administrator Jim Bridenstine Explains the Lunar Gateway, NASA director Jim Bridenstine says after about ...
503 views

### What are the parameters of the new Iodine electrical rocket engine developed by RSC Energia?

Several news outlets are reporting Energia Rocket and Space Corporation is nearing completion of a new electrical rocket engine using iodine stored as a solid and vaporized as needed. The new ...
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### How many spacecraft deployed from the ISS have escaped Earth orbit? Are there plans for any in the near future?

After reading Why did the Ulysses probe reach Jupiter much faster than Galileo? and answers to How many Space Shuttle payloads ended up beyond Earth orbit? and also What's the largest rocket that was ...
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### What's the lowest altitude that an ion engine has been used for a significant orbital maneuver?

I'm thinking about trying to calculate something for Where do ion propulsion's ions go? Do they remain in the solar system or shoot out into interstellar space? Excluding low altitude tests of ion ...
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### Is an electric fuel tug from LEO to moon orbit economically feasible?

Does it make economical sense to use an electricaly powered fuel tug to supply a moon landing program with fuel? I am imagining an architecture of launching a 25t payload of mostly fuel into LEO which ...
156 views

### Why haven't there been more space missions that use low-energy trajectories?

The Wikipedia article on low-energy transfers lists only 4 spacecraft over the past decades that at some point of the mission navigated low-energy trajectories, yet there has been extensive research ...
If I have a propeller with a continuous thrust of $1 \times 10^{-9}$ Newtons, can I take the satellite from LEO to the moon? How can I calculate the time it would take for a satellite of a certain ...