Timeline for When a planet has a high gravity, is it impossible to build and launch a successful chemical rocket to space?
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Jul 11, 2014 at 18:29 | comment | added | Emilio Pisanty | @ChrisWhite We use rocket stages on Earth anyway, so it's a question of when rather than whether you start needing them. The key point remains - you start needing them "exponentially sooner in $\sqrt{GM/R}$", which is the same as the considerations in my and Phil's answer. | |
| Jul 11, 2014 at 18:12 | comment | added | user10851 | One wonders how much rocket stages can help cc/ @PhilFrost (+1 anyway, so it's not like you'll get more points from me if you do more calculations ;) | |
| Jul 11, 2014 at 18:08 | comment | added | Phil Frost | Ah, I see. I was misled by "Now, there are a number of ways to get around this restriction", where I assumed "this" to mean "escape velocity". | |
| Jul 11, 2014 at 18:07 | comment | added | Emilio Pisanty | Yes, that is another mechanism which helps. What I had in mind, though, is that if you only want to orbit (instead of escaping), then a thinner atmosphere also opens up lower altitudes which are easier to get to and which are now safe from orbital drag. | |
| Jul 11, 2014 at 17:52 | comment | added | Phil Frost | I think worth adding that the thinner atmospheric limit doesn't "get around" the escape velocity, but just reduces the additional energy one must expend to overcome drag. That is, Earth's escape velocity at the surface is about 11.2 km/s atmosphere or no -- and then the atmosphere means the drag your craft will experience on the way up requires additional fuel to overcome. | |
| Jul 11, 2014 at 17:31 | history | answered | Emilio Pisanty | CC BY-SA 3.0 |