What's So Special About Low-Earth Orbit? | Hacker News Reader

What's So Special About Low-Earth Orbit?

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35 pointsAmorymeltzer16 comments

Beyond the information presented, this is really neat to see interactive visualizations with code that can be edited inline.

It reduces the apparent distance between "wow cool visualization" and the code that generated it.

The more people see code regularly, and can connect it with something they understand, the more likely they are to be code fluent.

Prolly off topic but: I show my code to my sister who is a professional artist every chance I get. It demystifies the process in her mind and makes me better at understanding what is happening around her.

From an energy perspective, as Heinlein pointed out "Once you get to earth orbit, you're halfway to anywhere in the solar system."

Except if you want to go somewhere - and then stay there.

Once you go somewhere, you're halfway to staying there.

Capture doesn't need all that much energy unless you're taking a really impatient path to a distant location.

I was delighted to learn recently you can get a nanosatellite to orbit for not very much money, and at the same time disappointed to find out that it would not stay up there for very long. Somehow I thought satellites could stay on orbit permanently

Yep there's still a good bit of atmospheric drag even at the ISS's altitude. Once you get beyond the atmosphere you get solar wind creating drag too. The ISS is periodically reboosted into a higher orbit by engines on one of the Russian modules.

Also, small satellites have much higher surface area to mass ratios.

Yeah that's another big factor in how fast they decay. The fact that they deorbit easily is good though, if they stayed up for a long time it'd be harder for NASA to approve so many so easily because they'd become a threat to LEO operations. A lot of them are launched from the ISS.

How do the approvals work if you are not in the US?

The ESA and JAXA both seem to run approvals too. I'm not sure about their current plans/proposal request statuses the only ones a surface googling finds are several years old so they might be in between proposal cycles.

There are a couple projects working on miniaturized ion drives for cube sats.

how much energy do these consume? would solar panels on a cubesat provide enough energy for staying on orbit for years?

I'd be interesting to see some example orbits re-scaled so that instead of showing physical distance, their "altitude" is actually the energy necessary to establish and maintain them for a reasonable period of time.

Someething like xkcd's Gravity Wells (https://xkcd.com/681/) but for orbits would be neat indeed.

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