# Thread: Haumea: what would iit take to make a space elevator from that object?

1. ## Haumea: what would iit take to make a space elevator from that object?

https://en.wikipedia.org/wiki/Haumea

It rotates so rapidly that it's very deformed, and the gravity due ro its mass is almost overcome by centripetal force at it's ends. It seems that except for its temperature it would be the ideal place for a space elevator.

2. ## Re: Haumea what would iit take to make a space elevator from that object?

Putting the numbers from Wikipedia into the formula for a geostationary orbit, I get a radius of about 1100 km for the height of that orbit. Haumea's longest axis is about 2100 km, so its highest "peak" on the equator would be about half of that or 1050 km. Thus, your elevator would need to be about 50 km high. 50 km would be challenging, but not impossible, to do on Earth. With the much lower gravity on Haumea (about a factor 50 lower than Earth's), it would be downright trivial. A simple steel rope would do, and have plenty carrying capacity to spare. Even starting from its lowest point (just for the challenge), you would need only about 500 km. Maybe that is a little much for a rusty steel rope you found in a scrapyard, but still easy if you use a good steel alloy or optimized material like Kevlar.

Thus, you have your space elevator on a frozen, far away piece of rock, that it takes decades to even transfer to. A rock, where a bullet from a handgun would already achieve escape velocity. While certainly interesting, there are probably more useful places to spend your space elevator efforts on, like Mars or the Moon.

3. ## Re: Haumea what would iit take to make a space elevator from that object?

Clearly, you want it so you can win a design contest by saying that technically you built a space elevator.

4. ## Re: Haumea what would iit take to make a space elevator from that object?

We will maybe one day remake planets, and I think one with Haumea's approximate shape but bigger and a rate of rotation to get that shape might be a good idea. A person could walk everywhere on it, but the effective surface gravity would vary from not much at the long bits, to maybe Earthlike or even above at the flatish poles.

5. ## Re: Haumea what would iit take to make a space elevator from that object?

Originally Posted by halfeye
We will maybe one day remake planets, and I think one with Haumea's approximate shape but bigger and a rate of rotation to get that shape might be a good idea. A person could walk everywhere on it, but the effective surface gravity would vary from not much at the long bits, to maybe Earthlike or even above at the flatish poles.
Problem with building a planet sized ellipsoid is, that this is effectively the same as building a heap, thousands of kilometers high. Which is quite impossible and the reason, why anything larger than Haumea is sphere-shaped.

6. ## Re: Haumea what would iit take to make a space elevator from that object?

Originally Posted by Seppl
Problem with building a planet sized ellipsoid is, that this is effectively the same as building a heap, thousands of kilometers high. Which is quite impossible and the reason, why anything larger than Haumea is sphere-shaped.
Nonsense. The reason Haumea is the shape it is is because it is spinning so fast.

Saturn also rotates relatively fast, and is squashed as a result, though not half as much as Haumea.

https://en.wikipedia.org/wiki/Saturn

If Haumea wasn't spinning, it would be more spherical than Ceres, though a little bigger.

https://en.wikipedia.org/wiki/Ceres_(dwarf_planet)

Haumea spins once in a little under 4 hours, Saturn in a little over 10 and Ceres a little over 9, To get a Haumea shape with an approximately Earth mass body would clearly take a rotation rate between Haumea and Saturn, but I don't know exactly what rate would be required.

7. ## Re: Haumea what would iit take to make a space elevator from that object?

Originally Posted by Seppl
Putting the numbers from Wikipedia into the formula for a geostationary orbit, I get a radius of about 1100 km for the height of that orbit.
There's another relevant equation: the Roche limit, which works out to about 140 megameters for Earth-Haumea.

Fiddling with the numbers, a gravitationally bound object in geostationary orbit would need to be over 8.2% the weight of earth.

The cable would also need to be mechanically attached to the counter weight, and Haumea isn't entirely mechanically attached to itself. It's surface it almost certainly loose dust/snow. There might be contiguous ice a km so so down, but that'll all evaporate if Haumea is brought into the inner solar system. It's probably something like a 100 km into that planetoid before anything we call solid rock appears.

8. ## Re: Haumea what would iit take to make a space elevator from that object?

The counterweight would not be a ball of dust, though. The simplest counterweight would just be to make the rope about twice as long. Tidal forces are not going to rip apart a steel wire a few meters in diameter.

9. ## Re: Haumea: what would iit take to make a space elevator from that object?

Thinking further about this, I suspect that due to it being in Hydrostatic equilibrium, such a object would be entirely covered by whatever atmosphere it may have, but due to the low effective gravity at its ends, I suspect its atmosphere would tend to drift away.