Home » News & Blogs » Lunar Sky Hook
Bookmark and Share
Hop's Blog

Lunar Sky Hook

9 Aug 2016, 04:00 UTC
Lunar Sky Hook
(200 words excerpt, click title or image to see full post)

Kim Holder has been urging me to do this blog post. Her comments in various forums have been helpful in thinking about this.Vertical Lunar Tether In A Polar OrbitThis sky hook is a gravity gradient stabilized vertical tether. It's in a polar orbit so it will pass over the poles as well as the lower lunar latitudes.Unlike an equatorial orbit, there are only two occasions during a lunar orbit where a tether's Vinf velocity vector is anti-parallel to the moon's velocity vector. So launch windows to earth would only occur each two weeks. That's still pretty often. These occasions are also good times to rendezvous with the tether.Playing with earth moon three body simulations, polar orbits seem to remain stable up to a radius of around 20,000 kilometers. That is where I will set the anchor mass at the balance point of this sky hook. I believe this is far enough above the lunar surface that the mascons won't damage this tether's orbit.Asteroid Anchor Mass Via a Keck vehicleWhat to use for the anchor mass? With the asteroid retrieval vehicle proposed in the Keck Report, it is possible for a vehicle of moderate mass to retrieve a much larger mass ...

Latest Vodcast

Latest Podcast

Advertise PTTU

NASA Picture of the Day

Astronomy Picture of the Day

astronomy_pod