From: vince@offshore.ai (Vincent Cate) Newsgroups: sci.space.policy Subject: Re: Asteroids or bust! References: <1085752782.723641@haldjas.folklore.ee> <40BE2C72.3040001@tabletoptelephone.com> <40BFC647.5090508@tabletoptelephone.com> NNTP-Posting-Host: 207.42.133.252 Message-ID: <9186edb5.0407071735.e199817@posting.google.com> alexterrell@yahoo.com (Alex Terrell) wrote in message news:... > "Perplexed in Peoria" wrote in message news:... > > Ok, lets plug these numbers into Vince's graph to find the mass ratio: > > http://spacetethers.com/tether.html> > > > > Rather large. I still think that tether will be something to behold. > > From what I've seen, Vince's site is for Earth Orbiting rotovators. > We're talking about what Zubrin called the hypersonic skyhook, and > this one's orbiting Titan, not Earth. I like "rotating tethers" because the secret truth is that all tethers are rotating tethers. A "hanging tether" like Zubrin advocated is a rotating tether that rotates once per orbit. :-) Since the tether is floating in space, the main question is still just how fast the tip is moving relative to the center of mass. A tether would not care much if it was around Earth or Titan. As a hanging tether gets really long, the gravity gradient will make for worse mass ratios than my graph shows. My simulator sample inputs include some hanging tethers. -- Vince ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Vincent Cate Space Tether Enthusiast vince@offshore.ai http://spacetethers.com/ Anguilla, East Caribbean http://offshore.ai/vince ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You have to take life as it happens, but you should try to make it happen the way you want to take it. - German Proverb