From: vince@offshore.ai (Vincent Cate) Newsgroups: sci.space.history,sci.space.policy Subject: Re: $5M Moon Rock Stolen From Malta Museum References: <373a0bc9.0405211458.bde154a@posting.google.com> <1ywsc.624$ZM1.488@bignews6.bellsouth.net> <9186edb5.0405250856.eeee6b9@posting.google.com> <9186edb5.0405260624.b0faebd@posting.google.com> <4d6b07f3.0405261021.5663547f@posting.google.com> <9186edb5.0405270445.7b321552@posting.google.com> <1085688231.56339@haldjas.folklore.ee> NNTP-Posting-Host: 207.42.133.252 Message-ID: <9186edb5.0405272142.48605589@posting.google.com> Sander Vesik wrote in message news:<1085688231.56339@haldjas.folklore.ee>... > Depending on whetever getting them would require going to an unkown > and anproven technology for which you not just can't really get > proven materials but also you need to do a many orders of magnitude > higher up-front investment. The main material is Spectra-2000. This is a well proven fishing-line and kite-line material. Because a tether system can be so much smaller, it should not be orders of magnitude more investment. > For initial profit based missions, tethers > simply don't enter into the picture. Time will tell. >Vince: > > I don't think it would cost $400 to $500 mil, but it is clearly > > hard to say. > > SMART-1 cost $100m. Its a small orbiter and was launched as a add-on > cargo on a flight where most of the expenditure was paid for by other > satellites. You are going to need the full capacity of a heavy launcher, > so $150 - $180m. Assuming that whatever you are launching cost you $200m > to develop and build is reasonable and you co-incidentialy have arrived > at $400m. There is some reason to believe that if a government organization can do something for $100 mil that a new startup company could do it for much less. The Falcon-V will take 10,000 lbs to LEO for $12 mil. This should be enough for a probe using a tether. We do not need a $150+ mil launcher. It is the all chemical rocket approach that need lots of starting mass. > > To me it seems much easier to justify an investment if you end up > > with a low ongoing cost and 100 kg a month than a deal with a > > onetime payback of 20 kg. > > Really? have you tried writing this up? How much mass doyou need to launch > and how much does the thing launched cost? And please use realistic present > day costs and not arbitrarily tweaked numbers until it worked for you. As I said about costs above, "... it is clearly hard to say". But a tether to lift 5 Kg from the moon only needs to be like 15 to 30 Kg. So the system does not need to be really huge. -- Vince