Is it really made of DU? According to the wikipedia and NASA's sites, LAGEOS-1 is a 60cm golf ball that weighs between 405 and 411kg. Wikipedia claims that it's a aluminum-covered brass ball, not DU. Given those parameters, LAGEOS-1 has a volume of 113,097 cm^3. That makes the average density of 3.6 g/cm^3. Uranium is 18.9 g/cm^3, brass is between 8.4 and 8.73 g/cm^3, and aluminum is 2.7 g/cm^3. It sounds like a solid sphere of aluminum with a brass coating to me. A 60cm ball of uranium would mass in at 2138 kg, more than 5 times its actual mass. This paper claims the Stella satellite has a DU core, but doesn't mention LAGEOS having one: http://geodesy.eng.ohio-state.edu/course/refpapers/Tapley_JGR_JGM3_96.pdf There's also a reference to a Starlette sat having a DU core but an overall mass of only 47kg and diameter of 48cm. Has anyone come across better documentation as to its construction? -- David Tiller Lead Consultant/Architect | CapTech Ventures -----Original Message----- From: seesat-l-bounces+dtiller=captechconsulting.com@satobs.org on behalf of George Roberts Sent: Tue 8/31/2010 10:31 AM To: Derek C Breit; 'JAY RESPLER'; 'SeeSat-L' Subject: Re: LAGEOS reentry > Ummmm... Don't they mean the Uranium will decay in 8 million years, and > are > not referring to the satellite?? Depleted Uranium has already decayed so it's not radioactive. It's very dense. Makes lead feel light in comparison. It's very popular in the military as it makes bullets that go through steel and such. It's also expensive. The lower the density of a satellite (such as a balloon) the faster it will decay. An inflatible satellite will decay faster than a rock. A satellite with solar panels will usually decay faster than one without. Also the higher the orbit, the longer it will take to decay. This altitude relationship isn't linear - it's probably exponential. This is because there is much less atmosphere when you go another few hundred miles higher. So 2X the orbital altitude and you might increase the lifetime by 100X. Combine high density with high orbit and you have a satellite that will decay in 8 million years. Very quick in astronomical terms but a bit slow in artificial satellite terms. Unless you were joking? Was that a joke and I just ruined it? You don't have to answer. - George Roberts http://gr5.org -------------------------------------------------- From: "Derek C Breit" <breit_ideas@poyntsource.com> Sent: Tuesday, August 31, 2010 9:22 AM To: "'JAY RESPLER'" <JRespler@superlink.net>; "'SeeSat-L'" <SeeSat-L@satobs.org> Subject: RE: LAGEOS reentry > > Derek > > -----Original Message----- > From: seesat-l-bounces+breit_ideas=poyntsource.com@satobs.org > [mailto:seesat-l-bounces+breit_ideas=poyntsource.com@satobs.org] On Behalf > Of JAY RESPLER > Sent: Tuesday, August 31, 2010 1:08 AM > To: SeeSat-L > Subject: Re: LAGEOS reentry > > > On 8/30/2010 5:08 PM, Dale Ireland wrote: >> Any speculation on what the reentry would be like or look like for an >> object like this? Uranium has a pretty high melting point of over 1100 >> C. 2ft sphere weighing over 1000lbs. Dale > > We'll have to watch for it in 8.4 million years. > >>> -----Original Message----- >>> On 8/27/2010 5:01 PM, Dale Ireland wrote: >>>> Has anyone seen the LAGEOS 1? >> It is 5000km out and only 2ft across with corner reflectors. Made of >> depleted Uranium it weighs half a ton and will not decay for 8.4 >> million years. >> >> I saw it back in Oct. 1994. >> Mag 11.0 >> >> -- >> Jay Respler > > -- > Jay Respler > ADVANCED BUSINESS MACHINES CO. > 732-431-1464 > -- > JRespler@superlink.net > SKY VIEWS& TYPEWRITERS ILLUSTRATED ENCYCLOPEDIA > http://uweb.superlink.net/jrespler > Freehold, New Jersey > > > _______________________________________________ > Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l > > _______________________________________________ > Seesat-l mailing list > http://mailman.satobs.org/mailman/listinfo/seesat-l > _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mailman.satobs.org/mailman/private/seesat-l/attachments/20100831/d55e5464/attachment.html _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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