[FRIAM] starlink trail

Tue May 28 02:17:55 EDT 2019

Daniel Suarez’s latest book, Delta-V, is great read - lots about the junk in orbit, the futility of Mars, and the viability of asteroid mining. Even has a Musk type ‘hero’.
dve west

On Mon, May 27, 2019, at 9:12 PM, Steven A Smith wrote:
> 
> <another long-winded anecdote> 
> I was born "under the rising sign of Sputnik" in 1957 (S1 & S2 went up late that year). I was just about 1 year old when Explorer 1 and then Vanguard 1 went up in early 1958. Vanguard 1, 2, 3 are still up there, being in an unusually high orbit for the time. The crowdsource Moonwatch <https://www.universetoday.com/100744/citizen-science-old-school-style-the-true-tale-of-operation-moonwatch/> project was already developing and was used to try to track/find Vanguard, but the first siting of an artificial satellite was of Sputnik. Ham radio folks were tracking the radio signals, but visual siting (telescope or binoculars) was much trickier.
> 
> Some here were born early enough to have been young adults at that time and probably have first-hand memories of these events, and perhaps even attempting their own observations? My first experience with direct satellite observation was *probably* when the Echo  <https://en.wikipedia.org/wiki/Project_Echo>"satelloons" were up. At roughly 100' diameter with a deliberately reflective surface (passive microwave relays), they were apparently highly visible to the naked eye. 

> We've come a long way baby! </anecdote>

> <speculation> We (humans collectively) now have something approaching 10,000 satellites or fragments in orbit... one man's "trash" is another man's "treasure" of course. I haven't heard Musk announce a SpaceX "Salvage Operation" yet, but at some point, that seems like a viable business, given the expense of launch... the materials in derelict satellites would seem to be valuable once a method for "recycling" those materials could be developed. I believe we are still in the early stages of a "radiation" of design-species in satellites, not having settled on any specific body plan and functional conceit... some might eventually depend on a modest amount of "foraging" once in orbit? 

> Delta-V is clearly the most valuable resource which for all but solar/mag-sail propulsion depends on reaction mass... which suggests turning "big ones into little ones" with space junk (grapefruit to bus-sized objects) into streams of (ionized) particles as small as individual molecules. Variations on "tether" and "sail" technology also may be good uses of captured "space junk". A big challenge to all this is the orbital mechanics sophistication to use less DeltaV matching orbits to "catch" junk than is gained by capturing it. Oh yeh... and still do something actually useful besides just wander around eating and pooping things.

> <speculation>

> 

> On 5/27/19 10:09 AM, Owen Densmore wrote:
>> A TLDR post. It points to a video of the "train" but brings up problems with the eventual number of the critters.
>> 
>>  -- Owen
>> Sightings of SpaceX’s Starlink satellites spark awe — and astronomical angst (3 minute read) <https://tracking.tldrnewsletter.com/CL0/https:%2F%2Fwww.geekwire.com%2F2019%2Fsightings-spacexs-starlink-satellites-spark-awe-astronomical-angst%2F/1/0100016af8bd48bf-94af9903-5a99-4bdc-914c-330937053b7f-000000/1p5yHFi__nt-eWCq_QXyb1VvhqluhaiG5EZV4OIiDqY=90>

>> SpaceX has launched 60 of its Starlink broadband satellites into the sky, creating a chain of satellites that could be observed by enthusiasts in a number of locations around the world. Some astronomers have expressed concern that the brightness from the satellites will interfere with observations of the night sky, especially when all 11,000 satellites are deployed. Elon Musk has confirmed that the satellites will be dark when the stars are visible.

>> 
>> On Mon, May 27, 2019 at 9:57 AM Stephen Guerin <redfishgroupllc at gmail.com> wrote:
>>> Any idea on how far separated ground cameras would need to to get triangulate 3d using a shift in the apparent RA and declination of the background start field?
>>> 
>>> On Mon, May 27, 2019, 8:49 AM Roger Critchlow <rec at elf.org> wrote:
>>>> The prediction has shifted to a few minutes earlier tonight, appears 20h53, disappears 21h04, track passes close to Vega then close to Arcturus. 
>>>> 
>>>> -- rec --
>>>> 
>>>> On Sun, May 26, 2019 at 10:15 PM Roger Critchlow <rec at elf.org> wrote:
>>>>> They were early, about 21h40m at the meridian, three were bright from 45d altitude, others may have flickered into visibility or may have been my imagination. 
>>>>> 
>>>>> The predicted pass in Santa Fe for Monday the 27th of May is from 21h01m10s to 21h12m23s, from SW to NE again, passing close to Vega. Give yourself some slack on the time, the speed depends on the altitude and the satellites are supposed to be boosting higher ever 90 minutes.
>>>>> 
>>>>> -- rec --
>>>>> 
>>>>> 
>>>>> On Sun, May 26, 2019 at 12:03 PM Roger Critchlow <rec at elf.org> wrote:
>>>>>> According to calsky.com the trail of the 60 starlink satellites rises in Santa Fe this evening at 21h40m28s in the SW and sets at 21h51m43s in the NE. They are 8.5mag at the horizon which is too dim to see, but they should reach 4.7mag at the meridian at 21h46m17s. Looks like they'll pass close to the last star in the big dipper's handle. 
>>>>>> 
>>>>>> -- rec --
>>>>>> 
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