Oh...the Humanity Ball!

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neufer
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Oh...the Humanity Ball!

Post by neufer » Fri Mar 23, 2018 3:35 pm

https://en.wikipedia.org/wiki/Humanity_Star wrote:

<<Humanity Star was a passive satellite designed to produce flares visible from Earth. Its shape was a geodesic sphere about 1 metre in diameter, similar to a large disco ball. Because of its highly reflective surface, Rocket Lab claims Humanity Star could be seen by the naked eye from the surface of the Earth. Its apparent brightness was estimated to be magnitude 7.0 when half illuminated and viewed from a distance of 1,000 kilometres, while its maximum brightness was estimated to be magnitude 1.6. The satellite was most likely to be visible in the night sky at dawn or dusk. According to Rocket Lab, it was meant to be "a bright symbol and reminder to all on Earth about our fragile place in the universe". Humanity Star was launched on 21 January 2018 at 01:43 UTC from Rocket Lab Launch Complex 1, located on the Māhia Peninsula of New Zealand. It orbited the Earth every 92 minutes in a polar orbit of approximately 290 by 520 km in altitude. According to Rocket Lab, the satellite's orbit was expected to decay after nine months, eventually burning up completely in Earth's atmosphere. However, the satellite re-entered on 22 March 2018 at about 13:15 UTC. Initial reactions by astronomers were negative, since reflective objects in orbit can interfere with astronomical observations. It has been described as an act of vandalism of the night sky, space graffiti, a "publicity stunt" and "glittery space garbage".>>
Art Neuendorffer

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MarkBour
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Re: Oh...the Humanity Ball!

Post by MarkBour » Sat Apr 07, 2018 4:17 pm

New Zealand has a launch complex? And this is their contribution? I wonder if anyone got any good photos of it while it lasted. In two months, it probably didn't produce very many good flare sightings. Of course, my reaction to its demise is "good riddance".

I won't continue my thread on "some people want to launch a ton of satellites", since I'm really just a late-comer, waking up to the news. But the story of Rocket Labs fits right in ... they are going to start commercial operations this month and hope to make a business of launching cubesats for "anybody" into low earth orbit. What rules will they be following, I wonder?
Mark Goldfain

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Chris Peterson
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Re: Oh...the Humanity Ball!

Post by Chris Peterson » Sat Apr 07, 2018 5:47 pm

MarkBour wrote:
Sat Apr 07, 2018 4:17 pm
New Zealand has a launch complex? And this is their contribution? I wonder if anyone got any good photos of it while it lasted. In two months, it probably didn't produce very many good flare sightings. Of course, my reaction to its demise is "good riddance".

I won't continue my thread on "some people want to launch a ton of satellites", since I'm really just a late-comer, waking up to the news. But the story of Rocket Labs fits right in ... they are going to start commercial operations this month and hope to make a business of launching cubesats for "anybody" into low earth orbit. What rules will they be following, I wonder?
There are rules that take into account satellite lifetime. How well they're followed I don't know. For reference, the least expensive option (a 1U cubesat in a 450 km orbit has a lifetime to reentry of under a year. At the highest orbits these are put into, that can extend to around 25 years.
Chris

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MarkBour
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Re: Oh...the Humanity Ball!

Post by MarkBour » Sat Apr 07, 2018 8:26 pm

Chris Peterson wrote:
Sat Apr 07, 2018 5:47 pm
There are rules that take into account satellite lifetime. How well they're followed I don't know. For reference, the least expensive option (a 1U cubesat in a 450 km orbit has a lifetime to reentry of under a year. At the highest orbits these are put into, that can extend to around 25 years.
I think the approach of assuring a limited lifetime is very helpful.

Still, the following graph, along with other measures of space-launch activity, just blows my mind.
https://en.wikipedia.org/wiki/CubeSat#/ ... _years.png
Mark Goldfain