Satellites : general discussion and musings

[lux]

We should all bow our heads for a moment of silence in respect to the December 2012 decommissioning of NASA's Landsat 5 satellite after 28 glorious years of service in space.

http://en.wikipedia.org/wiki/Landsat_5

NASA is very fortunate to have had access to rechargeable batteries in 1984 (when it was launched) that could last for 28 years -- in space no less.

I eagerly await the day when these batteries are finally made available to us mere mortals.

[simonshack]

We should all bow our heads for a moment of silence in respect to the December 2012 decommissioning of NASA's Landsat 5 satellite after 28 glorious years of service in space.

*
Tom Hill - who 'donated' his LEGO version of Landsat to ...LEGO... which go for around $30

lego_landsat.JPG (145.34 KiB) Viewed 5764 times

https://landsat.gsfc.nasa.gov/a-lego-landsat/
Read all about it!

In other words... HOW TO GET KIDS HOOKED ON SATELLITES.


[EDIT: Old links removed and screen grab of new link created. -HP Dec. 21, 2017]

[st]http://landsat.gsfc.nasa.gov/graphics/news/dyk0006.jpg
http://landsat.gsfc.nasa.gov/news/news- ... _0006.html[/st]

[lux]

I can't find a photo of any of the actual Landsat satellites -- just drawings.

[simonshack]

ADMIN NOTICE: I have moved a few of the latest posts here regarding our 'satellite', the moon (by bostonterrierowner, scud and totalrecall) over to this more appropriate thread : http://www.cluesforum.info/viewtopic.ph ... &start=150

[lux]

The Landsat 5 satellite has now set a Guinness world record, says NASA, "for being the longest-operating Earth observation satellite after almost three decades in orbit."

Article here.

So, my questions to NASA would be:

- How did this satellite avoid the 100 tons per day of meteoroids/micro-meteoroids including upon its delicate solar arrays for 30 years?
- How did the onboard fuel powering its thrusters manage to last for 30 years correcting course deviations caused by lunar gravity and other factors?
- How did its rechargeable batteries last for 30 years of constant recycling and where can I buy batteries like that?

I won't ask how the satellite avoided the effects of "cold welding" over such a long period (as has been discussed here) because that phenomenon is now officially labeled as a "myth" according to this wiki article which states:

Mechanical problems in early satellites were sometimes attributed to cold welding. However, in 2006, Henry Spencer stated that the phenomenon of spontaneous cold welding in outer space is "basically a myth", pointing out that "there are no documented cases of it actually occurring in orbit ...

Who the hell is Henry Spencer?

The only Henry Spencer I found with some connection to NASA has a blurb about him on a NASA web site here.

Henry Spencer is a Unix systems programmer, space historian, and long-time space enthusiast.

This qualifies him to declare that cold welding in space is a myth?
-

[Heiwa]

Once (not any longer) being a qualified welder of thick/thin/steel/alu ship structures I was curious about the cold welding in space stuff, i.e. metals just connect by themselves, e.g. electro-mechanical (!!) switches in space ships jam!

Three gentlemen, A. Merstallinger, M. Sales and E. Semerad of the Austrian Institute of Technology (AIT), A-2444 Seibersdorf, Austria, and one gentleman, B.D. Dunn, Manufacturing Technology Advisor of the Product Assurance and Safety Department, ESA/ESTEC, Noordwijk, the Netherlands, have solved the problem of 1.1 Failures due to cold welding in space (http://esmat.esa.int/Publications/Publi ... TM-279.pdf) I am happy to note:

Spacecraft subsystems contain a variety of engineering mechanisms that exhibit ball-to-flat surface contacts. These may be periodically closed up to several thousand times during ground testing and the operational life of the spacecraft. These contacts are usually designed to be static, but in reality they are often subjected to impact forces. Other static contacts are closed without impact, but will be subjected to fretting during the launch phase or during the deployment of arrays, as well as during the service life of the spacecraft. In the latter case, the fretting originates …

Enjoy! It is awful!

[lux]

The Swiss have a solution to space junk! It's a giant space claw!


full link: http://www.youtube.com/watch?v=qTAv7TsnjzA

More info:
http://motherboard.vice.com/blog/the-sw ... giant-claw

Here Swiss aerospace scientists demonstrate the high tech method used to grab space debris:

CleanSpace_zps52f648e9.gif (908.21 KiB) Viewed 5764 times

[st]http://i905.photobucket.com/albums/ac25 ... f648e9.gif[/st]
[ADMIN: PhotoBucketrap image replaced with CluesForum direct link for posterity. -HP Dec. 21, 2017]


But, don't they know that Mel Brooks solved this problem back in 1987 when he demonstrated Mega-Maid?
7uWz6Hx9t7E
[ADMIN: This video was removed. But if you watch 'Space Balls', you'll know what he's talking about. -HP Dec. 21, 2017]

[simonshack]

*
Priceless find, Lux !

Presumably inspired by...

spider-crap.JPG (19.03 KiB) Viewed 5765 times

Now, the Swiss are gonna have a lot of work on their hands ...

"More than 22,000 objects larger than 4 inches (10 cm) are currently tracked by the U.S. Space Surveillance Network."
http://www.nasa.gov/news/debris_faq.html

But aren't they going to put this NASA office out of business?
NASA Orbital Debris Program Office http://www.orbitaldebris.jsc.nasa.gov/

[lux]

Here is my design. I call it THOR (Technological Hitter Of Refuse):



It sneaks up behind the junk and gives it a good whack, sending it downward where it burns up in the Earth's atmosphere. I'm negotiating a contract right now for $30M in development money from NASA.

[simonshack]

I'm negotiating a contract right now for $30M in development money from NASA.

Good for you, Lux! (Your device looks quite efficient - and "THOR" is an apt name indeed!)

Let us know if you'll be able to put aside a spare million or two for Cluesforum to sponsor a program offering free trips to Mars. We could start by sending earth-junk such as this planet's media moguls up there - what do you think?

(PS: If Mars proves too expensive, we might just place them in geostationary orbit).

[lux]

^Or, we could send them up into an orbit within the Van Allen Belt to confirm its harmless effect on humans.

[Flabbergasted]

Project Loon, brought to you by Google X

Are we seeing real, feasible satellites going into operation now, or is this another loony-toony scientertainment show?

From the Wicked One:

Project Loon is a research and development project being developed by Google X with the mission of providing Internet access to rural and remote areas using high-altitude balloons placed in the stratosphere at an altitude of about 20 km (12 mi) to create an aerial wireless network with up to 3G-like speeds. Using wind data from the National Oceanic and Atmospheric Administration (NOAA), the balloons are maneuvered by adjusting their altitude to float to a wind layer after identifying the wind layer with the desired speed and direction. People connect to the balloon network using a special Internet antenna attached to their building. The signal bounces from balloon to balloon, then to the global Internet on Earth. The balloon system is also expected to improve communication in affected regions during natural disasters. Raven Aerostar, a company that makes weather balloons for NASA, provides the high-altitude balloons used in the project. Key people involved in the project include Rich DeVaul, chief technical architect who is also an expert on wearable technology; and Mike Cassidy, a project leader.
http://en.wikipedia.org/wiki/Project_Loon

Rolling them out:

Source: http://imagens9.publico.pt/imagens.aspx ... db=IMAGENS
http://fotoforensics.com/analysis.php?i ... fad.665611

Hypnotic/phallic red ball antenna:

Source: http://i.imgur.com/esF91eU.jpg
http://fotoforensics.com/analysis.php?i ... a3ab.98429

From the Sales Dept:

full link: http://www.youtube.com/watch?v=mcw6j-QWGMo

[Flabbergasted]

If you liked the guys in the video:

Captain-of-moon-shots Astro Teller
http://en.wikipedia.org/wiki/Astro_Teller
Teller's definition of artificial intelligence is "the science of how to get machines to do the things they do in movies".

Great-big-round-things Rich Devaul
http://devaul.net/
Devaul works in a secret Google lab that may or may not be filled with roving robots, space elevators, and talking refrigerators.

[Flabbergasted]

Sorry guys, just a silly association


Source of picture on the right: http://images.cdn.fotopedia.com/flickr- ... 576-hd.jpg

[Flabbergasted]

Here is a lot more information on the science ("variable buoyancy") and the corporate connections of the GoogleLoon thing:
http://www.wired.com/business/2013/06/g ... loons/all/ (link edited)

I may be a bit slow on the uptake: I can see how to make a gas balloon descend, but I still haven´t understood how to make it ascend to higher layers, even with electricity available. Another reader posted the questions below: