How long could a man-made earth satellite stay up?

Na, I watch maybe 30 mins of news a day and that's all. But Can you NAME the
object I've been talking about? It was the 2nd one lauched but the first to
reach orbit from the USA, the first one turned into scrap metal the first
try. I might be mistaken here, I'd have to go dig some books out, but I
knon it was the first major one in orbit and from the NASA sat traker it's
still up there.
almost 50 years now come 2009.


--
There are those who believe that life here, began out there, far across the
universe, with tribes of humans, who may have been the forefathers of the
Egyptians, or the Toltecs, or the Mayans. Some believe that they may yet be
brothers of man, who even now fight to survive, somewhere beyond the
heavens.


The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
Sidewalk Astronomy
www.sidewalkastronomy.info
The Church of Eternity
http://home.inreach.com/starlord/church/Eternity.html


"Chris L Peterson" wrote in message
...
On Sat, 20 Jan 2007 14:00:17 -0800, "Starlord"
wrote:

I'm sure they know about it, but while not running, it is still in orbit
and
has been tracked.

I think he was worrying- tongue in cheek- about them turning it into a
debris cloud for practice. (Been following the news the last few days?)

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Sat, 20 Jan 2007 15:37:39 -0800, "Starlord"
wrote:

Na, I watch maybe 30 mins of news a day and that's all. But Can you NAME the
object I've been talking about? It was the 2nd one lauched but the first to
reach orbit from the USA, the first one turned into scrap metal the first
try. I might be mistaken here, I'd have to go dig some books out, but I
knon it was the first major one in orbit and from the NASA sat traker it's
still up there.
almost 50 years now come 2009.

Not sure which you're thinking of. If you're talking about launches in
the 1950s, I know that Explorer 7 (1959) is still in orbit. I believe
all the earlier Explorers either failed to reach orbit, or have long
since decayed.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

"Starlord" wrote in
:

Na, I watch maybe 30 mins of news a day and that's all. But Can you NAME
the object I've been talking about? It was the 2nd one lauched but the
first to reach orbit from the USA, the first one turned into scrap metal
the first try. I might be mistaken here, I'd have to go dig some books
out, but I knon it was the first major one in orbit and from the NASA
sat traker it's still up there.
almost 50 years now come 2009.



warning spoiler...

http://home.swipnet.se/~w-52936/index20.htm

The post right after yours has the right answer.


--
There are those who believe that life here, began out there, far across the
universe, with tribes of humans, who may have been the forefathers of the
Egyptians, or the Toltecs, or the Mayans. Some believe that they may yet be
brothers of man, who even now fight to survive, somewhere beyond the
heavens.


The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
Sidewalk Astronomy
www.sidewalkastronomy.info
The Church of Eternity
http://home.inreach.com/starlord/church/Eternity.html


"Chris L Peterson" wrote in message
...
On Sat, 20 Jan 2007 15:37:39 -0800, "Starlord"
wrote:

Na, I watch maybe 30 mins of news a day and that's all. But Can you NAME
the
object I've been talking about? It was the 2nd one lauched but the first
to
reach orbit from the USA, the first one turned into scrap metal the first
try. I might be mistaken here, I'd have to go dig some books out, but I
knon it was the first major one in orbit and from the NASA sat traker it's
still up there.
almost 50 years now come 2009.

Not sure which you're thinking of. If you're talking about launches in
the 1950s, I know that Explorer 7 (1959) is still in orbit. I believe
all the earlier Explorers either failed to reach orbit, or have long
since decayed.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Yep that's it.


--
There are those who believe that life here, began out there, far across the
universe, with tribes of humans, who may have been the forefathers of the
Egyptians, or the Toltecs, or the Mayans. Some believe that they may yet be
brothers of man, who even now fight to survive, somewhere beyond the
heavens.


The Lone Sidewalk Astronomer of Rosamond
Telescope Buyers FAQ
http://home.inreach.com/starlord
Sidewalk Astronomy
www.sidewalkastronomy.info
The Church of Eternity
http://home.inreach.com/starlord/church/Eternity.html


"VicXnews" wrote in message
...
"Starlord" wrote in
:

Na, I watch maybe 30 mins of news a day and that's all. But Can you NAME
the object I've been talking about? It was the 2nd one lauched but the
first to reach orbit from the USA, the first one turned into scrap metal
the first try. I might be mistaken here, I'd have to go dig some books
out, but I knon it was the first major one in orbit and from the NASA
sat traker it's still up there.
almost 50 years now come 2009.



warning spoiler...

http://home.swipnet.se/~w-52936/index20.htm

Potentially, millions of years. The higher a satellite's orbit, the better.

Carl Sagan tackled this topic in one of his books; I think it was _Murmurs
of Earth_. IIRC, on board one of the GOES satellites (geosynchronous Earth
orbit, which means it's thousands of miles up) is a plaque with artwork that
shows the current placement of the world's continents, as well as how we
think the same continents were positioned millions of years ago... as well
as how we think the future shifting of the continental plates will take the
land masses millions of years into the future. Potentially, anyone finding
that satellite in the far-distant future will have a rough visual idea of
when that satellite was launched.

There are plenty of spacecraft which have left Earth's influence entirely
and will never return. Some are already past all of the major planets of
the solar system and are still heading out at high speed.

Sam Wormley wrote:
wrote:
Musing....

The earth is many orders of magnitude older than the time humans - or
even mammals - have been here.

And who knows what the future may bring.

As far as I can tell, any thought that we are not the first to inhabit
this planet belong in the realm of science fiction - but we may not
last, and there could therefore be other sentients after us.

If we wished to leave a notice that we'd been here, the best place
might be in orbit; by the time another sentient form reached that
level, they might be able to decipher and understand whatever we
decided to leave.

Low orbits decay - I assume higher ones do as well, just more slowly.
Could we place a satellite such that it would still be up there, say,
a million years from now? How about 100 million years?


Moon stays up.

Yup, bury something in a big steel vault 10m under the surface. Some
future civilization will recognize the magnetic anomaly. Just for grins
paint it flat black and make it a rectangular box with the ratio of the
lengths of the sides be 1:4:9
:-)



Shawn

Starlord wrote:
Na, I watch maybe 30 mins of news a day and that's all. But Can you NAME the
object I've been talking about? It was the 2nd one lauched but the first to
reach orbit from the USA, the first one turned into scrap metal the first
try. I might be mistaken here, I'd have to go dig some books out, but I
knon it was the first major one in orbit and from the NASA sat traker it's
still up there.
almost 50 years now come 2009.

FIrst attempts (in the USA) were made by the US Navy with their
Vanguard
rockets, but those had a miserable history of failure and explosions.

The first successful USA satellite launch was the US Army's Explorer I
on a
modifed Redstone rocket on the evening of January 31, 1958 (I was there
:-)

Explorer 3, a few months later, was the one that discovered the van
Allen belts
whose presence was hinted-at by data from Explorer I.

Haven't found anything indicating whethe Explorer I is still orbiting
or not.

On 21 Jan 2007 02:14:54 -0800, wrote:

Haven't found anything indicating whethe Explorer I is still orbiting
or not.

Explorer 1 decayed on March 31, 1970, after 12 years in orbit. The
Explorer program continues to this day, so many objects remain in orbit.
The oldest are Explorer 7 and 8, launched in 1959 and 1960 respectively.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

In article ,
Matt J. McCullar wrote:

Potentially, millions of years. The higher a satellite's orbit, the better.

However, there's one other thing to consider: the Moon. If the satellite orbit
is too close to (or in resonance with) the Moon, then the Moon will severely
perturb its orbit.

Carl Sagan tackled this topic in one of his books; I think it was _Murmurs
of Earth_. IIRC, on board one of the GOES satellites (geosynchronous Earth
orbit, which means it's thousands of miles up) is a plaque with artwork that
shows the current placement of the world's continents, as well as how we
think the same continents were positioned millions of years ago... as well
as how we think the future shifting of the continental plates will take the
land masses millions of years into the future. Potentially, anyone finding
that satellite in the far-distant future will have a rough visual idea of
when that satellite was launched.

There are plenty of spacecraft which have left Earth's influence entirely
and will never return. Some are already past all of the major planets of
the solar system and are still heading out at high speed.

True, however once a spacecraft has left the Earth's influence, it is
no longer an artificial Earth satellite but instead an artificial
minor planet. Such objects are likely to live for an extremely long
time, though.

--
----------------------------------------------------------------
Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
e-mail: pausch at stockholm dot bostream dot se
WWW: http://stjarnhimlen.se/