Two satellites set for close shave over US city of Pittsburgh - A drawing of one of the satellites on the near miss course.jpg

https://www.bbc.com/news/world-us-canada-51299638

A group tracking the satellites said it predicted a 1 in 20 chance of a
collision, calling it "alarming".

The satellites are not in operation, but it is feared a collision could create
pieces of debris that would damage other objects in orbit.

The last time a major satellite collision occurred was in 2009.

--- The satellites may pass within 40ft (12m) of each other, some 550 miles
(900km) above Pittsburgh at around 18:30 local time.

LeoLabs, a group that tracks space debris, reported that "it is still unlikely
that these objects will collide", but that due to the size of the satellites,
the chance of collision had gone up from prior calculations.

The objects in question are an Infrared Astronomical Satellite (IRAS) that was
launched in 1983 and another experimental US craft, the GGSE-4 satellite,
launched in 1967.

The IRAS satellite has a 60ft (18m) boom - equipment designed to deploy antennae
or solar sails - trailing it, which increased the probability of collision as of
Tuesday afternoon calculations by LeoLabs.

Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for
Astrophysics, said that given the size of the satellites - about the size of a
car and a rubbish bin - "a 15-to-30 metre predicted miss distance is alarming" -
a sentiment echoed by LeoLabs.

If they do collide, the debris poses no threat to the city, experts say, it will
burn up in the atmosphere before it can fall to Earth. But the debris cloud that
remains in orbit could threaten other satellites.

Debris can remain in orbit for decades to centuries.

The last large collision of satellites happened in 2009, when a US commercial
Iridium spacecraft hit a defunct Russian satellite over Siberia, producing
thousands of pieces of debris.

International guidelines state that satellites in low earth orbit must be
removed from orbit 25 years after being decommissioned, but these satellites
were launched prior to the rule changes.

The situation has renewed discussions over the importance of cleaning up space
debris.

"Events like this highlight the need for responsible, timely de-orbiting of
satellites for space sustainability moving forward," LeoLabs said.

Currently, there are around 2,000 active satellites orbiting the earth. There
are also more than 23,000 pieces of debris larger than 10cm (4in) in orbit,
according to Nasa.

According to data from the Union of Concerned Scientists, the US has 1,007
operating satellites, the most by far of any country. The majority are
commercial.

A 2019 article in the Massachusetts Institute of Technology (MIT) Technology
Review stated by 2025, there could be as many as 1,100 new satellites launching
per year.




*

Miloch wrote in
:

https://www.bbc.com/news/world-us-canada-51299638

A group tracking the satellites said it predicted a 1 in 20 chance of
a collision, calling it "alarming".

The satellites are not in operation, but it is feared a collision
could create pieces of debris that would damage other objects in
orbit.

The last time a major satellite collision occurred was in 2009.

--- The satellites may pass within 40ft (12m) of each other, some
550 miles (900km) above Pittsburgh at around 18:30 local time.

LeoLabs, a group that tracks space debris, reported that "it is still
unlikely that these objects will collide", but that due to the size of
the satellites, the chance of collision had gone up from prior
calculations.

The objects in question are an Infrared Astronomical Satellite (IRAS)
that was launched in 1983 and another experimental US craft, the
GGSE-4 satellite, launched in 1967.

The IRAS satellite has a 60ft (18m) boom - equipment designed to
deploy antennae or solar sails - trailing it, which increased the
probability of collision as of Tuesday afternoon calculations by
LeoLabs.

Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for
Astrophysics, said that given the size of the satellites - about the
size of a car and a rubbish bin - "a 15-to-30 metre predicted miss
distance is alarming" - a sentiment echoed by LeoLabs.

If they do collide, the debris poses no threat to the city, experts
say, it will burn up in the atmosphere before it can fall to Earth.
But the debris cloud that remains in orbit could threaten other
satellites.

Debris can remain in orbit for decades to centuries.

The last large collision of satellites happened in 2009, when a US
commercial Iridium spacecraft hit a defunct Russian satellite over
Siberia, producing thousands of pieces of debris.

International guidelines state that satellites in low earth orbit must
be removed from orbit 25 years after being decommissioned, but these
satellites were launched prior to the rule changes.

The situation has renewed discussions over the importance of cleaning
up space debris.

"Events like this highlight the need for responsible, timely
de-orbiting of satellites for space sustainability moving forward,"
LeoLabs said.

Currently, there are around 2,000 active satellites orbiting the
earth. There are also more than 23,000 pieces of debris larger than
10cm (4in) in orbit, according to Nasa.

According to data from the Union of Concerned Scientists, the US has
1,007 operating satellites, the most by far of any country. The
majority are commercial.

A 2019 article in the Massachusetts Institute of Technology (MIT)
Technology Review stated by 2025, there could be as many as 1,100 new
satellites launching per year.




India deliberately collided two satellites
awhile back creating even more space debris.


https://en.wikipedia.org/wiki/Mission_Shakti

In article , Mitchell Holman
says...

Miloch wrote in
:

https://www.bbc.com/news/world-us-canada-51299638

A group tracking the satellites said it predicted a 1 in 20 chance of
a collision, calling it "alarming".

The satellites are not in operation, but it is feared a collision
could create pieces of debris that would damage other objects in
orbit.

The last time a major satellite collision occurred was in 2009.

--- The satellites may pass within 40ft (12m) of each other, some
550 miles (900km) above Pittsburgh at around 18:30 local time.

LeoLabs, a group that tracks space debris, reported that "it is still
unlikely that these objects will collide", but that due to the size of
the satellites, the chance of collision had gone up from prior
calculations.

The objects in question are an Infrared Astronomical Satellite (IRAS)
that was launched in 1983 and another experimental US craft, the
GGSE-4 satellite, launched in 1967.

The IRAS satellite has a 60ft (18m) boom - equipment designed to
deploy antennae or solar sails - trailing it, which increased the
probability of collision as of Tuesday afternoon calculations by
LeoLabs.

Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for
Astrophysics, said that given the size of the satellites - about the
size of a car and a rubbish bin - "a 15-to-30 metre predicted miss
distance is alarming" - a sentiment echoed by LeoLabs.

If they do collide, the debris poses no threat to the city, experts
say, it will burn up in the atmosphere before it can fall to Earth.
But the debris cloud that remains in orbit could threaten other
satellites.

Debris can remain in orbit for decades to centuries.

The last large collision of satellites happened in 2009, when a US
commercial Iridium spacecraft hit a defunct Russian satellite over
Siberia, producing thousands of pieces of debris.

International guidelines state that satellites in low earth orbit must
be removed from orbit 25 years after being decommissioned, but these
satellites were launched prior to the rule changes.

The situation has renewed discussions over the importance of cleaning
up space debris.

"Events like this highlight the need for responsible, timely
de-orbiting of satellites for space sustainability moving forward,"
LeoLabs said.

Currently, there are around 2,000 active satellites orbiting the
earth. There are also more than 23,000 pieces of debris larger than
10cm (4in) in orbit, according to Nasa.

According to data from the Union of Concerned Scientists, the US has
1,007 operating satellites, the most by far of any country. The
majority are commercial.

A 2019 article in the Massachusetts Institute of Technology (MIT)
Technology Review stated by 2025, there could be as many as 1,100 new
satellites launching per year.




India deliberately collided two satellites
awhile back creating even more space debris.


https://en.wikipedia.org/wiki/Mission_Shakti



Looks like both sats missed each other....

A dead NASA space telescope and an old Air Force satellite likely avoided
colliding over Pittsburgh on Wednesday, beating 'alarming' odds

https://www.businessinsider.com/nasa...tsburgh-2020-1

...."However, at 9:04 pm ET on Wednesday LeoLabs said it had detected no new
debris when the satellites entered the range of its radars — suggesting that
they had passed each other without colliding.

The US Air Force, which tracks satellites for the government, did not notify
NASA of any potential satellite collision, the space agency told Business
Insider.

Executives at both LeoLabs and The Aerospace Corporation said the lack of a
government alert did not surprise them.

"Since [the satellites] were decommissioned, basically nobody was keeping a
close eye on them," LeoLabs CEO Dan Ceperley told Business Insider. "It's a big
threat in space, but not on the ground."

He added that the timing of the potential collision was right around sunset — an
ideal time for amateur astronomers to spot the satellites.

Thompson said even observers on the ground in Pittsburgh might have seen a
bright flash in the sky if the satellites crashed, like a shooting star.




*