7 ms·

Long-lost U.S. military satellite found by amateur radio operator

321 points by wglb 7y ago

callesgg 7y ago
The people at MIT that built that piece of junk are long gone. What the current people at MIT be able say.
tectonic 7y ago
See also: https://www.rtl-sdr.com/receiving-dead-satellites-rtl-sdr/ https://www.rtl-sdr.com/receiving-dead-satellites-rtl-sdr/
jandrese 7y ago
The "no comment" is really "everybody who worked on that has long since retired and nobody is in the office to check the paper records, if they even wanted to and were allowed to." The communication protocols used by that old bird are probably still classified.
- jcrawfordor 7y ago
  A satellite of that age would have used a very simple analog repeater or linear transponder, meaning that there is no communications logic occurring on the satellite. Any digital modulation, and more so encryption, would be the responsibility of the ground stations. This is still a common design pattern for satellites, referred to as the "bent pipe" model since the space segment is merely a "bend" with no logic, but it is subject to abuse by unauthorized operators so there's usually some degree of at least authentication today. Military satellites launched into the '80s continued to use analogue transponders and, to some extent to this day, see unauthorized use. The only real deterrent was the difficulty of obtaining inexpensive equipment for satellite bands but the widespread use of DVB and VSATs changed that during the '90s and '00s. That said, all related documents may very well have been classified at the time (owing especially to the lack of any authentication!) and even when declassify-on dates pass there is often institutional resistance to going through the motions of releasing this material, especially since Lincoln Labs (a contractor) would not be authorized to do so and would have to forward the request on to someone else. A more formal FOIA request, followed by appeals if necessary, can often unstick these wheels since it creates a legal obligation that a more casual media request does not.
  - tlrobinson 7y ago
    > A satellite of that age would have used a very simple analog repeater or linear transponder, meaning that there is no communications logic occurring on the satellite. It's broadcasting telemetry, isn't there a chance it also accepts commands? > Military satellites launched into the '80s continued to use analogue transponders and, to some extent to this day, see unauthorized use. The only real deterrent was the difficulty of obtaining inexpensive equipment for satellite bands but the widespread use of DVB and VSATs changed that during the '90s and '00s. WIRED had an article about this awhile back: https://www.wired.com/2009/04/fleetcom/ https://www.wired.com/2009/04/fleetcom/
    - jplayer01 7y ago
      Oh, this is fascinating. Just a bit disappointing that the article doesn't mention at all why it's possible for random people in Brazil to access these satellites.
      - oyebenny 7y ago
        > Oh, this is fascinating. Just a bit disappointing that the article doesn't mention at all why it's possible for random people in Brazil to access these satellites. This is my question as well.
        tonyarkles 7y ago
        The Fleetcom satellites are, if I recall, just “bent pipe” satellites. There receive on one frequency and retransmit on another with zero logic onboard. Analog, digital, whatever. If you wanted them to encrypt their broadcasts, you’d just encrypt the signal before transmitting on the ground and it would happily rebroadcast your encrypted signal back to earth.
        ColanR 7y ago
        From the article, to answer the hardware side of your question, which was mine as well. > To use the satellite, pirates typically take an ordinary ham radio transmitter, which operates in the 144- to 148-MHZ range, and add a frequency doubler cobbled from coils and a varactor diode. That lets the radio stretch into the lower end of FLTSATCOM's 292- to 317-MHz uplink range. All the gear can be bought near any truck stop for less than $500. Ads on specialized websites offer to perform the conversion for less than $100. Taught the ropes, even rough electricians can make Bolinha-ware.
imjustsaying 7y ago
This reminds me of another thing a lot of people have been noticing lately with more time to look up. What's been up with Venus? It's been really bright for weeks if not months now.
- Florin_Andrei 7y ago
  They just have more time now to actually look up. Venus is same as ever, the brightest object in the sky besides the Sun and the Moon. It was at its greatest elongation from the Sun in late March, so of course it's very visible.
  - deleted 7y ago
    [deleted]
- colordrops 7y ago
  Venus is currently very close to us. See: https://theskylive.com https://theskylive.com Also the air is a lot cleaner these days with everyone staying at home.
  - wglb 7y ago
    Actually, it was extremely bright here even before anyone ws in lockdown. I particularly remember when it was in the western sky near the moon several moons ago.
- teraflop 7y ago
  Venus is only a few weeks away from its inferior solar conjunction, which is approximately the point in its orbit (recurring about every 19 months) where it most closely approaches Earth: https://in-the-sky.org/news.php?id=20200603_11_100 https://in-the-sky.org/news.php?id=20200603_11_100 Interestingly, Venus' brightness is currently near its peak, even though the conjunction itself is still several weeks away. At the point of closest approach, the planet will be almost 3x bigger in angular area than it is today, but we will be seeing a much smaller fraction of its sunlit side.
themodelplumber 7y ago
1965. Wow. Watching and listening to that waterfall was fantastic. And by the way, great use of links in the NPR article. I found a new blog to follow, a lab I've never heard of, a Twitter account to check out, and _Gunter's Space Page_, which we hopefully all know via intuition is a quality work to be saved for later in-depth review. ;-)
- raginalix 7y ago
  When I got my first rtlsdr dongle I spent hours just surfing the frequencies looking for interesting signals and trying to decide them. It's a great hobby! SDR has opened up a new frontier for me, it gives me the same excitement I got when I discovered BBSs and then the internet. I was lucky enough to have a project come up last year that required gsm/4G and GPS simulation. I got budget to buy a bladerf and a nice SBC and built a box that could simulate a GSM, 3G/4G basestation and simulate GPS.
  - themodelplumber 7y ago
    That's awesome! Especially since your work experience seems to integrate with your hobby, and a very cool hobby at that. Just to re-balance the universe a bit here, I almost stepped on my RTL-SDR the other day, in a neglected corner of my workspace, and felt pretty guilty about it ;-) (Tangentially, I gave a cheap portable SW radio to my son the other day, after not using it for a while. I was trying to find a favorite FM radio station to demonstrate to him, and stumbled across one of the local emergency services instead, in the 150 MHz range. Haha, no wonder the dial markings don't match up at all. Now he's telling me what kind of makes & models he's hearing about over the air...)
jplayer01 7y ago
> "The reason this one is kind of intriguing is its telemetry beacon is still operating," Tilley says. What exactly is a telemetry beacon, and what kind of data would it be broadcasting?
- merlincorey 7y ago
  It's at a minimum simply a high signal on a certain frequency indicating the device is there and then you use math to gather telemetry data (position, speed, etc). At most, it's packets of data that indicate telemetry data such as position, speed, temperature, and the current state of any instruments on board. Telemetry data is typically pushed out at regular intervals to allow it to be recorded and graphed in a time series.
8bitsrule 7y ago
I wonder if anyone's ever heard from SNAP-10. It was the first fission reactor in orbit (1965). It had, uh, problems and was shut down after 43 days. In late November 1979 it had a 'anomalous event', and it had 6 more in the next 6 years... releasing '50 trackable pieces'. [0] https://web.archive.org/web/20170503083646/https://ston.jsc.nasa.gov/collections/TRS//_techrep/TP-1999-208856.pdf https://web.archive.org/web/20170503083646/https://ston.jsc....
- emptybits 7y ago
  Great document. One of many eye-openers: "The West German government sponsors a meeting called Safety Aspects of Nuclear Reactors in Space, in Cologne. Nietrich Rex predicts that Soviet space nuclear reactors will undergo 2-3 on-orbit collisions in the next 300 years. Each will result in world-wide reentry of radioactive debris." That's a prediction from November 1989.
  - Rebelgecko 7y ago
    I can't find a source after a cursory search, but IIRC the Soviet RORSATs are still the second or third biggest source of space junk today (#1 being the 2007 Chinese test of an antisatellite weapon). A few of them had nuclear reactors fail in dramatic ways, although a lot of their debris is just from leaking coolant.
    - Ironlikebike 7y ago
      Per this document it appears that (frequent) Delta second stage explosions were one of the most significant contributors. By 1981 27% of all tracked debris (of orbital period under 225 minutes) were from Delta second stage explosions. (I'm guessing these are considered high velocity debris). It's quite interesting that NASA was surprised by this (asking McDonnell-Douglas to find out why in May of 1981) considering how long they had been launching the Delta rockets and tracking debris. From the document, NASA officials continually approved work to track orbital debris, but often didn't give the reports administrative attention.
CalChris 7y ago
Reconnecting with an old satellite has been done before. Perhaps it be done again. The International Sun-Earth Explorer (ISEE-3) satellite was launched on August 12, 1978, and was originally meant to study the Earth's magnetosphere from the L1 Lagrangian point between the Sun and the Earth, where the gravity of both bodies cancel each other out. https://www.vice.com/en_us/article/pga3m7/techno-archaeologists-used-an-abandoned-mcdonalds-to-hijack-a-satellite https://www.vice.com/en_us/article/pga3m7/techno-archaeologi...
sciurus 7y ago
If you're intrigued by tracking satellites and their transmissions more generally, check out https://satnogs.org/ https://satnogs.org/
wrigby 7y ago
I feel like "lost" is a bit of a misnomer here - this spacecraft was of course being tracked still, and it only took a couple seconds of googling to pull up the detailed info on the orbit from Celestrak[1]. There's even a nice visualization available at [2]. 1: https://celestrak.com/satcat/tle.php?CATNR=02866 https://celestrak.com/satcat/tle.php?CATNR=02866 2: https://celestrak.com/cesium/orbit-viz.php?tle=/satcat/tle2.php?CATNR=02866&satcat=/pub/satcat.txt&orbits=1&pixelSize=3&samplesPerPeriod=90 https://celestrak.com/cesium/orbit-viz.php?tle=/satcat/tle2....
- azernik 7y ago
  For a somewhat cooler visualization, which also gives you a comparison to the GEO belt and other satellites but may be bad for browser performance, see http://stuffin.space/?intldes=1967-066E&search=1967-066e http://stuffin.space/?intldes=1967-066E&search=1967-066e
  - qubex 7y ago
    This kind of visualisation is fascinating, but it’s also (for reasons I shall now explain) the root of a very serious misconception. The misconception I speak of is the “junk in space” one. One sees images such as these and clearly reaches the conclusion that we’ve immersed ourselves in a thick fog of stuff which will soon become a barrier of fast-moving debris. But... if one thinks about it, these objects are small, and if one were to lay them all out upon the surface of the earth, they’d actually cover a tiny fraction of it, and there’d be miles between each one. And furthermore, higher altitudes define a larger sphere, and surface area depends on the square of radius, so there’s actually far more distance available to these objects (alternatively, to repeat the experiment on earth, one would need to considerably scale down the already comparatively tiny objects and satellites). And on top of that, we have a whole third dimension to deal with, so it’s not just one bigger sphere, but a continuum of spheres that all exist independently of each other. Which leads to my core contention: even visualising satellites as the smallest graphical depiction possible (a single pixel) leads a viewer to vastly overestimate their size, and therefore the density of objects that exist in our sidereal neighbourhood. And this irks me. </rant>
CraigJPerry 7y ago
I got interested in rf spectrum in 2014 and haven’t looked back. There’s just so much fascinating stuff out there.
3fe9a03ccd14ca5 7y ago
One of the satellites found by this sleuth: > Transit 5B5 was a US Navy navigation satellite launched by a Thor Able Star rocket. It carried a nuclear power source. Wait what? Nuclear powered satellites? How do they safely dispose of these??
- kjs3 7y ago
  Yes, it's a thing. Most of the deep space probes were radio-nucleotide powered. Earth orbiting is less common for obvious reasons. One option is boost to a parking orbit where it'll be stable and out of the way for a couple of thousand years. But the stuff from the '60s was often "it'll burn up on reentry (cross fingers) and it's a cost of doing Cold War business if a little get's scattered around".
  - perl4ever 7y ago
    There are plenty of earth orbiting actual fission reactors, not like the RTGs you have heard about. There were quite a few sent up by the Soviets (from 1967-1988) and at least one malfunctioned, failed to eject its reactor into a disposal orbit and scattered radioactive waste across northern Canada. Even the Soviets didn't intend to send nuclear reactors to burn up on reentry; I'd be surprised if that was anyone's plan. https://en.wikipedia.org/wiki/US-A https://en.wikipedia.org/wiki/US-A https://en.wikipedia.org/wiki/BES-5 https://en.wikipedia.org/wiki/BES-5 https://en.wikipedia.org/wiki/Kosmos_954 https://en.wikipedia.org/wiki/Kosmos_954 https://en.wikipedia.org/wiki/Kosmos_1402 https://en.wikipedia.org/wiki/Kosmos_1402 "...44 kg of uranium had been dispersed into the stratosphere after the incident..."
    - kjs3 7y ago
      I've more than "heard about" RTGs, and I'm well aware of the kind of reactors that have been shot into space. We can argue the level of "intend", but in the Cold War, the reentry of a nuclear reactor was considered an acceptable cost of doing business.
analog31 7y ago
This has me puzzled: >>> Confirmation will occur at ~0445 UTC this evening when the satellite should pass through eclipse. Shouldn't it be stationary, if it's in geostationary orbit? Or is it just that the satellite has drifted out of that orbit over time?
- azernik 7y ago
  The article says GEO, but actual quotes in the article say "GEO graveyard orbit". What this means is that, at the end of the satellite's service life, it was boosted into a lower (in this case [1]) or higher (also common) orbit out of the way of the GEO line. There isn't much space in GEO, as it's a one-dimensional space [2] - only true anomaly (position in the orbit) can be varied. So you want to free up the slot once you're not using it anymore. [1] This particular satellite is http://stuffin.space/?intldes=1967-066E&search=1967-066e http://stuffin.space/?intldes=1967-066E&search=1967-066e. Note the orbital period - it's shorter than a sidereal day of 1436 minutes, which means this is a lower orbit. It's also slightly inclined to GEO, which reduces the chance of collisions even further. [2] By contrast, the set of Keplerian orbits is generally a six-dimensional space, with singularities at eccentricity = 0 and inclination = 0. Well, also technically at semi-major axis = 0, but that's not a physically possible "orbit".
  - yellowapple 7y ago
    Are lower-than-GEO graveyard orbits common? I mean, I guess they are, judging by stuffin.space, but my intuition would be that it wouldn't take any more fuel to put a satellite in a higher-than-GEO graveyard orbit (and thus further minimize the risk of collision), no?
    - azernik 7y ago
      No particular reason why a higher orbit is any better than a lower orbit. As long as you're a good 1000 kilometers away from the GEO belt at closest, and preferably a little inclined so that closest approach only happens ~2 times a day, both high and low graveyard orbits are equally good for avoiding collisions.
JoeDaDude 7y ago
I guess that was before we had responsible satellite disposal. http://www.esa.int/ESA_Multimedia/Videos/2017/04/Space_debris_2017_-_a_journey_to_Earth http://www.esa.int/ESA_Multimedia/Videos/2017/04/Space_debri...
anonymousiam 7y ago
Rick Rhodes could really build ‘em!
deleted 7y ago
[deleted]

321 points by wglb 7y ago

The people at MIT that built that piece of junk are long gone. What the current people at MIT be able say.

See also: https://www.rtl-sdr.com/receiving-dead-satellites-rtl-sdr/ https://www.rtl-sdr.com/receiving-dead-satellites-rtl-sdr/

jandrese 7y ago

The "no comment" is really "everybody who worked on that has long since retired and nobody is in the office to check the paper records, if they even wanted to and were allowed to." The communication protocols used by that old bird are probably still classified.

jcrawfordor 7y ago
A satellite of that age would have used a very simple analog repeater or linear transponder, meaning that there is no communications logic occurring on the satellite. Any digital modulation, and more so encryption, would be the responsibility of the ground stations. This is still a common design pattern for satellites, referred to as the "bent pipe" model since the space segment is merely a "bend" with no logic, but it is subject to abuse by unauthorized operators so there's usually some degree of at least authentication today. Military satellites launched into the '80s continued to use analogue transponders and, to some extent to this day, see unauthorized use. The only real deterrent was the difficulty of obtaining inexpensive equipment for satellite bands but the widespread use of DVB and VSATs changed that during the '90s and '00s. That said, all related documents may very well have been classified at the time (owing especially to the lack of any authentication!) and even when declassify-on dates pass there is often institutional resistance to going through the motions of releasing this material, especially since Lincoln Labs (a contractor) would not be authorized to do so and would have to forward the request on to someone else. A more formal FOIA request, followed by appeals if necessary, can often unstick these wheels since it creates a legal obligation that a more casual media request does not.
- tlrobinson 7y ago
  > A satellite of that age would have used a very simple analog repeater or linear transponder, meaning that there is no communications logic occurring on the satellite. It's broadcasting telemetry, isn't there a chance it also accepts commands? > Military satellites launched into the '80s continued to use analogue transponders and, to some extent to this day, see unauthorized use. The only real deterrent was the difficulty of obtaining inexpensive equipment for satellite bands but the widespread use of DVB and VSATs changed that during the '90s and '00s. WIRED had an article about this awhile back: https://www.wired.com/2009/04/fleetcom/ https://www.wired.com/2009/04/fleetcom/
  - jplayer01 7y ago
    Oh, this is fascinating. Just a bit disappointing that the article doesn't mention at all why it's possible for random people in Brazil to access these satellites.
    - oyebenny 7y ago
      > Oh, this is fascinating. Just a bit disappointing that the article doesn't mention at all why it's possible for random people in Brazil to access these satellites. This is my question as well.
      - tonyarkles 7y ago
        The Fleetcom satellites are, if I recall, just “bent pipe” satellites. There receive on one frequency and retransmit on another with zero logic onboard. Analog, digital, whatever. If you wanted them to encrypt their broadcasts, you’d just encrypt the signal before transmitting on the ground and it would happily rebroadcast your encrypted signal back to earth.
      - ColanR 7y ago
        From the article, to answer the hardware side of your question, which was mine as well. > To use the satellite, pirates typically take an ordinary ham radio transmitter, which operates in the 144- to 148-MHZ range, and add a frequency doubler cobbled from coils and a varactor diode. That lets the radio stretch into the lower end of FLTSATCOM's 292- to 317-MHz uplink range. All the gear can be bought near any truck stop for less than $500. Ads on specialized websites offer to perform the conversion for less than $100. Taught the ropes, even rough electricians can make Bolinha-ware.

imjustsaying 7y ago

This reminds me of another thing a lot of people have been noticing lately with more time to look up. What's been up with Venus? It's been really bright for weeks if not months now.

Florin_Andrei 7y ago
They just have more time now to actually look up. Venus is same as ever, the brightest object in the sky besides the Sun and the Moon. It was at its greatest elongation from the Sun in late March, so of course it's very visible.
- deleted 7y ago
  [deleted]
colordrops 7y ago
Venus is currently very close to us. See: https://theskylive.com https://theskylive.com Also the air is a lot cleaner these days with everyone staying at home.
- wglb 7y ago
  Actually, it was extremely bright here even before anyone ws in lockdown. I particularly remember when it was in the western sky near the moon several moons ago.
teraflop 7y ago
Venus is only a few weeks away from its inferior solar conjunction, which is approximately the point in its orbit (recurring about every 19 months) where it most closely approaches Earth: https://in-the-sky.org/news.php?id=20200603_11_100 https://in-the-sky.org/news.php?id=20200603_11_100 Interestingly, Venus' brightness is currently near its peak, even though the conjunction itself is still several weeks away. At the point of closest approach, the planet will be almost 3x bigger in angular area than it is today, but we will be seeing a much smaller fraction of its sunlit side.

themodelplumber 7y ago

1965. Wow. Watching and listening to that waterfall was fantastic. And by the way, great use of links in the NPR article. I found a new blog to follow, a lab I've never heard of, a Twitter account to check out, and _Gunter's Space Page_, which we hopefully all know via intuition is a quality work to be saved for later in-depth review. ;-)

raginalix 7y ago
When I got my first rtlsdr dongle I spent hours just surfing the frequencies looking for interesting signals and trying to decide them. It's a great hobby! SDR has opened up a new frontier for me, it gives me the same excitement I got when I discovered BBSs and then the internet. I was lucky enough to have a project come up last year that required gsm/4G and GPS simulation. I got budget to buy a bladerf and a nice SBC and built a box that could simulate a GSM, 3G/4G basestation and simulate GPS.
- themodelplumber 7y ago
  That's awesome! Especially since your work experience seems to integrate with your hobby, and a very cool hobby at that. Just to re-balance the universe a bit here, I almost stepped on my RTL-SDR the other day, in a neglected corner of my workspace, and felt pretty guilty about it ;-) (Tangentially, I gave a cheap portable SW radio to my son the other day, after not using it for a while. I was trying to find a favorite FM radio station to demonstrate to him, and stumbled across one of the local emergency services instead, in the 150 MHz range. Haha, no wonder the dial markings don't match up at all. Now he's telling me what kind of makes & models he's hearing about over the air...)

jplayer01 7y ago

> "The reason this one is kind of intriguing is its telemetry beacon is still operating," Tilley says. What exactly is a telemetry beacon, and what kind of data would it be broadcasting?

merlincorey 7y ago
It's at a minimum simply a high signal on a certain frequency indicating the device is there and then you use math to gather telemetry data (position, speed, etc). At most, it's packets of data that indicate telemetry data such as position, speed, temperature, and the current state of any instruments on board. Telemetry data is typically pushed out at regular intervals to allow it to be recorded and graphed in a time series.

8bitsrule 7y ago

I wonder if anyone's ever heard from SNAP-10. It was the first fission reactor in orbit (1965). It had, uh, problems and was shut down after 43 days. In late November 1979 it had a 'anomalous event', and it had 6 more in the next 6 years... releasing '50 trackable pieces'. [0] https://web.archive.org/web/20170503083646/https://ston.jsc.nasa.gov/collections/TRS//_techrep/TP-1999-208856.pdf https://web.archive.org/web/20170503083646/https://ston.jsc....

emptybits 7y ago
Great document. One of many eye-openers: "The West German government sponsors a meeting called Safety Aspects of Nuclear Reactors in Space, in Cologne. Nietrich Rex predicts that Soviet space nuclear reactors will undergo 2-3 on-orbit collisions in the next 300 years. Each will result in world-wide reentry of radioactive debris." That's a prediction from November 1989.
- Rebelgecko 7y ago
  I can't find a source after a cursory search, but IIRC the Soviet RORSATs are still the second or third biggest source of space junk today (#1 being the 2007 Chinese test of an antisatellite weapon). A few of them had nuclear reactors fail in dramatic ways, although a lot of their debris is just from leaking coolant.
  - Ironlikebike 7y ago
    Per this document it appears that (frequent) Delta second stage explosions were one of the most significant contributors. By 1981 27% of all tracked debris (of orbital period under 225 minutes) were from Delta second stage explosions. (I'm guessing these are considered high velocity debris). It's quite interesting that NASA was surprised by this (asking McDonnell-Douglas to find out why in May of 1981) considering how long they had been launching the Delta rockets and tracking debris. From the document, NASA officials continually approved work to track orbital debris, but often didn't give the reports administrative attention.

CalChris 7y ago

Reconnecting with an old satellite has been done before. Perhaps it be done again. The International Sun-Earth Explorer (ISEE-3) satellite was launched on August 12, 1978, and was originally meant to study the Earth's magnetosphere from the L1 Lagrangian point between the Sun and the Earth, where the gravity of both bodies cancel each other out. https://www.vice.com/en_us/article/pga3m7/techno-archaeologists-used-an-abandoned-mcdonalds-to-hijack-a-satellite https://www.vice.com/en_us/article/pga3m7/techno-archaeologi...

sciurus 7y ago

If you're intrigued by tracking satellites and their transmissions more generally, check out https://satnogs.org/ https://satnogs.org/

wrigby 7y ago

I feel like "lost" is a bit of a misnomer here - this spacecraft was of course being tracked still, and it only took a couple seconds of googling to pull up the detailed info on the orbit from Celestrak[1]. There's even a nice visualization available at [2]. 1: https://celestrak.com/satcat/tle.php?CATNR=02866 https://celestrak.com/satcat/tle.php?CATNR=02866 2: https://celestrak.com/cesium/orbit-viz.php?tle=/satcat/tle2.php?CATNR=02866&satcat=/pub/satcat.txt&orbits=1&pixelSize=3&samplesPerPeriod=90 https://celestrak.com/cesium/orbit-viz.php?tle=/satcat/tle2....

azernik 7y ago
For a somewhat cooler visualization, which also gives you a comparison to the GEO belt and other satellites but may be bad for browser performance, see http://stuffin.space/?intldes=1967-066E&search=1967-066e http://stuffin.space/?intldes=1967-066E&search=1967-066e
- qubex 7y ago
  This kind of visualisation is fascinating, but it’s also (for reasons I shall now explain) the root of a very serious misconception. The misconception I speak of is the “junk in space” one. One sees images such as these and clearly reaches the conclusion that we’ve immersed ourselves in a thick fog of stuff which will soon become a barrier of fast-moving debris. But... if one thinks about it, these objects are small, and if one were to lay them all out upon the surface of the earth, they’d actually cover a tiny fraction of it, and there’d be miles between each one. And furthermore, higher altitudes define a larger sphere, and surface area depends on the square of radius, so there’s actually far more distance available to these objects (alternatively, to repeat the experiment on earth, one would need to considerably scale down the already comparatively tiny objects and satellites). And on top of that, we have a whole third dimension to deal with, so it’s not just one bigger sphere, but a continuum of spheres that all exist independently of each other. Which leads to my core contention: even visualising satellites as the smallest graphical depiction possible (a single pixel) leads a viewer to vastly overestimate their size, and therefore the density of objects that exist in our sidereal neighbourhood. And this irks me. </rant>

CraigJPerry 7y ago

I got interested in rf spectrum in 2014 and haven’t looked back. There’s just so much fascinating stuff out there.

3fe9a03ccd14ca5 7y ago

One of the satellites found by this sleuth: > Transit 5B5 was a US Navy navigation satellite launched by a Thor Able Star rocket. It carried a nuclear power source. Wait what? Nuclear powered satellites? How do they safely dispose of these??

kjs3 7y ago
Yes, it's a thing. Most of the deep space probes were radio-nucleotide powered. Earth orbiting is less common for obvious reasons. One option is boost to a parking orbit where it'll be stable and out of the way for a couple of thousand years. But the stuff from the '60s was often "it'll burn up on reentry (cross fingers) and it's a cost of doing Cold War business if a little get's scattered around".
- perl4ever 7y ago
  There are plenty of earth orbiting actual fission reactors, not like the RTGs you have heard about. There were quite a few sent up by the Soviets (from 1967-1988) and at least one malfunctioned, failed to eject its reactor into a disposal orbit and scattered radioactive waste across northern Canada. Even the Soviets didn't intend to send nuclear reactors to burn up on reentry; I'd be surprised if that was anyone's plan. https://en.wikipedia.org/wiki/US-A https://en.wikipedia.org/wiki/US-A https://en.wikipedia.org/wiki/BES-5 https://en.wikipedia.org/wiki/BES-5 https://en.wikipedia.org/wiki/Kosmos_954 https://en.wikipedia.org/wiki/Kosmos_954 https://en.wikipedia.org/wiki/Kosmos_1402 https://en.wikipedia.org/wiki/Kosmos_1402 "...44 kg of uranium had been dispersed into the stratosphere after the incident..."
  - kjs3 7y ago
    I've more than "heard about" RTGs, and I'm well aware of the kind of reactors that have been shot into space. We can argue the level of "intend", but in the Cold War, the reentry of a nuclear reactor was considered an acceptable cost of doing business.

analog31 7y ago

This has me puzzled: >>> Confirmation will occur at ~0445 UTC this evening when the satellite should pass through eclipse. Shouldn't it be stationary, if it's in geostationary orbit? Or is it just that the satellite has drifted out of that orbit over time?

azernik 7y ago
The article says GEO, but actual quotes in the article say "GEO graveyard orbit". What this means is that, at the end of the satellite's service life, it was boosted into a lower (in this case [1]) or higher (also common) orbit out of the way of the GEO line. There isn't much space in GEO, as it's a one-dimensional space [2] - only true anomaly (position in the orbit) can be varied. So you want to free up the slot once you're not using it anymore. [1] This particular satellite is http://stuffin.space/?intldes=1967-066E&search=1967-066e http://stuffin.space/?intldes=1967-066E&search=1967-066e. Note the orbital period - it's shorter than a sidereal day of 1436 minutes, which means this is a lower orbit. It's also slightly inclined to GEO, which reduces the chance of collisions even further. [2] By contrast, the set of Keplerian orbits is generally a six-dimensional space, with singularities at eccentricity = 0 and inclination = 0. Well, also technically at semi-major axis = 0, but that's not a physically possible "orbit".
- yellowapple 7y ago
  Are lower-than-GEO graveyard orbits common? I mean, I guess they are, judging by stuffin.space, but my intuition would be that it wouldn't take any more fuel to put a satellite in a higher-than-GEO graveyard orbit (and thus further minimize the risk of collision), no?
  - azernik 7y ago
    No particular reason why a higher orbit is any better than a lower orbit. As long as you're a good 1000 kilometers away from the GEO belt at closest, and preferably a little inclined so that closest approach only happens ~2 times a day, both high and low graveyard orbits are equally good for avoiding collisions.

JoeDaDude 7y ago

I guess that was before we had responsible satellite disposal. http://www.esa.int/ESA_Multimedia/Videos/2017/04/Space_debris_2017_-_a_journey_to_Earth http://www.esa.int/ESA_Multimedia/Videos/2017/04/Space_debri...

anonymousiam 7y ago

Rick Rhodes could really build ‘em!

deleted 7y ago

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