Somebody moved the UK's oldest satellite in the mid 1970s, but no one knows who
bbc.co.uk
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I recently encountered here on HN the suggestion that, the main reason you can't find particularly in-depth details on the Voyager space probes, is project security. Security through obscurity, mostly. If amateurs can detect the signal from the Voyager probes with a small dish antenna, it's at least conceivable someone might hook up a really powerful transmitter, aim it in the probe's direction, and start issuing commands. There's no cryptography, of course. The resources required to hijack like that in the 1970s would have been much greater, and I doubt being hacked was much on the designer's minds.
The Apollo Program was the same; today anyone with the documentation, a small dish antenna, a software radio, and some nerd dedication, would be able to hack Apollo midflight via its radio link. It was the equivalent of a root prompt with no password on an exposed port.
A bit closer to home, there's a tremendous amount of semi-functional orbital junk with a similar lack of security, decades-old computers still waiting for telecommands.
>would be able to hack Apollo midflight via its radio link. It was the equivalent of a root prompt with no password on an exposed port.
Indeed, but in that case it would be port opened with a switch: https://youtu.be/2Jt0PsxLM7k?t=1732
If one of them in particular were to happen upon this HN post, I honestly wouldn't put it past him to try messing with Voyager.
Compared to what? What was (or is) worth securing? From what? Talking about security in abstract is nonsensical
Besides, invoking the cold war explains little (aside from invoking the propaganda of the time). The soviets live-streamed the moon landing. The idea that they were necessarily antagonistic is simply inaccurate. Not to mention what they would gain from fucking with satellites remains unexplained.
You don’t see what America might have gained if it could de-orbit the USSR’s early-warning satellites at will?
The earliest active communication satellites — e.g. Telstar 1 — was done with "take signal in from vaguely the right direction, amplify with pure circuitry, rebroadcast in vaguely the right direction", no encryption possible on the satellite itself, and the thing itself was so primitive it was spin-stabilised rather than having an actively maintained orientation.
Weather satellites won't have mattered too much. Spy satellites I'm not sure about (what with this stuff being somewhat secretive and all), but they're obviously a thing where security matters.
For the airplane nerds, this was also how early radar jammers worked. They took an incomming radar signal, delayed it a little, and retransmitted. No processing required and no digital circuits. That worked very well once upon a time.
They can't, at least not for any reasonable definition of small. As I'm writing this, NASA is listening to Voyager using the DSS-14 antenna of the Deep Space Network, a dish with a 70 meter diameter, and the signal it receives is 10^-19 Watt. That's only 15000 photons per second. Coincidentally the area of that 70 meter dish is also roughly 15000 m^2, so a small dish of 1 m^2 will catch roughly 1 photon per second. Given that the datarate is 40 bits/second, it's physically plain impossible to receive the signal with a small dish.
Voyager's security is that it's really far away and you need a big, expensive dish to talk with it.
This works out to roughly 0.7 acres.
I had to look it up to check: my mental model was that a foot is some king's foot but there is more of a storied history.
Antennas at Goldstone Deep Space Communications Complex
Name Diameter Description
DSS 12: "Echo" 34m Decommissioned in 2012.
DSS 13: "Venus" 34m Beam waveguide antenna (BWG) on altazimuth mount, located in Venus, California. ~910 m2 aperture.
-> DSS 14: "Mars" 70m Cassegrain reflector on Alt/Az mount. ~3850 m2 aperture.
DSS 15: "Uranus" 34m "High Efficiency" reflector on Alt/Az mount
DSS 24, 25, 26: "Apollo" 34 m BWG reflector on Alt/Az mount
DSS 27, 28: "Gemini" 34 m BWG reflector on "High Speed" Alt/Az mount
https://www.jpl.nasa.gov/news/nasas-deep-space-network-looks...
As a sanity check, the video says the area of the dish is approximately one acre which would be ~4,046m2 and a 35m radius disk is ~3,850 m^2.
But you dont even need that. You need just enough outbound signal to jam the legitimate uplink, enough that voyager can no longer tell you from the real signal. That is likely much less than the power needed to send a command.
Or you could jam the nasa ground stations. A one-watt transmitter on a carefully positioned cubesat in low orbit would be enough to nullify voyager's real signal. (Setup the orbit to be over the deep space network stations every day as voyager comes into view.)
Violating these is already solved by law enforcement, even if a rogue nation state is protecting you it will be handled with big gun diplomacy, America after all has the biggest guns.
As xkcd put it, $5 wrench is all it takes no matter how strong your encryption, that works both ways, if a government can find a malicious actor all it takes is $5 wrench to stop you. There is limited value for nation state to protect you from hacking voyager, there is no military or strategic value in it. Dormant satellites in LEO or GEO can be used as kinetic weapons so are lot more valuable.
There are also tech solutions like active jamming that could easily be deployed to counteract you that civilized world can use first even if they don't/can't blow you up without risking retaliation from your state sponsor.
No one is going to war over ITU regulations or Voyager.
Voyager itself is not economically valuable, but it a cultural symbol of American achievement like say Eiffel Tower in itself does not have value economically (apart from tourism ) but it is very big part of their identity so yeah plausible it would start a war .
They'd go to war if they're threatened, but a violation is ITU regulations isn't a sufficient threat. I mean, North Korea and South Korea occasionally shell each other (much worse, https://en.wikipedia.org/wiki/2010_Yeonpyeong_bombardment), and no hot war has resulted.
> Voyager itself is not economically valuable but it a cultural symbol of American achievement...it is very big part of their identity so yeah plausible it would start a war.
I'm sorry, if you think that, you're in a bubble. Voyager is not a "very big part of [American] identity," it's a nearly-kaput space probe that science and science-adjacent geeks (a tiny minority) occasionally get enthusiastic about.
The absolute worst that would happen if a nation state sabotaged it at this point, is the American government would send a strongly worded letter, and the saboteur's ambassador would be summoned for a tongue lashing.
No one's would start a war over the sabotage, and if they did such a war would go down as one of the stupidest casus belli ever. FFS, no one would even have died.
And no one's signing up to die in a war to avenge it. Would you volunteer to be sent to something like the meat-grinder of Eastern Ukraine, because a Voyager became incommunicado a few years early?
Do you just mean plain impossible with the specific type of system used with Voyager, or are making a general argument that all systems that have a 1 photon/second rate cannot carry 40 bits/second of data?
where Eb is energy received per bit of information and No is noise spectral density.
This makes it paramount to collect as much energy per bit (Eb) as possible which in turn requires large antennas for far away objects such as Voyager probe.
DonHopkins on Jan 3, 2023 | root | parent | next [–]
John McCarthy trolled me once!
When I met him, we were chatting about Stanford, and I mentioned that I really admired that huge radio telescope that you could see around 280 and Page Mill Road in the hills above Stanford.
He looked puzzled and confused, and asked "Which huge radio telescope?"
I was flustered and explained how you couldn't miss it, right by 280 and Page Mill Road, it's out there in a field, its huge, it's enormous, gigantic I tell you, there's no way you can miss it, bla bla bla...
He let me go on and on, describing it, and acted like he had absolutely no idea what I was talking about, like I was crazy for hallucinating a gigantic radio telescope that both of us must have passed zillions of times.
Finally he let on and said, "Oh, you mean that SMALL radio telescope???"
inamberclad on Jan 3, 2023 | root | parent | next [–]
It's just called The Dish, and I mean, it's only medium sized (46 meters) compared to the main antenna at a DSN site (70 meters).
"from the beginning" doesn't really mean much of anything, and the system would need to be pretty sophisticated just to work, even if 100% of the users were operating in good faith 100% of the time.
I'd say that it almost certain that by the time Voyager was launched, there would have been robust authentication just out of necessity. By that time they'd have decades of experience dealing with software bugs, to say nothing of bad actors.
Literally they are not. The rockets used to launch the Voyagers were built by Martin and General Dynamics.
Can you link to the documentation for the authentication mechanism?
The techniques were probably closely held at the time to prevent Soviet interference, but these days you can just download the circuit diagram PDFs.
[0] Simulated, since the owner of the original AGC wanted it back.
https://www.theregister.com/2014/07/07/space_hackers_fire_up...
Is this right? In a recent curiosmarc video I got the impression the astronauts on board had to enable remote commands. This was frequently done but they did have a cutoff.
Strangely from that series, iirc, ground commands were "king", meaning if that switch was enabled, whatever ground wanted the ship to do, it did, no matter the input from astronauts
Many sats were and are similar, theres not much security. Newer ones with specific uses are most definitely encrypted.
The only real saving grace is that the size of dish/antenna and power you need to do anything with stuff actually in space at long distances is beyond what most people could do (not saying a very dedicated nerd couldnt, look at SaveItForParts for example).
On a tour of the satellite manufacturer, RCA Astro, years after the loss, we heard this story: during the transfer of control from NASA to RCA Astro contact was lost and not re-established. Eventually the U.S. military was asked, "Errrh, did you see where Satcom 3 went?". The answer came back "Yup, looks like isn't in the geosynchronous orbit you expected".
The thought was that during the handover a command to fire the apogee motor was inadvertently sent and obeyed!
The fix for FUTURE launches was a protocol of checksummed commands. Beyond that, the new, more cautious sequence, became:
1. uplink dangerous command.
2. spacecraft verifies checksum and downlinks a copy of the proposed dangerous command
3. a keylock on the RCA command console is turned on and the "execute that dangerous command" instruction is uplinked.
4. upon verifying the execute command's checksum, the dangerous command is executed.
Satcom 3's hulk is still in orbit.
See: https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id...
https://space.skyrocket.de/doc_sdat/satcom-1.htm#:~:text=Sat...
There was one of these just a couple weeks ago (and that was not the first),
https://news.ycombinator.com/item?id=41904346 ("Intelsat 33e breaks up in geostationary orbit")
1) unlike LEO, there's so little drag that both large particles and small fragments are essentially up there forever
2) all the satellites are concentrated in a line, not spread out in a 2D plane or (even better) a 3D volume (collisional probability scales as number density squared)
3) despite that, the moon perturbs any uncontrolled debris into a slightly inclined orbit that nevertheless crosses GEO with >500 m/s relative velocity
If you want to intentionally rendezvous with and deorbit satellite debris, GEO is certainly one of the orbits to prioritize.
>Almost certainly, it was commanded to fire its thrusters in the mid-1970s to take it westwards.
While the title says that it is not known who has moved an abandoned UK satellite used for military telecommunications, the article very strongly implies that it was someone from USA, who does not want to acknowledge this.
The satellite had been built by USA and initially operated also by USA, before being handed down to the UK, so they had the capabilities to control it at any time.
It is a testament to deGaulle's genius that he never fell into that trap.
> Launched in 1969 ... the spacecraft ceased working a few years later ...
Also, what makes you think the US didn't already have their own satellites for that purpose?
That said, it's an assumption in the article that the orbit change wasn't due to the cumulative effect of the normal gravitational perturbations the pull on all these vehicles. You'd need to dig up what orbit it was in 40 years ago and then calculate how the orbit would have drifted over those 40 yrs. Good luck.
I was going to put it back and then I got distracted and forgot.
A UK historian can't find in part classified paperwork that would be created by the U.S. Department of Defense who had control and moved a broken satellite in the 1970's
Re-framed as a puzzle, why was this location chosen it becomes interesting. But I get BBC are just chasing NPC clicks from sites like HN