In the summer of 1957 Soviet leadership was shown a model of the soon-to-be first man-made object in outer space. It was a shiny sphere with thin antennae. The energized chief designer didn't mince his words describing the propaganda value of the launch. Then premier Malenkov interrupted him and spoke calmly: "Comrade, the Party has decided to keep the first satellite launch a secret, we want the capitalists to continue wallowing in complacency. Paint your sphere in black and make it silent".

Let's say we need a radio transmitter on the satellite that occasionally beeps while flying over Russia and can be delivered by R-7 rocket.
Is it possible to make it undetectable for contemporary US telescopes and radars?

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    $\begingroup$ iirc, the US already had operational and functional early warning radar systems in the 1950s that could detect satellites and other ICBMs $\endgroup$
    – Dragongeek
    May 12 at 12:35
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    $\begingroup$ @ Dragongeek They did not have ICBM's or satellites until Sputnik. Sputnik was the first. $\endgroup$ May 12 at 13:29
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    $\begingroup$ Giving the entire world the finger by making it go beep was the whole point. If they DIDN'T make it go beep would any know except the CCCP? $\endgroup$
    – Mazura
    May 12 at 22:18
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    $\begingroup$ The bigger question is why would they want to keep it secret? The whole point was to show the world the superiority of Soviet technological prowess. They wanted everyone to know. No one even heard the BEEP until they told them what frequency to tune in to. $\endgroup$
    – Seth R
    May 13 at 2:34

7 Answers 7


Beyond all certainty, the answer is 'yes'.

Sputnik 1 was specifically designed as a propaganda ploy, the singular intention of which was to broadcast a radio 'beep' that could be picked up on regular AM radios. There was no other practical purpose of the ball. That's how we (by 'we', I mean my family and I, personally) detected it as it flew overhead. Of course, we were able to see it as well, given the time of night and the position of the sun reflecting from it.

Sputnik 1 was less than 23 inches (58 cm) in diameter in an orbit between 215 km. and 939 km. With the state of radar at the time, it would be undetectable by any Earth-based system unless they were specifically looking for it.

It wasn't until 1960 that America had a radar system sensitive enough to pick up satellites that did not emit radio signals.

Three weeks ago, headlines announced that the U.S. had detected a mysterious "dark" satellite wheeling overhead on a regular orbit. There was nervous speculation that it might be a surveillance satellite launched by the Russians, and it brought the uneasy sensation that the U.S. did not know what was going on over its own head. But last week the Department of Defense proudly announced that the satellite had been identified. It was a space derelict, the remains of an Air Force Discoverer satellite that had gone astray. The dark satellite was the first object to demonstrate the effectiveness of the U.S.'s new watch on space. And the three-week time lag in identification was proof that the system still lacks full coordination and that some bugs still have to be ironed out.

First Sighting. The most important component of the space watch went into operation about six months ago with the construction of "Dark Fence," a kind of radar trip wire stretching across the width of the U.S. Designed by the Naval Research Laboratory to keep track of satellites whose radios are silent, it is a notable improvement on other radars, which have difficulty finding a small satellite unless they know where to look. Big, 50-kw. transmitters were established at Gila River, near Phoenix, Ariz, and Jordan Lake, Ala., spraying radio waves upward in the shape of open fans. Some 250 miles on either side, receiving stations pick up signals that bounce off any object passing through the fans. By a kind of triangulation, the operators can make rough estimates of the object's speed, distance and course.

On Jan. 31 Dark Fence detected two passes of what seemed to be an unknown space object. After detecting several passes during the following days, Captain W. E. Berg, commanding officer of Dark Fence, decided that something was circling overhead on a roughly polar orbit. He raced to the Pentagon and in person reported the menacing stranger to Chief of Naval Operations Arleigh Burke. Within minutes the news was communicated to President Eisenhower and marked top secret.

But it begs the question be asked, 'Why would the Russians send up a satellite no one could detect, if the entire purpose of the launch was to prove to the Americans that Russia could do it?' It was only after this, that they sent up silent spy satellites that took high-res photographs, and then were retrieved to get the film.

So, you think taking your film to the local shop to get developed is a pain? Try being an American spy satellite in the 1960s. Getting your film developed then meant dropping it in a special ‘film bucket’ capsule from space, which the US Air Force then had to catch in mid-air.

Strange as this seems, this is in fact how it worked, as you can see in the video above. Photographs captured by these so-called “Corona” satellites were shot on special 70 millimeter Kodak film using two panoramic cameras that evolved over the course of the program.

From Wikipedia Note this refers to the booster, not Sputnik itself.

The booster rocket was located and tracked by the British using the Lovell Telescope at the Jodrell Bank Observatory, the only telescope in the world able to do so by radar.[48] Canada's Newbrook Observatory was the first facility in North America to photograph Sputnik 1.[49]

Edit Addendum

Sputnik 1 was the first, period.

There were no satellites before Sputnik.

There were no ICBMs before Sputnik.

There were no rockets capable of delivering a payload into orbit before Sputnik.

There was nothing, period, made by humans circling the Earth before Sputnik. There was zero capacity for any country to put anything into Earth orbit.

There was certainly absolutely no need for anyone to have any radar that was looking for anything orbiting the Earth. It just wasn't possible for anything to be there.

For anyone under the age of 70, it is very difficult to imagine a world when there was absolutely nothing made by humans orbiting or even capable of orbiting the Earth. But some of us are old enough to remember. We were alive when the only thing in space before Sputnik was in sci-fi novels and comic books.

And there was zero telemetry from Sputnik 1. All it did was beep. The only telemetry was a change in the frequency of the beep, depending on temperature and pressure - catastrophic failure of the vehicle. No other data was transmitted. The only purpose of the beep was to demonstrate it was in orbit. When they heard the beep 90 minutes later, over Russia, they new it was a success. End of story, end of data, end of reason for the beep except propaganda.

EDIT Addendum 2

America did not even have radar installations that would reach near-Earth orbits, nor that even covered their own air space, until after 1957.

The new radars will help CAA controllers accomplish this by scanning the skies for all aircraft up to 200 miles away, depending on size and altitude.

The 23 radars will be part of an expanding coast-to-coast traffic control network of more than 70 civil and military radar installations. The network will give controllers a picture of aircraft from 15,000 to 70,000 feet in virtually all the U. S. airspace, and of aircraft at lower altitudes on densely traveled routes. Thus, radar will serve to track the civil and military jets which move at 600 miles an hour or more in the higher altitudes, and the conventional aircraft traffic using the lower altitudes.

EDIT Addendum 3

The irony is, it was the Russian push for a propaganda victory that led to the Americans winning the race. Had the Soviets kept it a secret, world history would have been very different. America would not have changed their educational system towards the '60's version of STEM, physics would not have gotten the boost it did (PSSC Physics textbooks re-wrote the entire physics curriculum), America would probably not have put huge resources into space radar, and Kennedy would never have pushed for 'the Moon within a decade'. There would have been no Apollo program, no moon landing.

As for the timing deice, it was well within electronics/electricity to make a very simple capacitive timing device using diodes and resistors, to cause a capacitive discharge into a coil to produce a spark discharge every 90 minutes (the length of time it took for one orbit). The spark would have been so broad-band, it would have been picked up by receivers around the world, but would have been impossible to completely localize geographically, let alone be localized to space. The West would know something somewhere in Russia caused a spark, but they would have no idea what, and would probably not be able to differentiate it from say lightning. The Russians would know Sputnik completed an orbit, but no one else would have a clue. Recall that the Russians had absolutely no way to track it by radar either. They too needed it to send a signal.

The Russians could have developed their ICBM project in secrecy. They should just have kept their mouths shut, instead of going for publicity.

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    $\begingroup$ +1 but you miss the point of those old satellites that had to drop off their film, they were a great McGuffin for spy novels like Ice Station Zebra :-) $\endgroup$ May 12 at 23:33
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    $\begingroup$ It might be interesting to calculate the bandwidth of regularly dropped 70mm film canisters. $\endgroup$ May 13 at 3:29
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    $\begingroup$ @ Spehro Pefhany I don't think you COULD calculate the bandwidth. Maybe estimate it, but the margin of error would be huge. They used analogue film, so the 'pixels' were actually the grain of the film, and it was not in a grid. The color was true color, not digital color. Of course, once the pictures were digitized in the new century, the bandwidth of the digitized pictures might be easier to calculate. but would be a gross underestimation. $\endgroup$ 2 days ago
  • $\begingroup$ You say Sputnik was the first, which is true. But the US was very close in capability, launching Explorer only 3 months later. It's even said that the US gained by the Soviets launching first and establishing a legal principle that a satellite overflight of another country is not an airspace violation. And radio astronomers were able to track Sputnik within hours of becoming aware of it. $\endgroup$
    – The Photon
  • $\begingroup$ @ The Photon Radio astronomers? In 1957? Did you miss the part on 'the only telescope in the world able to do so by radar.', and that was only because they knew were to look and what they were looking for? And what they saw was the booster. not the satellite itself? $\endgroup$ 5 hours ago

At the time of the launch of the Sputnik, there was no system to detect rocket launch, but it was developed soon after

On October 4, 1957, from the Tyuratam range in the Kazakh SSR, the Soviet Union launched Sputnik 1, the world's first artificial satellite. The event, while a scientific triumph, also signified that the Soviet Union now had the capability to attack the United States with an intercontinental ballistic missile (ICBM). The R-7, the booster rocket that launched Sputnik 1 and Sputnik 2, could be loaded instead with a hydrogen bomb, bringing the threat of a surprise nuclear Pearl Harbor-style attack on the United States and Canada. To give an early warning of any Soviet sneak ICBM attack, the governments of the United States, Canada, and Denmark (with the authority over Greenland, where the main radar station was built at Thule Air Base) agreed to build the Ballistic Missile Early Warning System (BMEWS). This system would use radar to detect incoming ICBM warheads and give about 20 minutes of warning of an ICBM attack.

Spotting a small sphere of metal moving at few km/s around Earth is not easy, in particular with no clue where to look for. Maybe only around the terminator it could be spotted as a very fast moving light point. But that would be a negligible risk, considering its limited dimensions.

Probably the radio signal would have been the giveaway: with no technologies to detect position, you can't really instruct the satellite to beep only when above friendly territory. You can however create a circuit which answers back when it is called, and you make the call sign obviously only from friendly territory. However I am not sure a receiving antenna and the related circuitry would have fit into the balance of the Sputnik, plus the unknown of having such a system operate in space for the first time.

  • $\begingroup$ In 1956, the Russians better keep the sat from beeping around in SW radio frequencies. There were hobby folks listening in with their SW radio's all over the world.. When there's a possibility to recieve the sats radio transmissions, all you need is multiple reception reports with antenna directions and you may triangulate to locate the satellite. It would be a great hunt, every SW amateur participating. $\endgroup$
    – Goodies
    2 days ago
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    $\begingroup$ "Beep only when above friendly territory" is easy: orbits are quite predictable, so you just give it a timer that only turns on the transmitter at the right time. $\endgroup$
    – Mark
    2 days ago
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    $\begingroup$ @ Mark The problem is battery power. Battery technology was very primitive at the time. They did not even have electric watches, they were all wind up. That would be some spring action. vintagedancer.com/vintage/history-mens-watches $\endgroup$ 2 days ago
  • $\begingroup$ @Mark Not only did Sputnik have to deal with atmospheric friction (it came down in about three months), it also didn't make it into the orbit it was intended to launch into, winding up in one that was initially four minutes shorter. Without navigation systems or the ability to reprogram it on the fly, a simple timer wouldn't cut it. $\endgroup$
    – notovny
    21 hours ago

I think the answers so far are kind-of-right, but not exactly right.

  • The West certainly could have detected Sputnik, even painted black and without radio, if they had known where to look.
  • Without the radio, and without the press release, they would not have known where to look.

Any visual observer without instruments would have interpreted any one sighting as a meteorite or the like, and failed to recognize that it was an artificial satellite. A sufficient number of visual observations might have allowed the calculation of the orbit, but how would the various observers coordinate their data?

Things would look completely different if the was tipped off by agents to mount a systematic search.


Not if you want to communicate with it

Undetectability is impossible if it needs to send you something. In fact, the moment it needs to send a single beep from orbit with non directed antennae, that beep can be picked up by at least one NATO country, because radio waves go out in a sphere and it is flying so high, that every point over the Soviet Union is at least observable by some NATO or commonwealth country in the first or second reflection.

If the satellite flies the Sputnik 1 orbit, then it will be at its closest about 215 kilometers over earth. The ping will be listenable for 1670 kilometers - or when it does it in the center of Russia, it'd be listenable to most of Kazachstan and some areas of Mongolia and China. The first and second reflections carry the signal to India and Turkey. At its furthest, 939 kilometers over the earth, the ping reaches 3586.1 kilometers in the first instance and that means at the same point the unreflected signal can (almost/barely) be picked up in Deli, Oslo, and Ankara, and its first reflection will reach Tokyo and Berlin.

In fact, just about 230 kilometers more west and it can be heard in Berlin and only 1200 kilometers to the east to reach Tokyo instead of Ankara. And in any case, Spitzbergen is a very good listening post, allowing to hear the signal when it has about 3000 kilometers ping radius - which is at a height of 670.3 kilometers over the marked spot.

To visualize: these are the minimum and maximum circles of the direct signal, and that is without taking into account the effects the upper atmosphere has on signals - which usually make it carry much further.

enter image description here

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    $\begingroup$ Only signals from omni-directional antennas travel in a sphere at equal power. Directional Antennas can focus most of the energy along a narrow beam, preventing detection outside the narrow area they focus. A directional antenna and timing system would allow only certain regions to detect the signal. en.wikipedia.org/wiki/Directional_antenna $\endgroup$ May 12 at 20:42
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    $\begingroup$ @ConnorGarcia But did the Soviets of the time possess the technology to reliably aim an antenna on a satellite at the desired receiver? Especially without broadcasting telemetry back to the ground and receiving maneuvering instructions from a ground-based station? $\endgroup$
    – reirab
    May 12 at 20:59
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    $\begingroup$ @reirab The Soviets could have designed a directional antenna to always point at Nadir (atmospheric drag stabilized) and only emit when receiving from a similar ground antenna. This would effectively exclude other regions from detecting the signal without the necessity of telemetry or predict ephemeris for timing. $\endgroup$ May 12 at 21:12
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    $\begingroup$ @ConnorGarcia Sputnik had no reaction control system, which would be required. Without sputnik, it couldn't have been developed, as the telemetry of it was essential to lay the foundations to it. $\endgroup$
    – Trish
    May 12 at 21:42
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    $\begingroup$ The power of the radio transmitter on Sputnik was very, very weak. They did not have good batteries back then. $\endgroup$ 2 days ago

Well before 1957, it was possible to build a (vacuum tube) radio circuit that would respond to a pretty specific interrogating signal. Instead of a timer, that might cause your Sputnik to announce itself when the wrong nation is below, you send this circuit up.

Soviet ground station sends interrogation at the calculated time, and if the satellite is in the expected orbit and operating, hears the response. If the orbit is wrong or the satellite's battery or radio are dead, no one hears anything.

With appropriate tuning of the response signal strength (a few milliwatts might be sufficient, if the ground station has a directional, steerable antenna -- 1940s tech) the response from the satellite would only be audible to stations with large enough, high enough gain antennas, listening at the right time on the right frequency and in the right direction.

A much larger issue would be hiding the launch. R-7 used kerosene/oxygen engines, and the bright exhaust flame would be visible for thousands of miles from locations near the ground path (as happens now with Falcon 9 launches, though the flame would be smaller with the R-7). Any spy (especially with a mission to monitor missile activity) might see the launch, recognize it for what it is, and make a report. Combine this with other information from potential spies within the Soviet missile command, and it's possible American or British intelligence networks might learn of the launch in time to interrogate the satellite before its battery fails...

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    $\begingroup$ the bright exhaust flame would be visible for thousands of miles There is a reason they put the lauchpad in rural Kazakhstan. Any spies that could see it would be in deep and not easily in contact with home. In actual fact, the West was usually unaware of Soviet launches until after the Soviets publicized them. $\endgroup$
    – Seth R
    May 12 at 21:02
  • $\begingroup$ @SethR The launch ground track from Baikonur passes over Mongolia and China, and near Taiwan and southern Japan. Night launches might even be visible from South Korea, though early launches would usually be in daylight for easier visual tracking. For that matter, the early part of the launch would be visible from the Caspian. $\endgroup$
    – Zeiss Ikon
    May 13 at 11:04
  • $\begingroup$ @Seth R Yea but all the American satellites the US had up there would certainly see the exhaust flame. Wait..... $\endgroup$ 2 days ago
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    $\begingroup$ @ZeissIkon, rural Mongolia and China were, and still are, very sparsely populated, and poorly connected to the rest of the world, while the Caspian Sea is mostly surrounded by the Soviet Union. $\endgroup$
    – Mark
    2 days ago
  • $\begingroup$ Regarding a vacuum tube radio circuit, I'm skeptical of the power requirements for such a thing. Sputnik appears to have used three 2П19Б vacuum tubes, which only consume a couple watts max. I'd be interested to see a design that can receive and interpret a specific interrogation signal without dramatically increasing the power consumption. $\endgroup$
    – Chris
    2 days ago

Malicious compliance

This might seem like a joke, but it isn't. The URSS was a strange place to live, getting stranger by the moment. There were many rules to follow, sometimes contradictory, and therefore many comrades had to resort to malicious compliance if they wanted to survive.

The most popular example is Eduard Anatolyevich Khil, who was ordered to sing on national TV. But the song he had to sing spoke of a cowboy that was glad to return to his farm, which was a private property - and it was forbidden to mention private property in a positive light. The whole setup meant he would probably be taken straight from the studio to a gulag, but Eduard was a smartass. He went on stage and sang, but he replaced all the lyrics with "La lalaya lalaya la lala" and "Trololololo, lololo, lolo LOL". He went back home that night and managed to survive long enough to eventually become an internet meme.

Back to your guy, he can do both things. The chief designer can make Sputnik "silent" by making sure that the signal is so faint that not even the most sensitive receivers can pick it up. That makes it compliant with both requirements - it will beep and it will be invisible. As for beeping over Russia, put a timer on it. I would like to say that this is not rocket science, but calculating orbital periods and therefore when it beeps actually is rocket science. But still, nerding it out is in the comrade's job description.

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    $\begingroup$ knowing this just made Masha and the Bear became so much funnier. $\endgroup$
    – Nosajimiki
    May 12 at 13:09
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    $\begingroup$ An amusing suggestion, but I think you mean "receivers," not "radars." Radars do not listen for signals broadcast by the objects they are tracking. They broadcast their own signal and listen for reflections of it, which indicate the presence of something for their signal to bounce off of. (And, before anyone responds, "But secondary surveillance radar!," that isn't really radar. It's just called that because it serves the same purpose that actual radars served before it.) $\endgroup$
    – reirab
    May 12 at 21:08
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    $\begingroup$ @reirab thanks, I fixed it :) $\endgroup$ May 12 at 21:20
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    $\begingroup$ According to the quotes from Khil and from his son here (both from after the fall of the USSR), he didn't change the lyrics because they would get him in trouble, but because he either just didn't like the lyrics or wanted to get back at the lyricist. $\endgroup$
    – Hypnosifl
    May 13 at 1:56
  • $\begingroup$ Your example is false and not credible. His performance was in 1971. GULAG was disbanded in 1960. It is also not very credible that in 1976 someone would be sent to a prison camp for singing of a cowboy returning to a farm. $\endgroup$
    – gerrit
    May 13 at 7:16

The thing about Sputnik I is that it was a quickly conceived Plan B.

Plan A was to launch Object D in 1957, which was supposed to undertake a series of scientific measurements during a brief 3 or so week period, while in orbit.

There were problems however, Object D was too heavy and initially there was a problem with the R7 rocket in being able to provide enough specific impulse. There was also going to be a delay in the delivery of Object D, from 1957 to April 1958.

Plan B was to send the simplest satellite, and also a much lighter satellite, into orbit to claim the title of first orbital satellite launch.

Given the history of the launch of Sputnik I, it would be pointless trying to hide it, once it's launch was a success. Getting the Kudos for the first successful orbital satellite was something that appealed to Khrushchev, to "prove" the Soviet System was better than the American System, even if the first satellite was nothing more than just a radio beacon. Hence why he was eager to get the first animals, man and woman into space; amongst the other Space firsts the Soviet Union achieved.

If however, you want to develop an alternate story hiding Sputnik I, it's plausible, but the Soviet Union didn't hold on to the advantage it initially had, the Americans quickly overtook many of the Soviet achievements.


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