Linked Questions
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Sputnik: What took so long?
After WWII, both the US and USSR began developing their early rockets based on the German V-2 work. USSR flew their R-1 copy of the V2 in 1948; the US flew Corporal in 1947.
It wasn't until 1957 ...
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Why did Sputnik 1 have four antennas?
Sputnik was only launched a few hundred kilometers above Earth, and transmitted only a simple beeping signal. What was the purpose of having four antennas? Wouldn't one be powerful enough?
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Sputnik, Van Allen belts
Van Allen belts were discovered/confirmed by the satellite "Explorer", which was launched after Sputnik. If so, was Russia aware of VA radiation belts when they launched Sputnik? If not, how ...
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Why did Sputnik-1 transmit on both 20 and 40 MHz?
Wikipedia's Sputnik 1 and this answer to Why did Sputnik 1 have four antennas? say that Sputnik transmitted at both 20 and 40 MHz.
Why two different frequencies? Why so far apart?
It's worth noting ...
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What did Sputnik-1 sound like? Did it use multiple tones?
Radio transmissions from Sputnik-1 could be heard on short wave radios around the world.
Questions:
A carrier signal only would not be particularly audible to an AM radio listener, was it modulated ...
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Why were early satellites produced with polished "mirror-like" surfaces?
Many/most early artificial satellites were spheres with mirror-like polished outer surfaces.
I am guessing that for lower orbits the spherical shape minimized drag as well as simplified the analysis ...
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4
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When and what was the first successful photograph of an orbital spacecraft from Earth taken?
Early artificial satellites were tracked by radio and visually by amateurs, scientists and military personnel for various reasons including fun and improving the understanding of orbital dynamics ...
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How are gravity coefficients calculated?
I was reading Satellite Orbits - Models, Methods, and Applications by Montenbruck & Gill and was trying to use the equations in it to calculate $J_2$ as used in the GEM and JGM gravity models. ...
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Is Earth's "pear shape" mostly J₃?
@OrganicMarble's answer to 1959 Peanuts cartoon about the Fischer ellipsoid (Earth is “pear-shaped”)? finally let me see the cartoon that Mathematician, Engineer and Geoscientist Irene Fischer wrote ...
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When was advertising on Earth from space first proposed? By who?
How big will a space billboard have to be to be visible? can be seen to raise an interesting question.
Question: When was advertising on Earth from space first proposed? Who proposed it?
This can ...
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Puzzler: Is this a Sputnik?
I was enjoying the Trailer to the YouTube site Kinematic, and I noticed that the satellite or model shown in the beginning looks different than how I remember the original Sputnik - specifically the ...
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Why didn't early satellites have a way to recharge?
Sputnik 1 only worked for 21 days until its battery ran dry, explorer 1 ran for 111 days. It wasn't until Vanguard 1 that we started putting solar panels and recharge methods on satellites. It was ...
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Did the unmanned orbital test of the Buran shuttle yield any science results?
This question was inspired by the question Did Sputnik 1 tell us more than “beep”?
The Soviet Buran programme only had one orbital flight, mission 1K1, on 15 November 1988.
Did that mission yield any ...
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What will happen to Chang’e 5 orbiter?
What will happen to the Chang’e 5 orbiter which will return the collected samples to earth? Will it burn up in the atmosphere like Hayabusa, or is an extented mission planned?
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Calculating Orbital Velocity without Semi-Major-Axis
When playing Kerbal Space Program, I realized that there is a difference between surface speed and orbital speed; this difference is quite variable, although the Kerbin's surface speed is only 175 m/s....
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