How do Spacecraft Photograph the Planets & get the Images Back to Earth?


Over the past 50 years we’ve sent
robotic probes to explore our solar system and they sent back some amazing
close-up images of the planets asteroids and even comets but how did they take
these images and what sort of issues are there in taking photos in deep space and
getting them back to earth. In a previous video we looked at how the
first spy satellites used film to get the best quality available at the time
because electronically transferring images back to earth wasn’t of a high
enough quality for the reconnaissance purposes. They were in orbit just a few
hundred kilometers above the earth so we could drop the film back to earth but
for the first space probes going to the moon, Mars, Venus and beyond that wasn’t
an option. In 1959 Luna 3 became the first
spacecraft to photograph the far side of a moon ironically using captured film
that was temperature and radiation resistant and had been captured from US
Genetrix spy balloons that have been shot down over the Soviet Union. The
camera used was a dual lens system with a 200 millimeter wide angle that could
image the whole moon in one shot and a 500 millimeter for close-up shots of
regions of the moon, though close-up wasn’t really that close as Luna 3 took
images of a farside from around 65,000 kilometers. The camera was also
fixed at a body of a craft so Luna 3 was the first craft to used three axis
rotation to position itself to take the images. Once the images had been taken
the film was developed, fixed and dried on board and then scanned electronically
by passing it between a flying spot scanner and a light-sensitive sensor A
dot of light from a flying spot scanner traversed a film at a resolution of a
thousand lines per 35 millimeters frame this varying level of light was
converted to an electronic signal and transmitted back to earth. Here it was
shown on a slow scan TV and then that image was photographed and that became
what the rest of the world saw. The poor quality of images is hardly surprising
once you take into account that each stage of a processing the image quality
was reduced more and more. However it was 1959 and it was the first time it
had been done and they were still good enough to show that the far side of a
moon was very different to the earth-facing side. The very first image
of Earth from far away a low-earth orbit was by Explorer six and also in
1959 from 27,000 kilometers and was part of a test of an all electronic
scanning system to measure cloud cover. This images of the sunlit clouds above
the Central Pacific though it’s hardly what you could call good. Compare that to
the “Blue Marble” shot of the entire earth by the crew of Apollo 17 in 1972 whilst
on its way to the moon and using a 70mm Hasselblad with an 80mm lens.
millimeter lens things obviously had to Things had change a lot if we were to send space probes tens or hundreds of millions of kilometers to the planets and see
something better than the best telescopes on earth. In 1964 Mariner 4
became the first spacecraft to do a flyby of Mars and take close-up images.
Unlike Luna 3, Mariner 4 used the slow scan vidicon TV tube to gather the
images of the Martian surface. The analog signal output of the tube was then
converted to a digital format and then stored on a magnetic tape recorder, the
predecessor to today’s hard drives. After the camera finished taking the pictures
they were replayed back from the tape and sent back to earth for processing at
JPL. Because it was going to take the computer a long time to create the
images, we are talking about 1964 mainframe here and the need to get
something out quickly to the press when the first image data was received one of
the team at NASA used crayons from a local art store to color strips of data
that they saw on the monitor screen, a bit like painting by numbers and this
became the very first image of another planet. When the actual monochrome
version was assembled and printed out by the computer it was surprising how well
the hand-drawn version looked in comparison and
that is now on display at the JPL labs at Pasadena, California.
In 1975 the Soviets became the first to successfully take pictures from the
surface of another planet this time it was Venus. They knew the US was planning the Viking Mars Lander but due to budget restraints and issues with long-term
reliability of their navigation they chose Venus as a closer target. But a
Venus landing makes a Mars landing look like a walk in the park.
When it landed it recorded an atmospheric pressure 90 times that of
Earth and the temperature was 485 degrees Celsius. Although the surface of
Venus is completely obscured by thick clouds from above, from below the
pictures it sent back of the surface show but it’s about the same brightness
as an overcast summer’s day here on earth and with good visibility and
little atmospheric dust with rocks scattered around the lander. To get the
images back to earth for lander relayed the pictures back to earth via the
orbiter which had also carried the lander and this was also the first craft
orbit Venus. The lander had two 180 degree cameras which would have given a full
360 degree view but the lens cover of one failed to detach on landing. The
cameras themselves were photographic scanning devices with moving mirrors. The
resolution of each was about 70,000 pixels made up of a 500 by 128 pixel
frame. Although it was thought that the heat and pressure destroyed the lander
after 53 minutes on the surface, a Soviet source later said that the transmission
had stopped because he orbiter had moved out of a communication range of the
lander. Taking pictures of a planet hundreds of millions or billions of
kilometers away poses many problems firstly there is just the lack of light
the amount of sunlight compared to here. On earth is about a thousand times less
when you get out to the distance of Pluto. High noon on Pluto is equivalent
of what that’s a called Pluto time on earth
that’s around dusk and dawn and roughly when you would have to turn on the
headlights of your car. Taking images of asteroids is even harder and is akin to
photographing a piece of coal in moonlight whilst travelling faster than
a bullet. This means that the camera exposures must be much longer to gather
enough light but then the speed of the spacecraft,
New Horizons for example is traveling at 16.2 kilometers per second
almost 60,000 kilometers per hour and would introduce motion blur if the
cameras don’t exactly track the object they are flying by. And it’s not as if
you can just press a button here on earth and they will take a picture on a
spacecraft the distances are so great but it takes four and a half hours to
send a radio signal to Pluto at the speed of light so everything has to be
pre-programmed and timed to the second in order to turn the camera or the
spacecraft at the correct speed and at the correct time to get the exposure
without motion blur or missing the object completely and all that is done
by the spacecraft by itself. Only hours or days after will the team on earth
know if it’s work correctly. Then there is the radiation, not only the cosmic
rays from deep space but around the planets themselves. Just like the Earth’s
magnetic field captures and concentrates charged particles from the Sun in the
Van Allen belts, Jupiter and Saturn do the same only on a much larger scale. Due
to the interaction of Jupiter’s rings yes it has rings like Saturn but just
much smaller and the volcanic emissions from Jupiter’s moon Io, there are areas
of intense radiation around Jupiter some 10,000 times that of the Van Allen belts
around earth. So the cameras and electronics on spacecraft like the Juno
Jupiter orbiter which launched in 2011 and will fly closer to Jupiter than any
other craft are especially radiation hardened. The CPU on Juno is rated to
withstand 1 Million RAD’s and 20 million RAD’s over its
lifetime. If a human were exposed to a thousand rads for a few hours the result
would almost invariably be fatal. The CPU and other electronics are
encased in a radiation vault which has up to 25 millimeter thick titanium walls
which reduces the radiation by a factor of 800 the camera itself uses a Kodak KAI-2020 sensor with a resolution of 1600 by 1200 pixels with modifications
and a special housing to mitigate the intense radiation. The power supply the
length of time but it has to operate also limit the size of the cameras and
the strength of the transmissions back to earth. Nuclear-powered radioisotope
thermoelectric generators are used and can last for decades but their output is low
that just a few hundred watts. The voyagers used two cameras which were modified versions of the slow scan vidicon tubes used on the earlier
Mariner missions. One has a low resolution 200 millimeter wide angle
lens and aperture of f3 whilst the other uses a higher resolution 1500 millimeter
narrow angle F 8.5 lens. The resolution of the images after they’ve been
digitized was just 800 by 800 pixels. Although we see color images taken by
the Voyager probes, they actually only sent black and white ones each camera
has eight colored filters in a controllable wheel that rotates in front
of a camera so for a color image they would take three monochrome images, one
each through a different filter usually red, green and blue. These three images
would then be combined to make a full color image when they received back on
earth. Using this method they can get a higher resolution and if the camera used
a color camera tube. Often they might need to take images as part of a
spectrum which we can’t see like infrared or ultraviolet so a monochrome
camera and filter combination works much better. The cameras on Voyager could take up to 1,800 images per day, far quicker than could be sent back to earth.
These were stored on magnetic tape like on the Mariner probes. The digital data
would then be replayed back and sent to earth at a speed of around 7.2 kilobits
per second which was at a distance of around about Jupiter. With an individual
picture taking up about 5.2 megabits of data and allowing only for a basic
compression method available with time and error correction which sent extra
data in case some of a signal was lost, it would take about four to five minutes
to send each image so for a full day’s worth of 1,800 images who would take
just over six days to send them back to earth. By the time the voyages were at
the distance of the outer planets the bandwidth had dropped to around a
160 bits per second at this speed it now takes nine hours to
send one image an 1800 images would take 1.8 years. Even on modern spacecraft the
data rates are very slow compared to what we used to.
New Horizons data rate from Pluto in 2015 was just 2 kilobits per second not
2 kilobytes, 2 kilobits and it’s even farther away now. This is why it will
take up to a year to send back all the images of Ultima Thule taken in December
2018. Something that a lot of people don’t realize is that the pictures we
see are mostly for public consumption and PR but they’re not that important
from a purely scientific point of view. Most of the real science is done by the
other instruments which are carried onboard. Junocam was put on the Juno
Jupiter orbiter primarily for public science greater public engagement and to
make all the images available at NASA’s website. It’s low resolution and fixed
mounting to the spacecraft body led to it being referred to by some as Juno’s
dash cam. It was designed to survive eight orbits around Jupiter but as of
2018 had survived 17 so it’s now been tasked with more
scientific duties as well. If you are wondering why these billion dollar
spacecraft don’t use the latest multi megapixel camera sensors it’s because
they need reliability above everything else so they use tried and trusted
technology whichever time of the design is often a decade or more old. It then
takes years to build and then launch again working with the original trusted
design where possible. When New Horizons was launched in 2006 it was already
nearly a 15 year old design and it wouldn’t arrive at Pluto for another
nine years. Using this method of tried and trusted technology has proven itself
many times now with the best known examples of voyagers 1 & 2 working for
the best part of 50 years and maybe more if their nuclear power suppliers can
hang on in there a little longer. All of the missions we have launched to
photograph and find out more about our solar system have had unforeseen issues
which have had to be fixed with a craft hurtling through space millions or
billions of kilometers from Earth, problems that tax their creators and
operators every bit as much as they did their original design all those years
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100 Replies to “How do Spacecraft Photograph the Planets & get the Images Back to Earth?”

  1. You created very interesting channel, I respect you especially for numerical values and interesting facts in the field of engineering.

  2. A very interesting video on a not well understood topic! Thank you. I hope at some point you might take on the science and the history of thought behind global warming and climate change?

  3. Your videos are scholarly quality, when you present to your audience, especially to me. Thank you, Curious Droid! ***

  4. Are there any known and confirmed "test photos" from early NASA flights? E.g. blurred images of Moon/Earth/planets etc.? It would be interesting to watch, because we are used to see these high quality beautiful color images from the cosmos nowadays and for certain this technology had some trial-error and failures.

  5. Paul SHILLito. These vile freemasonic liars are taking the piss out of you. Wake up people to all their space lies

  6. I get that we’re talking about space photography here, but still..by any means, 200mm is not a wide angle

  7. 5:30 – Was that a cut there? Your voice sounded temporarily different I only noticed it when listening closely, was the wrong planet name was said and then redubbed or maybe its just my ears.

  8. Hi Paul, given that an Englishmen invented the fax machine in the 1830's approximately. It is so surprising that project corona, with Dr land and Kodak's input was needed. Was this simply because of poor download speeds by modem, or difficulties with encoding the data stream?

  9. Hi again Paul, I built perhaps the first if not the earliest 386 computer for sir Mark Oliphant in Australia. He was examining the first images of Saturn's rings. The data was provided by NASA, and it took over 12 hours to be compiled by the unit. Yes pre Pentium computers were very slow. I watched the rings forming for many, many hours. He liked his whiskey did the Sir. I must also add, he felt the greatest guilt over his assistance in developing the A bomb. He was not an alarmist pacifist by any means I assure you; simply a man implicated in a true horror.

  10. Satellites send electro magnetic waves to earth and are received via antennae and black magic over millions of miles in five god-damn minutes and I can't even get my phone to connect to wifi in a McDonalds on wednesdays.

  11. We ought to make some landers to go and explore some of the terrestrial objects around our Solar System, such as Ceres, Europa, Titan, and so on. It'd be great as well to perhaps set up a relay system that can orbit around some of these planets so that we can transfer data more easily, especially in the event when something is lost. Having some sort of semi-permanent orbiting satellite around some of these planets/moons would also be handy for future manned exploration, as it provides a potential backup computer to relay a message to in the event an orbiter fails.

  12. I once got close to her Uranas. But the heat from her Uranus began to melt away my protection shield and I had to abort my mission!

  13. Soviets bought crayons in the US and thanks to espionage they learned how to use them. Then they used the technique to produce their own image of a celestialbody.

  14. Soviets first tried to threaten the planet with a gulag if it doesnt transmit an electronic picture of its surface to Earth. That failed however, so they had to send a spacecraft with a camera there.

  15. this channel is almost like it was created to respond (intelligently) to all the flat earth crap that comes up and gets asked or challenged. I love it! keep it up.

  16. The film used for the photos of the lunar far side was an extremely sensitive one but it was also infra-red sensitive and when used for the Lunar Orbiter 5 mission to photograph the far side it was fitted with a Wratten 25a filter, so the images were infra-red. Subsequent far side imagers were all spectral devices and not ordinary colour cameras and the only Bayer filtered camera to see the lunar far side was the recent Beresheet mission which showed a fully lit far side looking extremely dark. There is no visible light photometric data available for the far side and until it can be shown otherwise it must be accepted that the far side is actually very dark. There is a scientific reason for that but it has not been tested .
    The Beresheet far side photo: https://cdn.mos.cms.futurecdn.net/rje4nPrsMto8cgRZdzCktK-650-80.jpg

  17. May I just say, sir, that your sound design and subtle use of music is excellent. Good background ambiance without being intrusive.

  18. Please donate as he is part of the chrome dome missile defense system and he needs a regular supply of chrome polish.

  19. They take the good photos and hide them, and then they make a cgi video for us to second guess how the planets looks like😤

  20. I love it. This whole series is of greater importance and less costly than collegiate certification. EXCELLENT, EXCELLENT, EXCELLENT.

  21. No wonder things get expensive when they go into space. I wasn't aware of titanium has such good radiation blocking qualities. I thought a thin sheet of lead would be preferable even if it weighs a little more.

  22. On Venus, the gravity is 9% less than Earth's. The Co2 atmosphere is only 39% denser than air at standard pressure and temperature. The weight of a given volume of this gas should exert a pressurization of only 30% greater than Earth, from 14.7 to a whopping 19.1 psi. I know it's hot, but it is still contained only by gravity, and heat would cause the atmosphere to expand readily. Where is the force that can hold an atmospheric pressure gradient at a factor of 93 times the pressure at Earth's? A factor of 93? This isn't the gravity of Jupiter, and carbon Dioxide is still a gas a fraction heavier than air, not a dense liquid, Gravity alone is the driving force.. No other force creates a pressure gradient. This makes no sense at all.

  23. Two kilobits per second is absolutely fine when you have years in which to send it before your next flyby – assuming there is another flyby, which there usually isn't. At 0:11 – nice dragon.

  24. Re: tried and true camera tech vs latest tech. Why not both with tried and true as the backup? The marginal weight cost would seem minimal.

  25. Thanks. Your videos are much more enjoyable than PBS Nova videos because your videos are more informative and they do not have that loud obnoxious music that is often louder than the people talking in Nova videos. Many so called professional people making videos would have much to learn from you.

  26. Your audio quality is good…but sometimes air voices make bit difficult to understand for people like me India…So kindly avoid air voice…

  27. @13:33
    1) I agree that these billion dollar spacecraft need to focus on reliability, above everything else.

    But would it be wildly expensive to include one or two additional cameras, that have more up-to-date technology?
    If they fail, then the tried-and-true older technology cameras are still present.
    Or has research concluded that additional up-to-date cameras will surly fail, and be a known wasteful endeavor?

    2) As to data transmission speeds being slow, due to distances, and slower, again, as the distances become more vast:
    Is there a reason for not positioning some type of spacecraft(s) at some interval(s) between earth and the craft taking the photos, and the additional spacecraft(s) would cut the distances in half, and even less if more spacecrafts are deployed, which would allow for faster transmission rates?

    In other words, is it necessary for the spacecraft that is taking the photos to make a home-run to earth, with all transmissions?
    Is there a reason that spacecrafts could not be deployed to act as relays for the transmissions of the digital footage?

  28. I know they go for reliability over quality but I really think it's worth it to stick the best most current high megapixel camera with an adjustable telephoto lens in a thick titanium housing and just hope for the best. Imagine the quality of photos we'd get.

  29. why are every space photo of landers even today (I am thinking of the JAXA Hayabusa images) they always look super wide angle and all you can see is the dirt and a few rocks….

  30. just when I think humanity is crap, I watch these sorts of clips and marvel at what can achieve when we want to. Now, I want a Mars mission and I want one NOW!!

  31. Why don't they add modern camera's on TOP of the older more reliable tech? Small weight, potential big extra leap in quality.

  32. Cartoons.. CGI imagination.. gas balls in a vacuum… Planets.. gas balls in a vacuum.. lol

    No, rockets cannot fly in a vacuum.. rockets don't fly to space…along with the fact every vacuum chamber test shows atmosphere surrounding rocket before any movement can occur.. Aerodynamics doesn't exsist in space to actually control any of this supposed miricale thrust motion. No way to direct… Control.. or reposition a space crafts.. and no gas jets don't work to position space crafts within a vacuum.. and weighted gyroscopes don't give motion in zero-g never mind within a vacuum.
    one minute they need to explode a force from themselves off themselves.. then it's just gas jets… Lmao never mind dock at 17500 mph on the ISS 9x the speed of a bullet..
    Oxidizer starts burn filling tiny vacuum with gas to allow any motion not the ever expanding space… Space is a lie.. CGI green screens augmented reality harnesses and wires.. zero-g planes. Camera 4th wall trickery.. space is a lie.. rockets don't go higher than 75 -100 miles.. 1000 miles down range.. check the trajectories.. while out of fuel.. also to note the the rocket engine burns 0.5 tons of fuel per second.. being these are usually 300 ton rockets they have about 10 minutes of lift until empty.. and don't fly off into space.. definitely can't fly to the moon.. never mind directing drones shaped like boat propellors billions of miles away.. that run on solar with no means of propulsion.. or direction… it's all Santa Claus, unicorns and theory tales.. for adults.. earth is an enclosed system and scientism is a cult founded on beliefs that don't match reality.

    Look at the sun… Divergent light rays as physical law would prove.. yet told science has proven light rays reach earth almost parallel.. then look at a solar eclipse diagram and they show 2 separate light sources emitting from the sun… Converging upon one another..

    No atmosphere to explain why ISS hasn't ripped itself apart in 20 years.. and how actronaughts can bounce about outside a craft moving 17500mph..
    Yet no atmosphere to use aerodynamics… Direct the motion.. balance within the rocket while fuel is moving and being used. Actors are moving about.. yet dock at 17500 mph..

    Can go to Aberdeen coast and see Norway's coast 325 miles away.. given calm sea conditions.. atmospheric moisture conditions and position of sun..

    No curvature… Just fish eyes..including our own to a degree… linear perspective.. vanishing point.. field of view your eyes create.. atmospheric conditions.. surface refraction..

    Travel from UK.. spins at 500 mph..take off and fly at 500 mph.. land on the equator which is 1000 mph.. and you can't measure test or experience any of it.. interesting..

    Sci-Fi dilusions… Wrapped in a web of lies..

  33. What a pile of fucking shit , your just here chating a pile of blar blar to feed the minds of the people who are not awake , show me a zoomed in pic or vid of the earth with a plane flying upside down or a ship on the side of the equator insted of shity so called planets millions of miles away please your just a paid shill show me the sea curving without a fisheyed lense…. ooops u can't 😬😂😂

  34. They don't. Satellites are suspended by balloons… there are no pictures taken from outer space – bc we've never been.

  35. I would have assumed that if one could be outside the Earth's reference frame and look upon it take a photograph that the image would be too bright from all the glare … and I would have assumed that because there's no medium light would have trouble displaying its colors to any camera

  36. Solar system is big fat lie.
    Hubble telescope don't exist in space because space is fake.
    Apollo moon landing hoax and fakery. There is no outer space. There is no curvature on this earth, it cannot be measured. A static universe, also referred to as a stationary.
    The earth is flat and stationery.

  37. We would have today cheap and affordable space tourism if the Soviets and American would have complimented each other in space exploration rather than competing

  38. Megabits or megabytes. 7.2 kilobits is under 1 KiloByte per second which means even if they compressed image to 1 MB (MegaByte) it would take 1000 seconds. So if we talk about 4-5 minutes for pictures, average picture was not 5.something MB/MegaBytes but Megabites! MegaByte is 8 Megabites.
    Further, second reason they don't use megapixel high end cameras because of how would they send 10 + MB pictures at such low bandwidth speeds.

  39. No means of disrespect Sir….we never went to the moon. Which is a fact. So how could we send this little machine way out there and we get pics sent back to us. When i can't get a signal on my cell in certain areas on warth. Then the Blue Marble pic was drawn. Not taken. NASA still to this day cannot give us a real pic of the earth. Always using fisheye lenz. There's so many cover ups, lies, losing documents, video tapes, etc. Thats why I dont believe none of the crap they say or show us. But this is just my belief & opinion. Not trying to put down anyone else's belief's or opinion.

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