It always seems to be a genuine question that is How can we download data from far away probes in instant. When New Horizons reached Ultima Thule, it took us quite a few months to have a great picture of the same though we predicted and analysed the Celestial body before the complete data being available. I know it takes few hours for data to be transferred from either side (even at the speed of light) but data download speed is in bits ( had read somewhere on the internet). How can we increase the download speed to a very great extent. As in Megabytes, Terabytes, etc.

  1. Will installing space probes and cube satellites around planets, comets and asteroids help?
  2. What are the options available?
  3. What would be the expenditure and feasibility?
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    $\begingroup$ a good answer will explain the difference between speed and latency. $\endgroup$
    – uhoh
    Feb 10, 2020 at 11:45
  • $\begingroup$ Similar question with good answers: space.stackexchange.com/q/7776/25911 $\endgroup$
    – Heopps
    Feb 10, 2020 at 14:26
  • $\begingroup$ Please do NOT post the same question to multiple sites. If deemed appropriate, the mods will move a question to a better site. $\endgroup$ Feb 10, 2020 at 19:19

1 Answer 1


There are two speeds involved in getting data from a space probe to earth.

Transmission travel time is fixed by the speed of light and being in a vacuum is already at its limit. New Horizons is far enough away that even at the speed of light it takes hours for any signal to reach earth. And any relay stations will just increase that time because of longer paths and processing.

The second speed is the one most impacting New Horizons data return and refers to the number of bits that can be moved per second. This is driven by the ability of the receiving station to detect the signal against background noise over the distance.

So the date rate is determined by the transmitter power and antenna size, the receiver antenna and sensitivity, the distance and the background noise, none of these offer options to boost by 100 or 1000 times on current technology.

Relay stations would help, but they would need to be at least 100 meters across, both to have a sufficiently large antenna and to gather enough solar power to drive a strong signal across the next leg. This would make them larger by a fair margin than the ISS, and costing similar amounts of money to build and send into suitable orbits.

There would also need to be at least three of them, since physics means that a relay between Earth and New Horizons would be moving in an orbit slower than Earth but much faster than New horizons(at least radially) so a relay of relay stations would be needed to get any benefit.

This makes the cost more than is currently justifiable, since the current method works for the amount of data current probes generate.

One potential method to increase data rate is LASER light, since this allows much higher sending and receiving gain, and lower background noise in sensible size/weight. This does require confidence that a sufficiently powerful LASER can operate for the decades so is still in development.

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    $\begingroup$ In general, the data & images we do get keep analysts busy for longer than it takes for the next set to arrive, so the "true" bottleneck is on the ground. $\endgroup$ Feb 10, 2020 at 14:02
  • $\begingroup$ I don't really see how "multi-megawatt nuclear-powered monster" isn't modern technology, even if it's not something we're currently using. That seems like it should solve the "MOAR POWER" problem quite nicely. $\endgroup$
    – ikrase
    Feb 10, 2020 at 20:14
  • $\begingroup$ @ikrase I deleted a whole chunk on nuclear power options, since it was heading off topic and made things more about politics than physics. Would certainly simplify a number of gas giant missions to be flying with a power budget in kW rather than watts. $\endgroup$ Feb 11, 2020 at 8:04
  • $\begingroup$ @GremlinWranger I still think a more explicit mention that Moar Power would help would be worthwhile $\endgroup$
    – ikrase
    Feb 11, 2020 at 9:27
  • $\begingroup$ @ikrase what is "MOAR POWER"? Do you mean more power? Before dealing with multi-megawatt we should handle multi-kilowatt. $\endgroup$
    – Uwe
    Feb 11, 2020 at 14:25

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