It's a pretty well known fact among the regulars of this site that New Horizons will take up to 18 months to completely upload the data from the Pluto encounter. When it was at Jupiter, it was much closer than it is today, and thus I would expect it would be able to upload the data faster. I expect that Jupiter had at least as much, if not more, data collected by New Horizons than at Pluto. How long did it take to download all of the data off of New Horizons after its Jupiter encounter?

  • $\begingroup$ NH collected less data at Jupiter than at Pluto. See answer. $\endgroup$
    – Hobbes
    Commented Jan 8, 2019 at 8:26
  • $\begingroup$ That actually surprises me, but I guess it is true. Huh. $\endgroup$
    – PearsonArtPhoto
    Commented Jan 8, 2019 at 22:53

1 Answer 1


According to NASA's NH Jupiter press kit:

  • Closest approach was on February 28, 2007
  • Download began on March 14

After the Jupiter encounter, the first hibernation mode cycle started on June 28, 2007.

On May 1, 70% of the data was downloaded. At that rate, it'd take 8.5 weeks to download the full data set.

About 70 percent of the expected 34 gigabits of data has come back so far

The data rate at Jupiter was 38 kbit/s, at Pluto it's 1-2 kbit/s. If they transmit at 38 kbit/s continuously, they could have transferred the data in 10 days. There are several factors that account for the longer transmission time.

  1. NH won't have a DSN antenna available full-time. If they have 8h/day, that adds a factor of 3.
  2. Because of 1. you lose time setting up each communications session, so not all 8 hours are spent downloading data.
  3. 34 Gbit is the net figure, probably. You need to add a lot more for error correction data, retries when a transmission is garbled etc.

The Jupiter encounter (34 Gbit) did not produce more data than the Pluto encounter (55 Gbit) or the MU69 encounter (50 Gbit).


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