How hard is it to fly through the tail of a comet? Has it been done?

Question

The line between comets and asteroids is somewhat blurred (see below) but when we see a big bright tail we at least like to call it a comet. This question is about exploration of the tails of big-tail-producing but otherwise small natural solar system bodies in heliocentric orbits.

Have spacecraft every been navigated through such a tail on purpose? If so, was it a challenge to predict the trajectory of the tail separately from the trajectory of the body producing it?

Sometimes there are a pair of tails (see this answer (voting to reopen the question)) responding differently to a mixture of forces, and sometimes there are many tails (see below). If this has happened, I'm wondering if there was a tail propagating algorithm used in order to target it with a spacecraft, and feedback from tail observations and subsequent tail-tracking trajectory correction maneuvers.

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• Is this object an asteroid or comet, and how can it produce so many tails?
• Do astronomers generally agree that the distinction between comets and astroids is not so clear?
• What makes scientists already so certain that Comet C/2019 Q4 (Borisov) is a comet and not an asteroid?

Answer 1

Ulysses, the shuttle-launched joint NASA/ESA probe to study the sun's polar regions, ran through three comet tails, more or less by chance.

Ulysses Catches Record for Catching Comets by Their Tails

• ...comet Hyakutake ...On May 1, 1996, while Ulysses was cruising through space studying the solar wind, its data suddenly went wild for a few hours.

• The once-in-a-lifetime chance encounter with a comet tail happened again in 2004 when Ulysses flew through the ion tailings of comet McNaught-Hartley

• Ulysses racked up its third, and perhaps most scientifically revealing, comet tail encounter this past February¹ when it again flew through the ion tailings of a comet named McNaught (a different comet than the one encountered in 2004, but discovered by and named after the same astronomer).

¹ 2007

Answer 2

Rosetta collected dust from 67P/Churyumov-Gerasimenko and analyzed it under an atomic force microscope, without landing on the cometary body itself; depending on your definitions this would seem to imply having flown through its tail.

Navigation isn't much of an issue; you simply navigate close to the cometary body and hang out on the sunny side -- though I guess technically that's the comet's head.

Answer 3

The two Vega probes comes to mind, ending their implausible sounding mission of slipping balloons into the atmosphere of Venus with a flyby of Halley's comet in 1986.

They took a heavy beating flying through the coma, which is the shell of dust and gasses surrounding the comet itself, at the start of the tail.

From a navigational point of view, the goal appears to just have been to come as close to the nucleus as possible.

Answer 4

The International Cometary Explorer spacecraft passed through the plasma tail of 21P/Giacobini–Zinner in September, 1985, which I think was the first time the human race had engineered such a rendezvous. Many years ago, in my salad days, I did my PhD research on the encounter.

Answer 5

In 1986, Giotto closely approached Halley's comet flying through dust and gas and surviving with less damage than expected.

I couldn't tell if Giotto was flying through Halley's tail or coma, but its journey can be taken as an upper bound of how harsh flying through the tail can get.