[foobarbecue]

If you want to go faster, you need more fuel, and eventually you max out the biggest rocket available. Clipper is the most massive planetary probe ever-- they had to use falcon heavy in fully expendable mode to get it up there.

[dr_orpheus]

Yep, for reference Europa Clipper is 6,065 kg [0]. It is an absolutely massive interplanetary probe. It is getting close in size to some of the largest GEO communication satellites. And to get it out to Jupiter they definitely need some of the gravity assist trajectories.

On the opposite end of the spectrum, New Horizons was only 478 kg [1] and still holds the record for the fastest thing ever launched from Earth. It also did a gravity assist flyby around Jupiter and it still took 9 years to get to Pluto.

[0] https://en.wikipedia.org/wiki/Europa_Clipper

[1] https://en.wikipedia.org/wiki/New_Horizons

[itishappy]

> New Horizons ... still holds the record for the fastest thing ever launched from Earth.

To expand on this a bit, it's the fastest launch. The unqualified speed record goes to the Parker Solar Probe in 2018, and was previous held by Helios B way back in 1976.

The distinction here is that New Horizons has spent it's life traveling away from the Sun, and it costs energy and thus speed to do so. Meanwhile, solar probes gain speed during their fall towards the Sun.

https://en.wikipedia.org/wiki/Parker_Solar_Probe

https://en.wikipedia.org/wiki/Helios_(spacecraft)

[CableNinja]

And parker is about to break its own record soon! Its currently about to (or has just) pass venus one last time before swinging by the sun once more, so close that it will be able to fly through the plasma loops.

[magicalhippo]

Cassini[1] was quite massive too at launch, at 5712 kg. Though to be fair, 320 kg was due to the Huygens[2] probe it carried with it.

[1]: https://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

[2]: https://en.wikipedia.org/wiki/Huygens_(spacecraft)