# Which deep-space spacecraft flew closest by Earth during a gravitational assist?

The extremely cool NASA JPL video Triumph at Saturn (Part I) is really worth a watch and/or listen. (Don't forget Part II as well!)

At about 26:30 it discusses Cassini's gravitational assists; first two at Venus then one at Earth:

...but the project's first priority was getting safely past the Earth, which occurred in the summer of 1999, giving Cassini another 12,000 miles per hour of speed.

and caption:

Earth Flyby: August 18, 1999, Cassini Speed: 99,000 mph

Several deep space spacecraft have use gravitational assists at earth via close flyby's. I'm wondering:

Question: Which deep-space spacecraft flew closest by Earth during a gravitational assist.

cued at 26:30

• There is a wikipedia page for this, though not fully complete Oct 26 at 12:45
• @BrendanLuke ya 11 out of 30 distances are absent. But that 301 km certainly seems a likely winner!
– uhoh
Oct 26 at 12:57
• @BrendanLuke15 several more days left on the bounty
– uhoh
Nov 19 at 23:10
• I might not get to this one for a while :0 Nov 19 at 23:13