"Blast Off" (get it?) w "X-Men" #99
(June 1976) written by Chris Claremont, penciled by Dave Cockrum, inked by Frank Chiaramonte, colors by Michelle Wrightson - in which Jean, Banshee, and Wolverine are trapped in space with the Sentinels, so the rest of the X-Men waltz down to Cape Canaveral and take off in a space shuttle to catch up with them.
*Emma Frost (Hellfire Club's White Queen) back cover by John Bolton, from the accompanying supporting story.
*Wolvie, Banshee & Jean are floating in space (like Spritualized), which seems scary, but we know from Leia in #TheLastJedi
that it's not really a big deal.
*FIRST APPEARANCE OF GERALDO RIVERA (for real)
*Cyclops, Storm, Colossus and Nightcrawler leave Earth via Florida *Jean mindlinks w Scott, and Scott reacts the way anyone decent dating Jean Grey would react.
*HELLFIRE CLUB - Claremont threw a retcon page in the issue dealing w the Hellfire Club (detailing w how Sebastian Shaw was only a pledge), and the supporting story looks into this further.
*Shaw first discovers Emma Frost is a telepath. This is the first time we've seen Emma even though her real first appearance doesn't come til issue #126
*Emma, pre-diamond power, is attacked by a Sentinel.
*Shaw murders his way to power, becoming the Black King.
*cover of original issue, reprinted in "Classic X-Men" #7
#XMen #Marvel #ChrisClaremont #DaveCockrum #FrankChiaramonte #MichelleWrightson #JohnBolton #JeanGrey #Wolverine #Banshee #Nightcrawler #Storm #Colossus #Geraldo #HellfireClub #SebastianShaw #BlackKing #EmmaFrost #WhiteQueen #Sentinels