Dave Cockrum credited with designing Yondu and Vance Astro's new costumes and the starship Captain America in the letters page for Marvel Two-In-One #6. Cockrum's starship design illustration also appears there. On-sale date from Comic Reader (Street Enterprises, 1973 series) #107, June 1974.
The Thing (also in flashback); Guardians of the Galaxy [Major Vance Astro (also in flashback, origin); Charlie-27; Yondu; Martinex]; Captain America [Steve Rogers] (also in flashback); Sharon Carter (also in flashback); Tarin (also in flashback); Zakkor; Qarl; Badoon (villain); Zom Soldiers (villains, also in flashback); Monster of Badoon (villain, also in flashback); Ebor; Lordsire Drang; Commander Ogg; Mr. Fantastic (flashback, cameo); Medusa (flashback, cameo)
The Thing, Captain America and Sharon Carter have traveled forward in time to the year 3018 and help the Guardians of the Galaxy drive the world conquering Badoon from earth.