From 1985: NASA's recruitment drive for the next generation: a Marvel Us ad for the YOUNG ASTRONAUTS program.
This tie-up turned nasty for Marvel and ended in an acrimonious split from the Young Astronauts Council and a subsequent lawsuit. As part of the initial deal, Marvel controlled the licensing rights to the property. Cornerstone to this plan was to (ahem) launch an animated TV show on CBS' Saturday morning schedules in the Fall of 1985.
However, the show was delayed when Marvel Productions, YAC and CBS couldn't agree on the type of show that everyone should be making. The educational remit of YAC dictated a show grounded in some sort of reality. CBS, on the other hand, wanted an exciting adventure show.
The show was delayed whilst a compromise solution was sought... and then cancelled outright by the network on 29 January 1986, the day after the Challenger space shuttle exploded 73 seconds after launch.
Marvel were also contractually obliged to publish at least six comic books based on the property. With no TV show to tie-into, these were delayed and then cancelled, despite being previewed in MARVEL AGE magazine.
The licensing deal broke down and ended in a lawsuit over unpaid monies. Marvel eventually won the suit, nabbing $185,547.40, plus interest of 9% (and another $75,000 from a previous ruling) in August 1990. Full details of the suit and settlement can be found here.
Some online sources speculate that one episode of the show did sneak out prior to the disaster... and that all thirteen were completed and ready to run. The legal transcript suggests that work was never actually completed on the pilot episode and there is no reference to anything ever having made it to air.