by the fans for the fans

Peter Young wrote: When the Sentinels movie got released in 2011, a text was added stating the SDF-3 never returned to Earth. Apart from that, has ever an in-canon explanation been given for its absence after #36 of the original series?

See, I kinda doupt its crew would accept never returning home without mutiny. They volunteered for a specific mission - going to Tirol -, not to be on board of an U.S.S. Entreprise and keep on exploring.

Heck, even the makers of Star Trek realised that was the weak point in the plausibility of the original series. Every incarnation starting from 'The Next Generation' dealt with the fact that even spaceship crew members want to see their relatives and their homes every now and again.

So I would let the SDF-3 return to Earth after a few years to report on what has happened after departure. The SDF-3 not being on Earth could be explained for other reasons. Most realistic seems to me that a colony had been founded more close to Tirol. That way, Earth could maintain contact with the new allied races AND that way, in case of a new invasion, not all of humanity would be conquered or destroyed at once.

That would not even contradict 'Masters Saga' and 'New Generation'. Why could Dana and Bowie not simply have returned to Earth to enter military training and then the army? Scott could have grown op on the colony and seen Wolfe from a distance there. And it would explain better how Rick could have heard about the Masters'invasion and send Wolfe back if contact had been kept between Earth and colony.

I write this also because the Sentinels' comics and novels seemed to have had an open end and the early 2000's attempts to wrap things up seem to have been impopular with the fans.

In a way, yes. The novels have the timeline with relative ages of the characters. Like it will say Lisa 45 (actual 50), what this means is the relative time difference between people who remained on Earth vs those on the deep space mission. All that time spent spacefolding and flying around in space, time passes relatively slower. So by Earth time, Lisa would have been 50, but from her own relative physical perspective, she was only 45. So all the time that has passed on Earth, that much time has not yet passed for those onboard the SDF-3. It doesn't seem like it has been that long to them.

There is real life scientific precedence for this.

Based on the original series, Rick, Lisa, Max, Miriya, Lang, Breetai and Exedore apparently were not on Earth when the Robotech Masters attacked and Rick was definitely an admiral during the New Generation.

In the worst case scenario, every one except Rick could have been deceased at the time of # 61 (I tend to consider TSC as non-canon). But after all the criticism on so many characters not surviving #37, I doupt if they would be so short-sighted again.

With Sentinels never being finished and the comics and novels being non-canon, a possible reviving of Sentinels could mean that everything beyond the battle for Tirol would be a blanc sheet.

I don't mind keeping the Edwards' Rebellion, provided Edwards would become a more three-dimensional character. All three series used for Robotech ended with the antagonists not being evil, only on the other side. Even Khyron, in many ways a rather one-sided character, can be understood: he completely adapted himself to the Zentraedi lifestyle and then gets told that had been wrong all the time?

Many ways to make him and his revolt plausible and feasible. None of those being used in the comics and novels shows that Macek and Mckinney were not infallable.

Alpha Bravo wrote:
In a way, yes. The novels have the timeline with relative ages of the characters. Like it will say Lisa 45 (actual 50), what this means is the relative time difference between people who remained on Earth vs those on the deep space mission. All that time spent spacefolding and flying around in space, time passes relatively slower. So by Earth time, Lisa would have been 50, but from her own relative physical perspective, she was only 45. So all the time that has passed on Earth, that much time has not yet passed for those onboard the SDF-3. It doesn't seem like it has been that long to them.

There is real life scientific precedence for this.

Always been better at languages and humanities than at maths and science.

This has been used im fiction more often ('Planet of the Apes', for example). It has actually been hinted at in # 11 and it might explain why it took the Robotech Masters that long to actually reach Earth.
And why Rick could still be active on the background during New Generation, despite his 'old' age.

There is however one big continuity problem with this: Jonathan Wolfe. See, even if travelling through hyper space means time passing at a slower pace than in 'real universe', it seems likely that the Masters and the RDF-3 would be in it for the same amount of time.

So even if both expeditions left at the same moment, it would take an equal amount of time for Wolfe to travel back to Earth. By the time he arrived, the Masters' war had been over already.

However, the Masters apparently left Tirol for Earth at least nine years before the RDF-3 left Earth...

In short: If Wolfe had been left out of the original series, your explanation might have been the best one. But even if the REF had discovered a way to send Wolfe back a lot faster, it doesn't change the fact that by the time they had liberated Tirol from the Invid, the Masters' invasion might already have been over in real time!

The Masters were nearly out of Protoculture, and made the trip to Earth under conventional power (as in, thrusters). That's why it took them so long to get here.