Reconciling the Sentinels with Robotech:
The Case for Delaying the Sentinels War.

by Peter Walker, Robert Morgenstern, Jason Smith, Pieter Thomassen, Aubry Thonon, Matt Willis and Tim Wing

Reconciling the Sentinels with Robotech:
The Case for Delaying the Sentinels War.

Home Separator


The premise of the Sentinels disagrees with the continuity of the original Robotech series in many ways. Though the show is unequivocal in its support for a timeline that has the REF return later than 2040, several inconsistencies appear if it is assumed that the REF arrives at Tirol immediately after the Sentinels video. The Southern Cross and General Leonard know nothing of a war or the proposed enemy. The narrator tells us the REF is searching for Tirol, not fighting the Invid. The show indicates that the RDF does not know where Tirol is, despite access to Zentraedi navigational information. We propose a reconciliation of the Sentinels concept with the original series continuity that delays the arrival of the REF at Tirol until the conclusion of the Second Robotech War. The benefits of such a reconciliation in explaining other poorly understood elements of the Robotech continuity are discussed.


It has been apparent to observers for some time that the concept Macek developed for the Sentinels is inconsistent in several ways with the continuity with the original series. Though this discomfort with the Sentinels has been vague, it has been persistent, and has motivated several luminaries within Robotech fandom (for example, Tom Bateman) to suggest that the Sentinels itself must be abandoned. In the course of our internal discussions on the subject of the reason for the long delay in the REF's return to Earth, we came upon the unmistakable fact that it was not possible to reconcile the show with the claim that the REF space-folded directly to Tirol. Either the REF hid the Sentinels War from the Southern Cross, the Sentinels War never took place, or more intriguingly, the Sentinels War took place some eight years after most fan-timelines, and five years after McKinney's timeline claims. Adopting this solves, or allows for solutions to, many of the outstanding difficulties in the Robotech continuity.

Review of the Timeline

Within the course of this discussion, it is absolutely essential to keep the original series' timeline in mind; things become quickly muddled if one tries to mix some of the fan- or novel-specific dates with those mentioned in the show. The subject of the Robotech timeline has been one of the most controversial in Robotech fandom, not because there is any ambiguity in the show as to the dates of the major events, but rather because preconceptions that stem from the novels, comics, and RPG has motivated certain parties to ignore the show's explicit time cues, or to explain them away with fanciful scenarios for tampering in the timeline. We will show in this review that the timeline of the series is indeed uniquely determinable to within a fair level of accuracy.

The end date of the Macross saga produces two schools of thought. The series concludes soon after Christmas, in December or January. The original Macross ends in Jan. 2012; however, Stan Bundy has convincingly shown that this produces an impossibly cramped timeline for Robotech, for two main reasons. In Robotech, the SDF-1 remains away from Earth after its disastrous space fold for a full year, longer than the seven months in the Macross timeline ("Gloval's Report", "Homecoming"). Secondly, the reconstruction period is listed by the narrator as two years, also far longer than the time allotted in the original Macross ("Reconstruction Blues"). These combine to make the only feasible date for the end of the Macross saga Dec. 2013/early 2014. We have adopted a date for the episode "To the Stars" of Jan. 2014, based on the sense that some time passes between this final episode and "Seasons Greetings", which takes place on Christmas Eve.

More controversial is the departure date of the Sentinels, though not through any ambiguity in the video itself. The narrator speaks of the REF suffering from "nearly ten years of inactivity", and while this may be construed to date to the apocalyptic battle against Dolza's fleet in "Force of Arms" rather than "To the Stars", a remark by Lisa is not nearly so forgiving. She tells Rick that he has had "nine years" to prepare for the Expeditionary mission, not to mention their marriage. Rick only learned of the Expeditionary mission in "To the Stars"; similarly, his unequivocal commitment to Lisa dates to this episode. Thus, the only date for the Sentinels departure that is consistent with the video and the original show is within six months of January 2023. Not coincidentally, this agrees with Macek's own estimate of the date of the departure of the REF, as given in Robotech Art 3 (p. 54ff). Macek gives the date as 2022, and the range from the analysis above allows dates from August 2022 on. We have adopted a date of Dec. 2022 for the purposes of this discussion.

It has been argued in certain quarters that Macek was somehow "forced" by outside factors to push back the date of the Sentinels forward to 2022/2023, and that his original intent was for it to take place immediately after Macross. The argument is that Macek, prevented from using the Macross properties by Tatsunoko, was forced to explain the change in mecha and uniforms by a delay. It suffices to say that there is zero evidence whatsoever for this proposition. Furthermore, Macek was forced to redub the Sentinels between its animation as an episode and its reformulation as an OVA; he had plenty of opportunity to reset the date, had that been his desire. The only gap that would be necessary would be a couple of years to explain the new (and in some cases experimental) mecha and uniforms.

The only piece of evidence advanced to support the assertion that the REF wasn't supposed to leave in 2022/2023 in Macek's conception is a quote from Robotech Art 3, p. 22: "The interfacing between the constructed timeline in Robotech and the proposed timeline in the Sentinels was virtually impossible to reconcile with the Japanese writers". However, damning as this quote might seem out of context, once one actually reads the surrounding paragraph, one finds that Macek was referring not to the date of the departure of the REF, but of the Japanese writers' total lack of interest in the established Macross characters, and Macek's suspicion that they were developing the Sentinels - sans Macross characters - for development as a series to be aired in Japan. Macek's use of "timeline" here is synonymous with "continuity", not "chronology". Indeed, the context of the passage is so unequivocal that use of this quote as evidence that Macek was forced to change his timeline is extremely deceptive. This is especially the case considering the fact that the average fan does not have access to this book, and can not check the context for this quote for themselves. As it happens, the Japanese writers were eventually sacked, American writers were brought in, and development continued. Even if this quote referred to the chronology, which the context indicates that it does not, the pressure on Macek was relieved as soon as the Japanese writers were sent their walking papers. The scripts that went to form the basis of the animation were precisely those Macek wanted.

Returning to the original series, a much less contentious date is the beginning of the Second Robotech War. At Dana's graduation ceremony in "Dana's Story", we are told that it is fifteen years to the day after the destruction of the SDF-1. The Masters' initial probing attack against Luna predates the full war by enough time for the Southern Cross to check out the situation at Luna, and for the state of alert to have subsided. These two observations lead to a conclusion that "False Start" takes place in early 2029. From the pacing of the episodes, and the apparent season of the final episodes of the Robotech Masters saga, we can conclude that the war ends in summer of 2030.

The most controversial aspect of the timeline for the series is the return date of the REF. The show gives us several implicit clues to this date. Firstly, the crew of the Horizont was all "born in deep space on a Robotech ship". Scott was a boy when Wolff left for Earth "when Admiral Hunter sent in the first wave against the Robotech Masters" ("Eulogy"). Lancer arrived on Earth more than three years before "The Secret Route", with the Invid firmly entrenched and rooting out resistance members with the help of the locals. One also takes note of the age of the old men in "Ghost Town", who supposedly served against the Robotech Masters. All of these cues, as well of numerous others one might mention, suggest an Invid occupation of a decade or more. However, there is one single explicit time cue in "The Invid Invasion" that settles the issue. In this episode, the narrator tells us that Earth is "a planet none of these newest Robotech defenders has seen in nearly twenty years". The operative word here is "none"; it will not allow a single person in the Mars Division fleet to have been on Earth more recently than the quoted twenty-year span.

Since Mars Division is a significant fraction of the total REF fleet, this absolutely dates the REF's return to nearly twenty years after the last large deployment of REF troops from Earth. The earliest possible candidate is the departure of the SDF-3, in 2022. Ships may have left earlier, but a single officer or crewman in Mars Division that left with the SDF-3 would require that this date, and not the earlier departure dates, be the reference point for this time span. Thus, the earliest the REF can return is the period between 2040 and 2042. This date can be pushed later if REF troops were ever reinforced in numbers from Earth. Reinforcements might have come as late as just before the Invid invasion itself, some time in the early 2030s, pushing the possible date of the REF's return to as late as 2053 or so. We choose to assume that the departure of the SDF-3 is the intended start date of this 20 year span, implying a REF return from 2040 to 2042, rather than deal with the increasing difficulties associated with return dates as late as 2053.

The contrary view, known as the "Early Return Scenario", is that the REF returns soon after the end of the Second Robotech War, implying a very short Invid occupation. This is the position taken by the novels, comics, and RPG. The main motivation for this position is a lack of ability to explain what might have kept the REF away for so long; surely they would have returned to Earth as soon as they could, since this is the world they were charged with defending. This is indeed a legitimate objection, but does not overturn the explicit time cues in the show and Sentinels that mandate the later return. While the advocates of this contrary position can not dispute the explicit time cues in the show, they choose to either challenge their canonicity by calling them "errors", or make the argument (refuted above) that in Macek's conception, the REF was "supposed" to have left in 2015 or so, in each case respectively ignoring either the show or the Sentinels video. We presume the canonicity of both the show and the Sentinels video in their entirety, and this analysis follows from that presumption. We consider the rejection of one or both as the establishment of an alternate continuity that is outside the scope of the present work. As we will show, reconciling the Sentinels concept with the original series not only completely rules out the early return, but it answers the question of what took the REF so long to come home.

"Born... On A Robotech Ship"

In "The Invid Invasion", an interesting claim made by one of the crewmen on Scott's Horizont. Explaining his indifference to seeing Earth, his "ancestral" homeworld, for the first time, he replies, "Why? We were all born in deep space on a Robotech ship".

This quote has been employed to argue for an early return for the REF, on the basis that it presents a problem for the late return scenario. It has been claimed that these people must have been born before the REF's departure, on a Moon or Mars base, or on the Factory Satellite, because after the REF reached Tirol, they would have been born on Tirol, and not on a Robotech ship.

Firstly, one may dismiss the Moon and Mars bases, as these are not "deep space", or a "Robotech ship", and the Factory Satellite presents difficulties, as it is in Earth orbit in the Sentinels video, and thus while it might qualify as a Robotech ship, would not satisfy the condition of not having seen Earth in nearly twenty years, or those birthed aboard it being born in "deep space", unless one again adopts the late return scenario.

A possibility suggested by some of the early-return advocates is that much of the REF was exploring deep space well before the SDF-3's departure, and that the crews were born in the interim between 2015 and 2022. This is an intriguing possibility, but does not lessen the unanimity with which the late return is evidenced by the show. As discussed above, the explicit cue from "The Invid Invasion" places the REF's return twenty years after the last major deployment of the REF, not the first. Thus, while ships may indeed have been sent out before the SDF-3's launch, the REF must still return twenty years after its launch.

The observation that the late return of the REF, along with the assumption that the Sentinels plot continues as Macek had intended, does produce a problem with the crew being born on or above Tirol rather than in "deep space on a Robotech ship" is indeed a legitimate one. However, this is not a problem with the late return scenario, but the first of a number of problems reconciling the Sentinels plotline with the original Robotech continuity. It suggests that the direct-to-Tirol route that Macek had intended would have been, had the series been completed, the first of a number of contradictions with the original show. On the other hand, if the REF did not take a direct route to Tirol after the launching of the SDF-3, but rather spent several years before reaching Tirol, this contradiction vanishes.

What Sentinels War? The Southern Cross in the Dark

Intriguingly, according to the original show, the Southern Cross Army has no knowledge of any war between the REF and the Invid, and indeed, do not know about the Invid at all. This has important implications on whether or not the Sentinels War took place at all, or if it did, when it occurred relative to the REF's departure and eventual arrival at Tirol.

The first piece of evidence is one of the most damning for traditional incorporation of the Sentinels plotline into the Robotech continuity. In the episode "False Start", the narrator tells us that Space Station Liberty is "Earth's only link to the Robotech defenders that have gone out into the cosmos searching for answers to the puzzling riddle of protoculture". This is a clear reference to the REF, but explicitly contradicts the presumption that the REF is engaging in the Sentinels campaign. The episode "False Start" occurs over six years after the SDF-3's departure, and yet not only is the Sentinels War not mentioned, the REF is described as engaging in an activity that is completely incompatible with the premise that they are busy liberating the Sentinels' worlds from the Invid. They are still "searching", implying that they have not yet found their objective. The other alternative, that the Sentinels war is finished, is ruled out by the the total ignorance of the Invid on the part of the Southern Cross, discussed below.

Along with this quote, the very existence of Liberty, and its description by the narrator as the "link" between the REF and Earth, strongly suggests that the Southern Cross was kept apprised of the activities of the REF, and unless one adopts the outlandish scenario that the REF was lying to the Southern Cross about its activities, it is an inescapable conclusion that Earth knew what the REF was doing at the time.

Whenever we see REF ships return to Earth, there is also a total lack of mention of any war in which the REF is engaged. Carpenter tells Leonard in "Outsiders" that he can expect no more help from the REF, but not that it is because the REF is engaged in a full-scale war. Since only flag officers were in the room with Carpenter, it can not be argued that the Southern Cross leadership knew, but that the war was classified. Furthermore, when a REF fleet returns in "Mind Games" to assist the Southern Cross in response to the original distress call from Space Station Liberty, Emerson apologizes for taking them away from their mission, not their war. Their mission, established in "To the Stars" and the Sentinels video, is not to fight the Invid, but to confront the Masters and prevent another war. We know that these returning ships are REF because we are told that they were responding to the original distress call from Space Station Liberty, which was sent to the REF. Similarly, Scott confirms the existence of waves of REF ships sent to fight the Robotech Masters in "Eulogy", and the subject comes up again in "Ghost Town".

Finally, in the final episodes of the Robotech Masters saga, Leonard is ordered by the Masters to surrender and evacuate Earth, because the Masters need to prepare for the pending arrival for the Invid. Leonard refuses, and muses that Earth had fought the Zentraedi and the Masters, and he's prepared to fight the Invid, "whatever they are". Leonard's ignorance of the very existence of the Invid makes it impossible that the REF had previously, or were currently, engaged in the Sentinels War. Again, unless one invokes a massive conspiracy of silence among the REF officers on Carpenter's ship, and among the entire relief fleet that appears in "Mind Games", there is no reasonable way that the REF could have spent any time fighting the Invid, and for Leonard still not know who the Invid were.

One is forced into the inescapable conclusion that by the end of the Second Robotech War, the REF had not yet encountered or identified the Invid. Either the Sentinels War never took place, or it took place some time after the end of the Second Robotech War.

Does Anyone Have a Map to Tirol?

If indeed the Sentinels War takes place after the Second Robotech War, one might wonder what the REF was doing in the period between the launch of the SDF-3 in 2022 and the onset of the Sentinels War, some time after 2030. One clue lies in some statements made in "To the Stars".

In the final episode of the Macross saga, as the first attempt to launch an expeditionary mission is about to get underway, both Lisa and Gloval explicitly claim that the location of the Robotech Masters' homeworld was unknown. At this point, the RDF had access to at least one fully functional Zentraedi flagship (Breetai's), and the friendly collaboration of its crew, for two years. If the information on how to locate Tirol, or even the core of the Masters' empire, was to be found in the Zentraedi's data banks or memories, it would have been found by "To the Stars". Clearly, it was not. This presents a quandary: how could the Zentraedi defend an empire whose capital they couldn't find? The solutions to this quandary provide for some entertaining speculation, but are outside the scope of this work. It suffices to recognize that it despite Zentraedi cooperation, the RDF was expecting to have to search for the homeworld of the Robotech Masters.

Barring a massive exploratory expedition prior to the launch of the SDF-3, no new information would have been available to Earth with regard to Tirol's location. Precisely such an expedition has been suggested in the past by members of the "early return" camp, as an attempt to get around the "born out in deep space on a Robotech ship" quote. Though such an early expedition does not in fact reconcile the early return scenario to the "nearly twenty years" quote, it does provide a point of departure for understanding what the REF was doing before it found Tirol some time after 2030.

Indeed, the show explicitly states that the mission of the REF was to search, not for Tirol, but for answers to the riddle of protoculture. The two are not at odds; finding one finds the other. And the quote from "False Start" requires that this search be ongoing as late as 2029. The search may have preceded the SDF-3's departure in 2022, but it must also postdate the SDF-3's launch at least another eight years.

Recognizing this provides a reconciliation of the late return timeline and the "born in deep space on a Robotech ship" quote with the Sentinels premise. The three are not irreconcilable as claimed by the early return advocates, precisely because the show makes it clear that the REF did not directly fold for Tirol, but spent at least eight years in space, more if ships left before the SDF-3, looking for the Masters' homeworld.

The Invid... Whatever They Are

The largest disconnect between the conventional wisdom picture of the Robotech backstory and that implicit in the show has to do with the level of knowledge about the Invid. The common assumption is that the Invid and Zentraedi are ancient enemies, engaged in a long G"otterd"ammerung of destruction and warfare. But is this consistent with the series? In fact, the opposite is required by the show.

Not once in the entire Robotech series, or even the Sentinels video, does a Zentraedi mention the Invid. Furthermore, they clearly did not brief the Earth militaries on the Invid's existence - otherwise, Leonard and other members of the Southern Cross would have known who the Invid were, if only second hand. The show makes it clear that they did not.

Similarly, in the Sentinels video, Rem and Cabell did not immediately recognize the Invid inorganics or transports, and only concluded that they were Invid based on the design of the eye sensor of the Odeon. While this might be expected for the Inorganics, as they are putatively new designs, why were the Invid transports not recognized? Elongated variants of the Mollusk ship seen in "The Invid Invasion", these ships seem to be a fairly uniform, and clearly distinctive, design. And yet they went unrecognized.

The Zentraedi's lack of mention of the Invid, and Cabell's slowness to recognize them, suggest that the Invid have been out of the picture for some time, and that in the interim their mecha and ships have been completely redesigned. It also suggests that the Invid began their campaign of conquest with Tirol, rather than ended with it, as the usual assumption goes. Otherwise, Rem and Cabell would have received reports of the Invid sweeping through the Galaxy. The Invid advance may have come only with their belatedly learning of the destruction of the Zentraedi armada, a force that vastly outnumbered the fleet we see the Regent sending to Tirol. Only with the Zentraedi gone would the Invid have an opening to attack. Placing the conquest of Tirol at the beginning of the Regent's campaign, rather than at its end, plays into the scenario presented below.

The Five-Year Fold Revisited

One way to delay the beginning of the Sentinels War is to invoke a fold-lag, as per McKinney's "five year fold", to make the REF's jump take more time on the Earth calendar than on their own. If the REF were in hyperspace for eight years, one might argue, then one can dispense with the decade of looking for Tirol.

Unfortunately, this doesn't work. Clearly, the fold-delay between Liberty's broadcast of Earth's distress call, and the return of the REF fleet seen in "Mind Games" and alluded to in "Eulogy", is not a matter of years, but at most of months (and this assumes the REF received the message as soon as it was broadcast). Clearly, if there was a fold lag, there was only the initial one.

But one datum stands out that precludes even an initial long fold lag. Around 2029, as Carpenter's ship is destroyed, Carpenter's aide laments the destruction of the ship, which had been their "home for the last fifteen years". Without a time-lag, this produces a launch date for Carpenter's ship of around 2014, give or take a year or so, consistent with the fact that Earth captured the Factory satellite in 2013. Whereas a fold lag sufficient to have the REF launch from Tirol in 2022, and arrive just in time for Carpenter's ship to return to Earth, would place the launch date of Carpenter's ship around 2007, prior to the launch of the SDF-1. This is clearly inconsistent with the Macross saga. Moreover, once again, in "False Start" we are told that the REF is searching, not in hyperspace.

On the other hand, the long occupation of Carpenter's ship does suggest that elements of the REF may indeed have left Earthspace before the departure of the SDF-3 in 2022.

Proposal for the Late Sentinels War Scenario

Out of this confusion comes clarity if one waits until 2030 to begin the Sentinels War, and has the REF in the process of searching for Tirol in the interim period. The following scenario begins to take shape.

2015-2022: *Preliminary REF navigational survey missions begin, including Carpenter's ship. Numerous children are born aboard the REF fleet in this period.
2022: *Regent captures Tirol, and leaves a garrison there under Tesla.
*SDF-3 launches and joins the fleet already engaged in the search.
2022-2029: *REF fleet searches the Galaxy for the Robotech Masters' empire
*En route they encounter a number of adversaries, all humanoid/ Tiroloid in origin, such as micronized Zentraedi, pirates, and report these encounters back to the Southern Cross, explaining why in the early part of the war, the Southern Cross alternately mistakes the Masters for all of the above.
*Still more children born in this period on the REF fleet.
2023-2031: *Regent proceeds to conquer the Sentinels worlds, in the opposite order with which they are liberated, with the last being Karbarra.
2029: *Robotech Masters cut off contact with Liberty and attack Earth.
*REF, engaged with remnants of the Zentraedi, notices the loss of signal and sends Carpenter's ship to investigate.
*Southern Cross reestablishes contact with Liberty, and sends distress call to REF.
*Carpenter's ship arrives at Earth and is destroyed.
2030: *REF finds location of Tirol, and folds there.
*REF is attacked by an unknown alien fleet there. SDF-3 is damaged in the fight and is left unable to fold.
*REF receives Liberty's distress call, but is unable to return because of its heavy commitment at Tirol.
*REF achieves space supremacy, freeing up ships to send back to Earth. Two waves of vessels are sent. Identity of aliens unknown at this time.
*Southern Cross links up with vessels from REF for the final two battles in "Mind Games" and "The Invid Connection".
*Second Robotech War ends
*REF lands troops on Tirol and takes the planet. Invid are finally identified as the enemy. Earth is notified.
*Sentinels arrive at Tirol.
2031: *Aware of the Invid threat now, Earth authorizes the REF to fight the Invid and assist the Sentinels, hoping to keep them from going to Earth.
2031-2039: *Sentinels War begins. Sentinels' worlds are liberated in the opposite order in which they are captured, to free the most industrialized and least entrenched worlds first.
*Early in this period, the Regess arrives at and conquers Earth.
2039: *End of Sentinels War; REF civil war between Edwards' and Hunter's factions.
*Reconnaissance missions to Earth begin.
2041: *Point K is established, and the REF learns for certain that the Invid hold Earth.
*Mars Division is sent to Earth, and is destroyed.
2043: *Remainder of REF fleet returns to Earth.
*Battle of Reflex Point.

This scenario resolves numerous outstanding problems created by the Sentinels. Now, the references to the REF searching for Tirol are explained, as is the ignorance of any major REF war and the existence of the Invid on the part of the Southern Cross leadership.

The realization that the Sentinels War can not begin before the end of the Second Robotech War simply adds one more nail in the coffin of the early return scenario. The REF could not possibly send many of its ships to relieve Earth in 2030 (something seen in "Mind Games", and confirmed in "Eulogy"), go on to fight a massive war against the Regent, and be done and ready to take the fight to Earth in a mere three to five years.

Furthermore, delaying the start date of the Sentinels War removes the main difficulty associated with the late return scenario. As discussed above, though the show mandates that Mars Division return no sooner than around 2040, one is left with the question: "what took them so long?". By recognizing that the Sentinels campaign must start later than 2030, we have the answer - the REF was inextricably entangled in the Sentinels War, and had already sent many of its ships back to help fight the Robotech Masters. This provides a framework for understanding why the REF knew so little about Earth; one can suggest that the Earth deliberately went silent in the hopes of preventing the Invid from noticing them, waiting for the REF to send the all-clear before re-establishing communications. The REF wouldn't notice Earth's silence until the all-clear was sent, and no reply from Earth came.


We have shown that the show strongly suggests that no Sentinels War could have taken place before the Second Robotech War's conclusion, because the Southern Cross did not know of the war or the Invid, when - had such a war occurred - at least Leonard should have known. The narration explicitly denies that such a war is taking place in 2029, but rather asserts that the REF is still doing what Gloval and Lisa said they would have to do in 2014 in "To the Stars", namely search for the homeworld of the Robotech Masters.

This forces one to either dismiss the Sentinels plotline entirely, or to delay it until 2030 or later. Doing the latter resolves a host of problems in explaining the whys and wherefores of the Robotech universe. Furthermore, the recognition of the long "searching" portion of the REF's mission allows us to finally put to rest the timeline controversy in favor of the one explicitly mandated by the show, namely the late-return scenario.

Submitted, 3 Mar, 2000 to,,,, The Robotech Cantina, The Robotech Message Board.

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