So this has been bothering me since I saw the teaser trailer yesterday, in the teaser they said it took 600 years to get to Andromeda from Earth. This just sounds WAY too short a period if time. So I did the math and assuming a constant velocity (which would be an underestimate of the max speed) the speed they would be 4219.99 times the speed of light. Which is so far in the impossible I can't even imagine. In the trilogy it's said that man kind can travel 50 times the speed of light. Now either they will have some explanation for this they will state in the game or they really didn't think the physics/astronomy though on this. Thoughts?

For those who care, here's the math Distance to Andromeda from Earth: 2.537 million ly Time: 600 y Assuming constant velocity v= d/t = 2.537 million ly/ 600 y = 4220 ly/y = 1,265,990,486,407.54 m/s = 4219.99c

Presviously stated speed 50c = 14,989,622,900 m/s   So the speed to get to Andromeda is 84.399 timed faster than the me3 speed.

I wanted to try and find a more accurate vmax but I instantaneous acceleration is really messing me up. If anyone wanted to do that calculation I'd appreciate the correction.

  • 2
    In the original trilogy, intergalactic travel was never a thing (except for Reapers, and they were implied to be vaguely close on the galactic scale). Probably because of exactly what you point out. So answer is... something changed? The game isn't out yet, so it' not like there's context to compare against.
    – Radhil
    Commented Nov 3, 2016 at 18:14
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    Now that I've watched it myself... it looks like they built a custom mass relay just off the moon. Non-progenitor tech = all bets are off? Or there's also the fact that this is supposed to be a recruitment video, and any propaganda wing can just make stuff up.
    – Radhil
    Commented Nov 3, 2016 at 18:21
  • I'd guess they've reverse-engineered Reaper or Prothean tech after the events of ME3 and are far more capable than they were when we last saw them. But there's no way to know anything at this point. Commented Nov 3, 2016 at 18:24
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    This question came up on the Close-Vote Review. I am voting to leaving open because I feel the question is asking about the physics within the game.
    – Skooba
    Commented Nov 3, 2016 at 20:28
  • @Radhil In the video it showed the arc ship that to my understanding is just a huge spaceship... but maybe it's got a extremely advanced drive core?
    – LexieStark
    Commented Nov 3, 2016 at 20:42

2 Answers 2


In the trilogy it's said that man kind can travel 50 times the speed of light.

Well... no. I'm not sure where you got that number from, but it disagrees with my sources.

The ME3 Codex gives top speeds of 30 ly per day (Reapers only) or 10-15 ly per day (everyone else), not counting mass relays (which give you extreme distances in very short periods of time, so it's difficult to compute a precise speed for them). 4219.99c = ~11.55 ly/day, right in the middle of the non-Reaper range. So by your own numbers, this is entirely reasonable.

Conventional FTL does, however, have the disadvantage that you need to discharge your core every few weeks or so, which is inconvenient in intergalactic space (very few planets, even fewer with magnetospheres). As far as I'm aware, we don't have an explanation for that yet. However, the very same Codex entry also says this:

Unlike Citadel ships, Reapers do not appear to discharge static buildup from their drive cores, although they sometimes appear wreathed in static discharge when they land on planets.

In principle, it is possible to build a drive which does not require discharge. Perhaps that's the key technological breakthrough which made the Andromeda Initiative possible.

Now that I've actually played (a little of) the game, I can say that the discharge issue is not prominently addressed in the first few hours. However the Codex has this to say:

Standard drive cores build up a static charge during operation, and must be discharged periodically. Otherwise the core discharges into the ship itself, with catastrophic results. The Initiative's drive cores, intended for long-term voyages, are designed to recycle or reduce static buildup.

As far as I can tell, that's probably all we're getting on this subject.

  • The drive core type is ODSY. I forget what that stands for, but I think the codex said. The fandom wikia says:
    – DCShannon
    Commented Mar 31, 2017 at 15:46
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    "With the Arks unable to refuel by traditional means in dark space, the journey to Andromeda is only made possible by the ODSY Drive System. The ODSY is a massive experimental drive core specifically designed for this trans-galactic voyage. It is capable of recycling static energy that would typically cause a starship to explode, instead storing it to power the Ark’s primary systems. Meanwhile, an electromagnetic ram-scoop will gather hydrogen from the Ark’s surroundings, converting it into fuel as needed. "
    – DCShannon
    Commented Mar 31, 2017 at 15:46
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    Found the actual codex entry online: masseffect.wikia.com/wiki/Codex_(Mass_Effect:_Andromeda)/… It's an "out-galaxy distributed static synch"
    – DCShannon
    Commented Mar 31, 2017 at 15:56

Although you appear to be looking for an in-universe explanation, it needs to be pointed out that time dilation permits this at slower-than-light speeds.

If you get in your spaceship and accelerate at 1g until the halfway point, then stop and decelerate at 1g the rest of the way, you can cross the 2000000 light-years to the Andromeda galaxy in about 26 subjective years. In the interim, 2000000 years will have passed back on Earth.

I'm not sure where you would get the fuel to do that, however.

Also: http://en.wikipedia.org/wiki/Intergalactic_travel and http://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration

  • 1
    This is problematic, because I'm fairly certain they meant 600 objective years (to the extent that "objective years" are even a thing, which I admit is somewhat questionable under relativity).
    – Kevin
    Commented Nov 12, 2016 at 20:53
  • Yess, well, undefined behavior is exactly that.
    – Spencer
    Commented Nov 12, 2016 at 23:00

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