A lot of people have recently started encountering space battles which appear randomly as you warp into a system. So far they've all been the same and they look exactly like in this video - you get a distress signal and as you approach it you're given an objective - "Rescue Cargo Freighters".
Things worth noting:
- Freighters and pirate ships were shooting at each other like crazy but doing 0 damage and in the demos a freighter was shown destroying a ship.
- There are no sentinel (or any other) ships helping you and randomly hitting a freighter will make them attack you.
- You can destroy freighter containers and they will fight back doing tons of damage, but this will not change your objective, so you can't pick a side.
- I finished the battle without landing on a planet or docking with a station, so I don't know if that would result in anything.
- After warping to the current system I DID fly in behind a couple of ships as in attack formation, but I believe those were pirate ships.
Here are a few screenshots I made as proof: http://imgur.com/a/Mil1j
and /u/IforgotwhatIwasdoing added:
Had to go back to space station to recharge my shields 3 times during the event. (...) Did not affect the event whatsoever, didn't end, same ships, nothing. Also space combat the loot is almost impossible to get as they disappear after a very short time. The only reward for success was Gek rep; same as killing pirates anywhere. Swiftly followed by the sentinels destroying me because auto-aim lasers hit a passing ship. Oh, you're battling a pirate? Well you obviously meant to shoot this passing neutral ship, here you go!
So, apparently, the space battle encounters in the game do exist but they look nothing like this - no huge fleets, no allied battle ships, no sides to choose and no actual battle going on - the ships are just firing blanks at each other until you step in.