It is feature for new chars and only for starting Starflier ship. You are invincible until you dock - this allow safe travel for buying new ship for new chars. You can transfer in space to new char equipment and money, and then go safe buy new ship in distant system ... WITHOUT dock on the way !!
There is one more "invincible" feature and this is only for PvP fights. Your character have less as 10 hours of play OR is your characer below lvl 40. Only one from these conditions need to be met for activate this automatic "pvp protection".