Here is the full list of all 26 ADIOS Amigos: Galactic Explorers trophies - there are 14 bronze, 4 silver, 7 gold and 1 platinum.
Been there, done that
Find all discoveries
Find 50% of all discoveries
Find 25% of all discoveries
Complete the Odyssey
Complete the Odyssey without using shortcuts
Complete the Voyage
Complete the Voyage without using shortcuts
Complete the Endeavor
Do the Kowalski
Find a botanical secret
Crash land a space station using its thrusters
Find a secret solar system
Successfully perform a powerful space station heist
Solve the mystery of the galactic caretakers
Establish communication with a gelatinous commander
Discover all flying lifeforms
Scan a sun without taking damage
Crack open an asteroid to reveal the goodies inside
Find the secret bakery
Drain energy from a broken energy source
Start a fashion trend
Defend yourself using M.A.D.
Enter a space station in orbit
Travel 6 lightyears in the Odyssey without using shortcuts
Finish Odyssey in less than 20 in-game minutes without starting from a shortcut