"Made for the sole purpose of finding creatures not from this world, this mech was sent into orbit, though the scientists made an error when programming it...
"They initially set its purpose to 'find any lifeform and return', but it seemed to take it as 'find ALL lifeforms and return', to which it set out to space... and it hasn't returned since. The last time it was seen was 500 years ago.
"And legends say that it will come back with all the information it has gathered. Not just a slim of information of other lifeforms, mind you, but ALL of it. It will likely trek across the universe until it has finally reached the end, where it will know absolutely everything that exists in our very Solar System."
This is pretty much just a story I've come up for this mech you designed, and I gotta say, it looks very otherworldly. Hell, it kinda reminds me of Evangelion a bit, too. You've really done a pretty good job with this model!