The Archon and the Angara
After completing everything you can (or care to) do on the Nexus, it’s time to venture off to the Onaon system in search of another Remnant vault. Given the extraordinary change the vault on Eos had on that planet, perhaps other vaults may similarly affect other planets? Perhaps these golden worlds are still golden, they just need some Remnant technology to make them shine again?
Pilot the Tempest to the Onaon system, where you’ll have an unwelcome, surprise encounter with an overwhelmingly superior force. Pick whatever dialogue options you wish in your quest to buy SAM some time, after which you’ll attempt an escape and shortly thereafter encounter ANOTHER alien threat. Oh well, one of the duties of the Pathfinder is establishing first contact with alien species - time to try your hand at diplomacy!
After a bit of scanning and introductions from Paaran Shie, you’ll be pestered by another Angara named Jaal before ultimately being directed to talk to somebody named Evfra. Afterwards, Paaran Shie will give you some directions, which you’d be wise to follow. Don’t wander around, don’t scan anything, just follow Paaran Shie and listen to the chatter as you go. When you reach your destination, endure some more chatter with Jaal and Evfra to learn a few things; namely that the Kett and the Angara are not best friends, and the latter’s experiences with the former make them somewhat distrustful of aliens. Fortunately, Jaal is willing to take a risk of working with you, providing him a chance to use you to achieve his goals, and for you to prove your worth to Evfra. It’s a roundabout way of accessing the vault on Aya, to be sure, but aside from going to war with the Angara, it’s really your only option.
Aya - Docks
When you’re done chatting you’ll find yourself back at the docks, where you’ll be confined until you prove yourself to the Angara. Despite this limitation, there is a bit to see and do in the docks, namely talk to an Angara named Sohkaa Esof to start the quest "Trading Favors" and Avela Kjar, who will give you the quest "Recovering the Past". When you’re done being exploited by Angara, talk to Enroh Bosaan, who will tell you a bit about the Angara. His assigned task is to answer your questions, but the Angara still don’t trust you much, so… he’s only so helpful. Kind of a fool’s errand, really. Pick up those two quests, learn what little you can from Enroh Bosaan, then active the "Docking Access Controls" to return to the Tempest.
Back on the Tempest
Fortunately your ship was able to be repaired - and without the rest of the crew even being able to leave! After flying off you’ll be treated to a group meeting, where Jaal will be introduced to the rest of the crew, and more importantly, he’ll reveal what you’re doing. You need to earn the trust of the Evfra, and Jaal has two jobs that need doing. You help him out, he’ll vouch for you, everybody wins. Sure, it’s extra work, but your crew whining doesn’t change the fact that the only way you’re getting to the vault on Aya is with the consent of the Angara. Besides, you fight the Kett, they fight the Kett… the enemy of your enemy?
You have two choices - head to Voeld and help the resistance there, or travel to Havarl and help some Angara scientists, the objects of the quests "Meet the Resistance" and "Helping Havarl’s Scientists", respectively. Completing one of these two quests will also become the focus of the Priority Ops "A Trail of Hope", and once one of them is completed, the aforementioned quest will advance. You can, however, complete both quests if you so wish, although after one is completed, the other will be demoted from Priority Ops status. Since the follow-up quest takes place on Voeld, you may as well do the quest "Meet the Resistance", which is what the guide will assume… although if you want to skip ahead to "Helping Havarl’s Scientists" and complete that quest first, everything works out just fine.
Before you run off to Voeld or Havarl, however, it’s time to chat with your crew. It’s been a busy day, and they certainly have new things to say, new quests to pursue, and new opportunities to flirt. Have an awkward conversation with Jaal, chat with Gil about his gambling addiction, Peebee and Cora complain about the Archon… there’s a lot of trivial encounters you can indulge in. Mixed in, however, are a few quests you can complete, if you’re willing to travel around a bit. Speaking of which, you can also explore the new systems in Heleus that are now unlocked. Again, it’s free resources and XP just waiting for you to scan and probe at your leisure. You’ll find these systems and the goodies you can scan in the "Space Exploration" section of the guide.
Note: Peebee’s companion quest "Peebee: Secret Project" will have started after reaching Aya. To advance it, just visit your e-mail terminal and read the message "Rem-Tech".
Note: After visiting Aya, the radiation on Eos will have lifted, allowing you to brave the nigh-impassible level 3 hazard zones, and also eliminating the general nuisance of traveling through level 1 hazard zones. This will be explained to you - as well as other, less desirable developments - by SAM when you set down on the planet next. The guide will reserve future bouts of exploration on Eos for a later date.