Warframe's solar map is, like the actual solar system, quite large, and unlocking all the worlds and completing their multitude of missions will keep you busy for some time. If you've already dusted them off, however, you'll eventually be able to go down the Steel Path, an upcoming hard mode that will be tested this weekend.
Digital Extremes hasn't given much away about the new system, but we know that the Steel Path will give players a new series of trickier missions that offer up exclusive rewards, like decorations, emotes and mastery.
Whatever shape it takes, it apparently won't be complicated. It's not a big new layer that you'll need to wrap your head around and it won't be split up into tiers—it's just higher level challenges and new stuff to add to your collection of tat.
If you've already completed the map, you can apply for the test now, but only around 1,000 players will be getting access this time. There are no patch notes yet, nor a date for the full launch.