Hmm, the first few of suggestions I feel answer if you roll threats/despair. If the check is outright failed, I would say they don't enter hyperspace. Proper calculations were not made and system fail-safes prevent entry. With that in mind, I don't always require an astrogation check unless there is imminent drama ("We'll lose them when we make the jump to hyperspace!") or they're attempting to navigate an extremely difficult route.

The key here is that the failure actually mean something. If it's just a routine check and the player simply has an opportunity to keep trying until he succeeds, then there is no point in making the check in the first place. Even with all the time in the world, perhaps failing a check for a difficult route means the player can't try again until he finds some key information he's missing in his data to feed the navicomputer.

Of course, if the plot hinges on the players getting to where they need to go, just "scene wipe" and get there cinematically. Leave astrogation out of it.

I think this is key. If time is not of the essence (or if the precision of the jump doesn't matter [ie - asteroids]), then simply have the player succeed. An experienced pilot will 100% get it right in a calm, non-threatening, situation.

When it matters is if they're being chased, under a time constraint, or have to make a precise jump in order to dodge an asteroid or black hole or something.

I like this idea a lot, depending on how many threat they roll, perhaps said asteroid field is the secret hideout of some space pirates who don't take too kindly to the PC's discovering their location!

I have about 10 or so pre-made "mini-encounters" that I would randomly use in the D6 system whenever the Wild Die came up a 1. Dropping out dangerously close to a black hole, Mynock infestation, damaged hyperdrive, appearing in the wrong system and so on. I figure I'll be pulling these out again with a few adjustments, such as including Skill Monkey's ideas.

Anybody have any suggestion for what should happen on a failed Astrogation check?

I can think of a few interesting despair scenarios (asteroid belt, close to a sun, inside a planet's orbit, etc.), but for just a regular failure?

Possibly end in a system roughly the same distance, but in a random direction?

I set up a google sheet algorithm that essentially adds time to travel for any Threats, Despairs result in bad situations on a Random generated chart (everything from coming out in an asteroid belt to ending up near a black hole). For a plain "You failed" I have their coordinates selected randomly and they are in Hyperspace for that much time unless they choose to drop out and recalculate.

There's a chart in Fly Casual for result suggestions.

Look at map roll scatter dice and put them a couple systems off from.their intended destination. Annoying but not so derailing

It's a good to have some pre-generated modular encounters handy for when things go awry in general. The malfunctioning hyperdrive/bad astrogation roll is a good one to have ready. You can just pick an appropriate system or location to match your encounter and have at it.

During an attempt to escape a losing space battle, my character Pips, piloting her ship alone, failed a painful series of astrogation checks.
Not only did she end up travelling to the wrong location, but she got picked up by an Empire Starship. This lead to a well meaning rescue mission by the other party members... which eventually resulted in some super tragic PC deaths.
Needless to say, I've trained some ranks in astrogation since then! *lol*

Nice suggestions. There isn't much to add other than this: keep in mind what kind of story you want to tell and how you want it paced, and you'll probably be fine. If timing is important and you want to keep the pressure on, an appropriate consequence is something that raises the stakes and tests your players' skill and resolve. If pacing isn't that important at the time or you'd like to give the players some room to breathe for a while before the next peak, give them a fun side adventure. The consequence of their failure can always come later, when they finish up their resting adventure and proceed on the previous course, only to jump into a situation similar to the one they might've just escaped earlier. Star Wars is Pulp Science Fantasy, so the universe works in very strange, narrative-centric ways.