May I recommend instead of a -xp, why not have a survival bonus? Say, you get +2% xp every X duraton (15 minutes?) you’re alive, up to +40% or something like that. Rebalance XP gain a little bit. Shouldn’t apply to XP gained from crafting, etc; just building/gathering/hunting.
That way, you are “rewarded” for not dying.
You could go further, and give players a beneficial buff when they die. Basically, trading the +%xp for +survivability, or something like that. This bonus shouldn’t be too strong, but noticeable. I would suggest something like +20% max hp. Meteors and the like should probably have an aoe effect that disables this bonus while you’re near them. Maybe planet level could reduce this, as well.