The big climax is the hero has just bonded with her new super sci-fi space suit that will let her fly up and help protect the earth from asteroids and stuff. She can fly, propel matter, and using pico-printer-gel*, disassemble and reassemble matter.

In the current draft, she has about 15 minutes to fly up and prevent an asteroid that's going to splatter the earth. This is the "last one", since the previous about a 100 years ago (which aligned with Asteroid Bennnu's description and timing). Mankind can't survive another hit.

There's limits to how much mass she can move, we don't have numbers, but the asteroid is too big. She's a sniper (back on earth) and tends to deal with problems distantly. I decided she'd have to get close for this one (and thus risk her life).

Since she can't just superman shove the asteroid off course, I thought she'd try aikido. Let's say she just got up to space and there's 5 minutes left. The asteroid is on her left (relatively) and coming in to kill us all. She flies right, around the planet, picking up speed (a lot of speed), gathering up matter to build a lattice that she can ram/cushion with. She rejoins the asteroid from behind and pushes with all her super-pushy-power. Thus adding speed along a vector the asteroid is mostly going, and thus, causing it to skirt past the earth instead of slaughtering the last of humanity.

I don't need exact math, but I think there's a hole in the idea. To get around a planet of 24K miles circumference in under 5 minutes is a whole lot of speed and acceleration. Assuming she can now handle higher g-forces, wouldn't her new speed be very much faster than the asteroid, causing her to splat, instead of line up to shove?

Is there a better solution for dealing with an asteroid in 15 minutes (5 assuming it takes 10 to get up there)?

I don't think Nukes has the right vibe and lots of articles disproved that as a solution.

Is the original plan workable if I adjust the effective starting point for the asteroid so it will be far enough away and have just the right speed for her to join it by orbiting the planet once?

I can play with the parameters a bit since it's just fiction, but I need a short timeline and personal risk. Her flinging an object at it might work, but how would she herself be at risk to add tension?

This is the big finish to my post-Ragnarok coming of age biker cultist story about a fallen angel.

Thanks!