Where's my Supreme Ordeal?

I'm re-writing Jade, a fifteen year old novel, right now,  I've always loved the central premise of a sentient world, and I wanted to take on the challenge of re-writing it and making the idea work in established science terms.

My research for the novel has ranged from cell biology and viruses to how thunderstorms form, submarine diving procedures, hypercapnia, and computing systems.  I've been happily explaining the events of the story in scientific terms.

But now that I've got two-thirds of the way through the re-write I'm getting bogged down.  And I've realised it's because I haven't paid enough attention to my story structure.  This is a novel I originally wrote from a five-line idea with no planning whatsoever, and it shows.  It's not the way I'd work these days.

The result is that I've realised my action is in the wrong order.  I've just written a big scene where my heroine's spaceship is about to explode.  Big drama, will she survive?  But it comes way too early in the book.  I've put in some tension and threats from the baddies, but what I haven't done is escalated the conflict.  Shooting that ship out of the sky is unjustified at this point in the story.  I need to save it for my Supreme Ordeal, close to the end of the book.  I need more tension first, to up the ante before I get there.

Time, teaching about plot, and Christopher Vogler's The Writer's Journey have made me aware of the problem.  And I've realised that in the place where my Supreme Ordeal should be there's precisely... nothing,

Fixing this means juggling about the last dozen chapters, but it must be done.  I need to create that rising wave of tension which finally explodes in the Big Bang of the Supreme Ordeal.

Hmm.  I may be some time...