Through those six minutes, my only thought was - and I cannot imagine I was alone - "what would I be thinking?"

So I try to imagine it as if it was me.

I'm in a van-sized, cone-shaped craft. There are three colleagues with me. We are hurtling through space at 40,000 kmph. We have no way to control our path, change the orientation of our craft. For we are reliant solely - absolutely, exclusively, whatever other such adverb siezes you - on science for how we are moving and where we are headed. Over most of the last ten days, we have been in constant, regular touch with our home base in Houston, and in fact with all of that exquisite blue planet we call Earth.

But that's about to change. As we have fully expected, and NASA has planned for, on re-entry into the Earth's atmosphere we actually bounce back out. "Skip re-entry", it's called. This is to dissipate some of the heat that first entry generates. Then we make a second entry that's relatively gentler and easier on us in the craft, though hold on to that word "relatively". At the very moment we have also expected, we lose radio contact with Earth. This is no trivial power cut, nor a radio malfunction, nor a broken antenna - nothing like that. This is a consequence of our craft blazing - no other word quite fits - through the atmosphere. For the time being, we are just another shooting star. Meaning, an object from space that enters and falls through the atmosphere, and the resultant friction burns it up.

Yes, we are sitting in a craft, Integrity, that's burning, that's a fireball. Those are competely accurate descriptions of our situation. And this is some serious burning - the temperature on the outside of Integrity is nearly 3000°C. That's better than twice as hot as lava from an erupting volcano, about half as hot as the surface of the Sun. Heat like that turns the air around Integrity into electrically-charged plasma, which is opaque to radio transmission. Which is why we have six minutes of radio silence.

And the heat is only centimetres - no exaggeration, centimetres - from where the four of us sit. That's the thickness of the layer of protective material that's our frontline defence - well, our only defence - against the heat. And we can look out our large windows to actually see the air heating up. We are just a tiny distance from superheated oblivion. We are unable to speak to anyone but each other, if that. Unable to control the flight of Integrity. Trusting absolutely to mathematics, physics and engineering that we'll see the other side of the six minutes. Mathematics, for the calculations of the precise angle of our skip re-entry into the atmosphere, the precise orientation of Integrity as we do so. Physics, to understand what happens to the air that surrounds us and what that means for radio signals. Engineering, for the material that protects us, for the way Integrity was designed and built.

Verily, I am - we are - falling to Earth, but cradled by science.

We are acutely conscious of that as we look through our windows at the streaming, flaming plasma, as we are buffeted by intense G forces and our shuddering Integrity: relatively gentler, remember. Yet we are strangely calm. You might think that's because we really have no option, and what purpose would it serve to shout, or even shiver, in fright? But that's not the reason at all. We have trained all our professional lives for these moments, indeed for the constraints and stresses of space travel. We have learned to trust absolutely, implicitly, to science. To the incredibly precise calculations that made this trip possible - from the gravitational slingshot the Earth was for our journey to the Moon, to the point where we started our swing around the Moon, to Integrity's angle of attack as we entered Earth's atmosphere again ... to so much more. We know all this in our bones. We know in our bones that the science will take us through these six minutes and soon after, drop us gently into the Pacific. The precision, the design, the calculations - that's our protection. So we are calm.

So all that's what I'd be thinking, if it was me. But it wasn't me. So instead, like millions around the planet, I watched in fascination and wonder, riveted to my screen, NASA's live broadcast of the return of Artemis II. The laconic back and forth between the crew and the ground team. The views of Mission Control in Houston, men and women staring at widescreens, laptops beside them, large schematics on the wall.

The separation of service and crew modules, exactly on schedule. The tension as those six minutes approached. My fingernails as the six minutes passed, for did it really take only six? Were they twelve? Eighteen? An hour?

And the wonder doesn't end, really. Not for us, not for the astronauts. I listened to Jeremy Hansen, the Canadian on board, saying this about returning to Earth:

"Re-entry is just such a magical experience. ... It got sporty, as the Gs built up. We had close to 4Gs a couple of times. We saw the plasma coming ... it was red, but then it was green and bluish and it was bright. It was like someone was welding outside the capsule. ... And then once we skipped back out of the atmosphere, then came back in again, more G forces, and then we came out of the blackout period. There was this weird bobble as we got kind of pointed straight down at the Earth. ... You really hear the thrusters, they're loud. Bang, bang, bang, the capsule's moving around. And then the violence of the drogue chutes coming in, you're whipping all over the place ... and then they release and you're falling again, and bang! More parachutes, more sounds. And then, the finale, you hit the water ... so soft."

And that's only some of what we've heard from the four astronauts about what they went through. This was one soaring, inspirational, captivating mission. I am struck by the immense grace of Christina Koch, speaking of the impact Artemis II had on her and us all:

"It was superceding any lines, any identities that people had. And when my husband looked me in the eye on that video call and said 'no really, you've made a difference', it brought tears to my eyes. I said, 'that's all we ever wanted.' ... We've done this together. We took your hearts with us. Your hearts lifted our hearts. ... In the beginning, three years ago, we were being celebrated for something that we hadn't done. And having put in the work and having seen our team's successes, I think we're ready to share in that inspiration and to celebrate it."

Reach the moon, but supercede identities, lift hearts: Think of what science accomplished here. What humanity accomplished here.

(Two photographs above are from this report.)

Postscript: I'm making a promise to you and to myself here. One essay (at least) a week. If I can keep that promise over the next month - so till mid-May - I will then ask you to pay for these. As always through my years writing, that will keep me on my toes. I know I need that. Thanks.