I’ve combined two scenes into a single post here, mainly because one of them was quite a bit shorter than all the others so far (just under 500 words), and also because I felt like keeping on writing after that one.
You’ll recall that the crew of the starship Aniara has been accelerating in toward the planet Kepler 62f, around which they’ve discovered what appears to be an orbital ring station — the first indication that somebody once lived here, even if they may not be here any longer. They are now halfway there, and it’s time to begin decelerating.
The “flip and burn” maneuver. No, I didn’t coin that phrase. For that, I have to credit a pair of my favorite authors, collectively known as James S.A. Corey (a pen-name for the writing duo Daniel Abraham and Ty Franck), best known for their science fiction series The Expanse (and the SyFy TV series of the same name). In the opening chapters of the first book, and the pilot episode of the show, the interplanetary ice hauler Canterbury needs to alter their acceleration trajectory in order to respond to a distress call. The executive officer, James Holden, warns the crew, “This will be a high-G maneuver. Prepare for flip and burn.” (I think the dialogue in the book was slightly different from that in the show, but I digress.)
That, right there, was what made me want to see that show, and then after to read those books, which I now consume just as fast as Abraham and Franck can churn them out. No magic “artificial gravity,” no spaceships that fly around like fighter jets in an atmosphere, just full Newtonian physics at work. If you want to change the direction of your ship, or slow it down, you need to point engines ahead of your travel vector and burn.
If your engines are efficient enough, and you can carry enough propellant, then the fastest way to get somewhere is to accelerate constantly until you reach the halfway point, then flip the ship around and decelerate the rest of the way. That’s without taking into account matching aphelion and perihelion of initial and final orbits, but again, I digress.
Aniara, of course, is not burning as hard as the Canterbury. She’s moving very fast, due to twenty-one days of constant acceleration, but the acceleration itself is relatively minor. At the halfway point, the crew shuts down the engine, flips the ship, and restarts it, for twenty-one days of deceleration. They aren’t changing the direction of their vector, just reducing speed, so no massive G forces on superstructure or crew are necessary.
So, that’s our first scene here, followed by arrival at the ring station. Enjoy!
image credit: NASA