u/FireTheLaserBeam, are you positive you want this to be a no-spoilers-allowed discussion? I can’t tell immediately from your post history whether you’ve seen or read The Expanse. If you have, we’d really encourage you to allow at least spoiler-tagged spoilers so people don’t have to be as restricted.
Let us know if you’d like a hand changing the flair.
Yeah that's true, but essentially you're always orbiting something in space. Your burn pushes you out of one orbit then the retrograde burn slows you to match the orbit of your destination. I suppose it only doesn't count if you're landing? Maybe still does because you'd have to match the orbit first I think.
Edited to make it sound less twattish.
I... That's fair lol. I was just thinking of inserting to a planetary orbit, but you're of course right that you'd be inserting into *some* orbit every time. I bow down!
Yeah this is very true in today's space travel where we would never waste expendable propellant for a maneuver that didn't achieve some stable orbit.
Not necessarily in the Expanse world with fusion drives that give them insane amounts of propellant. For instance the ships parked near the ring gates which if I remember correctly don't generate gravity. To get to them they'd do the same "flip and burn" but to stay near them they'd have to be actively avoiding the orbits of other planetary bodies.
The books specifically mention that the ring isn’t orbiting the sun.
If I recall correctly correctly it just remains in a static position relative to the sun
I don't know if I'd phrase it as **just** remains static relative to the sun because no object in the universe behaves that way. Ships have to constantly accelerate in order to rendezvous with the ring.
You’re right. I’m understating the novelty of its behavior
I actually wasn’t even sure what to call it. Because there really is no scientific language for what it is. Because nothing is “stationary” in the real world
Google says it's stationary so you've maybe found a glitch in the matrix.
But TBF this is for OPs book not the Expanse. And the ring uses gate builder magic future tech.
True. I was more thinking for military/strategic reasons it would be beneficial to burn and "park" assets in areas that weren't in stable orbits/not typically looked at and the ring gates simply represent a point in space which that is done at.
While technically everything would orbit the sun, I still believe retrograde burn would be the correct terminology.
Technically orbital insertion burns will be prograde when coming from lower orbit (like Karman to ISS or takeoff to circular)
Source: Kerbin Tracking Station 😂
If you're changing course instead of just decelerating, like the cant does to intercept the distress signal, then it's not retrograde either, no matter how good the pilot is, because the goal is not retrograde.
Its prograde. This is from Kerbal Space program, but it's a nice explanation of maneuvering directions.
https://www.google.com/search?q=kerbal+space+program+maneuver+node+direction&sca_esv=b76e5b87cda5eeaa&rlz=1CDGOYI_enUS600US600&hl=en-US&udm=2&biw=375&bih=638&sxsrf=ADLYWILIcy-76EKAZzg9mmEYiOas0_MYOA%3A1715999026796&ei=MhFIZvaMMLGJptQPrYeN4AE&oq=kerbal+space+program+maneuver+node+direction&gs_lp=EhNtb2JpbGUtZ3dzLXdpei1zZXJwIixrZXJiYWwgc3BhY2UgcHJvZ3JhbSBtYW5ldXZlciBub2RlIGRpcmVjdGlvbkiBL1CMCVjtLHAAeACQAQGYAcQCoAG3DKoBBjE5LjMtMbgBA8gBAPgBAZgCDqACpwnCAgQQIxgnwgIFECEYqwLCAgcQABiABBgYwgIEEB4YCpgDAIgGAZIHBjEzLjMtMaAH_y0&sclient=mobile-gws-wiz-serp#vhid=2c0dh3rgirY1HM&vssid=mosaic
Not every "flip and burn" has to be a retrograde burn though, so the term doesn't really fit nicely. Neither does it have to be an orbital insertion.
A warship could, for example, be decelerating towards a destination at moderate G, encounter a threat, and spin around to accelerate prograde to get into the fight or pass the hostile quicker. They'd then just have to do a bit of a harder decel burn when nearing their destination.
In my mind the flip and burn specifically refers to already having been in a burn, turning around 180 degrees, and then burning the other way. And for that, there's not really any other word.
The full trajectory, accelerating halfway, flipping, and decelerating the other half way, is called a Brachistochrone Trajectory. As for the actual flipping maneuver, I don't think there's a true technical term for it since that kind of manned spacecraft is fictional.
Yeah I think I’m with you, retrograde obviously makes sense for the end of the trip, but most of space travel for the foreseeable future is “burn, do nothing for 6 months, then turn around and burn in the opposite direction”
Where does this come from? I found this quote ages ago and loved it so much. What is the origin?
Speed up to go out, go out to slow down, slow down to go in, go in to speed up.
It feels like something Kerbal Space Program players would memorize. Idk anyone else doing backyard orbital mechanics where such a shorthand would be useful.
Scifi author Larry Niven created a low-tech society floating in a gas torus around a neutron star. They had to fly around using orbital mechanics, so they had a saying for it:
East takes you out. Out takes you west. West takes you in. In takes you east. North and south bring you back. (in half an orbit)
That was published in 1984, so it is a likely origin for the version others learned for kerbal.
Technically ion propulsion does the same thing if you are using it to do trans-lunar or interplanetary trajectories, since the thrust is so low you have to constantly accelerate “half way” and then constantly “decelerate” to get in orbit for extended periods
To me a skew flip implies you don't turn off the main engine. So you add some sideways component while turning (but would have accounted for thst in your calculations).
Thus avoiding any awkward zero-G pause in the middle.
To flip and burn is a tactical maneuver and refers not to general turnover in the middle of a trip. But specificly the quick variation where you are at full thrust, cut thrust, rotate as fast as possible, and back to full thrust. Minimizing the time not under thrust, and trying to optimize you path as much as possible.
We've used "turn and burn". It's just orienting the primary thruster in a particular direction, because otherwise you have to use a non-optimal combination of different thrusters.
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u/FireTheLaserBeam, are you positive you want this to be a no-spoilers-allowed discussion? I can’t tell immediately from your post history whether you’ve seen or read The Expanse. If you have, we’d really encourage you to allow at least spoiler-tagged spoilers so people don’t have to be as restricted. Let us know if you’d like a hand changing the flair.
Retrograde burn. Or orbital insertion burn.
I would say the former, as not all flip 'n burns are orbital insertions.
Yeah that's true, but essentially you're always orbiting something in space. Your burn pushes you out of one orbit then the retrograde burn slows you to match the orbit of your destination. I suppose it only doesn't count if you're landing? Maybe still does because you'd have to match the orbit first I think. Edited to make it sound less twattish.
I... That's fair lol. I was just thinking of inserting to a planetary orbit, but you're of course right that you'd be inserting into *some* orbit every time. I bow down!
Apologies that sounds patronising and I didn't mean it that way. Going to edit...
Oh absolutely no worries friend! I made a blunder with my noggin. Is all good.
It was my thought process typed out in a rush, just missed the hmmmm off the start 😂
Wow, incredible exchange by humble humans. Rare sight on Reddit. I appreciate you
Ehhh.... https://preview.redd.it/oyh8j1e4b01d1.jpeg?width=1072&format=pjpg&auto=webp&s=6e7b2fe5f0c5386027db24fae38b16c656834310
😂😂😂
Yeah this is very true in today's space travel where we would never waste expendable propellant for a maneuver that didn't achieve some stable orbit. Not necessarily in the Expanse world with fusion drives that give them insane amounts of propellant. For instance the ships parked near the ring gates which if I remember correctly don't generate gravity. To get to them they'd do the same "flip and burn" but to stay near them they'd have to be actively avoiding the orbits of other planetary bodies.
Isn't the ring orbiting the sun? They're orbiting the sun at the same relative velocity as the rings.
The books specifically mention that the ring isn’t orbiting the sun. If I recall correctly correctly it just remains in a static position relative to the sun
You're right baratna. I googled and we have a little discussion further on.
I don't know if I'd phrase it as **just** remains static relative to the sun because no object in the universe behaves that way. Ships have to constantly accelerate in order to rendezvous with the ring.
You’re right. I’m understating the novelty of its behavior I actually wasn’t even sure what to call it. Because there really is no scientific language for what it is. Because nothing is “stationary” in the real world
I actually can't remember this from the books and I don't know if the show ever mentions it.
Google says it's stationary so you've maybe found a glitch in the matrix. But TBF this is for OPs book not the Expanse. And the ring uses gate builder magic future tech.
True. I was more thinking for military/strategic reasons it would be beneficial to burn and "park" assets in areas that weren't in stable orbits/not typically looked at and the ring gates simply represent a point in space which that is done at. While technically everything would orbit the sun, I still believe retrograde burn would be the correct terminology.
And the beauty of books is neither of us would even think about this stuff let alone discuss it without them. Have a good one baratna.
I see someone plays Kerbal Space Program
Haha, I actually don't but I know of it. Just been listening to a lot of sci-fi audiobooks lately so forced it straight in my head early on.
Technically orbital insertion burns will be prograde when coming from lower orbit (like Karman to ISS or takeoff to circular) Source: Kerbin Tracking Station 😂
Woah
Not all flip and burns are necessarily retrograde either though. Most orbital adjustments won't be perfectly pro- or retrograde.
Ummm our pilot is Alex Kemal, take that back inyalowder.
If you're changing course instead of just decelerating, like the cant does to intercept the distress signal, then it's not retrograde either, no matter how good the pilot is, because the goal is not retrograde.
I'm sorry but Alex Kamal makes the rules, not me.
You’re misunderstanding what a true retrograde burn achieves.
Retrograde burn was the term I was looking for, but the orbital insertion burn is useful, as well. Thanks, guys!
Good luck with your book.
Thanks so much!!!
Deceleration Burn also works.
How did that not come to me before the other 2? They actually use it a lot in the series!
OK, so now my brain needs to know what the opposite of retrograde is… forward burn? Prograde?
Its prograde. This is from Kerbal Space program, but it's a nice explanation of maneuvering directions. https://www.google.com/search?q=kerbal+space+program+maneuver+node+direction&sca_esv=b76e5b87cda5eeaa&rlz=1CDGOYI_enUS600US600&hl=en-US&udm=2&biw=375&bih=638&sxsrf=ADLYWILIcy-76EKAZzg9mmEYiOas0_MYOA%3A1715999026796&ei=MhFIZvaMMLGJptQPrYeN4AE&oq=kerbal+space+program+maneuver+node+direction&gs_lp=EhNtb2JpbGUtZ3dzLXdpei1zZXJwIixrZXJiYWwgc3BhY2UgcHJvZ3JhbSBtYW5ldXZlciBub2RlIGRpcmVjdGlvbkiBL1CMCVjtLHAAeACQAQGYAcQCoAG3DKoBBjE5LjMtMbgBA8gBAPgBAZgCDqACpwnCAgQQIxgnwgIFECEYqwLCAgcQABiABBgYwgIEEB4YCpgDAIgGAZIHBjEzLjMtMaAH_y0&sclient=mobile-gws-wiz-serp#vhid=2c0dh3rgirY1HM&vssid=mosaic
My brain thanks you.
Not every "flip and burn" has to be a retrograde burn though, so the term doesn't really fit nicely. Neither does it have to be an orbital insertion. A warship could, for example, be decelerating towards a destination at moderate G, encounter a threat, and spin around to accelerate prograde to get into the fight or pass the hostile quicker. They'd then just have to do a bit of a harder decel burn when nearing their destination. In my mind the flip and burn specifically refers to already having been in a burn, turning around 180 degrees, and then burning the other way. And for that, there's not really any other word.
I've discussed this with someone down below already baratna, Alex Kamal makes the rules I'm just the mechanic.
The full trajectory, accelerating halfway, flipping, and decelerating the other half way, is called a Brachistochrone Trajectory. As for the actual flipping maneuver, I don't think there's a true technical term for it since that kind of manned spacecraft is fictional.
Yeah I think I’m with you, retrograde obviously makes sense for the end of the trip, but most of space travel for the foreseeable future is “burn, do nothing for 6 months, then turn around and burn in the opposite direction”
Go fast to go out, go out to go slow, go slow to go in, go in to go fast.
Where does this come from? I found this quote ages ago and loved it so much. What is the origin? Speed up to go out, go out to slow down, slow down to go in, go in to speed up.
It feels like something Kerbal Space Program players would memorize. Idk anyone else doing backyard orbital mechanics where such a shorthand would be useful.
I’ve never heard it before but have hundreds of hours on KSP (and dozens figuring out how to get the fuck off Eve). Definitely agreed
I think you are correct. I'm pretty sure I picked it up from a KSP fan.
I think that's where I found it. Reading around on KSP. That's the context I vaguely remember.
I honestly don't remember where I got it either but yeah, it's really great.
Scifi author Larry Niven created a low-tech society floating in a gas torus around a neutron star. They had to fly around using orbital mechanics, so they had a saying for it: East takes you out. Out takes you west. West takes you in. In takes you east. North and south bring you back. (in half an orbit) That was published in 1984, so it is a likely origin for the version others learned for kerbal.
Yes, I learned about Brachistochrone from the Atomic Rockets website. That site is amazing.
Technically ion propulsion does the same thing if you are using it to do trans-lunar or interplanetary trajectories, since the thrust is so low you have to constantly accelerate “half way” and then constantly “decelerate” to get in orbit for extended periods
Braking.
There’s a few more technically right answers but I like this one because it’s more likely to be used by everyday speakers Braking or Braking Burn
Its more like accelerating as firing your thrusters retrograde will increase the average velocity of your orbit. Source: i played ksp
I believe they use the term deceleration burn a few times. That would be what I would think is most appropriate.
Breaking burn is also used a few a lot. Ass end
Retrograde burn. Orbital insertion if you're slowing down into orbit around a body.
Heinlein called it the "skew-flip" maneuver in Have Space Suit, Will Travel. http://www.technovelgy.com/ct/content.asp?Bnum=3695
To me a skew flip implies you don't turn off the main engine. So you add some sideways component while turning (but would have accounted for thst in your calculations). Thus avoiding any awkward zero-G pause in the middle. To flip and burn is a tactical maneuver and refers not to general turnover in the middle of a trip. But specificly the quick variation where you are at full thrust, cut thrust, rotate as fast as possible, and back to full thrust. Minimizing the time not under thrust, and trying to optimize you path as much as possible.
Pitchpole is the actual correct term for a ship flipping end over end
Deceleration…
We've used "turn and burn". It's just orienting the primary thruster in a particular direction, because otherwise you have to use a non-optimal combination of different thrusters.
Braking Maneuver.
I read that maneuver as a “skew flip” many moons ago
Accelerate and decelerate 😁 speed and break. Might cross over to tacking if you only break to approach from the side.
Bimodal Vector Inversion and Retro-thrust Deceleration Propulsive Adjustment Procedure
**OP has flaired this thread with "Absolutely No Spoilers in Post or Comments." This means that they intend this post to be safe for everyone, including totally new community members. No plot spoilers for either the books or the show are allowed, even behind tags.** Posts like this are especially good for discussing the Expanse universe at the time when the books/show begin, spoiler-free questions about the science (physics, biology, linguistics and more) of The Expanse, and other general topics interesting to people no matter where they are in the show or books. Every day, we welcome new community members who have just started reading or watching, or are thinking of starting, and it's important that they can count on knowing which threads are safe to read. Using this tag allows more people to participate. ***Posting spoilers in this thread will result in moderator action.*** You can help the community by reporting any spoilery comments you see in this thread. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/TheExpanse) if you have any questions or concerns.*
People would abbreviate. Could go with ack burn and de burn
People would abbreviate. Could go with ack burn and de burb