Gemini - Rendezvous for Dummies...

[yamsi3467]

Can someone help me with a really simple step by step rendezvous primer. I feel like an idiot. Been trying the early access mission on the subject. I'm talking really, really simple. Hand holding simple. I am college educated but this one has me stumped.

[Hector Melo]

Thank you for playing our wonder Sim, After you completed successfully the Gemini Academy missions I could suggest you a couple of video tutorials: https://www.youtube.com/watch?v=KwoPVz3RqMg

Also take a look at this: https://steamcommunity.com/sharedfiles/filedetails/?id=1605225201

Remember that you are also free of joining us at our Discord channel: http://discord.gg/reentrygame there you can ask me anything, keep in orbit Reentrynaut!

[yamsi3467]

Okay. I looked at that, and it didn't help. This says Simplified Docking unchecked and advanced. Can I get something a bit simpler.

[hunterlg]

The way I docked to the agena was having to diverge from the checklist and mission a bit, for example: When doing the initial burn to the agena's altitude to rendezvous, I got my apogee as close to the agena's alt as possible and did NOT circularize orbit after this like the mission and checklist says to do, I simply coasted to the agena at apogee and docked. (after turning on radar and configuring computer to rendezvous mode of course.)

[yamsi3467]

That sounds helpful. I may try that. I still am shaky on the changing altitude bit.

[yamsi3467]

The more I think about it, I'm just going to give up on rendezvous for Gemini. I can do just about everything else. Maybe as more features are added and worked on, this will get more user friendly.

[hunterlg]

Originally posted by yamsi3467:

The more I think about it, I'm just going to give up on rendezvous for Gemini. I can do just about everything else. Maybe as more features are added and worked on, this will get more user friendly.

Make sure you circularize orbit after insertion, another tip is to begin circularization burns a bit before perigee or apogee, as your spacecraft will still be going towards them during it. The time in which you start the burn is up to the user, mine typically range from 15 to 60 seconds before. Also make sure you've requested the target burn and have the proper core loaded into the gemini's computer. Checklists will help with this.

[yamsi3467]

Okay. Thanks for the info, but I am still not grasping this, and the checklist are not helping me at all. I will read them again, but I really just have given up on this part of Gemini.

[Johnno]

What part are you getting stuck on, considering that the checklists aren't helping you?

Is it capsule functionality you don't understand? Orbital mechanics? Flight computer programming? At what point do you get stuck and what resources have you attempted to use so far to learn?

Perhaps someone will be more willing to help if you give specifics, rather than asking them to dedicate their time to teaching you by holding your hand and spoon-feeding you.

[yamsi3467]

Okay, thanks for the attitude. As I said, I am college-educated and teach computer science. I have been studying Mercury, Gemini, and Apollo since I was a small boy. I get hung up on the burning at apogee and perigee concept. I wasn't asking for "spoon feeding" I regret saying hand holding. Poor choice of words. As I teacher, I know how daunting a new concept can be. I was asking for clarification. I understand the systems. I read the checklists. I just wanted a good primer that I could go off of. If you don't want to help, then don't help. I apologize for even starting this. I forgot how brutal some can be.

[Johnno]

My sincerest apologies, I was not attempting to be crass or offensive.

The concept on burning at apogee and perigee is orbital mechanics, in which case you'd want a primer on that. In short, burning prograde increases the opposite side's altitude, so if you burn prograde (direction of travel) at apogee you increase your perigee altitude, up to the point where it's identical to your apogee altitude, thus a circular orbit. If you burn retrograde (opposite direction of travel) you lower the opposite altitude, thus doing that at perigee drops your apogee for a circular orbit.

Beyond that you'll get into ascending node, descending node, and burning perpendicular to your direction of travel and direction toward the body you're orbiting, to change your inclination.

I mean, at that point you'll be better off googling for basic orbital mechanics, or watching some videos on youtube (I can recommend Scott Manley for example).

[yamsi3467]

Thanks. This does help, and I am googling orbital mechanics.

[yamsi3467]

So, from what you tell me, I need to make sure I am SEF (Gemini) before doing the burn at apogee? You have really been helpful with your second post.

[Johnno]

Originally posted by yamsi3467:

So, from what you tell me, I need to make sure I am SEF (Gemini) before doing the burn at apogee?

For raising your perigee / achieving a circular orbit, yes.

[yamsi3467]

Just tried it. Doing the rendezvous early access mission. After 1hr 37 mins I was supposed to zero my IVIs but they were already zero. I am missing something somewhere.

[hunterlg]

Originally posted by yamsi3467:

Just tried it. Doing the rendezvous early access mission. After 1hr 37 mins I was supposed to zero my IVIs but they were already zero. I am missing something somewhere.

Ensure the radar was properly warmed up and is set to ON, and that computer module loaded is rendezvous. Also note: you'll want to make short burns to slightly increase velocity towards the Agena, as safe docking speed is very very slow. The reason I did not circularize orbit once near the Agena at my apogee was because it increased my velocity relative to the Agena in order to bring up perigee and you already coast to the Agena at a good rate once you raise your apogee to the Agena's altitude. Also note: I have encountered a bug in which your orbit and the Agena's orbit displayed on the orbital map are not the same as the actual appeared position once you start falling to perigee on the orbital map but the Agena still appears near your spacecraft, and during this attempting to dock with the Agena will create unusual bugs such as the clipping of the Agena's model disappearing and it's position changing when you go from internal to external views. I recommend trying to dock as quickly as you can while still taking it easy if you catch what I mean.