Periscope

[ibanez074]

Anyone point me to a guide on the periscope and in particular how to zero the gyros with it please? Not getting much luck with discord
Thanks!

[DMDash]

Same, this would be a great help.

[Old Flier]

As I see it (which could well be wrong) the Gyro Align checklist is printed backwards It tells you how to align the gyros then tells you to do a Horizon Check which kinda hints that you have to do the alignment first. It should say FIRST to do the horizon check THEN do the alignment IF NEEDED. (it does say at the top only do this if needed) In dozens of flights I've never yet needed to re-align the gyros. As far as the periscope goes, if the needles are zeroed with the ASCS MODE SELECT switches set to NORM / AUTO / GYRO NORM the world should appear to be moving backwards parallel with the lines and out the window your nose pointed down about 25-30 degrees. If that's what it looks like then all's right with the world. If you are really determined to mess with it I've discovered that if you switch ASCS to FLY BY WIRE and GYRO CAGE, change your attitude to whatever you want then change your gyro to FREE then that will be your new 0,0,0 attitude for as long as you leave it on FREE. Caution-sideways re-entries void the spacecraft warranty.

[ibanez074]

Thnaks for that cant really find any online help with the periscope so ill look into what youve said!

[peterbyrnes1]

This is one area where I struggle. How do I know that it will eventually point me in the correct reentry attitude?

[Old Flier]

Assuming you have equipment failure option turned off, as long as you have the ASCS MODE SELECT switches set to NORM / AUTO / GYRO NORM it will put you into the right attitude. With the ATTITUDE SELECT switch set to RETRO you will be pointed about 30 degrees down toward the earth. When you switch it to RE-ENT after retrofire you will be pointed just about even with the horizon. In both cases the world should be moving from the bottom of the periscope to the top staying nice and parallel to those vertical lines. Oh, and in case you didn't know. the top right button on the periscope zooms in the view which makes it a lot easier to see the ground drift. Well, that all applies until you get to the last campaign mission, "Hawaii". By then you should have a good handle on it. :)

[ibanez074]

Great thanks! If your in retro shouldn't the world be moving from the top to bottom of the periscope though?!

[Old Flier]

The periscope view is the same view you would have if there was a window in the bottom of the capsule between your feet. The bottom of the periscope shows what is behind the capsule, the top of it shows what is in front of it. In retro and re-entry you are traveling backwards (retrograde attitude) so the world in that view is moving from behind you to ahead of you. If the world view in the periscope is moving from top to bottom you are facing forward (posigrade) and firing your retros would just boost you to a higher orbit.

[ibanez074]

Thanks Chrome. Yeah pretty comfortable with everything space related though I'll have to get my head around the fact earth goes from bottom to top in peri view if in retro position!
I was more wondering exactly what the lines mean and where/what to line them up with (obviously earth but what exactly!) and when lined up what exactly does that mean.

[Old Flier]

The only reason the periscope LOOKS complicated is that the dev is trying to keep everything looking as historically accurate as possible. I'm sure in the real Mercury all those lines and compass degrees around the edge and the ability to rotate the lines had some technical and scientific purposes. For our purposes in the sim you are not lining up with any particular object. The only thing that matters is that the ground moves as straight as possible up the periscope and for that the central line helps you see if you are turned straight or angled off to one side a bit.

[ibanez074]

Brilliant thanks!