Issue 62

Jack’s Astro Corner: Video Edition!

In this Astro Corner I'm going to share with you 3 YouTube videos I made in the April-May 2020 timeframe. In my role at the National Space Defense Center I'd be given 10 minutes at the weekly “all-hands” call and share a short astro lesson. I had fun giving those “speed” lessons in astro. The folks on watch seemed to…

In this Astro Corner I’m going to share with you 3 YouTube videos I made in the April-May 2020 timeframe. In my role at the National Space Defense Center I’d be given 10 minutes at the weekly “all-hands” call and share a short astro lesson. I had fun giving those “speed” lessons in astro. The folks on watch seemed to enjoy them too. Well, the health crisis back then prevented those gatherings, so I decided to give YouTube’ing a try and make short astro YouTube videos. In this Astro Corner you’ll have the chance to see 3 of these creations of mine.

The topic of the videos is RELATIVE MOTION. That is the stuff that’s behind all this Rendezvous and Proximity Operations (RPO) happening out there. It’s basically down to perspective, that is how you look at the motion of one satellite relative to another. We are so used to looking at orbits from an inertial perspective, but when two spacecraft are close and hanging out with each other it looks different when examined from one of the spacecraft. So, what I ask is you give each YouTube a viewing, they are about 12 minutes each, and really focus on the relative coordinate frame (called the RIC frame) and then how a single Delta-V (thruster firing) in a particular direction can induce relative motion. I fix the RIC frame on the Target spacecraft, the one that’s not maneuvering and the Chaser’s motion is noted.

Here’s the first 2 of 3 YouTube’s…enjoy them.

Video 1: Relative Motion-Natural (1 of 2)

Video 2: Relative Coordinate Frame (the RIC frame) and Radial maneuver motion (2 of 2)

The last YouTube explains another option and that is Forced Motion where we can hurry along the Chasers path around the Target.

Video 3: Relative Coordinate Frame (RIC), brief natural motion review and FORCED motion circumnavigation

Dragon in final approach to dock with ISS.