Map the Debris formula video

Hey guys.

So I’ve been working on this for the past few days, but not with coding… just with figuring out the formulas to use!

My math isn’t very good (I’m 34, haven’t touched math in ages) but being able to figure out more advanced math is pretty cool.

For anyone trying to learn the formulas for how to calculate orbital velocity and periods, I recommend watching this video:

The professor really breaks it down over the period of 10 minutes. Watch it a couple times, break out the calculator and follow along, and you’ll learn it pretty quickly.

Now I gotta program it all in!


This is good info, I just did not see him add the hight of the satellite in the last equation.

@Torgian, I wrote a blog post on Map the Debris a couple months ago, though it covers more of the javascript side than the math side… (don’t worry, I give a warning before I post my solution) Thought maybe it could help.

I know this is a month old now, but I’m in the same boat with you @Torgian. It’s been a long time since I really worked with Math (except some Khan Academy here and there). Being exposed to all of this Pre-Calc in the Advanced Algorithms has been extremely fun, and I have found taking the approach towards coding the formulas first to be extremely helpful in the process.

To go with that awesome video you linked, here’s the first formula in JS:

var velocity = Math.sqrt((6.67 * Math.pow(10, -11)) * (5.98 * Math.pow(10, 24)) / 6378000);

@jer244 I will definitely check out the blog post! I want to try my best to tackle it solo first, but I’m more than sure the article will contribute not matter what happens. Thanks!

Nice! Yeah, I’ve been busy with doing the front-end projects now and learning about timing functions in Javascript. Thanks for your function!

Since that project I’ve been looking into learning more math and relearning a lot of stuff up to Calculus. I never was good at math, but coding has opened up some new avenues of interest in Mathematics.

I just wanted to mention that this made me laugh just a little. I’m 44 and I’m pretty sure I’ve never used math like this. For me, trying to figure out more advanced math is like torture, and actually being able to do it seems to be beyond my capability.

The Wikipedia article linked in the challenge made almost no sense to me and the video made even less sense. I noticed that the presenter said “of course” a lot. So, I guess that his intended audience was already familiar with the material.

I finally finished the challenge after posting my own thread in frustration and confusion. I couldn’t see how we had all the necessary information for the formula until someone explained it to me. After that, the actual code posed no problem for me at all.



@VAggrippino Congrats! It’s great to hear you at least finished it! :smiley:

You are absolutely right! It all seemed like “assumed knowledge” without being mentioned. Not only that with this specific problem, some of the variables were not entirely clear, and did not match up with the wikipedia page and video. I had to hit a few other resources to double check variables, and other formulas to make sure I was getting the right idea.

Good thing for the forum though.

I’m an engineer and the problem is making me angry. sputnik average altitude is 35873.5553.

35873 what? feet? Miles? kilometers? inches? this is silly. I shouldn’t have to do more research just to find what mysterious units of measure are being used.

I know from googling sputnik’s altitude was 529 miles. But I cant find any reasonable unit of measure that converts 529 miles to 35, 873 of anything…


I know how you feel, I felt the same way.

Honestly, don’t worry about units of measurements. Just take the number as it is. Use that in your mathematical formula.

Don’t over think it. Just take the number and plug it into the right formula. Don’t convert it into a different measurement or number.