EtherDragon
Members
Posts
719 
Joined

Last visited
Content Type
Profiles
Forums
Developer Articles
KSP2 Release Notes
Everything posted by EtherDragon

Hey KSP fans! It's newyear's eve and I'm streaming... RIGHT NOW! I'll be streaming until after Midnight PACIFIC TIME, that's about 8 hours from now, as of this post. https://gaming.youtube.com/watch?v=YKAGnVXDU7g&feature=livechatpromo

Hey all! It's been a while since I've done one of these, but I have a Let's Play under way for Season 1.1. This one is "Duna or Bust!" There's a new episode coming out almost every day! Here's a link to the playlist:

Hi! It's SimGamerTV, and I'm going live in just 20 minutes  starting at 10am Pacific time for some Kerbal Space Program 1.1! Our recent missions brought us to the Mun, and even landed on Minmas, it's time to see what we can do next! Thanks, Abraham

Hi all! Today, I will be LIVEStreaming KSP at 3:00pm Pacific time! (As of this post, that's just over an hour away!) Check me out at https://gaming.youtube.com/simgamertv Hope to see you there!

SimGamerTV  Let's Play Season 2: Duna or Bust! (Vanilla)
EtherDragon replied to EtherDragon's topic in KSP Fan Works
Episode 7 brings is another traversal to Duna, orbital entry and we get set to send a lander to the surface of Ike: 
SimGamerTV  Let's Play Season 2: Duna or Bust! (Vanilla)
EtherDragon replied to EtherDragon's topic in KSP Fan Works
It's episode 6  time to setup and make the Burn for another trip to Duna  this time with a manned Ike Lander in tow: Here is the build! 
SimGamerTV  Let's Play Season 2: Duna or Bust! (Vanilla)
EtherDragon replied to EtherDragon's topic in KSP Fan Works
In this extended play, we build our first candidate rover and test it by driving around the KSC and gathering Science! 
SimGamerTV  Let's Play Season 2: Duna or Bust! (Vanilla)
EtherDragon replied to EtherDragon's topic in KSP Fan Works
With our Science! in tow, it's finally time to return home from Duna and reap our rewards: 
SimGamerTV  Let's Play Season 2: Duna or Bust! (Vanilla)
EtherDragon replied to EtherDragon's topic in KSP Fan Works
In Episode 3 we collect a bunch of Science from Orbit around Duna and plan our return trip to Kerbin! 
SimGamerTV  Let's Play Season 2: Duna or Bust! (Vanilla)
EtherDragon replied to EtherDragon's topic in KSP Fan Works
In Episode 2, we reach Duna orbit and begin our Science! 
My space program has reached a point where it's time to start looking at reaching other planets. This video series covers the episodes and bonus features for Season 2: Duna or Bust! Episode 7 brings is another traversal to Duna, orbital entry and we get set to send a lander to the surface of Ike: In Episode 1 we build a Duna capable ship and set our sights to collect Science! and complete contracts from one of Kerbin's closest neighbors:

Now that all your friends are gathered, I would like to tell you why we're really here... You have a problem, and this is an intervention!

A follow up! How did I come up with the equation above? Well  let's start with Kepler's Third Law: r=p2/a3 This defines that the ratio between the Period Squared and the SemiMajor Axis Cubed is always the same for all orbiting objects with the same center of mass. We can use that fact to find out some things: Let's define the orbital period of Kerbin to "1 year" and plug in Kerbin's semimajor of 13.6 millionkm. If we wanted to know how many orbits Duna completed during a single Kerbin orbit, we can set up the following equation: pk2/ak3=pd2/ad3 Where pk is the period of Kerbin's orbit ak is the semimajor axis of Kerbin's orbit pd is the period of Duna's orbit and ad is the semimajor axis of Duna's orbit Since we defined "1" as the Period for Kerbin we get: 12/13.63 = pd2/ad3 Simplify to: 1/13.63 = pd2/ad3 We're looking for the Period of Duna compared to Kerbin  as that's the unknown, but to get there we need to plug in what we do know: Duna's semimajor axis is 20.7 millionkm. Thus: 1/13.63=pd2/20.73 20.73/13.63=pd2 ~3.526=pd2 Ã¢Ë†Å¡~3.526=p p=~1.878 Kerbin Years for each complete orbit of Duna. Now, we can really do the same thing for a Hohmann Transfer since the following equation must be true: ph2/ah3=pt2/at3 Where ph is the period of our full transfer orbit ah is the semimajor axis of the transfer pt is the period of the target orbit, in this case Duna and at is the semimajor axis of the target orbit To get the general form that can be used for any two planets we start by defining our Hohmann Transfer period as "1": 12/ah3 = pt2/at3 Solve for P: at3/ah3 = pt2 Ã¢Ë†Å¡(at3/ah3) = pt So we have how many of our orbits we will complete compared to Duna. Now we need to convert that into Duna orbits. Again, by setting our period to "1" we get this equation as the ratio between our Hohmann orbit and Duna's: rh = 1/pt Now our Hohmann Transfer is not a full orbit, it's a half of one: rt = 1/(2pt) Substituting in the full equation for Pt, above: rh = 1/(2Ã¢Ë†Å¡(at3/ah3)) Fin. Notes: *1  On Earth an AU is defined as the SemiMajor Axis for the Earth around the Sun.

Here it is  the step by step  point by point  bit by detailed bit picture guide to calculating your own Hohmann Transfers. Part 1: What is a Hohmann Transfer? Simply put, a Hohmann Minimal Energy Transfer Orbit, commonly referred to as a Hohmann Transfer, is a special orbit used to transfer from one planetary orbit, like Kerbin, to another planetary orbit, like Duna. This math tutorial will make it dirt simple for you to calculate your own Hohmann Transfers from any planet to any other planet. Have a look at this: The solid lines are the orbits of the planets in question, in this case, Kerbin and Duna. The dashed line is the proposed Hohmann Transfer. Looking at this we see that we're starting at Kerbin at about 3 oclock and we want to meet up with Duna at 9 oclock. The trick is, we need to figure out how much of Duna's orbit will Duna traverse, during the same time our ship is traversing the Hohmann Transfer. Time for some math! Part 2: The Math, Part One  The Big Equation The equation below is derived simply from Kepler's Third Law of Planetary Motion which says, "The square of the orbital period of a planet is directly proportional to the cube of the semimajor axis of its orbit." In mathematical terms: r = p2/a3 where: r is the ratio, which is constant for any system p is the orbital period and a is the semimajor axis This means that for any two planets the following equation must be true: p12/a12=p22/a23 On other words the ratio for Duna's period squared to Duna's semimajor axis cubed, must the the same as the ratio for Kerbin. This is extrapolated to any two orbits, not matter their eccentricity! What this means is that the same ratio holds true for a Hohmann Transfer. Our goal is to solve for the unknown, which is which portion of Duna's Orbit will be completed during our transfer. With that in mind, we do some algebra, to derive the final equation: It looks more complicated than it really is, so don't sweat it too much. At this point, all we need to do is plug in some numbers. Part 3: Gathering the Data We need just two pieces if information to plug into the equations above. First, we need the semimajor axis of our starting point. In this example, we'll use Kerbin at 13.6 millionkm. Second we need the semimajor axis if our destination, which is Duna at 20.7 millionkm. Now, we need to calculate our Hohmann SemiMajor Axis for use in the larger equation. Part 4: The Math Part 2  Hohmann SemiMajor Axis The Hohmann Semi Major Axis is equal to the average of the Apoapsis and Periapsis. In math terms: ah=(ha+hp)/2 So we plug in our numbers: (ha+hp)/2 = (20.7+13.6)/2 = 17.15 That's it! Now we can plug that into the final equation! Part 5: The Math Part 3  The Transfer Solution In the final equation, we have some terms to fill in. ah is what we determined above in Part 4. at is the semimajor axis of the target planet, in this case Duna at 20.7 millionkm. The rest is just plugging in numbers to work through them: at3/ah3 = 20.73/17.153 = ~1.7585 2*Ã¢Ë†Å¡1.7585 = ~2.6521 1/2.6521 = ~0.377 thus rt = ~0.377 Duna will traverse about 37.7% of its orbit during our Hohmann Transfer. Converting that to a clockface basically says that we should depart when Duna is at about 1:30! Now I leave it to you to determine the return trip from Duna back to Kerbin: (I get 70.8% of Kerbin's Orbit, or a departure from Duna when Kerbin is at 5:30 on the clock...) Coming soon  the Video version of this tutorial

SimGamerTV  Let's Play Kerbal Space Program Career Mode
EtherDragon replied to EtherDragon's topic in KSP Fan Works
Here is Part 2 of Episode 20, where I finally land a fully functional base station on the Mun: 
SimGamerTV  Let's Play Kerbal Space Program Career Mode
EtherDragon replied to EtherDragon's topic in KSP Fan Works
It's the finale of the season and this is the first part. We head to the Mun to establish our first permanent base: 
SimGamerTV  Let's Play Kerbal Space Program Career Mode
EtherDragon replied to EtherDragon's topic in KSP Fan Works
In Episode 19, we retrieve some unknown debris from Low Kerbin Orbit: And here's the build: 
SimGamerTV  Let's Play Kerbal Space Program Career Mode
EtherDragon replied to EtherDragon's topic in KSP Fan Works
In episode 18, it's time to mount a rescue to get a stranded crew person from the Mun and retrieve their Science! And, there's a build, too: 
SimGamerTV  Let's Play Kerbal Space Program Career Mode
EtherDragon replied to EtherDragon's topic in KSP Fan Works
In episode 17, our space agency places it's first permanent manned space station in Low Kerbin Orbit: And here's the build: 
Does is possible to asteroid hit Kerbin
EtherDragon replied to Pawelk198604's topic in KSP1 Gameplay Questions and Tutorials
No matter how big or fast an asteroid hits Kerbin the planet will go on without noticing. 
SimGamerTV  Let's Play Kerbal Space Program Career Mode
EtherDragon replied to EtherDragon's topic in KSP Fan Works
Time to try and land on the Mun ... again. Maybe this time we can land AND return AND rescue some stranded Science! 
Jeb, getting up on a Monday  walking to the pad  only to see the Rocket has just blasted off. That might ruin his Monday.

New reentry and parachutes.
EtherDragon replied to MathmoRichard's topic in KSP1 Gameplay Questions and Tutorials
The deceleration curve for parachutes has changed once fully opened. I noticed this in testing some saved craft in Sandbox. Make sure you change your parachutes to open at 1000m AGL instead of 500. 
SimGamerTV  Let's Play Kerbal Space Program Career Mode
EtherDragon replied to EtherDragon's topic in KSP Fan Works
In Episode 15 we make some quick modifications and another attempt at landing on the Mun: