Scenario Mars Orbit Exercise

[blixel]

Greetings everyone. I recently spent quite a bit of time attempting dgatsoulis' Martian moons tour challenge. After several tries, I succeeded! While refining my efforts for that challenge, I found that I was wasting 200+ m/s just taking off and getting into orbit around Mars.

That revelation gave me an idea. I set up a basic scenario so that I could try various fuel saving ideas for getting into orbit around Mars. I thought it would be fun to share this scenario with the members of this group.

Note that I do not consider this a challenge; I consider this an exercise. The objective of this exercise is very simple. Take off from Olympus and get your vessel into an orbit that has a minimum ApA/PeA of 200km.

This exercise is easy enough for everyone to try, even the absolute Beginner, but the exercise has a fuel budget that is so tight that even Advanced/Expert Orbinauts may be surprised to find themselves unable to complete the exercise on their first try.

A big thanks to dgatsoulis for his Martian moons tour challenge which gave me the idea to set up this scenario, and another big thanks to dgatsoulis for writing the lua script to accompany the scenario.

Good luck and be sure to post a screenshot of your most successful effort.

P.S. All the usual rules apply. Do not use the scenario editor to add fuel to the vessel, and do not remove the CHM from the XR2 or drain any of the LOX/APU fuel.

I'll start the score keeping with my own attempts:

-----------------------------------------------------------------SCOREBOARD----------------------------------------------------------

Top |

DeltaGlider​

| Pilots

#​

|

Name​

|

DeltaV​

#1 |

downloaderfan​

|

3653.5​

#2 |

dgatsoulis​

|

3660.3​

#3 |

blixel​

|

3666.7​

#4 |

Max Pain​

|

3668.9​

#5 |

​

|

​

|

Top |

XR2 Ravenstar​

| Pilots

#​

|

Name​

|

DeltaV​

#1 |

downloaderfan​

|

3620.3​

#2 |

vsfx​

|

3622.0​

#3 |

Max Pain​

|

3625.5​

#4 |

blixel​

|

3637.5​

#5 |

​

|

​

 

[downloaderfan]

Greetings,David
Pretty fun challenge,dv is pretty tight,took me a few tries to perform successfully.

http://s1350.photobucket.com/user/downloaderfan/media/Image4_zps2fa7967f.png.html
http://s1350.photobucket.com/user/downloaderfan/media/Image3_zps7374bca9.png.html

BTW,i watched all of ur videos to learn orbiter,without those videos,i wouldn't have been an orbinaut AT ALL!!!!!!.

Thanking you for all ur efforts with my deepest heart,cheers buddy

 

[blixel]

Greetings,David
Pretty fun challenge,dv is pretty tight,took me a few tries to perform successfully.

Nice job! I updated the scores.

BTW,i watched all of ur videos to learn orbiter,without those videos,i wouldn't have been an orbinaut AT ALL!!!!!!

Thanks for the encouraging feedback. It's always great to hear that my videos are helping people.

 

[vsfx]

Just tried this a dozen times, it's NOT easy, at least for me... Best attempt so far is a 200 x 50 km orbit :facepalm:

 

[Max Pain]

Thx for this nice challenge blixel (and dgatsoulis for the script) :thumbup:. It's short and perfect for practising purposes.

It took me 3 tries until I completed it. I know it's not the best score, maybe I will try again later.

 

[dgatsoulis]

Here is my DeltaGlider score. I hope I'll get the chance to improve it over the weekend.

Thanks again for this nice exercise blixel. :tiphat:

 

[blixel]

Here is my DeltaGlider score. I hope I'll get the chance to improve it over the weekend.

Thanks for all your help with the lua coding for this exercise.

It will be interesting to see just how far someone can push the vessel to squeeze out every drop of efficiency. I have in the back of my mind that I want to get to a 200x200 orbit and still have enough fuel left to deorbit and land back at Olympus (within 50km or so) in 1 orbit. I'm not sure if it's possible. The best I've done so far was to bring my PeA down to about 100km after completing the 200x200 requirement.

 

[downloaderfan]

Did a few with the standard delta glider.I never really used DG ever for any atmospheric flights so the first few attempts had me discovering things about the DG and some other,trying to control the DG attitude,I'm still quite terrible in controlling the attitude of the DG as i want.Anyway here's my best out of all those:

http://s1350.photobucket.com/user/downloaderfan/media/Image1_zps60d3a0f2.png.html
http://s1350.photobucket.com/user/downloaderfan/media/Image2_zps6ceca388.png.html

 

[blixel]

Did a few with the standard delta glider.I never really used DG ever for any atmospheric flights so the first few attempts had me discovering things about the DG and some other,trying to control the DG attitude,I'm still quite terrible in controlling the attitude of the DG as i want.Anyway here's my best out of all those:

Nice job! New high score. I updated the score table.

 

[downloaderfan]

Just one question,why would the DG take more fuel than the ravenstar?

 

[blixel]

Just one question,why would the DG take more fuel than the ravenstar?

I'm just guessing here, so someone who knows more about this than me will have to give a more qualified answer, but it appears to have to do with the Lift to Drag ratio. You will notice when the standard Delta-glider is flying up through the atmosphere, its AoA is negative. Whereas when the XR2 is flying up through the atmosphere, it has a positive AoA. So the aerodynamics are more favorable for the Ravenstar, providing more "free" lift, which means it uses less fuel.

If I'm an idiot babbling nonsense here, then someone will have to correct me.

 

[dgatsoulis]

After MANY tries, I got the score of the DG down to 3660.3

 

[blixel]

After MANY tries, I got the score of the DG down to 3660.3

Wow - that is awesome! I believe that leaves enough fuel to bring your PeA down enough so you could land in 1 orbit.

 

[dgatsoulis]

I didn't try it on that flight, because I used the orbit circulization program from IMFD and the message popped up as soon as the PeA reached 200km. (ApA was 207.4). The AP kept burning after the congrats message, so I couldn't test if I could drop back to Mars.

On a previous attempt with a 3662.6 score, I was able to get the PeA back down to 62 km, but my ApA was slightly higher (209.3)

 

[blixel]

Gave this another go myself. Set a new best score for myself, beating my old best by 6 m/s.

I ran my RCS out afterwards to see how low I could get my PeA. It's definitely low enough to land in 1 orbit.

It won't be long before the battle for top score is decided by 0.x m/s

 

[vsfx]

Finally nailed this. Just need to improve the score now.

 

[Max Pain]

I just throw in a XR2 score for me. Don't know why it is so much better than my DG score (was my first try with the XR2). I should try to improve my DG score as well.



---Edit---

Just improved my Deltaglider score:

 

[downloaderfan]

Got this score with the DG that day while i was testing hover MFD.The funny thing is that it used hover engines during my initial pitch ascent but then gave me a very good control of the DG.

http://s1350.photobucket.com/user/downloaderfan/media/Image3_zpsaef72dfd.png.html

And improved my ravenstar score:

http://s1350.photobucket.com/user/downloaderfan/media/Image3_zpsd05c41ce.png.html
http://s1350.photobucket.com/user/downloaderfan/media/Image2_zpsb3d842fc.png.html

---------- Post added at 01:05 PM ---------- Previous post was at 12:58 PM ----------

I'm just guessing here, so someone who knows more about this than me will have to give a more qualified answer, but it appears to have to do with the Lift to Drag ratio. You will notice when the standard Delta-glider is flying up through the atmosphere, its AoA is negative. Whereas when the XR2 is flying up through the atmosphere, it has a positive AoA. So the aerodynamics are more favorable for the Ravenstar, providing more "free" lift, which means it uses less fuel.

If I'm an idiot babbling nonsense here, then someone will have to correct me.

hmmm,i always thought that the AOA was the angle u made with the velocity vector,if ur angle is below the velocity vector,u have a -ve AOA,or else +ve.
I think we can control it during our flight.

BTW,sorry for the late reply,i know people in this forum reply very quickly,but i get to access the internet only twice a week,so i cant come here any time i want. Plz understand my situation.

---------- Post added at 04:35 PM ---------- Previous post was at 01:05 PM ----------

Improved my DG score yet again.

http://s1350.photobucket.com/user/downloaderfan/media/Image2_zpse36e3147.png.html
http://s1350.photobucket.com/user/downloaderfan/media/Image1_zps50b8be2a.png.html

was able to get my PeA low for re-entry
http://s1350.photobucket.com/user/downloaderfan/media/Image3_zpsed7ca268.png.html

 

[blixel]

Improved my DG score yet again.

New top score! Congratulations.

 

[Ripley]

...hmmm,i always thought that the AOA was the angle u made with the velocity vector,if ur angle is below the velocity vector,u have a -ve AOA,or else +ve...