Programming Question Asteroid reconfig?

[guitarist473]

well 2nd time lucky on this post... last time my computer crashed when i clicked post and i lost about 20minutes of post... GRRR!

Hello all!

Anyways heres a shortend version... I downloaded A.R.T of orbithangar which is a addon simulating the mission proposal for a rendezvous and tag mission to the NEO Apophis asteroid.

It can be found here: [ame="http://www.orbithangar.com/searchid.php?ID=3470"]www.orbithangar.com/searchid.php?ID=3470[/ame]

I was testing the add on and when i go ahead to the predicted earth inpact date the asteroid does not impact the earth and is infact about 300G away from the earth.

Is it possible to edit the config of the asteroid in a way so it DOES inpact the earth in 13 April, 2036?

I wanted to plan an armageddon styled mission (just for fun) with a DGIV to see if i could nuke the asteroid.

My programming skills are terrable so i was wondering if anyone knows if it can be done and how?

Thanks,

Guitarist473

 

[Izack]

Apophis isn't going to hit the Earth. It is supposed to come within lunar orbit, though. 300Gm is a substantial error.

Adjusting planetary orbits requires no programming skill. Simply find the configuration file (presumably Aphophis.cfg) and change the orbital parameters to your liking. A good way to easily and visually find an orbit that results in Earth impact is to load any scenario in Orbiter and use the editor to put a vessel in a solar orbit similar to Apophis', and then adjust it so that it hits Earth. Then, use its elements in Apophis' configuration file. It's not realistic at all, but then again neither is a mass extinction by a small asteroid passing near us.

 

[guitarist473]

I looked at the apophis config to see what im going to need to mess with... and im a bit confused... mainly with all the numbers :uhh:

What do they all mean, i know it says whet they are but what are the units?

Il need to understand this befor i edit, is it ok to post the text from the config here for an example or would the author not like that?

; === Configuration file for asteroid Apophis ===

Name = Apophis
EllipticOrbit = TRUE
HasElements = TRUE

; === Planetary Mean Orbits ===
;***cfgBatchDataCalculator
Epoch = 2013.19507186858
SemiMajorAxis = 137936169037.34
Eccentricity = .19120244678809
Inclination = 5.81276597297881E-02
LongAscNode = 3.56439387905661
LongPerihelion = 5.77164914156141
MeanLongitude = 9.18172127039956

; === Physical Parameters ===
Mass = 2.1e10
Size =250

; === Rotation Elements ===
SidRotPeriod = 109935
SidRotOffset = 0
Obliquity = 0
LAN = 0

; === Visualisation Parameters ===
MaxPatchResolution = 0

I also had another thought, instead of editing the config etc, why not just launch a DG into space and go chasing after this asteriod, thinking its going to hit earth and blow it up befor a possible impact date without having to edit anything, because even if i fail it wont hit, but just for the simulation il pretend it will if i fail.

How would i go about doing this, i have sort of mastered interplanetary flights to mars, i even made it to saturn once but flying to an asteroid... thats a hole new story.
First off it have barely and gravity, so once i get to the PEA of the asteroid im going to have to burn in retrograde like hell to get anywhere near it, and i tried this, it went wrong! it passed by my DG at about 4000km away travelling faster than i could get the ship to turn to chase, by time i had my ship in the correct position for burning for the chase, apophis was already about 23,000km away.

So if iwas to do this mission with the origional config, how would i do it?

Thanks

Guitarist473

P.s i have found some wiki information on apophis so i can see what to change in the config...

here: [ame="http://en.wikipedia.org/wiki/99942_Apophis"]99942 Apophis - Wikipedia, the free encyclopedia[/ame]

 

[Wishbone]

Use BurnTimeCalc 2.0 to do a velocity matching burn. TransX and/or IMFD are necessary to get as close as possible to the asteroid, minimize the closest approach with small RCS pulses when you're far from the target. And watch the encounter velocity closely - unless you're going to kinetically disrupt the asteroid with your multi-billion craft, it is best kept low, too.

 

[Izack]

OrbiterConfig.pdf has a good description of all of the lines in a planet's configuration file.

I'll go with Wishbone on this; IMFD/TransX will get you there (or rather you will use them to get yourself there.) At the very least, lower your closing velocity long before the last second (PeA.) If you start the burn at periapsis you'll waste Dv catching up to the asteroid again, instead of coming to a relative 'stop' near it. Also, it's generally a good idea to align your craft to an upcoming burn hours or days before doing the manoeuvre.

 

[guitarist473]

Turns out UCGO demolition charges cant destroy celestial bodys, After a 1year flight to apophis in my DGIV i got there, deployed a nuke and got the outta there! befor my ship was caught in the blast. i looked back over my shoulder to see that the asteroid was still there smiling at me as she hurtled through space unnaffected by the nuke. :uhh:

Anyways i got there and managed to plant the bomb but unfortunatly the earth was not saved. mass damage was done when Apophis unexpectedly impacted the earth late 2036, although alot of the population lived.

thank you all for your help!

Im gonna try this again with a bigger amount of explosives later...
[evil laugh] 99942 apophis here i come! [DGIV flies off into the horizon]

Btw: yeah i no it wont hit in real life, this only happend in my story/scenario.

 

[garyw]

UCGO Nukes won't destroy anything and as your Apophis is ruled by the power of the config file. You'll find that you can smack jupiter into it and nothing will happen.

 

[guitarist473]

Well some one could of told me that before i flew 300 gillion miles into space!
hehehe. Just kidding! it was a fun flight and i learned alot from the different way the interplatery phase of the flight had to be executed.

If somehow apophis could be reconfigured as a vessel and not a celestial body... then the UCGO nukes would rip through it! but... I dont no how to pull that off so i guess its back to the drawing board with my scenario.

Thank you all for your posts!

Guitarist473

 

[Izack]

You can probably get away with

ClassName = Apophis
MeshName = Apophis
Mass = 2.7e10

(assuming that the mesh is actually called Apophis.msh.) I'm not how Orbiter will react to a vessel with a mesh and mass that large, though.

 

[Apophis2004nm]

; === Configuration file for asteroid Apophis ===

Name = Apophis
EllipticOrbit = TRUE
HasElements = TRUE

; === Planetary Mean Orbits ===
;***cfgBatchDataCalculator
Epoch = 2329.29270025
SemiMajorAxis = 137937149838.36
Eccentricity = .19120244678809
Inclination = 3.130060043540561
LongAscNode = 3.564393879056611
LongPerihelion = 5.78169914156141
MeanLongitude = 9.18172127039956

; === Physical Parameters ===
Mass = 2.1e10
Size =250

; === Rotation Elements ===
SidRotPeriod = 113910
SidRotOffset = 0
Obliquity = 0
LAN = 0

; === Visualisation Parameters ===
MaxPatchResolution = 0

try this...apophis will pass...about 30.000km...2029.04.13...its no realistic but something...