Flight Question SpX-Dm1 (Demo-1 Falcon 9)

[BobSpiders]

Hi,

as I have been trying lately several times to lift off with the Atlantis and dock to the ISS, I was interested to see the parameters of the recent SpX-Dm1 NASA mission (the SpaceX Falcon 9 that lifted off early this morning from Cape Canaveral). I was expecting, as in my simulations, that lift off happened when the ISS was near the launch site, but looking up (www.satflare.com) it seems that the ISS at that time was orbiting over the Middle East!

Also, from the NASA video feed, it seems that after SECO (secondary engine cut-off) altitute was about 200km, and not 350-400 km, so quite far from the ISS orbit altitude.

I know that NASA is right and I am wrong, of course , but can someone explain me how this mission profile works? I tried to find more data on the Internet but so far no luck. Will the ship use its own engines to raise its orbit from 200km to 400k (it seems a lot ...)? And how has the launch window been determined compared to the ISS position?

Thanks,
Roberto

 

[Donamy]

Look up, orbital plane.

 

[BobSpiders]

Thanks, not very useful ...

I know about the orbital plane, and if you launch with the correct azimuth you end up on the same orbital plane as your target. However, all the tutorials I've seen recommend to launch when the ISS is near the launch site so that, once in orbit, the distance will be small - are the tutorials just over-simplifying everything just to make things easier? Are they plainly wrong? Or is NASA just preferring some other type of orbit maneuver to approach the ISS (I don't know, high elliptic orbits?)?
And what about the orbit altitude?

 

[Donamy]

The orbital plane has to be over the launch site, not the ISS. The Dragon2 is placed in a lower orbit altitude, so it will travel faster, to catch up with the ISS, then raise it's orbit and slow its speed, with its engines to rendezvous.

 

[BobSpiders]

Thanks Donamy, now I understand what you mean.

How can I see on Orbiter when a specific orbital plane (i.e., the ISS one) is passing through my launch site? Is it in the MAP function of the MFD with the display parameter set to "orbit"?

 

[Donamy]

Yes. While in the mapMFD, set the display mode to Orbit Plane. Or Load the Align Plane MFD and it will tell you when to launch.

 

[boogabooga]

Thanks Donamy, now I understand what you mean.

How can I see on Orbiter when a specific orbital plane (i.e., the ISS one) is passing through my launch site? Is it in the MAP function of the MFD with the display parameter set to "orbit"?

Get Launch MFD...