Flight Question Bringing down XR5 Vanguard from orbit

[thumper235]

/RAGEMODE OFF/
/FRUSTRATIONMODE OFF/ (lol)

Ok, I am attempting to bring the XR5 down from orbit. I am attempting to do this free hand and the idea of the scenario is my computer has malfunctioned so I must do the de-orbit/land free hand.


Click retrograde and burn until im roughly 4.500-5.000 in speed.
Click prograde and then turn it off so that I may level my craft out.
As I start to hit the atmosphere I make adjustments to my pitch as to not plunge into the atmosphere dying a burning death.


Could someone throw me a couple parameters to go by? As in how much of a retro burn I need, angle of attack and anything else that might be helpful?

 

[Kaito]

Well, what you could probably do is grab your calculator, a piece of paper, and a pencil...

Odds are, you will know your current altitude (if nothing else, ground control can give it to you). You know your velocity. You know the Earth's diameter. Using some math, you can calculate your orbit (I don't know the equations, but some quick googling can tell you.) Now, start playing around with different speeds and seeing how low they bring you. From my memory, you want to shoot for a PeA of about 60km, but that's very dependent on the orbit.

Manual AoA will be difficult to judge manually. Shoot for 40 degree's pitch, and slowly pitch down as your decrease speed. Good luck, and let us know how it turns out!

 

[Hurricane]

Okay, here are some of my thoughts about reentries:
Aim for a glideslope of -0.7 degrees.
Keep your V/S between -80 and -70 unless you are >VERY< light.
Uhm, don't be hasty!
Make sure to be able to pass by your landing field, which means that you must come close to it by the time you stop flaming.

That's about it.

 

[Jarvitä]

Click retrograde and burn until im roughly 4.500-5.000 in speed.

No, you're just wasting too much dV, and I doubt that steep a re-entry is even survivable in an XR5.

"Eyeballing" a precise re-entry and landing is pretty much impossible.

The rule of thumb is, 1.) sync orbit with your target base, 2.)initiate de-orbit burn on the other side of the planet, 3.) burn until your PeA is around 30 km, 4.) maintain a 40 degree AoA. Results will vary wildly, but this should bring you to within a 1000 kilometres of your target. You can forget about an unpowered landing this way, but you just might have enough scram/main engine fuel to make it back and land.

 

[thumper235]

Wow,

I cant show enough appreciation for ALL the replies I got here. Thank you! Ok, Instead of fouling up my post with my inability to quote people, I will just reply taking bits and pieces from all posts.

@kaito In a perfect world that would be what I would need to do good sir. That I can accomplish, but my goal is to see if I can do it without such means. The scenario is one where it is not allowed. The goal mainly is just to safely re-enter earths atmosphere, landing at KSC is a bonus. But you point is definitely taken. Sometimes (for me atleast) its fun just to sit back accept a challenge and mindlessly play. You know what I mean?


@jarvita THANK YOU. This is exactly what I was looking for.

@Hurricane THANK YOU as well.

I know some of you probably read this and think I am a fool. Perhaps I am, or perhaps its just one way I like to challange and entertain myself. This really is a challenge, and I have been told the craft im using is one of the hardest to do it with.


EDIT: I did it!!!! I also had barely enough fuel to land at KSC! SCORE!