Deorbiting accuratly

[AtlantisOnline]

Hey guys
I am realatively new to orbiter but have got some of the basics down...acheieving orbit, deploying HST, ect. The one thing I cant do is deorbit accuratly. I know how to deorbit into earths atmosphere but try as I might I can not come out of orbit near cape canaveral or any where else to land besides ocean on blank areas of greenery. I would appreciate an answer telling me a mfd, autopilot or just how to do it. The main shuttles I use are the delta glider that comes with orbiter and space shuttle atlantis.

 

[Hmuda]

Welcome to the forum!

There is a Recommended Addons link at the to top of the forum. There you can find Aerobreak MFD and BaseSync MFD. Using those two together you can pretty much land wherever you like more accurately than you hope to be able to now.

Also, under Orbiter Tutorials, you can find Oceanic's wonderful DG-IV re-entry tutorial with video and detailed description. That helped me tremendously, and works not just for the DGIV.

 

[insanity]

A fairly simple rule of thumb is that you start a deorbit burn on the oppisite side of the world from where you want to land. Aerobrake and Basesync will help you drill it down to the runway. Remember that Aerobrake will give trajectories modified by the atmosphere at 200km. I always do a deorbit burn and when I drop below 200km I make small adjustments to clean it up for the AoA I'm using.

 

[AtlantisOnline]

Thanks Guys I will try that by any chance is there a tuturial on how to use those 2 mfd's

 

[agentgonzo]

I'd highly recommend trying to do some accurate landings with the DGIV or DG or XR2 before trying to do it with the space shuttle (if that was your intent) as they are a lot more forgiving until you get the hang of it. There is a tutorials section on this forum (under FAQ I think). There may be a tutorial on using the MFDs in there.

 

[Tommy]

There's quite a bit of instruction on those two MFD's in these threads:

http://orbiter-forum.com/showthread.php?t=5900&highlight=basesync

http://orbiter-forum.com/showthread.php?t=10153&highlight=aerobrakemfd

http://orbiter-forum.com/showthread.php?t=10043&highlight=aerobrakemfd

 

[AtlantisOnline]

Thanks guys so much this is the most helpful forum I have ever been on. If you have any other ideas feel free to post them buy I will try to get the techniques you mentioned down....Thanks

---------- Post added at 10:26 AM ---------- Previous post was at 08:56 AM ----------

Thanks guys so much this is the most helpful forum I have ever been on. If you have any other ideas feel free to post them buy I will try to get the techniques you mentioned down....Thanks

Also when i deorbit I can not picth up or down thanks

 

[Oceanic]

welcome,
what ship are you using?

if you are using the DG-IV you have to know that the ship is not intended for a manual reentry, however it is possible and not that hard if you had some training but you need to trick the DG-IV a bit to use the elevons and the RCS at the same time. you need to select "elevon and gear" and switch to the glas-cockpit (F8) and click on RCS after that go back to the 2d-panel view (again F8)

 

[AtlantisOnline]

welcome,
what ship are you using?

if you are using the DG-IV you have to know that the ship is not intended for a manual reentry, however it is possible and not that hard if you had some training but you need to trick the DG-IV a bit to use the elevons and the RCS at the same time. you need to select "elevon and gear" and switch to the glas-cockpit (F8) and click on RCS after that go back to the 2d-panel view (again F8)

I figured out that problem but know I have a new one... How do I use the transfer MFD I know there is a turorial for it which I will use if you recomend but your answers are easier to understand than orbiters thank you

 

[Oceanic]

what do you want to do with the transfer MFD? transfer to a station or the moon?

or is it a typo?

have to admit only used it a few times to fly to the moon, so i not sure if i can help you there.

 

[AtlantisOnline]

its to go to the moon using the delta glider also as for deorbiting accuratley how do I get an orbit path over the station I want to aligian at (cape canaveral) I know how to use the base sync but that uses lots of fuel if you aren't very close to the station on your orbit path thanks

 

[Tommy]

as for deorbiting accuratley how do I get an orbit path over the station I want to aligian at (cape canaveral) I know how to use the base sync but that uses lots of fuel if you aren't very close to the station on your orbit path

You can wait for a closer pass, otherwise just lower the AoA a bit and use bank angles in the direction you need to regulate your descent. You can easily get over 1M crossrange in any of the gliders.

 

[AtlantisOnline]

I keep hearing AoA (I know what it stands for Angle of Attack (the Differece between (at least in aircraft) the gun cross and the nose)) How do I change the AoA thanks

 

[insanity]

its to go to the moon using the delta glider also as for deorbiting accuratley how do I get an orbit path over the station I want to aligian at (cape canaveral) I know how to use the base sync but that uses lots of fuel if you aren't very close to the station on your orbit path thanks

On BaseSync, switch to direct mode with E/D. Closest Approach is the orbit in white. When you get close to one of the gray lines, burn the opposite direction (If BastSync says "+" burn "-" as you approach the gray line). Burn until closest approach is to you liking (heading, distance, etc..). Circularize the orbit, and then refine closest approach. Time accelerate until closest approach is on current orbit, then begin deorbit burn using the techniques described above.

AoA is the position of the airfoil relative to the vector its moving in. To change it simply pitch up or down.

 

[Tommy]

With a standard DG just pull back on the stick to rotate nose up to around 40 degrees, and use the AoA hold on AerobrakeMFD to hold that angle. With the DGIV or XR series, use their built-in attitude hold autopilots.

AoA (angle of attack) is the difference between the ships forward axis and the direction of travel (which is indicated by the Prograde Velocity indicator, or "gun cross")

If you are in the stock DG, I'd recommend getting "Delta Tweak" (at Orbit Hanger) which will adjust the DG's aerodynamics to allow a more realistic high AoA re-entry than the stock version.

As for Transfer - I'm at work so don't have any references and I've long ago "graduated" up to more complex and capable tools like IMFD and TransX, but here goes from memory -

Align planes with the Moon using AlignPlanesMFD. In TransferMFD, select target as Moon. Src (or source) should be self (I think) and the reference should be Earth. Add hypothetical Dv in a prograde direction until your orbit will reach the Moons orbit, then adjust the TEj until you are arriving at the Moon when it gets there. Guesstimate your burn time (or use BurnTimeCalcMFD) and start the burn 1/2 of that before TEj = 0.

 

[AtlantisOnline]

Thanks Guys

 

[george7378]

I would recommend you use AutoFCS for Shuttles:

http://www.rmnorman.com/Orbiter/AutoFCS2.zip

It makes for very accurate shuttle re-entries, while retaining a good amount of realism. This is an autopilot which flies you from de-orbit to final touchdown and wheel stop. Re-entries are automated in real life too, but it is always nice to take over and land yourself.