Question DG-IV reentry autopilot...how does it work?

[Pilot7893]

I am used to the XR class vessels with the hold attitide autopilot, so you can set the angle for reentry to arrive at the base. But the DG-IV doesn't have attitude hold, just reentry hold autopilot. In school yesterday, I came up with a crazy concept. You use some unknown tool to let the oboard computer know what base you want to go to, set a deorbit, and the reentry autopilot will automatically reenter you at the right angle to put you right over the base for you. This is a total guess, but is it true?

 

[cr1]

Yes, AutoFCS does that for Shuttle Fleet (but it's not really in the "onboard computers")

I don't think there's anything like that for XR class vessels or the DGIV yet tho...
I usually do reentries with DGIV by trial and error with PRO105SPEC40, so at least I don't burn up.

 

[Cairan]

Actually one could modify the source code from Aerobrake MFD, and add the option to automatically control the angle of attack and conduct S-turns to hit the target base.

 

[Tommy]

The DGIV has two re-entry programs. One (PRO 104 SPEC xx, where xx is the AOA you want to start with) is simply an attitude hold, much like the XR series. AOA and bank can be adjusted inflight in five degree increments using keypad 2 4 6 8. While it isn't as "fine tunable" as the XR series, it will hold up to a 90 degree bank at high AOA, which makes it more usefull for aerodynamic plane changes and high cross-range re-entries.

PRO 105 SPEC 50 is a more automated re-entry. It will adjust the AOA to maintain a 70 to 80 ms descent rate, but won't adjust bank or target a base. Having the correct plane and de-orbit are needed for that to get you on target.