PriestLizard
Member
Hi all,
I'm using the Space Transportation System 2016 add-on, together with Glideslope 2.7 and BaseSync, and I'm having trouble understanding why my velocity after EI is not going down. This is the procedure:
At around EI, I engage the autopilot in Glideslope to hold the reference AoA.
Starting EI, I control the bank angle to maintain a VSp roughly around reference value to ensure a descend rate that's according to Glideslope. I also use https://www.orbiterwiki.org/wiki/Intuitive_Atmospheric_Entry as a reference for rough bank angles but I suppose its to be expected that the actual bank angle needs to be different as the aerodynamics are not 100% accurate.
And this is where things really go astray.
Again - after EI, at altitudes around 120km to about 60km, I control the bank angles manually to maintain an appropriate descent rate along the glideslope, while the AUT autopilot maintains a 40deg AoA. But the problem is - I'm just not slowing down.
See attached image. I'm at an altitude of 70km, a bit over glideslope, and I'm not slowing down at all. Still flying at 7.5k TAS, and as per Glideslope reference, I should be down to 6k by now. This then of course messes up the rest of the reentry quite severely. I managed to land pretty close to runways a few times, but its usually a very awkward scramble as I'm totally overshooting the target.
I tried multiple things already:
I was thinking that maybe it is related to the Shuttle model in STS2016, but I tried de-orbiting with the default DG and I had similar results (even though I didn't go through that amount of extensive testing).
So - how can I slow down in the upper atmosphere at around 100km? Based on the reference data in Glideslope, I'm supposed to slow down right around the EI, and I can never make it happen.
Thanks in advance for any pointers,
Cheers
I'm using the Space Transportation System 2016 add-on, together with Glideslope 2.7 and BaseSync, and I'm having trouble understanding why my velocity after EI is not going down. This is the procedure:
- Undock from MIR, at roughly 400x400 orbit.
- Use Glideslope to select Cape Canaveral (tried other bases too) with appropriate runway, also make sure that the selected ship is "Space Shuttle" in the Glideslope config.
- Sync BaseSync with Glideslope and find closest orbit to target.
- Auto burn in Glideslope based on BaseSync's closest passage, EI angle roughly 0.7-0.8.
- Auto burn happens, and coast to EI.
At around EI, I engage the autopilot in Glideslope to hold the reference AoA.
Starting EI, I control the bank angle to maintain a VSp roughly around reference value to ensure a descend rate that's according to Glideslope. I also use https://www.orbiterwiki.org/wiki/Intuitive_Atmospheric_Entry as a reference for rough bank angles but I suppose its to be expected that the actual bank angle needs to be different as the aerodynamics are not 100% accurate.
And this is where things really go astray.
Again - after EI, at altitudes around 120km to about 60km, I control the bank angles manually to maintain an appropriate descent rate along the glideslope, while the AUT autopilot maintains a 40deg AoA. But the problem is - I'm just not slowing down.
See attached image. I'm at an altitude of 70km, a bit over glideslope, and I'm not slowing down at all. Still flying at 7.5k TAS, and as per Glideslope reference, I should be down to 6k by now. This then of course messes up the rest of the reentry quite severely. I managed to land pretty close to runways a few times, but its usually a very awkward scramble as I'm totally overshooting the target.
I tried multiple things already:
- Tried de-orbiting from different orbit altitudes (not sure if BaseSync/GS are assuming a MIR/ISS orbit altitude).
- Tried different perigee of the orbit. The default burn from GS/BaseSync seems to lower the perigee to around 80km, but tried to lower it further to 40km as well. Same result.
- Tried banking less, which would mess up the descent speed, and still doesn't slow me down.
- Tried lowering propellant/mass during re-entry, no change.
I was thinking that maybe it is related to the Shuttle model in STS2016, but I tried de-orbiting with the default DG and I had similar results (even though I didn't go through that amount of extensive testing).
So - how can I slow down in the upper atmosphere at around 100km? Based on the reference data in Glideslope, I'm supposed to slow down right around the EI, and I can never make it happen.
Thanks in advance for any pointers,
Cheers
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