Well, here's something that I don't think most of you have done:
A full reentry: from deorbit, through EI, to constant drag to the HAC and a perfect landing.
There's a catch to it however: all unpowered (except the deorbit burn of course!) and WITHOUT ADDON MFDS >>AT ALL!<<
Have you ever done that? Well I don't wanna be rude, but I don't think you have (;
Never have I used external MFDs, especially for reentries for 2 reasons:
1) I dislike them because I'm too lazy to learn them
2) I thought that if I could make a safe reentry without advanced aids, I could do even more precise and safer reentries with such aids.
Reason no. 2 is the bigger rationale as to why I didn't use any addon MFDs. But again, now that I know how to properly establish a deorbit location and get to my landing site without too much hassle, I think that I understand the physics of reentry enough.
Also I didn't want to use addon MFDs until now because I thought it was better to learn the physics of reentry by hand. That's me! :lol:
It's time to move on: to BaseSync and aerobrake. :tiphat:
I used the DGIV scenario 'Docked to ISS', undocked and waited for two ingame days. Luckily enough, after 2 days there appears to be an orbital groundtrack that goes within 100 km from KSC - enough to deorbit and establish a reentry. I waited until I was about 18.25 thousand kilometers from KSC and went ahead for a reentry at an angle of 0.9 degrees. Descent into the atmosphere went smoothly as I was making final preparations for the reentry: 19 tons, ATM auto, all hatches secured, etc etc with EI occuring at about 122 km, a standard altitude: the V/S began to rise and I put the DGIV on a 80* bank to make sure that the trajectory goes over KSC.
As the business began to warm up, I slowly decreased the bank angle to maintain a reasonable V/S of between -90 and -65 m/s. The rest of the reentry went smoothly: making some course adjustments and checking my overall progress every once in a while.
It was above the west coast of Florida when I realized that I'm in a problem (or so I thought!!). I was about 160 km away from KSC, decelerating through 2 km/s at a deceleration of more than 2 g. You can see where this is going: I'm gonna come short, by a few kilometers.
Immediately I took over the controls, disabling the autopilot and pitching down into a feathered configuration, where the nose faces the airstream and the drag is at its lowest.
I managed the rest of the hypersonic glide to KSC pretty nicely, but when I was almost over the SLF, I realized that I was going too fast!!
facepalm::facepalm::facepalm. So I cranked up the airbrakes and let the DGIV go over and away from the landing site, initiating a HAC about 7 km after the base. The HAC was perfect, aside from the fact that it was a 3 g pull. (Again: :facepalm.
After that I was perfectly aligned with KSC SLF runway 15's centerline and at a neutral glidpath of -25*, ready for a classical IFR landing.
I made a perfect preflare, and pushed forward to the IGS. I wanted to pull the gear down at 30m AGL, just like the space shuttle but the annoying GPWS warning scared the hell out of me so I decided to lower it at 50m AGL.
A gentle, -1 m/s touchdown soon followed, with a mixed relief of mine:
-Phew, I made it down alive!
And:
-HOW COME THAT I NEVER FIND THE WHEELBRAKES ON THAT THING! :facts::compbash:
I used the retro thrusters to slow down and disengaged them at 40 m/s.
Wheelstop.
"Congratulations on return to assembly".
And that is, the story of the first [fully] successful reentry of mine, as well as a few lessons:
1) Again, I'm ready for BS and AB MFD! YAY!
2) I recommend a deorbit burn at 18.2 thousand kilometers away, which will bring you to a -0.8* reentry trajectory.
3) Always be ready for the unexpected! You may think that you are undershooting, while, as a matter of fact, you are OVERSHOOTING, much like I did! If you want to, keep an eye on the mini-HUD's range output, but bear in mind that it only is accurate if you are neither decelerating nor accelerating.
4) Make sure to keep SOME (not too much!) excess energy, you may never know if you will need it later on. That's why the STS did (subsonic!) HACs.
~Oz out!
P.S. Stay tuned on some news about the Arrowhead! :tiphat:
A full reentry: from deorbit, through EI, to constant drag to the HAC and a perfect landing.
There's a catch to it however: all unpowered (except the deorbit burn of course!) and WITHOUT ADDON MFDS >>AT ALL!<<
Have you ever done that? Well I don't wanna be rude, but I don't think you have (;
Never have I used external MFDs, especially for reentries for 2 reasons:
1) I dislike them because I'm too lazy to learn them
2) I thought that if I could make a safe reentry without advanced aids, I could do even more precise and safer reentries with such aids.
Reason no. 2 is the bigger rationale as to why I didn't use any addon MFDs. But again, now that I know how to properly establish a deorbit location and get to my landing site without too much hassle, I think that I understand the physics of reentry enough.
Also I didn't want to use addon MFDs until now because I thought it was better to learn the physics of reentry by hand. That's me! :lol:
It's time to move on: to BaseSync and aerobrake. :tiphat:
I used the DGIV scenario 'Docked to ISS', undocked and waited for two ingame days. Luckily enough, after 2 days there appears to be an orbital groundtrack that goes within 100 km from KSC - enough to deorbit and establish a reentry. I waited until I was about 18.25 thousand kilometers from KSC and went ahead for a reentry at an angle of 0.9 degrees. Descent into the atmosphere went smoothly as I was making final preparations for the reentry: 19 tons, ATM auto, all hatches secured, etc etc with EI occuring at about 122 km, a standard altitude: the V/S began to rise and I put the DGIV on a 80* bank to make sure that the trajectory goes over KSC.
As the business began to warm up, I slowly decreased the bank angle to maintain a reasonable V/S of between -90 and -65 m/s. The rest of the reentry went smoothly: making some course adjustments and checking my overall progress every once in a while.
It was above the west coast of Florida when I realized that I'm in a problem (or so I thought!!). I was about 160 km away from KSC, decelerating through 2 km/s at a deceleration of more than 2 g. You can see where this is going: I'm gonna come short, by a few kilometers.
Immediately I took over the controls, disabling the autopilot and pitching down into a feathered configuration, where the nose faces the airstream and the drag is at its lowest.
I managed the rest of the hypersonic glide to KSC pretty nicely, but when I was almost over the SLF, I realized that I was going too fast!!
facepalm::facepalm::facepalm. So I cranked up the airbrakes and let the DGIV go over and away from the landing site, initiating a HAC about 7 km after the base. The HAC was perfect, aside from the fact that it was a 3 g pull. (Again: :facepalm.After that I was perfectly aligned with KSC SLF runway 15's centerline and at a neutral glidpath of -25*, ready for a classical IFR landing.
I made a perfect preflare, and pushed forward to the IGS. I wanted to pull the gear down at 30m AGL, just like the space shuttle but the annoying GPWS warning scared the hell out of me so I decided to lower it at 50m AGL.
A gentle, -1 m/s touchdown soon followed, with a mixed relief of mine:
-Phew, I made it down alive!
And:
-HOW COME THAT I NEVER FIND THE WHEELBRAKES ON THAT THING! :facts::compbash:
I used the retro thrusters to slow down and disengaged them at 40 m/s.
Wheelstop.
"Congratulations on return to assembly".
And that is, the story of the first [fully] successful reentry of mine, as well as a few lessons:
1) Again, I'm ready for BS and AB MFD! YAY!
2) I recommend a deorbit burn at 18.2 thousand kilometers away, which will bring you to a -0.8* reentry trajectory.
3) Always be ready for the unexpected! You may think that you are undershooting, while, as a matter of fact, you are OVERSHOOTING, much like I did! If you want to, keep an eye on the mini-HUD's range output, but bear in mind that it only is accurate if you are neither decelerating nor accelerating.
4) Make sure to keep SOME (not too much!) excess energy, you may never know if you will need it later on. That's why the STS did (subsonic!) HACs.
~Oz out!
P.S. Stay tuned on some news about the Arrowhead! :tiphat:
