General Question XR2 Reentry Request - Orbiter-Forum

Samuel Edwards · 05-26-2012, 03:02 PM

Hello: tiphat:

Before I get into my request I want to make this clear. YES, I have searched the forums and read previous threads on this subject.

None of which helped me in my goal to finally deorbit and land my XR2 back on Earth. I know that many of you will just link me to previous threads, but like I already stated, the thread you give me a link to, probably didn't help me when I read it.

As for my request...I was hoping that someone could post, down below, the steps that they personally take to deorbit the 'XR2', both using BasesyncMFD and AerobrakeMFD, and by just using stock Orbiter MFDs.
I don't mean to be a bother at all; I just want be able to successfully get my crew back home, and to perfect my reentry skills .

Thanks,

SE

**Cras** · 05-26-2012, 03:22 PM

I use DVTools, and a BaseSync deorbit settings of 1.2 degrees, 90 degree anticipation, 80km atmo, for a normal re-entyr, or just switch anticipation to 70 degees for a steeper one (like if I am low on APU for some reason)

DVTools has a great tutorial walking you through the steps with pictures and everything. To use DVTools, you need BaseSync, Aerobrake, and IMFD.

Spacethingy · 05-26-2012, 04:55 PM

| BasesyncMFD to get in an orbit that passes over my base in daytime (using clockMFD).

| Basesync to know roughly when I'm opposite my base (ie. 180deg away).

| OrbitMFD to then burn to roughly 70ish km up minimum altitude (Pe or Ap? I can't remember...

| Wait till I'm at altitude of 100km, pull in radiator, nosecone etc.

| Point forwards, use XR2's attitude autopilot, initially at 45degs pitch/AOA (I don't know what the difference is...)

| Use Aerobrake to monitor where my glideslope will take me. You get to the useful map page by pressing pg and proj if i remember correctly...

| Gently adjust XR2's attitude AP to keep landing point within 100km of the base, pull up to correct overshoot, pitch down to correct undershoot. Keep vertical speed below 100 m/s at all costs or you'll die a nasty death. There's a funny bit in the middle of reentry when for about a minute you start going back up again slowly, I guess that's at the lowest part of the orbit. Hold on, you start going down again.

| If I'm too late (i.e. serious overshoot is on the cards) a bit of banking from left to right helps bleed off excess energy.

| By 15-25 km altitude you'll probably be slow enough to fly normally down to the base. With my terrible skills, I now probably have to use the scram engines to make it as I'm probably completely in the wrong place...

I can't remember MFD buttons awfully well and I've just pulped my Orbiter install due to a suddenly rather full HDD, so sorry about lack of help there...

Samuel Edwards · 05-26-2012, 06:02 PM

Well, can someone explain why I just bounce back into space after raising the AOA to 40*?

I'm confused with that part.

Jarvitä · 05-26-2012, 06:09 PM

Quote:

Originally Posted by Samuel Edwards

Well, can someone explain why I just bounce back into space after raising the AOA to 40*?

I'm confused with that part.

If you're still bounding off at 40 deg AoA, your re-entry angle is probably too shallow. Deorbit harder!

**Cras** · 05-26-2012, 06:33 PM

Quote:

Originally Posted by Samuel Edwards

Well, can someone explain why I just bounce back into space after raising the AOA to 40*?

I'm confused with that part.

What is your perigee after your de-orbit burn? I often end up with a perigee under the surface of the Earth.

mojoey · 05-26-2012, 06:40 PM

iirc, the XR guide says 40* AOA with 50km PeA.

**PhantomCruiser** · 05-26-2012, 06:44 PM

When I start my de-orbit burn, using basesyncMFD (180 degrees from my desired touchdown point) I tend to set the other MFD to ORBIT for the duration of the burn.

I'll stop the retroburn when my PeA is around 45K or so, this will give me some wiggle room for an over-field break (or HAC turn) if I need one.

Oceanic's video tutorial is how I learned, it's applicable to the entire XR series, even though it was filmed with the DGIV.

Samuel Edwards · 05-26-2012, 07:12 PM

@Cras, it was between 45 - 50 km.

I reentered successfully 30 minutes ago. :D

I started at 120km and did my de orbit burn over the Indian Ocean. My AOA was 40, and I increased-decreased it as necessary. I landed at EDW AFB.

Finally!!

Thanks for all of your help.

SE

Evil_Onyx · 05-26-2012, 08:11 PM

Well, as the first post asked for ways we personally de-orbit the XR2, I will try and do a step to step guide how i do it. (This method also works for most DG based craft)

From an orbit of about 250-400km
1. Using BasesyncMFD adjust orbit to pass somewhere over your target base, I usually have less than 500km cross range (I've successfully performed a underpowered landing using these steps at a cross range of 2000km).

2. Place your ship at an AoA of 40 and open AerobrakeMFD and set it to Map Projection then set the target to your target base.

3. Set in AerobrakeMFD a hypothetic deltaV of between 90-150 m/s then adjust so the landing point predicted by AerobrakeMFD is only just appearing, rather than continuing on an orbit.

4. Wait till the predicted landing point is about 1000km short then turn retro grade, then perform your de-orbit burn of what ever figure of hypotetic deltaV you worked out.

5. Prepare for Entry, keep the radiators out as long as you can.

6. At 100km i have a AoA of 75, but reduce this to 40 as you descend to 80km.

7. Using S-terns and moderating AoA place the Predicted Landing point on your target and keep your temps in an acceptable range.

8. As you near your base( less than 1000km) decide what approach you are going to use and set radios .

From this point its all practice and judgment.

Always remember that in a winged craft it is easy to extend a reentry but hard and risky to shorten it.

Samuel Edwards · 05-26-2012, 08:36 PM

I want to personally thank all of you for guiding me on how to successfully deorbit the XR2 and for posting their own steps to landing this remarkable add-on.

I just landed HASSESA's XR2 "Raven" back at Wideawake International. It was a glorious landing. The XR2 was manned by two crew members.

Thanks!

SE

Scav · 05-26-2012, 08:38 PM

Quote:

Originally Posted by Samuel Edwards

I just landed HASSESA's XR2 "Raven" back at Wideawake International.

...with one hand at the wheel, right?

Samuel Edwards · 05-26-2012, 08:45 PM

Quote:

Originally Posted by Scav

...with one hand at the wheel, right?

The pilot is cocky enough. You would know him from "In Luna". The Pilot was John Wiley.

---------- Post added at 04:45 PM ---------- Previous post was at 04:39 PM ----------

Does anyone mind if I cut and paste all of the suggestions you gave me into one document so that if anyone asks how to deorbit the XR#, we can give the link to a single document that could help them?

**blixel** · 05-28-2012, 02:08 AM

Quote:

Originally Posted by Samuel Edwards

As for my request...I was hoping that someone could post, down below, the steps that they personally take to deorbit the 'XR2', both using BasesyncMFD and AerobrakeMFD, and by just using stock Orbiter MFDs.

Perhaps watching someone else do it would help? If so, I have a couple videos on my youtube channel. I find videos at least as useful (if not more so) than reading bullet points.

Note, of course, that this is not necessarily the "right" way to do it. But as you stated, "...the steps that they personally take to deorbit the 'XR2'...

Annotated video:

Orbiter 2010 - De-orbit and Reentry [ISS to Wideawake International] - YouTube

This one is not annotated:

Orbiter 2010 - De-orbit and Reentry [ISS to Wideawake International] Take Two - YouTube

theshhh · 05-29-2012, 01:07 AM

Quote:

Originally Posted by blixel

Perhaps watching someone else do it would help? If so, I have a couple videos on my youtube channel. I find videos at least as useful (if not more so) than reading bullet points.

Note, of course, that this is not necessarily the "right" way to do it. But as you stated, "...the steps that they personally take to deorbit the 'XR2'...

Annotated video:
Orbiter 2010 - De-orbit and Reentry [ISS to Wideawake International] - YouTube

This one is not annotated:
Orbiter 2010 - De-orbit and Reentry [ISS to Wideawake International] Take Two - YouTube

Good tutorial

05-26-2012, 03:02 PM	#1
Samuel Edwards Orbinaut	XR2 Reentry Request Hello: tiphat: Before I get into my request I want to make this clear. YES, I have searched the forums and read previous threads on this subject. None of which helped me in my goal to finally deorbit and land my XR2 back on Earth. I know that many of you will just link me to previous threads, but like I already stated, the thread you give me a link to, probably didn't help me when I read it. As for my request...I was hoping that someone could post, down below, the steps that they personally take to deorbit the 'XR2', both using BasesyncMFD and AerobrakeMFD, and by just using stock Orbiter MFDs. I don't mean to be a bother at all; I just want be able to successfully get my crew back home, and to perfect my reentry skills . Thanks, SE

05-26-2012, 08:11 PM	#10
Evil_Onyx Orbinaut	Well, as the first post asked for ways we personally de-orbit the XR2, I will try and do a step to step guide how i do it. (This method also works for most DG based craft) From an orbit of about 250-400km 1. Using BasesyncMFD adjust orbit to pass somewhere over your target base, I usually have less than 500km cross range (I've successfully performed a underpowered landing using these steps at a cross range of 2000km). 2. Place your ship at an AoA of 40 and open AerobrakeMFD and set it to Map Projection then set the target to your target base. 3. Set in AerobrakeMFD a hypothetic deltaV of between 90-150 m/s then adjust so the landing point predicted by AerobrakeMFD is only just appearing, rather than continuing on an orbit. 4. Wait till the predicted landing point is about 1000km short then turn retro grade, then perform your de-orbit burn of what ever figure of hypotetic deltaV you worked out. 5. Prepare for Entry, keep the radiators out as long as you can. 6. At 100km i have a AoA of 75, but reduce this to 40 as you descend to 80km. 7. Using S-terns and moderating AoA place the Predicted Landing point on your target and keep your temps in an acceptable range. 8. As you near your base( less than 1000km) decide what approach you are going to use and set radios . From this point its all practice and judgment. Always remember that in a winged craft it is easy to extend a reentry but hard and risky to shorten it. Last edited by Evil_Onyx; 05-26-2012 at 08:26 PM.

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05-26-2012, 03:22 PM	#2
Cras Spring of Life!	I use DVTools, and a BaseSync deorbit settings of 1.2 degrees, 90 degree anticipation, 80km atmo, for a normal re-entyr, or just switch anticipation to 70 degees for a steeper one (like if I am low on APU for some reason) DVTools has a great tutorial walking you through the steps with pictures and everything. To use DVTools, you need BaseSync, Aerobrake, and IMFD.

05-26-2012, 04:55 PM	#3
Spacethingy Keyframe Cop	\| BasesyncMFD to get in an orbit that passes over my base in daytime (using clockMFD). \| Basesync to know roughly when I'm opposite my base (ie. 180deg away). \| OrbitMFD to then burn to roughly 70ish km up minimum altitude (Pe or Ap? I can't remember... \| Wait till I'm at altitude of 100km, pull in radiator, nosecone etc. \| Point forwards, use XR2's attitude autopilot, initially at 45degs pitch/AOA (I don't know what the difference is...) \| Use Aerobrake to monitor where my glideslope will take me. You get to the useful map page by pressing pg and proj if i remember correctly... \| Gently adjust XR2's attitude AP to keep landing point within 100km of the base, pull up to correct overshoot, pitch down to correct undershoot. Keep vertical speed below 100 m/s at all costs or you'll die a nasty death. There's a funny bit in the middle of reentry when for about a minute you start going back up again slowly, I guess that's at the lowest part of the orbit. Hold on, you start going down again. \| If I'm too late (i.e. serious overshoot is on the cards) a bit of banking from left to right helps bleed off excess energy. \| By 15-25 km altitude you'll probably be slow enough to fly normally down to the base. With my terrible skills, I now probably have to use the scram engines to make it as I'm probably completely in the wrong place... I can't remember MFD buttons awfully well and I've just pulped my Orbiter install due to a suddenly rather full HDD, so sorry about lack of help there...

05-26-2012, 06:02 PM	#4
Samuel Edwards Orbinaut	Well, can someone explain why I just bounce back into space after raising the AOA to 40*? I'm confused with that part.

05-26-2012, 06:09 PM	#5
Jarvitä Orbinaut	Quote: Originally Posted by Samuel Edwards Well, can someone explain why I just bounce back into space after raising the AOA to 40*? I'm confused with that part. If you're still bounding off at 40 deg AoA, your re-entry angle is probably too shallow. Deorbit harder!

05-26-2012, 06:33 PM	#6
Cras Spring of Life!	Quote: Originally Posted by Samuel Edwards Well, can someone explain why I just bounce back into space after raising the AOA to 40*? I'm confused with that part. What is your perigee after your de-orbit burn? I often end up with a perigee under the surface of the Earth.

05-26-2012, 06:40 PM	#7
mojoey k*256^2+2083	iirc, the XR guide says 40* AOA with 50km PeA.

05-26-2012, 06:44 PM	#8
PhantomCruiser Wanderer	When I start my de-orbit burn, using basesyncMFD (180 degrees from my desired touchdown point) I tend to set the other MFD to ORBIT for the duration of the burn. I'll stop the retroburn when my PeA is around 45K or so, this will give me some wiggle room for an over-field break (or HAC turn) if I need one. Oceanic's video tutorial is how I learned, it's applicable to the entire XR series, even though it was filmed with the DGIV.

05-26-2012, 07:12 PM	#9
Samuel Edwards Orbinaut	@Cras, it was between 45 - 50 km. I reentered successfully 30 minutes ago. :D I started at 120km and did my de orbit burn over the Indian Ocean. My AOA was 40, and I increased-decreased it as necessary. I landed at EDW AFB. Finally!! Thanks for all of your help. SE

05-26-2012, 08:36 PM	#11
Samuel Edwards Orbinaut	I want to personally thank all of you for guiding me on how to successfully deorbit the XR2 and for posting their own steps to landing this remarkable add-on. I just landed HASSESA's XR2 "Raven" back at Wideawake International. It was a glorious landing. The XR2 was manned by two crew members. Thanks! SE

05-26-2012, 08:38 PM	#12
Scav Mostly Harmless	Quote: Originally Posted by Samuel Edwards I just landed HASSESA's XR2 "Raven" back at Wideawake International. ...with one hand at the wheel, right?

05-26-2012, 08:45 PM	#13
Samuel Edwards Orbinaut	Quote: Originally Posted by Scav ...with one hand at the wheel, right? The pilot is cocky enough. You would know him from "In Luna". The Pilot was John Wiley. ---------- Post added at 04:45 PM ---------- Previous post was at 04:39 PM ---------- Does anyone mind if I cut and paste all of the suggestions you gave me into one document so that if anyone asks how to deorbit the XR#, we can give the link to a single document that could help them?

05-29-2012, 01:07 AM	#15
theshhh 2 year orbiter player	Quote: Originally Posted by blixel Perhaps watching someone else do it would help? If so, I have a couple videos on my youtube channel. I find videos at least as useful (if not more so) than reading bullet points. Note, of course, that this is not necessarily the "right" way to do it. But as you stated, "...the steps that they personally take to deorbit the 'XR2'... Annotated video: Orbiter 2010 - De-orbit and Reentry [ISS to Wideawake International] - YouTube This one is not annotated: Orbiter 2010 - De-orbit and Reentry [ISS to Wideawake International] Take Two - YouTube Good tutorial