coming down

[startrekmaniac]

Okay so, I can get into orbit with the DG. Now I need to know how to get back to the cape.

 

[Urwumpe]

Errrm... pass entry interface at the right distance to the cape and the right angle?

And download reentry MFD from orbitermars.co.uk, this really helps getting close enough to the cape.

 

[RAF92_Moser]

Fire your rockets retrograde until your orbit hits the atmosphere...(I do 30km). Do S-turns to bleed off any excess energy, and watch your AOA.

The rest is timing and practice. Wow, that was crude.

 

[Bullethead]

Jarmo (the maker of IMFD) has a BaseSynch MFD that tells you how to line up with a base and when to make the deorbit burn, and how hard to do it. You can find it HERE. After that, it's up to you.

 

[MJR]

Turn into retrograde. Once you did that, burn your engines until you ApA is negative on the orbit MFD. If you want to make it to the Cape directly, wait until your Orbit intersects with Cape Canaveral or KSC. Wait until you are about half an orbit from the base and burn your engines until your ApA is negative on the Orbit MFD. When it is negative, you know that your periapsis or lowest point of your orbit is in Earth's atmosphere. Bank left and right to "bleed" your speed down to an favorable re-entry speed. In this case since you are probably using the stock Delta Glider, you really do not need to do that. Once you get really close to the base, turn really steep and try to line up with any runway that is available. That is the quickest and broadest way that I can tell you how to get back into Earth. Good luck.

 

[NukeET]

Don't forget AerobrakeMFD.

 

[Agent0ne]

De-Orbiting/Re-Entry Phase Procedure (DG).

Hi everyone;

Since most people skip the entry phase (i cant figure why),
I did my own procedures, according with NASA's archived docs from missions,
and with space flight tech data,

These procedures are my Delta Glider Flight Standards-

Here is the Delta Glider basic procedures for
Atmosphere/Gravity De-orbiting/re-entry phase:

*Plan to Retro burn 60 degrees Longitude BEFORE the Landing site (ARP),
and add 5 degrees (tot: 65 degrees) for burn time.

Starting Altitude: 500Km/PeD = 5.300
Prograde Mode,
Retro Doors: Open,
set Auto Horizon: On / RCS Mode: LIN / AF CTRL: On,
Retro Burn (untill the descent curve reaches your Landing Site, on the MPD),
Close Retro Doors,
set LVL HORZ: Off,
Open Spoiler (keys Ctrl + B),

*Monitor the AoA (Angle of attack), ALT(altude) and SPD(speed),

Pitch: Maintain AoA +60 degrees (CRUCIAL for decreasing velocity),

References (Descent Rate);
ALT: 300Km (SPD: 6911),
ALT: 200Km (SPD: 7041),

Pitch: Maintain AoA +60 Degrees,
RCS Mode: ROT,
set MFD to HSI: ARP Rwy,

At ALT = 150Km:
Maintain pitch +60 Degrees,

At ALT = -90Km:
Lower the nose to Level with the Horizon (let it settle gently...), Pitch -3 Degrees,

At ALT = 30Km:
RCS Mode: Off,
AF CTRL: ON,
Pitch: -3 Degrees,
Let the velocity (SPD) decrease...

At ALT = 20 000m:
Level with the Horizon, Monitor the SPD,

At SPD = 500m/s: Enter Spoiler,

At SPD = 400m/s: Engines ON,
Maintain flight level (20 000m) toward ARP,
then descent/enter approach phase...


I hope this procedure will help those who like it real...

Ag1

 

[Kodiak]

In the Orbiter manual page 88, there are checklists for de-orbiting and landing at KSC

Or if you are more ambitious you can complete the various chapters in "Go play in Space"

http://orbit.medphys.ucl.ac.uk/manual.html

 

[pete.dakota]

AgentOne:Though your re-entry 'procedure' may get you from orbit to the surface, it's frighteningly unrealistic. You have to remember that the stock DG is indestructible. Your profile has no angle of attack from 90km down to 30km. Realistically, the DG would not be slowed enough in the upper atmosphere, and, if the nose doesn't melt (which it almost certainly will), the aerodynamic forces on the DG in the thicker, lower atmosphere would destroy it. If you tried a re-entry like that with the DGIV you'll see the nose temperature go sky high P) and the ship would break up. The idea of a winged body re-entry is to manipulate a high angle of attack to create lift during the deceleration so that most of the speed is bled off before the atmosphere gets too thick as the craft falls through it. Your method has all of the high angle of attack periods occur above 100km, and to then have no AOA below 90km. There is no notable atmosphere above 90km so having a high angle of attack is redundant.

Using the DGIV an entry only needs one addon MFD, aerobrakeMFD.

Ensure your craft is under re-entry weight. From ISS altitude (350km -+), burn retro to a PeA of around 40km when 18.50M from and closing on KSC/EAFB, coast down to 120km, then program the DGs entry autopilot to 40 deg AOA and whichever angle/direction bank is needed to favour, directionally, your landing site. Then you can just sit and wait, adjust the bank here and there accordingly, keep an eye on the predicted landing point on aerobrakeMFD, dropping the AOA after passing through peak heating accordingly, then, when you're <800m/s2 and closing on the cape, turn off the autopilot and the RCS and glide to your runway (still keeping a notable AOA at first).

It really is quite easy once you've managed it a few times. Simply, without aerobrakeMFD, you're making things VERY hard for yourself.

 

[Urwumpe]

Also, maintaining AOA above 120 km is interesting - and useless. Orbiter does not model Earths atmosphere beyond 150 km and before 100km altitude, the speed required to balance gravity with lift would be as high as orbital speed (thus 100km is called kalman line). The higher drag at 90 km with 60° pitch would have some impact on drag - but the difference as only the effect on the scale of milli-G of acceleration.

The better method I can suggest is using reentry MFD:
Lower periapsis at de-orbit to roughly 0 km from LEO. This is not accurate, but you can correct this error later. Activate now Surface MFD, Surface HUD and Reentry MFD. Select your target base in Reentry MFD (SHIFT+B). Trim fully up.

When passing below 180 km, orient the DG for reentry - AOA to 40°, wings level. Now just keep this attitude until your vertical speed is zero again (at about 60 km - 70 km) and now watch Reentry MFD. The trick is now to regulate your vertical velocity and altitude in a way, that your decelleration meets the target of Reentry MFD. You do this by banking to the side and fly S-turns. The circle at the bottom of Reentry MFD is your cue how far your ground track is away from the target base, called cross range error. Once the circle reaches one side of the MFD, you need to do a roll-reversal = You bank to the other side.

When you are only a few 100 km away from the base (I use 200 km for the DG), start saving energy for landing. put the cross-range error circle on the target, make wings level and trim for a good glide - even if you now gain a bit of altitude, it is not a problem as long as you don't waste energy by making hard maneuvers.

The DG glides very well at about 15° flight path angle, this means you should keep the velocity marker of the HUD on the 15° mark once you are as close as 115 km to the target.

It takes some training to get a feeling for it, but it finally works really accurate and you can use this for ANY spacecraft which produces lift. Capsules and winged spacecraft are only different in the amount of lift you have available. For a capsule, I would not use the full range of the cross-range error scale, but instead make a roll reversal already when the error is at 1/3 of the way from the middle to the edge of the MFD. This means more banking to you usually, but you are not too far away from your landing site.

But more important than all tools is training. You need to learn estimating the behavior of the vehicle, and doing this means repeating the reentry again and again and again, and if you finally landed, do it again for making sure the method really works or was just luck.

 

[Agent0ne]

Well its been workin' for me;

[ Complex flight Model checked on,
[ Damages and failures Simulation checked on,
[ Gravity-Gradient Torque checked on,

For more than 2 years now...

Placing each and every controls on Auto-Pilot isnt quite piloting !
It took me 20 hours to finally get these parametres,
to set a Re-entry/Descent procedure
not to trigger the "Damages and failures alert" On !


Why dont you try it...


Anyway,
Im not here to argue with any body,
Im simply offering my own experience to others who may need it,
to those who like piloting and might not have all that experience yet...

 

[Urwumpe]

AgentOne: In case you don't want to argue, we are also just telling those you want to teach, why your approach is drawing the wrong conclusions.Eg about using AOA, when there is no atmosphere which causes any effect.

See my post about the other physical aspects.

We all have our own experiences. That does not mean that we drew the right conclusions. I once believed that a cool reentry means as little flames as possible. I was wrong, but hey, that's why we keep on learning.

If your approach works for the DG - fine. We don't want to argue about results.

It currently takes me maximal two flights with a new spacecraft to get a perfect intact reentry on Earth or about 1 hour. Some more when I have to get used to a new fictional planet. My method works for lifting capsules and winged spacecraft alike. That is simply because physics are on my side (most of the time. Sometimes it teaches me that reentry heating comes quickly)

So, if you don't want to argue - fine. But let others do that, even if they argue about your experiences and discard many of them. We are all not perfect astronauts yet. :lol:

BTW: Are you somehow related to AgentOne from Agents of Gaming? :lol:

 

[Agent0ne]

???

you kno the internet with those kids skipping identity !!!


There is only 1 REAL "Agent0ne", and its me !

http://agent0ne.faces.com/Profile/


Now, why dont we go back to flying...

Ag1.