Flight Question Bouncing off of the atmosphere?!

[Hurricane]

Hello everyone. After doing a couple of successful lunar transfers, next stage for me is reentries. But when I try to do a reentry, no matter with what vehicle, I keep bouncing off of the atmosphere at about 65km. I have tried everything, including autopilots, and yet no success. Please Help me, because I keep bouncing off of the atmospehre even with the DGIV's reentry computer. Like everyone say, I make it a ~1 degree entry, but I STILL BOUNCE OFF! :facepalm:

Please help me soon! :tiphat:

 

[agentgonzo]

You must increase your Angle of Attack so that your wings stall and produce less lift. If you are still having too much lift then roll to the side by 60-90° so that your 'lift' is sideways, not upwards. Normal AoA for reentry is ~40°

 

[Hurricane]

Do you use a Capsule or a spacecraft with Wings to reenter?

DG-class mostly.

You must increase your Angle of Attack so that your wings stall and produce less lift. If you are still having too much lift then roll to the side by 60-90° so that your 'lift' is sideways, not upwards. Normal AoA for reentry is ~40°

Thanks, I'll try that later once I'm good at ISS docking

 

[N_Molson]

Or practice the famous "inverted reentry", a classic among bold DG-pilots

 

[Ripley]

...Or follow this thread
http://orbiter-forum.com/showthread.php?t=18671

 

[agentgonzo]

Or practice the famous "inverted reentry", a classic among bold DG-pilots

From LEO that'll just decrease your vertical speed and kill you even faster.

 

[Hurricane]

...Or follow this thread
http://orbiter-forum.com/showthread.php?t=18671

Yeahh... Did I mention that I don't like MFD addons? I like to have the greatest challenge is a factor... And I also would like to do reentries all by my own, so autopilots are a 'worst case scenario' getaway for me.

 

[agentgonzo]

Yeahh... Did I mention that I don't like MFD addons? I like to have the greatest challenge is a factor... And I also would like to do reentries all by my own, so autopilots are a 'worst case scenario' getaway for me.

Why do you hate MFDs? They are just tools for helping you, like asking on the forum or using the rule of thumb of 'deorbit burn on opposite side of planet'. If you want to make it even more challenging you could do it blindfolded? or with the keyboard upsidedown.

 

[diogom]

I'd say, learn it with the MFDs, and when you're really good at it, try withouth them. Don't start on the hardest.

 

[Hurricane]

Why do you hate MFDs? They are just tools for helping you, like asking on the forum or using the rule of thumb of 'deorbit burn on opposite side of planet'. If you want to make it even more challenging you could do it blindfolded? or with the keyboard upsidedown.

Haha I don't HATE them, I just don't like them because they make it WAYYY too easy :lol:
Blindfolded seems nice, but let me first get it right not blindfolded! And by the way, upside down keyboard is easier, because it's counter-intuitive to something counter-intuitive, so actually that's intuitive! :thumbup:
Ughh... Long day that was... I think I'll try again only tomorrow.

 

[agentgonzo]

Okay, do one of garyw's challenges

1. Get a blindfold and get into Lunar orbit with a Shuttle-A and a cargo (any kind)
2. Get the Shuttle-A into a Earth transfer orbit.
3. after doing 2, release the Cargo and make it land somewhere near KSC

all of this WITHOUT GETTING INTO THE EARTH'S SPHERE OF INFLUENCE

[ame="http://www.orbithangar.com/searchid.php?ID=4301"]I did that a few years ago[/ame]... but without the blindfold

 

[Hurricane]

Okay, do one of garyw's challenges

1. Get a blindfold and get into Lunar orbit with a Shuttle-A and a cargo (any kind)
2. Get the Shuttle-A into a Earth transfer orbit.
3. after doing 2, release the Cargo and make it land somewhere near KSC

all of this WITHOUT GETTING INTO THE EARTH'S SPHERE OF INFLUENCE

Ugh, you guys are just too serious about it. I don't use, won't EVER use ever and have EVER, EVER used add-on MFDs. Period. But I can still do great things such as lunar transfers and ISS dockings. So to sum up, if I start rising, what do I do?
~Thanks in advance. :tiphat:

 

[Ripley]

[polemic mode on]
TransX is a "third-party" add-on MFD, now included with Orbiter core distribution.
Do you consider it as a NO-NO-getaway add-on, or is it as good as, say, Orbit MFD?
Or maybe you don't even use Orbit MFD?
[polemic mode off]

 

[agentgonzo]

So to sum up, if I start rising, what do I do?
~Thanks in advance. :tiphat:

Start doing more complicated things. Try doing transfers to Mars/Venus without MFDs. Then a slingshot trajectory (Jupiter-->Saturn). Then multiple slings (like Cassini's VVEJ GA). Then trajectories via lagrangian points like GRAIL the one GRAIL's on now. Precise reentry from a Lunar orbit (ie apollo-style lunar missions where you have a target of (say) 100km/100km on the Earth that you need to land in. Transfers to Jupiter using a sling around one of the moons (probably Io) to reduce speed and enter Jovian orbit without an orbital-insertion burn.

There are lots of things!

 

[Cras]

In short, if you start rising, start banking, and you need to start banking the second you see your vertical speed start to climb. If you wait too long, your only hope is that you burned off enough speed so that you will stay in Earth orbit to give it another shot, otherwise, use press F4 and press the Exit button.

High AoA will increase drag as well as increase lift, but the DG is forgiving enough that the drag is greater than the lift, but be prepared to jack the AOA up to 45 or 50, there are times when I was about to overshoot the KSC and had to essentially AOA up to 80 degrees and bring the DGIV to a slammin halt in the air. Easy to do in the DG, not so much in XR2 since that aircraft simulates wing stress and a change from that drastic an attitude to one with lift on the wings my cause damage and render your control surface worthless.

And bank angles of 80 degrees may be needed. Taking a DG from lunar orbit is very very hard. I myself have only been able to do it inverted, that is head down and maintain the vertical speed that way. The goal being get into the higher parts of the atmosphere and keep the vertical speed zero as I slowly get the speed down to near LEO velocity then can flip the plane over and re-enter like normal.

 

[agentgonzo]

TransX is a "third-party" add-on MFD, now included with Orbiter core distribution.

TransX is far more complicated than a lot of the 3rd party addons that are out there. If you use TransX then I'd say that all your arguments about "not using MFDs because it makes it too easy" are worthless. If you're just using things like orbitMFD etc (ie, NOT transx) then I'd say your argument has merit.

I've always considered TransX a 3rd party addon (for obvious reasons and) because you have to add it in in the module tab.

---------- Post added at 15:40 ---------- Previous post was at 15:35 ----------

Ugh, you guys are just too serious about it. I don't use, won't EVER use ever and have EVER, EVER used add-on MFDs. Period. But I can still do great things such as lunar transfers and ISS dockings. So to sum up, if I start rising, what do I do?
~Thanks in advance. :tiphat:

Or you could learn to reenter properly without bouncing off the atmosphere?

 

[Spacethingy]

How do you know that you're rising without an MFD? :lol:

Pitch up to stall, as mentioned above. If you're REALLY desperate, retroburn... Bear in mind that bouncing slightly at about 65 km isn't necessarily a problem. Having a profile like:


\ __
......\.......


...can be good.

 

[Hurricane]

[polemic mode on]
TransX is a "third-party" add-on MFD, now included with Orbiter core distribution.
Do you consider it as a NO-NO-getaway add-on, or is it as good as, say, Orbit MFD?
Or maybe you don't even use Orbit MFD?
[polemic mode off]

I don't use transx. I use only Orbit, Docking, VOR/VTOL on the moon, transfer, align planes and sync orbit MFDs.

Start doing more complicated things. Try doing transfers to Mars/Venus without MFDs. Then a slingshot trajectory (Jupiter-->Saturn). Then multiple slings (like Cassini's VVEJ GA). Then trajectories via lagrangian points like GRAIL the one GRAIL's on now. Precise reentry from a Lunar orbit (ie apollo-style lunar missions where you have a target of (say) 100km/100km on the Earth that you need to land in. Transfers to Jupiter using a sling around one of the moons (probably Io) to reduce speed and enter Jovian orbit without an orbital-insertion burn.

There are lots of things!

:facepalm:

TransX is far more complicated than a lot of the 3rd party addons that are out there. If you use TransX then I'd say that all your arguments about "not using MFDs because it makes it too easy" are worthless. If you're just using things like orbitMFD etc (ie, NOT transx) then I'd say your argument has merit.

I've always considered TransX a 3rd party addon (for obvious reasons and) because you have to add it in in the module tab.

---------- Post added at 15:40 ---------- Previous post was at 15:35 ----------


Or you could learn to reenter properly without bouncing off the atmosphere?

:thumbup:

---------- Post added at 02:51 PM ---------- Previous post was at 02:43 PM ----------

How do you know that you're rising without an MFD? :lol:

Pitch up to stall, as mentioned above. If you're REALLY desperate, retroburn... Bear in mind that bouncing slightly at about 65 km isn't necessarily a problem. Having a profile like:


\ __
......\.......


...can be good.

I come from the atmospheric flight simulation world... I'm trained to work with the heads up and with malfunctioning parts of the standart six, working things up from there.

And I do not SLIGHTLY bounce, I climb up ALL THE WAY to 90 km... (HUH?!)

 

[Rtyh-12]

I come from the atmospheric flight simulation world

This isn't atmospheric flight. This is space flight. You can't do it without MFDs. For example, I could do a looping or a corkscrew without instruments (in a sim for obvious reasons :shifty On the other hand, I could never land on the Moon or perform a Jupiter-to-Saturn slingshot without MFDs.

Actually, I can't perform the sling with MFDs either...:shifty:

MFDs are just instruments, to help you in your travels. It is true that there are autopilot MFDs that fly everything for you. But most MFDs don't. TransX, for example, just lets you (basically) input the maneuver(s) and then it calculates what your ship will be doing. Then you can go change the maneuver until eventually you'll see that the path takes you where you want to go. Sure, it tells you how and when to fire your engines, and you may consider it cheating. But even real astronauts have computers to help them.

Hey, real astronauts (used to) get flown into orbit by an autopilot. They don't fly the Space Shuttle during launch. A computer telling you when to burn is certainly not cheating compared to this... :lol:

 

[Linguofreak]

Pitching up only really works, though, if you're flying one of the addon DG type craft (for example, the XR series) that can actually get to a high (~40 degree) AOA. In the stock DG, you have to use bank angle to control your descent rate.

You can probably fly a reentry without addon MFD's, but actually landing at a specific base without something like Aerobrake MFD is going to be incredibly difficult.

In any case, aside from making it difficult to control your landing point and feeling rather sloppy, bouncing up to 90 km isn't too much of a concern. It will make it take a bit longer to get to the ground, but you should be down in fairly short order.