Getting to know the Ravenstar:)

[Robsoie]

That's a great improvement.

If it can help, it seems i refined my method a bit and managed to get a (roughly) 230x230 km while having a bit more than 62% main fuel left.

Here it is :

Take off Full engine at 100km/h with Attitude Hold autopilot set to pitch 50 degree, then Gear Up.

Wait until you're at 12km, now set the Attitude Hold to 2.5 degree, by the time the XR-2 is now at 2.5 pitch you should be at +/- 20km altitude.

Stay like this until you reach 900km/h then open the Scram doors and set full Scram engine. Now shutdown the Main engine.
Set the Attitude Hold to Pitch 5 degree

In the autopilot panel, change its display to see the hull temperatures, you'll see it increasing (in external view you'll see you XR-2 burning).

No worry the XR-2 can take it, a bit before the temperature reach yellow numbers, lower the Scram engine power until the temperature start to drop.
Then increase it progressively, the goal is to get at full Scram speed and get the temperature green and decreasing, so play with the Scram engine power accordingly until you're in this situation. You should be finished with the temperature / Scram main engine game at between 30 and 32 km altitude.

At 35 km altitude drop the Attitude Hold pitch to 2.5 degree and let it like this until you run out of Scram fuel (if you followed this method exactly, you should run out of it before the scram diffuser temperature get critical).

Hull temperature at that angle will start to re-increase after some time, but don't worry it will start to decrease again soon enough (at +/- 45 km altitude) and will never reach critical (and with this method it should not even reach yellow too).

Just when you run out of Scram fuel, set the full Main engine power and close the Scram door immediately.

Set your Attitude Hold autopilot Pitch to 20 degree and wait until your Orbit MFD display to your LEO Apogee target, by example 230km .

Shutdown main engine, deploy radiator and shutdown APU once it's deployed, you can go Prograde now or wait a bit before reaching the Ap node, but be sure to be Prograde autopilot before reaching that node.

So wait until you reach the apogee/apoapsis node on your Orbit MFD then Full main engine burn to build your perigee/periapsis to get your circular orbit.

At (roughly) 230x230 km with this method you should be over 62% main engine fuel left.

 

[Tommy]

"Roller Coaster" can occur at real time as well. It usually indicates that your pitch angle is too steep. Keep in mind that the effect I'm talking about isn't pitch instability - it's a result of getting too much VS. You'll end up at a higher altitude then the wings can hold you, and sink down a bit before ascending again.

You have to be watching the Vertical Speed to see this effect. It will happen more often if you are using Pitch control, but can happen with AoA control as well - if the AoA is too high.

One of the reasons I like using elevator trim is that it keeps me conscious of the amount of "effort" the elevators are making to hold VS where I want, which makes it easier to know when I'm too high or too low for efficiency. If I need more than .5 upward trim then I know I'm ascending faster than I should.

Still, use whatever works best for you!

 

[Quintuss]

I did few stupid mistakes. Last night i scored 65%, this time 63.5 Can you fast foward replays ? At the end i forgot to circularize. Its ~200km after 3 orbits. Does that count ? Ill post a better one soon.

http://www.sendspace.pl/file/f32861a47990468eb5abd55

Are replays always that buggy? In one i never got to orbit, in another i overheated XR2 before circularization and in another one i scored 63.9% fuel. What the heck ?

So my score is 63.5% at roughly 200km orbit

And and 68-70% is not at all optimistic if u fly a craft without cargo or crew like i do. I belive that Rodney McKay brings bad luck to a ship hes boarding

 

[Robsoie]

After figuring out where the download button was on your link, i noticed you uploaded a .scn (your replay file i guess ?)
But you didn't uploaded the flight datas (in the Flight folder you have a sub folder that have the same name as the replay file), without the flight datas, you can view this replay.

Usually replays can be buggy if you time accelerate a lot when watching them (assuming the recorder didn't enabled the "Record time acceleration" so you can time accelerate yourself when watching) , usually X10 is fine but try to not accelerate more than X100.

 

[Quintuss]

How about now ? http://www.sendspace.com/file/eorajh

 

[Robsoie]

It worked,
Nice ascent, i liked the part in which you accepted to lose a bit of altitude to stay under 55km altitude, good trick to keep most scram efficiency and have increased speed.

I will have to try that to see if it can spare more fuel.

I noticed in the release candidate thread of the next XR-2 update that dbeachy1 managed to allow more events to be recorded along improving performance and bugfixes, very interesting.

 

[Tommy]

Are replays always that buggy? In one i never got to orbit, in another i overheated XR2 before circularization and in another one i scored 63.9% fuel. What the heck ?

The flight recorder only records certain things, and records them only so often.

The "in one I never got to orbit" part puzzles me. This would seem to indicate that the playback ended prematurely.

The recorder records position and attitude, so if you got to orbit while recording, you will get to orbit during playback - unless the recording ends prematurely (leaving the craft flying on it's own, or there is some other problem with the recording.

The case where you burned up is understandable - the recorder doesn't keep track of hull temps - those are recalculated during the playback, and there is a certain amount of "random" on whether or not the ship explodes when in the red. Some playbacks will survive, others won't.

Fuel usage is also not recorded, rather it is calculated from the throttle positions. While throttle positions are recorded, they are only recorded when the change is over a "threshhold", so small reductions in throttle aren't reflected well. This can lead to a playback using more fuel than when you recorded the flight. This is quite common when recording flights made with IMFD, it reduces the throttle slowly, and playbacks always show more fuel use than the original flight.

The flight recorder doesn't record the entire flight, it records events which it can later use to "reproduce" the entire flight.

 

[dbeachy1]

Are replays always that buggy? In one i never got to orbit, in another i overheated XR2 before circularization and in another one i scored 63.9% fuel. What the heck ?

What XR2 version are you using? With the current 1.3 (public) build all damage except for crashes/gear collapse is disabled during playback, so the playback should never damage the ship unless it crashes into the ground.

 

[Quintuss]

Ver. 1.3. I speed up one playback - i overheated xr before i reached 70km alt. In that "i never got to orbit" aparently i did not close the scram doors before engaging main engines and went KABOOM.

And if we talking wierd things about XR2. A few times during reentry my nose shield reached critical temp of 44 deg C. White hot at 44 deg Something with nosecone left open, yet it was closed. Checked both visually and with reentry check.

Happens only in Tex scenario "Solar system today" when i load Carina2 sattelite. Not every time, not even twice on same aproach when i load it again.

Btw. my current score is 64.4% and ill try to record it sometime this month.

 

[dbeachy1]

Ver. 1.3. I speed up one playback - i overheated xr before i reached 70km alt. In that "i never got to orbit" aparently i did not close the scram doors before engaging main engines and went KABOOM

That's a good catch! :tiphat: It turns out I was missing a playback check in the SCRAM overheat code, so it will be fixed in the new XR releases coming tomorrow.

As for the nosecone showing open during playback, that's a weird one since only a replay event should be able to open or close the nosecone. Can you please re-test in a clean installation? Also, if you can post a link to the replay scenario I can try to reproduce it tonight.

 

[Quintuss]

Nosecone issue showed during gameplay not during replay. As it was so wierd i tried to fraps it, yet it refuse to show itself then. I believe that i might bugged it by stowing jetpack with noscone or outer airlock closed. If thats even possible, ill try it today when i get back from work.

Issue looks like: Everything is closed shut, yet computer continue to scream at me that nosecone is open. Reentry check shows green. Then when i enter upper atmosphere and im starting to heat up. When noseshield gets to 30 deg computer starts to yell critical temp. warnings. Seconds later at 40+ deg. things get white hot and BOOM ...

 

[dbeachy1]

Can you please post a scenario saved shortly before the problem occurs? Then I can test it here. [Also, please re-test it in a clean installation (without FRAPS, too) to make sure it's not caused by another add-on trashing memory.] If the nosecone indicator shows 'closed' but you're still getting 'nosecone open' warnings then something bizarre is going on.

Also, if the nosecone is overheating at 30 degrees C it looks very much like memory corruption since the temperature thresholds are stored internally as a structure inside the XR vessel class; they are initialized during startup and never altered. That's why I suspect another add-on is the problem here.

 

[Quintuss]

Sadly, i always delete saves of my unsuccsesfull missions. I like it hardcore :lol: Ive spent last few hours recreating the conditions and doing reentries. No wierd behaviour observed during 25+ tries. Considering it being so dificult to recreate, i guess its not worth the trouble. Im sorry that i brought it in the first place without any proof. If i stumble on it in the future, ill bring something solid with me.

Note to self: you cant stow turbopacks with nosecone or airlock closed

 

[EnDSchultz]

When I launch I try to keep the hull temps as low as possible; it doesn't seem plausible that in reality you'd want to put any more heat or dynamic stress on the hull than necessary, so while it may be more fuel efficient to blast through the atmosphere to get max thrust out of your SCRAMs, I usually try to get quite high (and therefore also quite fast) using the mains before I engage SCRAM.

Then again, maybe in reality they'd use some sort of first-stage booster to get the vessel up to altitude and SCRAM velocities.

 

[paddyb270]

I had a question about the XR vehicles. When I'm landed on Earth (or just simply idle on Earth) the instruments are very jumpy. And when I try to do external things, like refuel, LOX replenishment, I get a "doesn't work, ship still in flight" when I'm clearly on the ground. Is there a way to fix this? Or is this a known issue?

 

[jangofett287]

Press space, this cancels any running autopilots, and trust me the XR fleet have quite a lot of them. Also check all your throttle levers are at 0.

 

[Cras]

I had a question about the XR vehicles. When I'm landed on Earth (or just simply idle on Earth) the instruments are very jumpy. And when I try to do external things, like refuel, LOX replenishment, I get a "doesn't work, ship still in flight" when I'm clearly on the ground. Is there a way to fix this? Or is this a known issue?

You running a graphics client and/or have very high frame rates? I have seen this with high frame rates, where it becomes difficult to get a vessel to switch over from active mode to inactive (landed) mode, and thus be able to use the refueling lines and external cooling.

 

[paddyb270]

Hm. I tried the space bar and that didn't work. And my frame rate is pretty standard, 60Hz (i'm not sure if there's a specific Orbiter frame rate you're speaking of). I feel like the issue is like what you said, how the XR vessels fail to switch over to inactive mode when on the ground. It still thinks it's in flight, but near 0 altitude and near 0 velocity. I'm not sure what's wrong.

 

[Ripley]

Press "F" to show your Orbiter fps.
Could it be a stuck key??
What if you apply wheelbrakes?

 

[Cras]

when I am flying using the D3D9 client, my frame rates can get extremly high, and this exposes certain things in Orbiter. This is one of them. UMMUs will tend to skip when you try to walk, especially so on low gravity worlds like the Moon. And ships have a hard time switching to landed mode. I experience this either as constanst bouncing up and down of the ship (like when landing an XR-2 on the Moon), or reduced braking performance, when landing the XR-2 on Earth.

Follow Ripley's advice and have a look at your Orbiter FPS. It will display in the upper right hand corner. If it is above 400 or 500 fps, this may be what you are seeing.