Flight Question deltaglider's autopilot.

[Urwumpe]

ok. umm at what altitude should i begin coasting to apoapsis. now i know this sounds like im still trying to get into to space but i think i can get that part. im just trying to fine tune an orbit now.

No special altitude. If you reach Apoapsis = target, MECO.

if you fly halfway effective, by flying as shallow as possible (which means you need less fuel for fighting against gravity), you shouldn't require MECO below 95 km altitude. usually, in Deltaglider class vehicles, I aim for MECO in 120 km altitude, and coast from there to the target orbit.

Remember, for winged vehicles, it is even more important to fly pretty shallow, since this permits you to gain more from the wings.

Again: Remember that your "guidance" scheme during ascent aims for getting into a target orbit as effectively as possible. It is not about fixed cut off altitudes, or getting a time table cast in stone. It is about simply knowing when you have reached your intermediate goal. You read your altitude, your velocity vector, check your orbit plane, and then decide if you are still on track, or need to change your former plan for adapting for deviations. The less corrections you need, the better your plan was, but in spaceflight, you should better remember the wisdom of Clausewitz (adapted to spaceflight):

No flight plan survives the contact with reality.

 

[rocketdued]

ok. i was aiming for 200.0k for meco. cause im also going by the orbiter help for the checklist scanrio dg to iss. but so far i have got no where near iss:lol:

 

[Urwumpe]

ok. i was aiming for 200.0k for meco. cause im also going by the orbiter help for the checklist scanrio dg to iss. but so far i have got no where near iss:lol:

That takes a lot of precision, so don't worry if it takes a while. If you have just 1° relative inclination between your orbit plane and the plane of the ISS, you can be up to 111 km away from the ISS despite having all five other parameters right. And have also 135 m/s lateral velocity at the intersections.

If you have more than 0.5° there after launch, it is bad for your training: The DG has enough fuel for correcting this (around 10 km/s should be left in the tanks after a good orbit insertion), but it means that this fuel is no longer available for the fun stuff.

 

[rocketdued]

oh ok. now the orbiter help system says to turn right to 140 degrees heading. i think i'll skip that part and try a straight out departure. and see if i can get it then?

 

[Urwumpe]

oh ok. now the orbiter help system says to turn right to 140 degrees heading. i think i'll skip that part and try a straight out departure. and see if i can get it then?

Straight out is good enough for just getting into any orbit, but if you plan to get into a special orbit plane, like the orbit plane of the ISS, you need to launch a the right time (launch window) into the right direction (Launch azimuth).

The 140° is the correct direction for getting to the ISS, if you launch from the latitude of KSC (28°) and the ISS travels in southern direction on its ground track, when the orbit plane of the ISS passes over your launch site.

The orbit plane is not exactly the line you see on Map MFD, but the plane in which the ISS orbits around Earth - every orbit is inside such a flat plane, and such a orbit plane is always centered around the center of Earth: You can't for example have an orbit that is always at 30° N latitude, but an orbit at 0° latitude is possible.

 

[rocketdued]

aha. thats another thing im doing wrong im launching early. but im just trying to get into orbit. i suppose after i get into orbit enough time i'll have that down. then the next step will be getting to iss.

 

[Urwumpe]

aha. thats another thing im doing wrong im launching early. but im just trying to get into orbit. i suppose after i get into orbit enough time i'll have that down. then the next step will be getting to iss.

Try to put the next step into controlling your orbit shape: Sma and Ecc (ApA and PeA are calculated from these two elements).

That is still fairly easy.

Just randomly select a few random target orbits, eg 500x500, 800x800, 400x400, 1500 x 1500. And then go there. In that order. if you can do that in your sleep, you are on the right track.

Next, try to end every mission with a successful landing. Even if you just practice, landing is also pretty hard and requires some training. Especially if you later use spacecraft with better damage simulation. (Remember what was said before: you might think it is just like in an aircraft, but it isn't)

First you can be happy by just landing anywhere in one piece. If you are lucky anywhere on land. Later you can land on the next runway or LPAD. Finally you can deorbit precisely and land smoothly on any target spaceport.

 

[rocketdued]

well i can try those with a differrent ship. this delta gliders doing the same thing it was doing when i first started. and i have not done any thing differrently. in the way i take off. :beathead:

 

[Urwumpe]

well i can try those with a differrent ship. this delta gliders doing the same thing it was doing when i first started. and i have not done any thing differrently. in the way i take off. :beathead:

Remember: Aerodynamic control surfaces don't work in space, the thinner the air gets, the less reaction you get. You need to enable the RCS. For controlling your rotation, put the RCS into ROT mode.

 

[rocketdued]

i did at 30 km just like it said. but at a certain altitude the cross in the circle starts dropping and when it dose it keeps going till it goes to 10 degrees nose down pitch and the deltaglider follows suit. so im not gaining any thing. :idk:

 

[garyw]

i did at 30 km just like it said. but at a certain altitude the cross in the circle starts dropping and when it dose it keeps going till it goes to 10 degrees nose down pitch and the deltaglider follows suit. so im not gaining any thing. :idk:

Ok, Rocketdued, time to learn. I'm not going to give you answers any more as we've all done that and you still haven't learnt. Instead I'm going to fire questions back at you in order for you to have to do some research and learn. It'll help in the long run.

1. does not dose. Could you please use a spell checker? It is sometimes hard to understand what you are asking.

2. What is the cross in the circle? What does it mean? Find the answer to that and you'll start to understand what's going on.

3. What was your speed at 30km and your attitude just before the 'cross in the circle' dropped?

 

[Urwumpe]

The answer is "What is a VVI". :lol:

 

[rocketdued]

vvi=vertical velocity indicator

 

[Urwumpe]

vvi=vertical velocity indicator

Wrong.

It is Velocity vector indicator in the context of HUD symbols. :lol:

 

[rocketdued]

:compbash: you all win i give up. every things an argument here.

 

[garyw]

Urwumpe was pointing out that you still think that flying in Orbiter is the same as flying in FS2004. It is not. In space it's important to know where the velocity vector is because that's the direction you are going even though your nose might be pointed somewhere else entirely.

 

[Rtyh-12]

Simply put, the cross in a circle shows you the direction you are going, relative to a body. Right now, that body is the Earth. If it starts going down, then you are not necessarily going down too. If you keep flying at pitch +30 degrees, then the cross in a circle will drop. This is normal. Just keep going: you'll only go down if it goes under 0 degrees, which will not happen if you continue to fly at 30 degrees.

Edit: Don't give up, you'll do it eventually. Try [ame="http://orbithangar.com/searchid.php?ID=5024"]this[/ame].

 

[Tex]

ok. umm at what altitude should i begin coasting to apoapsis. now i know this sounds like im still trying to get into to space but i think i can get that part. im just trying to fine tune an orbit now.

rocketdued: WATCH THIS for an example of an ascent. Furthermore, stop punishing yourself and watch my DG4 to ISS tutorial which explains, step by step, how to get to ISS.