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Orbiter Instrument Training

Tutorial 6 - Launch into stable orbit

You should begin by reading JPL's How Orbits Work.

From the Orbiter Main Menu "Launchpad" select the Deltaglider MK3 scenario.

You should have an external view of the Delta-Glider.  Press [ F3 ] to change ships. Select SH-02 from the pop-up menu for Shuttle A. Press [ F1 ] and get inside.

Note: The Delta-Glider has a control panel, so it's time to get use to the MFDs. You should have the surface MFD and launch/ landing MFD active by default.

Then press [ H ] to bring up the HUD to SRFCE as indicated on the top left of screen.  Also notice that there are three indicator bars, Fuel, Main and Hovr.

Now  begin to hover by pressing the [ 0 ] key on the numpad, bring it up until you rise off the pad. 

Use numpad [ 1 ] , or the joystick,  to rotate the nose due east,  90 on the HUD ribbon. Once you're at 90, take the main thrust up to full. The momentum from the thrust will secure this heading for the most part. Now...

Use numpad [ 2 ] , or the joystick,  to pitch the nose up to over  +70 on the HUD. When you see the target vector ball± rise up on the HUD  gradually lower the hover thrust, we don't want to be pushed over on our back. What we want is the target ball± to sit on top of our aim around +70.

To achieve orbit we will need horizontal momentum to build. Switch out the Launch MFD with the Orbit MFD, right[Shift][O]. Take note of the horizontal velocity (Vel) which is indicated on the Orbit MFD. Make sure Orbit MFD is in Proj: ship mode. Press [Shift][P] to toggle.

Use my 50/50, 500 rule. When you reach an altitude of 50 you may slowly  dipped to + 50 on the pitch ladder by bleeding off hover thrust.  This will help increase horizontal velocity and bring the vertical speed to ~ 500k/s.  The vertical  speed (Vspd) is indicated on the Surface MFD.

Note: If the Vspd reads > 1.00,  notice the decimal, it means you are over 1000k/s, you must knock off all hover thrust and pitch down on the ladder until you have negative Vacc. If you are far below 500k/s you must pitch your nose up some.

The key is to hold vertical speed to ~ 500.  If the vspeed climbs pitch down a little, if it falls below pitch up some. Keep going until your'e above 200km altitude.  Now start working your nose aim down the ladder to around +10 and wait for the horizontal velocity to get above 5.

Note: The increase in horizontal velocity will balance the effect of gravity pulling the ship back to earth. Too little and the ship plummets back to earth surface, too much and we sling out into space and escape earths hold on us.

Once horizontal velocity is above 5 and altitude is above 250 turn on auto prograde[ [ ] . Toggle [H] on the key board to turn HUD from SRFCE to Orbit. Horizontal velocity must rise to 7.7 to keep gravity from pulling the ship back to earth surface. Give it a chance to climb to that speed while you watch the ecc.

Eccentricty is indicated as (ecc) on the Orbit MFD. Let it get as close to zero as possible ( anything below 0.0050 is fine ). Then kill all thrust, numpad[*] key. This should bring us into a stable orbit with the MFD showing a  green circle completely outside of the gray circle.

 Look at the Orbit MFD graphic. As long as the green circle ( ship orbit) is completely outside the gray cirlce ( earth surface ), you are successful.

In each of the two example diagrams, this is the case and the ship will be fine as long as it dosn't skim the atmosphere at periapsis.

The diagram on the left is an eliptical orbit while the one on the right is circular. The eccentricty of the above right diagram is near zero and is what to aimed for during launch.

Change the shape of orbit

You can change the shape of your orbit if you feel periapsis is too close to the atmoshere and you want to change the altitude,  or if you simple feel better with a more circular orbit.

The task is simple. You wait until your ship reaches apoapsis, indicated by the rotating line, turn on auto prograde and thrust until the ecc reads anything below 0.0100. This will push the periapsis to the altitude of apoapsis. You'll be amazed how easy it is to reach zero ecc this way. You can use small burst of thrust if it helps.

For even more fine tuning rotate your ship level with autolevel. Then use linear thrust to zero out any vertical speed ( Vspd on the Surface MFD).

Tip! Use time compression of 10X or 100X to get you quickly to apoapsis.

Change the altitude of orbit

To change altitude, use the Orbit MFD. To increase orbit altitude, thrust prograde at PeD to increase Apd and visa versa. To decrease orbit altitude thrust retrograde at PeD to decrease Apd and visa versa.

To match orbit altitude with target altitude press [Shift][T] in the Orbit MFD. Select target and change your orbit using above technique. You can match numbers or just do a crude adjustment until the two orbits overlap in the graphic display.

 

  Instrument page | Align orbital plane

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