LagrangeLaunchMFD v.250215
For Orbiter2016


INSTALLATION
Unzip into your Orbiter root folder as usual.
Activate LagrangeLaunchMFD in Orbiter launchpad Modules tab.


ADDITIONAL REQUIRED ADD-ONS
It is strongly recommended to use InterplanetaryMFD and LagrangeMFD to visualise and adjust your trajectory after completing Trans-Lagrange-Insertion (TLI) burn.

InterplanetaryMFD
https://www.orbiter-forum.com/resources/interplanetary-mfd.5500/

LagrangeMFD
https://www.orbiter-forum.com/resources/lagrangemfd-1-5-for-orbiter-2016.2868/


WHAT DOES IT DO?
LagrangeLaunchMFD provides information for launching from Earth to a halo orbit around Sun-Earth L1 or L2.

It does NOT do anything clever like computing stable gravitational manifolds around Lagrange points  it just provides information to achieve a suitable transfer trajectory for a large halo orbit around the selected Lagrange point (L1 or L2 only).


DATA DISPLAY
LAUNCH
Inc.(Equ.)		Required parking orbit inclination (Earth equatorial frame)
			[Warning displayed if inclination is too low for launch latitude]
Azimuth		Required launch azimuth at liftoff
Countdown		Time until next instantaneous launch opportunity  launch at T- 0

TLI
dV(Prograde)	Required dV in prograde direction for TLI burn
Burn Duration	Length of burn computed for maximum throttle on Main Engine
Burn Start		Time until ignition  start at T- 0


BUTTONS
[VES]			Select vessel being monitored by LagrangeLaunchMFD
[STS]			Switch MFD On/Off
[LP  ]			Select Sun-Earth Lagrange Point L1 or L2
[NOD]			Select Ascending Node (Northerly launch azimuth) or
			Descending Node (Southerly launch azimuth)
[PO ]			Set planned (circular) parking orbit altitude



NOTES
Once parking orbit is achieved, TLI burn should be performed while vessel maintains Prograde attitude.

After separation from launch vehicle, trim velocity while monitoring your trajectory on InterplanetaryMFD Map.
If your trajectory is escaping away from Earth, burn Retrograde (relative to Earth orbit).
If your trajectory is falling back toward Earth, burn Prograde (relative to Earth orbit).

You want a trajectory that forms an Eye shape on InterplanetaryMFD Map

Once past 100,000km altitude from Earth, use LagrangeMFD display to make course corrections  burn towards or away from Sun. You are aiming for a nice Lasso shape trajectory on LagrangeMFD Rotating Frame display.

Assuming an accurate TLI burn, you should need very little dV to correct and maintain trajectory (typically < 10m/s).

BrianJ
Feb 2025
