EliNaut
New member
Greetings Orbinauts!
Today i'll be talking about making lunar landings with only using the standard MFDs!
Lets get right to it....
I am a big NASSP fan. So, after getting frustrated watching my LM richochet off the Moon's surface when trying to use autopilots like Land MFD, Base Land, or Lola, I did some mental simulation about what exactly needs to go on to make a smooth decent and touchdown. I'll start out by describing the process in steps, with of course, using NASSP(6.4.3)
Starting out:
A prefferable orbit around the moon should be around 80-100km, and for the most part circular. Power up the LM's RCS and decent stage and undock from the CM.
First burn:
You may have noticed, if you tried to go retrograde or prograde, it is 90 degrees off due to the fact the LM's forward axis is from the cockpit facing out, not up and down on the LM.
But also remember that the NML settings are 90 degrees off from prograde, so we can use those attitudes to offset the rotation so the engines are facing the right way. If you do not understand a word of what I just said, than heres what i'm trying to say:
NML+ is retrograde, instead of the RETRO button.
HOWEVER this does not mean NML- is Prograde. See for yourself.
And note that this is only for the Eagle LM supplied with NASSP.
So, once in true retrograde, gently increase the thrust to about 0.5, so we can accurately set the Pe. Its best to do this on the dark side of the moon(Pink floyd!
), so we can land on the day side. Keep burning until your Pe is around 8km. You could try a lower Pe for different results, but i havnt tried lower than 8km yet. Kill the engines and drift on to your Pe.
Making the second burn + Landing
When you're close to your Pe, hit NML+ again and turn it off once the LM stops manuvering. Heres where some technique gets involved. Have the Surface MFD open and ready!
Throttle up to 100%!
The idea here is to decrease our linear speed while managing vertical speed.
On the Surface MFD, keep tabs on the vertical speed.
When above 3km, a good vertical speed will be around 30-40m/s
To manage verticle speed, use 4 or 5 on the number pad to adjust your angle.
Continue burning until your velocity on your HUD is equal to your verticle speed (suggesting your only moving on the z-axis, up and down)
As your altitude gets lower, decrease your verticle speed to whatever satisfys you, but in any case should be around 10-20m/s when you hit 3km.
The tricky part occurs once your linear speed is near zero.
You'll need to cut thrust on your engines when your all stopped and quickly rotate so your level with the ground now.
Thrust rating should be kept at a low, while you keep your verticle speed under control.
As you approach 1000-500m, verticle speed should be at the most 10-5m/s
When 50m gets called out, lower your veticle speed to 1 or less m/s for a soft touchdown!
Congradulations if you made it!
Any questions, you know where to put them.
I'll do my best to clear anything up that you didnt understand.
Also I might put up a diagram.. I'll see what I can do.
Happy orbiting..
~EliNaut
Today i'll be talking about making lunar landings with only using the standard MFDs!
Lets get right to it....
I am a big NASSP fan. So, after getting frustrated watching my LM richochet off the Moon's surface when trying to use autopilots like Land MFD, Base Land, or Lola, I did some mental simulation about what exactly needs to go on to make a smooth decent and touchdown. I'll start out by describing the process in steps, with of course, using NASSP(6.4.3)
Starting out:
A prefferable orbit around the moon should be around 80-100km, and for the most part circular. Power up the LM's RCS and decent stage and undock from the CM.
First burn:
You may have noticed, if you tried to go retrograde or prograde, it is 90 degrees off due to the fact the LM's forward axis is from the cockpit facing out, not up and down on the LM.
But also remember that the NML settings are 90 degrees off from prograde, so we can use those attitudes to offset the rotation so the engines are facing the right way. If you do not understand a word of what I just said, than heres what i'm trying to say:
NML+ is retrograde, instead of the RETRO button.
HOWEVER this does not mean NML- is Prograde. See for yourself.
And note that this is only for the Eagle LM supplied with NASSP.
So, once in true retrograde, gently increase the thrust to about 0.5, so we can accurately set the Pe. Its best to do this on the dark side of the moon(Pink floyd!
), so we can land on the day side. Keep burning until your Pe is around 8km. You could try a lower Pe for different results, but i havnt tried lower than 8km yet. Kill the engines and drift on to your Pe.Making the second burn + Landing
When you're close to your Pe, hit NML+ again and turn it off once the LM stops manuvering. Heres where some technique gets involved. Have the Surface MFD open and ready!
Throttle up to 100%!
The idea here is to decrease our linear speed while managing vertical speed.
On the Surface MFD, keep tabs on the vertical speed.
When above 3km, a good vertical speed will be around 30-40m/s
To manage verticle speed, use 4 or 5 on the number pad to adjust your angle.
Continue burning until your velocity on your HUD is equal to your verticle speed (suggesting your only moving on the z-axis, up and down)
As your altitude gets lower, decrease your verticle speed to whatever satisfys you, but in any case should be around 10-20m/s when you hit 3km.
The tricky part occurs once your linear speed is near zero.
You'll need to cut thrust on your engines when your all stopped and quickly rotate so your level with the ground now.
Thrust rating should be kept at a low, while you keep your verticle speed under control.
As you approach 1000-500m, verticle speed should be at the most 10-5m/s
When 50m gets called out, lower your veticle speed to 1 or less m/s for a soft touchdown!
Congradulations if you made it!
Any questions, you know where to put them.
I'll do my best to clear anything up that you didnt understand.
Also I might put up a diagram.. I'll see what I can do.
Happy orbiting..
~EliNaut
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