Difference between revisions of "Tutorial:Aeris 4A mission"

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m (!cat name;)
(Going to 10° AoA @ 15,000m doesn't work (in 0.22, at least), drag kills your ascent before you reach 20,000m. It seems better to just maintain 30° all the way up. Also, expanded significantly on much of the tutorial.)
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=== Takeoff ===
 
=== Takeoff ===
  
# Activate SAS  
+
# Activate SAS (holding the brakes on while doing this will prevent the small chance of the SAS locking onto a slightly false velocity vector and causing a crash during rollout).
 
# Activate turbojet engines with the 1 key.  
 
# Activate turbojet engines with the 1 key.  
# Set throttle to maximum
+
# Set throttle to 100%.
# Wait until you are at the end of the runway
+
# Wait until you have achieved a speed of around 80–100 m/s.
# Raise the nose very, **very** carefully to avoid scratching the runway with the liquid fuel engine
+
# Raise the nose '''very carefully''' to avoid striking the runway with the liquid fuel engine (this can be significantly improved by replacing the supplied LV-T30 engine with the Toroidal Aerospike Rocket, without any significant downside).
 +
# Gear up when clear of the runway.
  
 
=== Atmospheric ascension ===
 
=== Atmospheric ascension ===
  
# ascend in a vertical angle of about 30° to a height of 15km
+
# Maintain 100% throttle.
# Reduce your vertical angle to about 10° and keep raising watching your intake air level on the Resources panel
+
# Ascend with a nose angle around 30° above the horizon.  Your prograde vector will be somewhere around 10–20° with this nose angle.
 +
# Occasional tiny amounts of nose down input will be required to correct the pitch due to the curvature of the planet.
 +
# Watch your altitude, and intake air on the resources panel.
 +
# You should be able to ascend easily, gaining speed all the way, to 20,000m on the dual turbojets.
  
 
=== Orbital ascension ===
 
=== Orbital ascension ===
  
# When your intake air level reaches 0.07, deactivate the jets and intakes with action group 3 to avoid a flame-out. Then activate the liquid fuel engine with action group 2 and activate RCS.
+
# When your intake air level reaches 0.07 (or at around 20,000m altitude), it is necessary to change from the turbojets over to the rocket engine.
# Keep accelerating in your prograde direction while watching your apoapsis on the map view
+
# Activate the liquid fuel engine with action group 2.
# When your apoapsis exceeds 100km, set your throttle to 0%
+
# Shutdown the jets and close the intakes with action group 3 to avoid an asymmetric flame-out. Intake air starvation will occur somewhere around 22,000m.
# wait until you've reached your apoapsis and circularize your orbit with another burn
+
# Maintain 100% throttle.
 +
# Continue to ascend at an angle of around 30° above the horizon, applying occasional small amounts of nose down to follow the curvature of the planet.
 +
# Watch your apoapsis on the map view.
 +
# When your apoapsis reaches 100km, set your throttle to 0%.
 +
# Wait until you've reached your apoapsis and circularize your orbit with a prograde burn.  If the ascent went well, this should be a fairly short burn, probably somewhere around 10s.
  
 
=== Orbital maneuvers ===
 
=== Orbital maneuvers ===
Line 29: Line 37:
  
 
# To land at (or at least near) the KSC, perform your deorbit burn when you are approximately over the large impact crater. Burn retrograde until your trajectory hits the continent east of the KSC.
 
# To land at (or at least near) the KSC, perform your deorbit burn when you are approximately over the large impact crater. Burn retrograde until your trajectory hits the continent east of the KSC.
# turn your craft to face prograde
+
# Alternatively, perform your deorbit burn when KSC is on the directly opposite side of the planet, i.e. 180° from your current position.  Burn retrograde until your new periapsis is at approximately 35km directly over KSC.  Once atmospheric drag is accounted for, this should bring you down below 20,000m (where you can regain atmospheric flight control) a little to the west of KSC, and about 5–10,000m approaching the mountains.
 +
# Turn your craft to face prograde.
 
# Due to a construction mistake the jet engines won't work when there is no liquid fuel in the tanks connected to them They can't take fuel from the central tank. So pump the liquid fuel from the central jet fuel tank into the two outer FL-T400 tanks before you proceed. Make sure that the distribution between them is as equal as possible to avoid moving your center of mass to the side.
 
# Due to a construction mistake the jet engines won't work when there is no liquid fuel in the tanks connected to them They can't take fuel from the central tank. So pump the liquid fuel from the central jet fuel tank into the two outer FL-T400 tanks before you proceed. Make sure that the distribution between them is as equal as possible to avoid moving your center of mass to the side.
 
# Shut down the rocket engine by right-clicking on it and selecting "Shutdown Engine"
 
# Shut down the rocket engine by right-clicking on it and selecting "Shutdown Engine"
# Re-activate the air intakes with action group 3
+
# Re-activate the air intakes with action group 3.
# Re-activate the jet engines with action group 1, but do not activate throttle until you have intake air again.
+
# Re-activate the jet engines with action group 1, but do not activate throttle until you have intake air again, at 20,000m or lower altitude.
  
 
=== Re-Entry ===
 
=== Re-Entry ===
  
# You will start to notice atmospheric drag reducing your speed at about 40km height.
+
# You will start to notice atmospheric drag significantly reducing your speed at about 40,000m height.  This will continue to have significant effects down to around 20,000m.
# From now on, keep the roll parallel to the horizon and the nose pointed at the prograde marker on the nav-ball at all times.  
+
# From now on, keep the roll parallel to the horizon and the nose pointed at , or just above the prograde marker on the nav-ball at all times.  
# When you are at about 10km height and 400 m/s speed, you will be able to fly properly again. Put some power to the jet engines and try to get into a level flight with constant speed.
+
# When you are below 20,000m altitude and 400 m/s speed, you should be able to begin to fly normally again.
 +
# Wait until your speed is low enough, or altitude is becoming critical before attempting to convert to normal flight.
 +
# Put some power to the jet engines while pointing prograde and try to get into a level flight with constant speed.
 
# Navigate to the KSC or find another suitable spot for landing.
 
# Navigate to the KSC or find another suitable spot for landing.
 +
# With some practice on getting the deorbit burn from a circular 100km orbit timed just right, it is possible to regain atmospheric flight control at around 15–20,000m altitude, and be in a controlled straight and level flight at 10,000m just in time to start a gentle controlled descent and approach for landing on the KSC runway.
 +
# When approaching KSC from the west, remember to keep above 5,000m until you are clear of the mountains.
 +
# Since you are probably low-ish on fuel, keep the throttle somewhere in the range of 33–66% (lower is usually better), while flying in, for maximum fuel efficiency (you use significantly more fuel fighting air resistance at higher speeds).  Reduce throttle to 20% or less (or even 0%) when descending.
  
 
=== Landing ===
 
=== Landing ===
Line 46: Line 60:
 
You do not necessarily need to land on the runway. Try it when you want to show off, but landing on the flat plain around the KSC is much easier.
 
You do not necessarily need to land on the runway. Try it when you want to show off, but landing on the flat plain around the KSC is much easier.
  
# Make sure the landing gear is out and activate the brakes
+
# Planting a flag on the grass at each end of the runway can help you find it and line up with it from a distance.  The runway is 09/27, i.e. 090° or 270°.
# Go on slow, very low and in a very flat angle
+
# Switching to the chase camera view can be quite helpful when flying an approach and landing.
# gradually reduce the speed while trying to remain level until you drop to the ground while your nose is still pointing slightly upwards
+
# Go in slow, very low, and at a very flat angle.
# let the brakes bring you to a halt
+
# Plan to be established on a controlled, stable approach at around 10km out from the runway, and certainly no later than 5km out.  If approaching from the west, this means as soon as reasonably possible after you clear the mountains, but is possible without a violent descent.
# Congratulate yourself
+
# An altitude of 500–1000m when 10km out, and 250m when 5km out should be good for a nice gentle final approach.
 +
# If you are unstable between 5km and the runway, or very badly aligned to the runway at that point, it's usually better to go around and try again, if you have the fuel to do so.  Try to avoid violent control inputs on the last 5km of approach.
 +
# Make sure the landing gear is down.
 +
# On final approach, a speed of 60–100m/s should be good, with a vertical speed of less than 5m/s, nose up 5–10°.
 +
# Check your heading, it should be 090° or 270° on final approach.
 +
# Gradually reduce the speed while trying to remain level until you very gently drop to the ground while your nose is still pointing slightly upwards.  Don't try to kill lots of speed at the last moment, it's probably not going to work.  Get the speed fully under control by 5km out, if possible.
 +
# Ideally you should gently touch down on the rear wheels only, with the nose up 5–10°, then the front wheel.  Front wheel (or all 3) first is both very bad style; and can be uncontrollable, resulting in a crash.
 +
# If the nose is too high at touchdown, you may strike the LV-T30 on the runway (unless you replaced it with the Toroidal Aerospike, as suggested earlier).
 +
# If your vertical speed is too high, expect the engines (or more) to fall off on touchdown, if you don't just explode.
 +
# It's a long runway, don't try to force the plane down.  Better to touch down a little late than leave smoking wreckage on the threshold!
 +
# Throttle to 0% just before touchdown.
 +
# For a perfect landing, the rear wheels should gently touch down on, or just after, the "piano keys" at the start of the runway.
 +
# Use the brakes to bring you to a halt.
 +
# Congratulate yourself!
  
 
[[Category:Tutorials]]
 
[[Category:Tutorials]]

Revision as of 19:15, 15 November 2013

The Aeris 4A ready to start

This is an outline for a typical mission with an Aeris 4A a SSTO.

Takeoff

  1. Activate SAS (holding the brakes on while doing this will prevent the small chance of the SAS locking onto a slightly false velocity vector and causing a crash during rollout).
  2. Activate turbojet engines with the 1 key.
  3. Set throttle to 100%.
  4. Wait until you have achieved a speed of around 80–100 m/s.
  5. Raise the nose very carefully to avoid striking the runway with the liquid fuel engine (this can be significantly improved by replacing the supplied LV-T30 engine with the Toroidal Aerospike Rocket, without any significant downside).
  6. Gear up when clear of the runway.

Atmospheric ascension

  1. Maintain 100% throttle.
  2. Ascend with a nose angle around 30° above the horizon. Your prograde vector will be somewhere around 10–20° with this nose angle.
  3. Occasional tiny amounts of nose down input will be required to correct the pitch due to the curvature of the planet.
  4. Watch your altitude, and intake air on the resources panel.
  5. You should be able to ascend easily, gaining speed all the way, to 20,000m on the dual turbojets.

Orbital ascension

  1. When your intake air level reaches 0.07 (or at around 20,000m altitude), it is necessary to change from the turbojets over to the rocket engine.
  2. Activate the liquid fuel engine with action group 2.
  3. Shutdown the jets and close the intakes with action group 3 to avoid an asymmetric flame-out. Intake air starvation will occur somewhere around 22,000m.
  4. Maintain 100% throttle.
  5. Continue to ascend at an angle of around 30° above the horizon, applying occasional small amounts of nose down to follow the curvature of the planet.
  6. Watch your apoapsis on the map view.
  7. When your apoapsis reaches 100km, set your throttle to 0%.
  8. Wait until you've reached your apoapsis and circularize your orbit with a prograde burn. If the ascent went well, this should be a fairly short burn, probably somewhere around 10s.

Orbital maneuvers

You can now do an EVA or attempt to rendezvous and dock with another craft in orbit, but try not to use too much liquid fuel, as you will need some left for deorbiting.

Deorbiting

  1. To land at (or at least near) the KSC, perform your deorbit burn when you are approximately over the large impact crater. Burn retrograde until your trajectory hits the continent east of the KSC.
  2. Alternatively, perform your deorbit burn when KSC is on the directly opposite side of the planet, i.e. 180° from your current position. Burn retrograde until your new periapsis is at approximately 35km directly over KSC. Once atmospheric drag is accounted for, this should bring you down below 20,000m (where you can regain atmospheric flight control) a little to the west of KSC, and about 5–10,000m approaching the mountains.
  3. Turn your craft to face prograde.
  4. Due to a construction mistake the jet engines won't work when there is no liquid fuel in the tanks connected to them They can't take fuel from the central tank. So pump the liquid fuel from the central jet fuel tank into the two outer FL-T400 tanks before you proceed. Make sure that the distribution between them is as equal as possible to avoid moving your center of mass to the side.
  5. Shut down the rocket engine by right-clicking on it and selecting "Shutdown Engine"
  6. Re-activate the air intakes with action group 3.
  7. Re-activate the jet engines with action group 1, but do not activate throttle until you have intake air again, at 20,000m or lower altitude.

Re-Entry

  1. You will start to notice atmospheric drag significantly reducing your speed at about 40,000m height. This will continue to have significant effects down to around 20,000m.
  2. From now on, keep the roll parallel to the horizon and the nose pointed at , or just above the prograde marker on the nav-ball at all times.
  3. When you are below 20,000m altitude and 400 m/s speed, you should be able to begin to fly normally again.
  4. Wait until your speed is low enough, or altitude is becoming critical before attempting to convert to normal flight.
  5. Put some power to the jet engines while pointing prograde and try to get into a level flight with constant speed.
  6. Navigate to the KSC or find another suitable spot for landing.
  7. With some practice on getting the deorbit burn from a circular 100km orbit timed just right, it is possible to regain atmospheric flight control at around 15–20,000m altitude, and be in a controlled straight and level flight at 10,000m just in time to start a gentle controlled descent and approach for landing on the KSC runway.
  8. When approaching KSC from the west, remember to keep above 5,000m until you are clear of the mountains.
  9. Since you are probably low-ish on fuel, keep the throttle somewhere in the range of 33–66% (lower is usually better), while flying in, for maximum fuel efficiency (you use significantly more fuel fighting air resistance at higher speeds). Reduce throttle to 20% or less (or even 0%) when descending.

Landing

You do not necessarily need to land on the runway. Try it when you want to show off, but landing on the flat plain around the KSC is much easier.

  1. Planting a flag on the grass at each end of the runway can help you find it and line up with it from a distance. The runway is 09/27, i.e. 090° or 270°.
  2. Switching to the chase camera view can be quite helpful when flying an approach and landing.
  3. Go in slow, very low, and at a very flat angle.
  4. Plan to be established on a controlled, stable approach at around 10km out from the runway, and certainly no later than 5km out. If approaching from the west, this means as soon as reasonably possible after you clear the mountains, but is possible without a violent descent.
  5. An altitude of 500–1000m when 10km out, and 250m when 5km out should be good for a nice gentle final approach.
  6. If you are unstable between 5km and the runway, or very badly aligned to the runway at that point, it's usually better to go around and try again, if you have the fuel to do so. Try to avoid violent control inputs on the last 5km of approach.
  7. Make sure the landing gear is down.
  8. On final approach, a speed of 60–100m/s should be good, with a vertical speed of less than 5m/s, nose up 5–10°.
  9. Check your heading, it should be 090° or 270° on final approach.
  10. Gradually reduce the speed while trying to remain level until you very gently drop to the ground while your nose is still pointing slightly upwards. Don't try to kill lots of speed at the last moment, it's probably not going to work. Get the speed fully under control by 5km out, if possible.
  11. Ideally you should gently touch down on the rear wheels only, with the nose up 5–10°, then the front wheel. Front wheel (or all 3) first is both very bad style; and can be uncontrollable, resulting in a crash.
  12. If the nose is too high at touchdown, you may strike the LV-T30 on the runway (unless you replaced it with the Toroidal Aerospike, as suggested earlier).
  13. If your vertical speed is too high, expect the engines (or more) to fall off on touchdown, if you don't just explode.
  14. It's a long runway, don't try to force the plane down. Better to touch down a little late than leave smoking wreckage on the threshold!
  15. Throttle to 0% just before touchdown.
  16. For a perfect landing, the rear wheels should gently touch down on, or just after, the "piano keys" at the start of the runway.
  17. Use the brakes to bring you to a halt.
  18. Congratulate yourself!