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

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(*moved this into a tutorial;)
 
(→‎Ascent to Orbit)
 
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This is an outline for a typical mission with an [[Aeris 4A]] a SSTO.
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[[File:Aeris 4A on runway.png|thumb|The Aeris 4A ready to start]]
  
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=== Takeoff ===
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This guide will help you fly the [[Aeris 4A]] into orbit, and land back at the KSC runway.
  
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# Activate SAS
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The Aeris 4A is an SSTO spaceplane that has air-breathing Turbo Ramjet Engines for use at lower altitude and speed, while a Toroidal Aerospike Engine takes over when the ramjets become ineffective.
−
# Activate turbojet engines with the 1 key.
 
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# Set throttle to maximum
 
−
# Wait until you are at the end of the runway
 
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# Raise the nose very, **very** carefully to avoid scratching the runway with the liquid fuel engine
 
  
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=== Atmospheric ascension ===
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For simplicity, this guide will call the Turbo Ramjet Engines “jet engines”, and the Toroidal Aerospike will simply be called “rocket engine”.
  
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# ascend in a vertical angle of about 30° to a height of 15km
+
This guide assumes that you have never flown a spaceplane into orbit before, but some of the details here should be interesting for experienced KSP players as well. Hopefully, this guide will help you become familiar with the operational principle of air-breathing SSTO spaceplanes, allowing you to not only be able to fly the Aeris 4A, but also design much better vehicles of your own.
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# Reduce your vertical angle to about 10° and keep raising watching your intake air level on the Resources panel
 
  
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=== Orbital ascension ===
 
  
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# 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.
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== Takeoff ==
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# Keep accelerating in your prograde direction while watching your apoapsis on the map view
 
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# When your apoapsis exceeds 100km, set your throttle to 0%
 
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# wait until you've reached your apoapsis and circularize your orbit with another burn
 
  
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=== Orbital maneuvers ===
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Before we get into space, the Aeris 4A takes off and flies just like a regular plane.
  
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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.
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# Activate SAS
 +
# Activate jet engines (Default Hotkey: 5)
 +
# Throttle to 100% (Default Hotkey: Z)
 +
# Pull up after speed reaches 70m/s
 +
#: Note: Aeris 4A is not at risk of a tailstrike during takeoff, but it is still good form to pull up gently.
 +
# Gear up after altitude reaches 80m
 +
#: Note: The KSC Runway has an altitude of 70m and the altitude is read from the cockpit. Even with an altitude reading of 72 meters, the rear wheels may still be on the ground.
  
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=== Deorbiting ===
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== Ascent to Orbit ==
  
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# 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.
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In case you didn’t know, being in orbit means that you are in free fall (i.e. being accelerated toward the surface of the planet by gravity, just as a skydiver would be) but your pro-grade velocity (speed in the direction you are traveling around the planet) is so high that you keep missing the planet's surface. So, basically, you're falling ''around'' the planet.
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# turn your craft to face prograde
 
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# 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.
 
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# Shut down the rocket engine by right-clicking on it and selecting "Shutdown Engine"
 
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# Re-activate the air intakes with action group 3
 
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# Re-activate the jet engines with action group 1, but do not activate throttle until you have intake air again.
 
  
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=== Re-Entry ===
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You will need a pro-grade velocity of around 2270m/s to acheive orbit. You will also want to be above 70km; under 70km, air resistance will slowly eat away at the speed you worked so hard to gain; above 70km, there is no air resistance, and your speed won’t be lost. Thus, you stay in space forever without having to expend fuel.
  
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# You will start to notice atmospheric drag reducing your speed at about 40km height.
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So let’s start spinning around our planet by heading eastward.
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# 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.
 
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# 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.
 
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# Navigate to the KSC or find another suitable spot for landing.
 
  
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=== Landing ===
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# Maintain a heading of 90 (East)
 +
#: Note: Because the planet Kerbin spins eastward at 175m/s, it means that you get 175m/s for free when entering into a west-to-east orbit. While the Aeris 4A is capable of entering into a different orbit, the procedure will be different, and this guide will only cover getting into the simplest west-to-east orbit.
 +
# Keep aircraft nose pointed 15 degrees above the horizon
 +
# When altitude exceeds 18km, and speed exceeds 1380m/s, active rocket engine (Default Hotkey: 6)
 +
#: Note: The Aeris 4A’s jet engines are 11 times more fuel efficient than the rocket engine, so we want to use them for as long as possible.
 +
# Keep aircraft nose pointed 10 degrees above the horizon
 +
# Go into map view (Default Hotkey: M)
 +
# When apoapsis reaches 80km, cut throttle to 0% (Default Hotkey: X)
 +
# Keep aircraft nose pointed prograde
 +
# Coast toward apoapsis
 +
# About 10 seconds before arriving at apoapsis, throttle back up to 100% again, and keep nose pointed prograde
 +
# When periapsis rises to about 80km, set throttle to 0%
  
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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.
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Congratulations, you flew a plane into orbit! You can now stay in space forever, until you voluntarily fire your engines to deorbit yourself.
  
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# Make sure the landing gear is out and activate the brakes
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== Orbital Mission ==
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# Go on slow, very low and in a very flat angle
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# gradually reduce the speed while trying to remain level until you drop to the ground while your nose is still pointing slightly upwards
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The stock Aeris 4A can be used to perform theses missions:
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# let the brakes bring you to a halt
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# Congratulate yourself
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*Create crew reports and EVA reports, then send them back to Kerbin for Science Points.
 +
*Transporting one Kerbal to another ship or space station.
 +
*Docking with and refueling another ship or space station.
 +
 
 +
 
 +
If you want to get back to Kerbin from an 80km by 80km circular orbit, you will need this much fuel: 66 oxidizer and 54 liquid fuel.
 +
 
 +
== Deorbit and landing ==
 +
 
 +
This part is hard. I am sorry to say that the Aeris 4A’s Mk1 cockpit is not very heat resistant, and very prone to burning up during reentry. To ensure safety, I suggest a long and arduous “skip reentry”.
 +
 
 +
We will first get low in the atmosphere, bounce off (skip) to a pretty high altitude again, and then perform a second descent. The long and winding path traveled will spread the heat over a greater amount of time, and ensure survival.
 +
 
 +
The long and winding path will also make an accurate landing at the KSC runway difficult. However, with practice, accurate unpowered landings can be consistently done.
 +
 
 +
Imagine a point halfway across the ocean separating the KSC continent and the continent to its west, we will call this Location A. From Location A, imagine following the equator westward for a distance equal to 1/4 of Kerbin's circumference. This position, which is close to the giant impact crater, we will call Location B.
 +
 
 +
# When your orbital path takes you above Location B, start burning retrograde.
 +
# When your current projected path ends at Location A, stop the burn.
 +
# Deactivate the engines.
 +
#: Note: Because they don't don’t work in space, you may not realize the jet engines are still on.
 +
# Keep your nose pointed prograde as you descend through the atmosphere.
 +
# When your altitude reaches 35km, start pulling up gently.
 +
# When your nose is stable at about 10 degrees above the horizon, pull up hard and keep it pulled.
 +
#: Note: The large delta wing will ensure you won’t backflip. If you eased into this maneuver gently your nose won’t oscillate up and down.
 +
# Around 43km you will begin descending again. Point the nose back down until it is aligned with prograde.
 +
# Nose up if you think you will undershoot the KSC runway; nose down if you think you will overshoot. Make yaw and roll adjustments as needed. If you need to lose speed, use the “nose up and down” maneuver, but don’t do it too hard, or you will rip your wings off.
 +
#: Note: If you end up too far off course to glide, you can try to reignite your jet engines and do a powered flight back to the KSC.
 +
# For a gentle landing, you should hit the runway at less than 100m/s airspeed, and less than 5m/s vertical speed. Apply wheel brakes (Default Hotkey: Hold B) to come to a full stop.
 +
 
 +
Congratulations! You went to orbit and back! In a plane! And you didn’t jettison any parts during the journey!
 +
 
 +
[[Category:Tutorials|Aeris 4A mission]]

Latest revision as of 00:16, 6 July 2020

The Aeris 4A ready to start

This guide will help you fly the Aeris 4A into orbit, and land back at the KSC runway.

The Aeris 4A is an SSTO spaceplane that has air-breathing Turbo Ramjet Engines for use at lower altitude and speed, while a Toroidal Aerospike Engine takes over when the ramjets become ineffective.

For simplicity, this guide will call the Turbo Ramjet Engines “jet engines”, and the Toroidal Aerospike will simply be called “rocket engine”.

This guide assumes that you have never flown a spaceplane into orbit before, but some of the details here should be interesting for experienced KSP players as well. Hopefully, this guide will help you become familiar with the operational principle of air-breathing SSTO spaceplanes, allowing you to not only be able to fly the Aeris 4A, but also design much better vehicles of your own.


Takeoff

Before we get into space, the Aeris 4A takes off and flies just like a regular plane.

  1. Activate SAS
  2. Activate jet engines (Default Hotkey: 5)
  3. Throttle to 100% (Default Hotkey: Z)
  4. Pull up after speed reaches 70m/s
    Note: Aeris 4A is not at risk of a tailstrike during takeoff, but it is still good form to pull up gently.
  5. Gear up after altitude reaches 80m
    Note: The KSC Runway has an altitude of 70m and the altitude is read from the cockpit. Even with an altitude reading of 72 meters, the rear wheels may still be on the ground.

Ascent to Orbit

In case you didn’t know, being in orbit means that you are in free fall (i.e. being accelerated toward the surface of the planet by gravity, just as a skydiver would be) but your pro-grade velocity (speed in the direction you are traveling around the planet) is so high that you keep missing the planet's surface. So, basically, you're falling around the planet.

You will need a pro-grade velocity of around 2270m/s to acheive orbit. You will also want to be above 70km; under 70km, air resistance will slowly eat away at the speed you worked so hard to gain; above 70km, there is no air resistance, and your speed won’t be lost. Thus, you stay in space forever without having to expend fuel.

So let’s start spinning around our planet by heading eastward.

  1. Maintain a heading of 90 (East)
    Note: Because the planet Kerbin spins eastward at 175m/s, it means that you get 175m/s for free when entering into a west-to-east orbit. While the Aeris 4A is capable of entering into a different orbit, the procedure will be different, and this guide will only cover getting into the simplest west-to-east orbit.
  2. Keep aircraft nose pointed 15 degrees above the horizon
  3. When altitude exceeds 18km, and speed exceeds 1380m/s, active rocket engine (Default Hotkey: 6)
    Note: The Aeris 4A’s jet engines are 11 times more fuel efficient than the rocket engine, so we want to use them for as long as possible.
  4. Keep aircraft nose pointed 10 degrees above the horizon
  5. Go into map view (Default Hotkey: M)
  6. When apoapsis reaches 80km, cut throttle to 0% (Default Hotkey: X)
  7. Keep aircraft nose pointed prograde
  8. Coast toward apoapsis
  9. About 10 seconds before arriving at apoapsis, throttle back up to 100% again, and keep nose pointed prograde
  10. When periapsis rises to about 80km, set throttle to 0%

Congratulations, you flew a plane into orbit! You can now stay in space forever, until you voluntarily fire your engines to deorbit yourself.

Orbital Mission

The stock Aeris 4A can be used to perform theses missions:

  • Create crew reports and EVA reports, then send them back to Kerbin for Science Points.
  • Transporting one Kerbal to another ship or space station.
  • Docking with and refueling another ship or space station.


If you want to get back to Kerbin from an 80km by 80km circular orbit, you will need this much fuel: 66 oxidizer and 54 liquid fuel.

Deorbit and landing

This part is hard. I am sorry to say that the Aeris 4A’s Mk1 cockpit is not very heat resistant, and very prone to burning up during reentry. To ensure safety, I suggest a long and arduous “skip reentry”.

We will first get low in the atmosphere, bounce off (skip) to a pretty high altitude again, and then perform a second descent. The long and winding path traveled will spread the heat over a greater amount of time, and ensure survival.

The long and winding path will also make an accurate landing at the KSC runway difficult. However, with practice, accurate unpowered landings can be consistently done.

Imagine a point halfway across the ocean separating the KSC continent and the continent to its west, we will call this Location A. From Location A, imagine following the equator westward for a distance equal to 1/4 of Kerbin's circumference. This position, which is close to the giant impact crater, we will call Location B.

  1. When your orbital path takes you above Location B, start burning retrograde.
  2. When your current projected path ends at Location A, stop the burn.
  3. Deactivate the engines.
    Note: Because they don't don’t work in space, you may not realize the jet engines are still on.
  4. Keep your nose pointed prograde as you descend through the atmosphere.
  5. When your altitude reaches 35km, start pulling up gently.
  6. When your nose is stable at about 10 degrees above the horizon, pull up hard and keep it pulled.
    Note: The large delta wing will ensure you won’t backflip. If you eased into this maneuver gently your nose won’t oscillate up and down.
  7. Around 43km you will begin descending again. Point the nose back down until it is aligned with prograde.
  8. Nose up if you think you will undershoot the KSC runway; nose down if you think you will overshoot. Make yaw and roll adjustments as needed. If you need to lose speed, use the “nose up and down” maneuver, but don’t do it too hard, or you will rip your wings off.
    Note: If you end up too far off course to glide, you can try to reignite your jet engines and do a powered flight back to the KSC.
  9. For a gentle landing, you should hit the runway at less than 100m/s airspeed, and less than 5m/s vertical speed. Apply wheel brakes (Default Hotkey: Hold B) to come to a full stop.

Congratulations! You went to orbit and back! In a plane! And you didn’t jettison any parts during the journey!

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