Difference between revisions of "Tutorial:Basic SSTO Design/zh-cn"

Latest revision as of 19:09, 2 May 2019

本教程解释了如何构建一个单级入轨（SSTO）的空天飞机。SSTO能够发射到太空中并返回，而不会抛弃任何部件。

动力方案

所有希望去其他地方的飞行器都需要引擎。 SSTO有三种流行的选择。

喷气引擎

首先是喷气引擎。 相对较高的效率和推力，以及低成本，使它们成为全面的和明智的动力。 在设计SSTO飞行器时，因为这些喷气发动机无法在真空中运行，我们将需要喷气引擎的工作高度尽可能的高。 虽然Basic Jet Engine成本较低，耗油量和金钱较少，但目前TurboJet Engine 是更明智的选择。 Basic Jet Engine无法在高海拔地区具有良好的性能。

喷气引擎使用液体燃料和空气提供动力。 液体燃料可以由常规的火箭燃料桶提供，但考虑到较高的经济性和液体燃料的单独供应，喷气式机身将是更合理的选择。 空气由进气口提供。根据您安装的数量，您的喷气发动机的最大工作高度大概在15公里到30公里之间。 Shock Cone Intake是目前进气量最高的进气口。

火箭引擎

其次是火箭引擎。是火箭引擎将你的飞行器送入轨道。 Toroidal Aerospike Rocket是其中一个很好的选择，因为小巧和高比冲（比其他发动机表现更好）。 对于更经济的设计来说，LV-T45不是一个坏的选择。 然而，它的巨大尺寸可能会使从跑道起飞而不破坏发动机变的十分棘手。

R.A.P.I.E.R 引擎

R.A.P.I.E.R引擎在KSP 0.23版本中被引入，正是SSTO所有需求的“二合一”解决方案。 它可以用作“吸气模式”下的喷气引擎，也可以用作“闭路循环”模式下更强大的火箭引擎。 在Kerbin大气中3.7马赫时推力达到465.462 kN，真空中也有180 kN，R.A.P.I.E.R引擎确实是一款最合适的SSTO引擎。 虽然发动机可以自动切换模式，但为了达到最佳性能，应该观察推力输出（通过在飞行中右键点击发动机），一旦轨道速度停止增加，就应强制性地将所有引擎转换为闭路循环。 建立一个行动小组是最好的方式来做到这一点，并在同一时间关闭全部进气口以，减少助力。

Stability

空中稳定性是SSTO的性能如何的一个最重要的因素。稳定的飞行器将比不稳定的飞行器更为理想。 KSP中有几个力对SSTO飞行器的飞行特性有影响。

质心

首先是质心。 质量中心简称质心，指物质系统上被认为质量集中于此的一个假想点。作为任何旋转力的中心支点。 任何飞行器的质量中心都将因燃烧燃料而发生变化，但这对于SSTO来说尤为重要，因为解体和其他灾难性的稳定性故障将阻碍其进入太空的能力。

升力中心

其次是升力中心。这可以说是在建造SSTO时设计师应该考虑的最重要的因素。 为了防止spin-outs和其他灾难性的稳定性失效，最重要的是升力中心始终位于质量中心的后方。

推力中心

有时被忽视的因素是推力中心。 它是推力作用在飞行器上的地方。 尽管这对于大多数SSTO系统来说可能不是问题，但检查一下你的推力中心是否与你的质心和升力大致在一条直线上是明智的。

底线：确保你的质量中心始终在你的升力中心之前，你的质心在推力的延长线上。

阻力

真实世界的阻力是非常复杂的，早期版本的ksp里简化为一个系数乘以部件的质量。最近版本的ksp里，阻力复杂得多，锥帽可以减少阻力。飞行时按F12可以显示阻力和升力，在设计界面里无法显示阻力中心（或许也不存在阻力中心），我们大致可以认为阻力中心在形心附近。设计时阻力中心最好要在质心后面，就像羽毛球那样，才能保值稳定。但实际上很难做到这点，因为引擎的密度往往比其他部件大很多。如果飞行器的质心非常靠后，那么最好让升力中心靠后的更多，以保持飞行器的稳定。

其他系统

这些是SSTO作为飞行器的通用部分（然而驾驶舱是必须的，像往常一样）

驾驶舱

可能性是无限的。 您可以创建有人或无人SSTO。 只需要记得载人的要有船员和无人的要有电。 例如Mk1 Cockpit是一个有人驾驶的指挥舱，而Probodobodyne HECS是一个无人驾驶的指挥舱。卫星用的控制核心probe将需要整流罩或货舱来保持空气动力学的流线型。

Takeoff Gear

这里称为“起飞装置”，是因为可以使用发射固定支架发射飞行器并使用降落伞降落。

但是对于传统的SSTO，小型起落架就是飞行器起飞所需要的。 请记得在起飞后立即收起，并在着陆前将其放下。

降落伞对于SSTO是有用的，因为它不需要降落到跑道。 只需部署就能安全地返回到地面。

SAS

On most SSTOs with a command module or similar central pod there is going to be an ASAS. Since the standard cockpits are supplied with their own SAS and a decent one mind you, it is mostly unnecessary to add additional SAS to your SSTO, in the form of reaction wheels. However, for larger craft it may be important to include external SAS to help maneuver with the extra mass, and you can always disable external SAS at your whim.

SAS is a stability augmentation system, which basically means it helps your craft fly straight. In order to accomplish this, it could hijack the circuits to your control surfaces but it also provides "torque", which would be applied here as "movement". This helps your craft maneuver in vacuum, even without RCS, and where conventional control surfaces are ineffective.

RCS

RCS is required for maneuvering in a vacuum, a must-have if you plan to actually perform tasks in orbit. Otherwise it is unnecessary for simple orbiting/deorbiting. However, on heavier and/or less stable craft, an RCS coupled with SAS can make flying much easier.

RCS is activated the with the "R" button with stock controls, first and foremost. RCS is fueled exclusively by Monopropellant tanks. When your monopropellant stores are depleted your RCS will fail to function.

Aerodynamics

Specifically Wings and Control Surfaces. These are what allow the SSTO to function as an atmospheric craft. The Delta Wing is a solid choice, with a large surface area handy for attaching additional objects to, as well as being rather symmetrical and easy to work with.

However, the Delta Wing is fixed and cannot provide any kind of maneuvering (it only makes your plane fly). In order to turn in-atmosphere, you are going to need control surfaces. The numerous elevons, rotating winglets, and canards are all considered control surfaces. Control surfaces have the distinction of being to pivot or otherwise react to controls, providing lift in certain directions. This is contrasted with regular winglets, which are fixed and cannot move.

Power

Depending on your conditions, you may need to provide additional electrical power to your SSTO. This can be stored in batteries and/or supplied by solar panels, RTGs, or fuel cells. Electricity is used to turn the ship via its reaction wheels, to transmit science back to Kerbin with antennas, to conduct research in Mobile Processing Labs, to operate ion engines, and to operate mining excavators and resource converters.

In general, at least 1-2 solar panels is recommended for nearly everything going into space to avoid being unable to rotate due to loss of power, or losing control of unmanned spacecraft.

Extra batteries may be desirable if you do not have enough power production to meet the needs of your antenna(s) when transmitting data back to Kerbin. For example, if you're going to take an ion-powered spaceplane to Eeloo and want to use a Communotron 88-88 antenna to send back an orbital gravity scan, the antenna will require 100 electricity per second for 3 seconds. You could store that much energy in three Z-100 Rechargeable Battery Packs (0.03 mass), or you could try to produce it as you use it with 125 RTGs (10 mass), or, due to the distance from Kerbol, you'd require 244 Gigantor XL Solar Arrays (73.2 mass). The batteries are the obvious winner in this case.

Putting the pieces together

Now that the basics of SSTO design have been covered, it is time for you to assemble your first SSTO.

Remember to consider everything above to create a working SSTO.

Troubleshooting

Answers likely questions people may run into when designing SSTOs. However, if you even try to build an SSTO you will need a basic understanding of Kerbal Space Program physics, so check there as well if this can't answer your question(s).

It doesn't take off.

Make sure your landing gear is placed such that your craft can achieve a positive angle of attack while it's on the runway. Typically you'll have either a nose wheel and two wheels slightly behind centre of mass that act as a fulcrum (your elevators push down on the tail and lift the nose, rotating around the rear wheels), or a tail wheel that's placed higher than two other wheels (which are ahead of the centre of mass) so that the craft has a positive angle of attack even when stationary on the runway and will naturally lift off at the right speed without pitching upwards.

It spins out on the runway.

Make sure your landing gear is placed symmetrically and your center of mass and lift are both in the center of the craft. A common issue with wing mounted landing gear is they will be 5 degrees toe in or 10 degrees toe out. Use the SHIFT key to make smaller rotations to get them aligned straight. You will also need horizontal aerodynamic stability, which is classically accomplished with a vertical tail fin. As with launch stability of rockets, you may find your pilot has too much control authority in the yaw dimension and is overcompensating - try using a different part as a tail fin.

I keep blowing up my engines when trying to lift off

Be slightly gentler on the stick, change the layout of your engine modules to be slightly forwards, or make your landing gear taller so your tail won't hit the ground when you pitch up.

It flips out whenever I move/start flying.

This is likely a result of a poor center of mass/lift. If this occurs just after liftoff, check these in the Spaceplane Hangar; you will be most likely find your answer there. If this occurs late-flight, it is a result of either something breaking off or fuel moving around and changing the center of mass (probably the latter). This is a relatively easy to fix problem. Before entering the atmosphere again, move your fuel forwards to hopefully place the center of mass ahead of the center of lift.

I can't reach orbit

This is the result of not having enough Delta-V, or just poor flying. For most SSTOs, a safe procedure is to: Take off from the runway, make a 45-degree angle climb. You should know at what altitude your jet engines burn out, so shut them off and close intakes. Immediately start your main engine(s) and keep climbing till you reach your desired orbit height. Burn towards the horizon until your periapsis is at least above 70km.

I hit the runway when landing and died.

Coming in for hot landings (usually above 80 m/s) will cause your aircraft to either bounce off the runway or blow up. Slow your descent by throttling back when around a kilometer from the runway, then nose up slightly and deploy landing gear and flaps (right click your ailerons and elevators and deploy them - this will generate extra lift and drag). When you contact with the tarmac, apply brakes. If you die again you were either too fast or your center of mass was off. If you can't slow down enough, try adding air brakes and deploying them before landing.

How can I make landing easier?

Just burn retrograde when in orbit until your trajectory is intersecting with the planet. Have a parachute or two on standby and deploy them when you think you're close enough to the ground (they will activate for you but will induce significant G-force on your craft). You will probably not land where you wanted.

Is there any way to make it better than it already is?

Chances are if you have already reached this point it is unnecessary to create a new craft for the purpose of this previous craft. Your SSTO is no longer a prototype and is finally a complete, but better yet working design! You can always modify the design to suit a particular need.

See also

• Tutorial: Basic Plane Design
• Tutorial: Spaceplane basics
• Tutorial:Spaceplane to Laythe