Designing a Launch Pad
I’m still in the process of preparing the assets for my new video which will explain the concept of Gravity. Assets are computer models of objects which you would find in the real world and which are included in the video to give a sense of realism. For my video on Gravity I will be going into space to explain weightlessness, and to get into space I need a rocket. This will be launched from my launch pad and this is what I have been modelling over the last few weeks. The model is shown below.
To start the process I had to do a bit of research on launch pad design and that started a long time ago. In the summer of 1981, following completion of my first year at Glasgow University, I went on a family holiday to Florida and visited the Kennedy Space Centre. Since I was studying aeronautical engineering it was amazing to see the facility. The rockets were enormous and the vertical assembly building seemed impossibly large. There was a lot of excitement regarding the recent successful first launch of the space shuttle. In the visitors centre shop I remember looking at the amazing photographs of the launch of the shuttle Columbia from launch pad 39. More than 30 years later I now find myself trying to reproduce those pictures using the models I’m preparing for my latest video.
To do the modelling and animation I use the Blender software. This is free to use and may be obtained from the Blender website. The way I create the models is to first look at reference videos and pictures from the internet. The NASA website has a large collection of reference material and articles which are perfect for providing visual guides to the objects you may find at a launch pad. The models are essentially meshes made up of points, with lines which connect the points, and surfaces which fill in the areas between the lines. You can then apply materials to those surfaces to create the models of the objects.
The first challenge I had in creating the models was to understand the relative scale of the various objects. This meant getting dimensional data on the typical height of rockets and the associated structures of the launch pad. Thankfully this information may be found on various websites. My next challenge was designing the layout of the launch pad so I could get dramatic shots of the launch. In order to limit the amount of modelling, you typically identify where the cameras are going to be positioned and model only those objects and areas which will be in the camera view. This is easy to plan if you are going to be doing a single image of the scene. However for video, you tend to move the cameras around and therefore there are many more areas of the scene that need to be modelled.
When I was conducting my research I started to see things on the launch pads which I had not noticed in the past, such as the large vertical tower like structures surrounding the launch pad. When I looked closer I realised that there were wires running between these towers. “What are those for?” I asked myself. It turns out that these towers are there to protect the rocket from lightning strikes. In the event of a lightning strike, the wires conduct the lightning down to the ground and safely away from the rocket and launch vehicle. If you look closely you can see the faint wires in the image of the model I created below (look to the right hand side of the image). I used a cool feature of Blender to make a mesh and then apply a wireframe modifier to the mesh to render the wires.
The next step is to model the fire and smoke as the rocket launches. From my research I found out that the smoke is actually mainly steam. Just before launch the pad is flooded with water. This minimises damage from the sound waves from the rocket engines as they ignite. The heat from the engines during launch heats the water on the pad and this produces the large quantities of steam. The water flows down from the water tower which you can see in my model in the first image in this post. It is the tall white ball like structure in the top right corner of the image with a large pipe running down to ground level.
The water discharge and steam will be visualised as part of the smoke simulation I will create in Blender. Then everything will be in place for me to finally launch my rocket from my version of launch pad 39.