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Interview with Orbiter Sim creator Martin Schweiger
Have you ever dreamed of being an astronaut? Have you every imagined youself aboard the Space Shuttle for a visit to the International Space Station? Have you ever wondered how travelling to Mars would feel like? Have you ever wanted to take in the magnificence of the Solar System, from Saturn’s rings to Jupiter’s moons, across an astronaut’s windshield?
Then Orbiter Space Flight Simulator is the piece of software for you. A realistic spaceflight simulator which lets you fly like past, present and future astronauts. Thousands of add-ons are out there and will let you fly virtually any spacecraft, from Stanley Kubrick’s futuristic vessels to Youri Gagarine’s legendary capsule.
Oh, and and you can download Orbiter for free.
Martin Schweiger has been developing the program as a hobby for ten years now, and released the latest version one week ago.
TechHaze: Martin, you are a Senior Research Fellow at University College London. Can you tell us more about what you do for a living, and what educational path brought you there?
Martin Schweiger: I am working at the Department of Computer Science at UCL, and my field of expertise is medical imaging, mathematical modelling and inverse problems. Most of my time is spent trying to find image reconstruction solutions for diffuse optical tomography, a novel imaging modality for brain imaging.
I did my degree in Physics in Munich, before coming to London for my Ph.D. During my studies I also did a few semesters in astrophysics, but never really considered that for a career path (then as now it was mainly a hobby).
TH: Can you explain in a few words what your Ph.D. thesis was about?
MS: It was entitled Application of the finite element method in infrared image reconstruction of scattering media. I developed a numerical finite element model for photon propagation in diffuse media, and for reconstruction of optical parameters from time-resolved boundary measurements of light transmission. This method can be used for functional imaging of brain activity. It was popularised in the movie “Minority report”, although the idea of using it to read someone’s mind belongs purely in the realm of science-fiction.
TH: What originally inspired you to create Orbiter Sim?
MS: I usually dread this question, because I haven’t really got a good answer. I have always been interested in space flight, like probably most kids, and I used to play video games (again like a lot of kids). Most of the space-themed games seemed to be woefully lacking in anything like a proper physics-based flight model – they insulted players’ intelligence by behaving like F1-racing or WW-I flight sims. So I guess some lazy afternoon I decided to try and find out if I couldn’t do better than that. At the time I didn’t have any experience in 3-D graphics programming, so I acquired that along the way. The original versions were extremely basic indeed, although the fundamental structure was probably created within the first few weeks. The rest took the last 10 years. I quite like the result.
TH: Ten years have past since the first version of Orbiter was released to the public. What were your goals then?
MS: Orbiter was a lot more modest then. I didn’t expect it to grow to anything like its current complexity (or popularity). It was mainly for my own entertainment, although I did publish it fairly early on for download. The real breakthrough came with the introduction of the programming interface, which changed the whole project from a one-person effort to a community project. Instead of having to use my pedestrian spacecraft models, users could now create their own sophisticated vessels, instrumentation, bases, and the whole thing really took off from there. These days, I am trying to provide the environment (the physics and the general rules of the simulation), while addon developers are populating the world with increasingly complex spacecraft.
TH: In a few words, how has the online community affected your work in particular?
MS: Apart from practical aspects like bug reporting, it’s a great inspiration to see people really enthusiastic about Orbiter. This is what mainly keeps me going on improving and updating it.
TH: Of all the add-ons that have been created, which ones are you favorite?
MS: Tricky – I hardly ever have opportunity to use addons, because most of the time I am running orbiter for bug fixing and feature enhancements, where addons would only get in the way. Usually the only situation where I install an addon is where it is required to reproduce a bug.
Having said that, I guess the favourite addon that I did try is Dansteph’s sound addon. It is a really essential component and increases the whole experience a lot.
TH: So apart from programming and finding bugs, do you use Orbiter at all?
MS: Well, programming and bug fixing already takes up most of my nights. There’s not much left to just enjoy the view from orbit. Usually the most genuine Orbiter experience I get is when recording flights for tutorials and examples for a new version. Even then, it usually doesn’t work the first time, so I have to repeat it so often that by the end it’s no longer a pure enjoyment. But that’s ok – I get my kicks out of creating, rather than playing Orbiter.
TH: You released Orbiter 2010 into the wild a week ago. What do you consider being the main achievements of your latest release?
MS: The most important feature in terms of code development is certainly the separation of the graphics engine from the simulator core. It will allow to replace the (somewhat aging) DirectX-7 engine by more modern graphics subsystems. Artyom “Artlav” Litvinovich already developed an OpenGL-based plugin graphics engine available that adds new features. More will come in the future. From a user perspective, the introduction of a scripting interface might be most interesting. It opens the way for all sorts of new ways to interact with Orbiter, e.g. by writing interactive tutorials, autopilots, rapid prototyping of vessels and instrumentation.
And of course there is a good deal of visualisation improvements as well, in particular higher resolution of planetary surface rendering, better support for instrument panels and HUDs.
And finally there were also a few improvements in the physics: better atmosphere models for Earth, and support for radiation pressure effects.
TH: Do you think that you might one day fully port Orbiter to OpenGL so as to support different operation systems?
MS: To be honest, inter-platform compatibility is not my main concern. Over time, quite a bit of platform-dependent code has crept in, not just in the graphics subsystem. To make orbiter platform-independent would probably require a rewrite more or less from scratch. I don’t think I’ll be able to do that. However, some people have managed to get orbiter running (with some limitations, as far as I know) on Linux. The new version should be supported better in that respect, in particular the “server” version (orbiter_ng), which is only externally connected to the graphics engine.
TH: I noticed performance (framerates, loading times, etc.) has increased dramatically with Orbiter 2010. How did you manage that step forward?
MS: The loading times have improved because orbiter now uses a load-on-demand system for planet textures. Textures in view of the camera are now loaded dynamically, rather than at program start. This was necessary because with the higher texture resolutions the loading times would have otherwise been prohibitive.
The in-game frame rate improvements are mostly due to replacing legacy graphics output, e.g. line-drawing of HUD elements with rendering calls that are handled more efficiently by modern graphics cards.
TH: Do you have anything else to add about Orbiter 2010?
MS: I guess now that Orbiter 2010 is released, the real work only begins.
TH: How do you see Orbiter 5 -10 years from now?
MS: It’s a bit scary thinking 10 years ahead for what is really just a hobby. I tend to take it from day to day. Every now and then I think of a new thing that might be cool to implement, and then I may just go ahead and do it. As to what orbiter might look like in 10 years – I am as keen to know as the rest of the community.
TH: Have you ever thought of making money out of Orbiter Sim, or, on a completely opposite level, of making the project open-source?
MS: I haven’t seriously considered marketing it. This would take more of my time than I can spend on it without sacrificing my scientific career, and I’m not quite ready to do that.
As for going open source, I have considered that but I think that the current development model of a closed source core with extensive API is actually working quite well. Orbiter is partly moving towards an open source model, since the graphics system is now open, and graphics client development is going on at sourceforge. The graphics seems to be the most critical component for users according to the feedback I get, so I hope that in the future more people will jump on board to contribute. I’ll see how that develops before deciding on opening up more of the code.
TH: Do you think X-Plane (or any other simulator, for that matter) could be a “threat” to Orbiter Sim’s overwhelming dominance in matters of spaceflight simulation?
MS: Luckily I don’t have to compete with anyone. If other simulators will be better than orbiter at modelling spaceflight, then good for them! I’ll continue for my own entertainment, or I’ll retire Orbiter and think of something new. Until then, I think orbiter still has some potential left.
TH: What do you think are Orbiter’s main strengths (and limitations) as a flight simulator?
MS: Orbiter is now pretty good at what it’s designed to do: simulating flight between low orbit and interplanetary space. It’s not as good at modelling atmospheric flight as dedicated flight simulators, but it’s adequate to simulate launch and reentry. At the other extreme, towards interstellar flight, there is not much support yet, but this may change in the future. This may also require the step from Newtonian to relativistic modelling, which would certainly be an interesting challenge.
TH: Can you tell us a few words about Orbiter’s flagship, the Delta-glider? Where does it come from, and why a futuristic vehicle?
MS: The DG was the first vessel modelled in Orbiter. I wrote the first mesh for it by hand (!) and it was correspondingly basic. Later a much improved version was donated by Roger “Frying Tiger” Long, and it has been Orbiter’s icon vessel ever since.
A futuristic vessel without the constraints of real spacecraft is perfect for demonstrating the principles of space flight (interplanetary transfers, gravity-assist maneuvers, orbit changes) without petty real-life limitations getting in the way. In that sense, the DG is the physicist’s spacecraft, where the also included Space Shuttle appeals more to the engineers among the users.
TH: When telling the fans I was to interview you, I got this remark:
I’d like to know if [Martin] realizes that he actually changed some people’s minds and lives by steering them into real science, which is beyond the boring and unmotivating classes’ blackboards, and programming from which you can make a living. For example – my master thesis is strictly connected with Orbiter and I program for a living.
How do you feel about the undeniable influence you had on spaceflight enthusiasts around the world? Did you ever imagine a student could base his master thesis1 on your simulator?
MS: This is great, and it’s exactly the idea I had for orbiter in the first place: making learning about physics fun. I know that orbiter has been used as a teaching aid in classrooms, but being responsible for people’s choices in planning their careers is obviously a real honour. This is the kind of message that keeps me going on with development.
TH: To conclude, I’d like to ask you what you think of the new direction the Obama administration has issued to NASA. Do you think it is a big step forward or just do you think it will just break all motivation because of the lack of deadlines?
MS: The targets set by the previous administration always seemed over-ambitious, so a revision was probably inevitable. For manned spaceflight to be viable, it will eventually have to move away from government-funded prestige projects like the moon race, and become commerically successful. Public funding is going to be tight in the future, and space projects are unlikely to be exempt from cuts. From a purely scientific point, unmanned missions are clearly better value for money in terms of conducting science in the solar system, but there is no denying the sex appeal of a manned mission to an asteroid or to Mars.
TH: Thank you for your time, Martin, it’s been a pleasure. And I’m sure the entire Orbiter community would like to give you a round of applause for the newest release of your breathtaking simulator!
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You can find Orbiter’s official website at orbitersim.com.
1 You can find more information about the project here.