MacDirectory Magazine

Warren Manser

MacDirectory magazine is the premiere creative lifestyle magazine for Apple enthusiasts featuring interviews, in-depth tech reviews, Apple news, insights, latest Apple patents, apps, market analysis, entertainment and more.

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Page 104 of 115

INTERVIEW The cameras are not designed for looking at planets. You might be able to pick one up, but it would be a tiny, faint, single pixel. MA > But do you feel there is a need for users to view such images of Earth beyond mere curiosity? As I understand, SkyCube will take low-res images and we now enjoy a constant flow of new high-res images from NASA — including those from the Curiosity rover on Mars. TD > This is a new area where we can't entirely predict the answers. For starters, these are your images, not NASA's. You control when/where they are taken. We've already had inquiries from organizations like the International Dark Sky Association about things like documenting light pollution on the Earth's night side. It may be possible for individuals to capture weather patterns, etc. - or make a movie of the entire Earth from orbit. The point is that folks will come up with ideas and uses that we haven't - and they can utilize our satellite to realize them. MA > I understand that for one dollar a user can broadcast a message using SkyCube. Are the broadcast messages relayed back to Earth or to any specific individual? TD > They are broadcast at the speed of light out into the universe, in general. That includes the Earth. Anyone with the right kind of amateur radio gear can "hear" them directly from orbit - provided the satellite is over the horizon - and we'll provide such gear to our $1,000-and- up sponsors. For the vast majority of everyone else, the satellite will have its own Twitter stream which parallels what the satellite is physically broadcasting in orbit. We'll also display the current message in our mobile and web apps. So at the moment, we visualize this is a "message in a bottle" that you, the user, will cast off into the cosmos and into the Twitterverse simultaneously. MA > What measures have you taken to ensure that the SkyCube camera and its balloon will deploy and work as planned? TD > The camera is identical to one that has already been flown in space and operated successfully on other CubeSats. We will obviously test the heck out of our own cameras before launch; we have located a space-grade vacuum chamber in San Francisco for that purpose. The balloon, on the other hand, is new. We're relying on the expertise of our balloon manufacturer, Global Western, to design one that will work for us, and test that design exhaustively. Global Western has many years of building high-altitude balloons for NASA and JPL - they were once contracted to design a balloon that could be remotely inflated in the atmosphere of Mars - so I trust that they'll do a competent job. Nevertheless, we've specified a fairly exhaustive set of tests that GW's balloon must pass before we accept it. MA > The balloon deployment appears to be a critical part of the mission and likely its internal software. Can you elaborate on SkyCube's software? SkyCube's firmware engineers are Chris Phoenix and Scott Cutler, under the guidance of hardware designer Kevin Brown. Chris currently owns the firmware of our SkyFi wireless telescope controller, and has 20+ years of embedded firmware experience starting at Electronics for Imaging in the '90s. Scott is full-time firmware engineer at NVidia, and has been volunteering on SkyCube part-time. Kevin has designed multiple CubeSats for other university programs; his CubeSat radios have a 100% successful track record in space. Four of them are in orbit right now. The firmware is basically all written in C, with a scattering of ARM assembly code. The IDE is TI's Code Composer Studio. MA > How about the SkySafari app development? Who developed the app and can you tell us about the challenges of developing it? TD > That is a pretty big topic! I myself wrote most of SkySafari's internal astronomical dynamics and graphical rendering engine; also most of the telescope-control code is mine. The UI, on the other hand, was almost entirely written by app architect extraordinaire Bill Scummy (who used to work at NeXT with Steve Jobs in the '90s.) It's a good team. MA > Wow, sounds like a huge project! TD > Challenges? Where do I start? We had to take a desktop code base that assumed GHz CPUs and GBs of RAM, and slim it down to run on mobile hardware on par with desktop computers from 10 years before. We had to take a complex UI and make it workable on something the size of a postcard. Then when we ported to Android, we had to do it all again - almost from scratch. Our apps are structured so that the core computing engine/rendering code is all in ANSI/ISO C and C++, using OpenGL ES to draw the sky. That code is basically identical on Mac/Android/iOS. Above that, though, the UI is completely different. On iOS, it's Objective-C on Cocoa Touch APIs. On Mac OS X, it's Objective-C and Cocoa. On Android, the UI is all written in Java, with an unbelievable amount of JNI glue code between the UI and the engine. It was a lot of blood and sweat to make this all work right. And testing, and more testing, and more testing. MA > Once SkyCube is in orbit, how much control you will have over it? Can you elaborate on the satellite control mechanism? MacDirectory 103

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