View Full Version : Flight system design on Stargate

2006-May-04, 07:57 PM
Atlantis 202 'The Intruder'

I am actually feeling much better about this one than I did on first viewing. There is actually quite a lot to like about it. It is about solving a sensible problem and in fact a lot does make sense.

One line I missed first time round was the reference to the life support systems being a physically independent system from the infected computer. No only does this explain the Bond villain plan to kill the crew (Yes! The ticking crock!) but is good engineering. Having spent ages lately blasting Greenpeace for failing to understand the concepts of diversity and isolation in vital systems, it is excellent to see this shown here.

Now about F-302s. When it comes to flying these aircraft, I think we can say there are three different, but interconnected systems: flight management computer (FMC), fly-by-wire (FBW), full authority digitial engine controls (FADEC). Because of the interconnectivity between the 302 FMC and the navigational systems of the Daedalus, they have become affected. Because the FMC is affected, it means the 302 Shepherd is flying early on is successfully hijacked by the virus. So far so good, though I'm still not convinced about the idea Shepherd could not have regained control by pulling the breaker on the autopilot.

Later on, the virus uses the FMCs on the 302s to hide out during the system reboots of the Daedalus. Makes sense. It can then reinvade the systems from there. Shepherd and McKay fight this by physically removing the FMCs from the 302s. Good stuff. But what about the FBW and the FADEC? Having removed the FMC from the 302 Shepherd and McKay take shelter in, Shepherd now has complete control to fly out and take out the other rogue 302. This means that the virus could not invade the FBW and FADEC, merely control it from the FMC.

This would make sense if the FBW and FADEC were not rewritable. They were hardwired for their purpose. The virus could not enter either system because it could not write itself into them. This makes sense to me. Does it make sense to anyone else?

2006-May-04, 08:46 PM
but, what about.. the.. plot?
if it all made perfect sense, there would be no drama, no conflict...

2006-May-05, 04:12 PM
Hmmm... Well, many systems do use a combination of general purpouse computers and application spesific circuits. A computer is adaptable and the only limitation on what you can use it for is what you can impliment on the available resources. Application spesific systems are optimized to do a spesific set of tasks very quickly, though this optimalisation comes at the cost of versatility. Having both can greatly improve the usefulness of the whole system.

The computer would probably use general purpose CPUs, It would also seem likely that the Daedalus use the same set of CPUs, only a much greater number, as that would mean they could use the same operating system and some of the same software on both. It would also mean that it would be easier for the same team of developers could work on both systems(an advantage when you have a secret project like this, I would think)

The ASC could probably be updated from the computers, but since the firmware would be in a totaly different format, its rather unlikely that a virus could infect both systems, and its likely that the virus would not be adaptable enough for this. Even if it could, its not likely that the sytem is implimented in a way that allows for software uploads from the ASC, as there would never be a use for this. Firmware download would be a special scenario, in usual operation the communications would be pure data.

Of course, a system could be built in such a way that every device connected had drivers and applications in their ROMs, and that these could be uploaded when the system runs some sort of new hardware detection(unless the computer allready have a newer driver for the device), so that you could use any system you connected without actually installing drivers and stuff. Still, it would be rather complex to make a virus that could use such things...