If you were flying into out-of-space, you would expect to travel in a space shuttle powered by tons of fancy and modern computers to ensure a safe journey to and from space. You may assume that the system would have tons of RAM, hard drive space, a superfast processor and much more. However the current space shuttle being used actually only run of 1MB of RAM. The computer’s technological framework is based on models from the 1980’s with a few recent upgrades added.

With no fancy GUI such as that included in Windows 7 or MAC OS X Leopard, the totally UNIX-based system that is command driven, does not require a ton of temporary memory space or a fast processor to monitor data from its sensors, or manage systems controls. Even though the entire code may look very complex, it was made to run on that 1980’s processing system, and still does today. Unlike a regular computer, the programs don’t have to be updated to match today’s needs, since there are no new needs really. It’s been basically the same series of launch events 30 years ago and that has allowed them to work with the older system.

But why not upgrade anyway? Cost and risk are two main reasons for working with the current system. Considering NASA’s tight budget, they would have to spend lots of time and lots of money testing those systems time and time again to ensure a shuttle take of is near fail-safe. Installing and upgrading the software and hardware basically puts them back into a place where they have to rebuild their knowledge base about how the system operates and there would be significant risk of some failure along the line.

Source

Lately I’ve been working with a very smart software developer who began working in the industry in the early 80s, and one of his observations is that many of the systems we’re developing today are very similar in overall functionality as the systems he developed early on but require thousands of times the processing power and memory to function. A large portion (perhaps the majority) of this processing power and memory is going to driving user interfaces, but a large portion is because developers have been developing towards re-usability and reducing their development time rather than developing more efficient systems; which (in many/most cases) is probably a reasonable choice.

An example of what he is talking about is that we’re braking up large complicated enterprise systems into smaller and smaller independent applications, and having them communicate with each-other through soap or rest interfaces; and this typically involves the creation and parsing of XML data. Now, what this means is that to transfer an integer (as an example) rather than having 4 or 8 bytes of data somewhere in memory that you enter into a function you now have a 16 byte string representation of the integer wrapped in another 32 bytes of characters to make the XML tags at both the local and remote destination with additional memory devoted to an XML parser; and you use additional processing power to convert the integer into a string, convert that string into XML, transfer that XML, parse the XML, and convert the string back to an integer.

Applications that would run in 64k of memory on an Motorola 68k now require 512 MB of memory on a Core 2 duo because of all the complexity we have wrapped around them.

Or to put it another way, if it is a working system than I doubt they would benefit much from moving to better hardware.

to think that one of the most complex pieces of technology has less RAM then my Nintendo DSi

Well what do you expect... this is the government more or less.

Hell the new rockets are being put on hold due to budget reasons, so this is really all we've got.

Meh, if it doesn't need then why upgrade?

Doesn't seem like a problem to me, when the current system works well for all their needs, then why overhaul the whole thing?

Obviously its great technology. Built to last.

This retro fad has gone too far!

It's one of those things. You'll probably find that the computer mainly serves as a communication point to an even larger computer on Earth.

It's like the story about Apollo 11 having the computing power of a washing machine, but the truth is the computers back on Earth driving it were some of the most powerful on Earth at the time (apparently about the same spec as a modern day laptop, although I find this claim dubious). The computer as powerful as a washing machine primarily communicated with computer the power of a laptop.

I imagine NASA, in a bid to reduce payload or whatever, have all the bulky powerful energy hungry computers here on Earth and just use the computer on the space shuttle to communicate the processes of these Earth based computers to it.

As someone who has worked on Satellite hardware, I can give some insight on why this is true.

Electronic hardware needs to be Rad Hardened. This is a technique of shielding the boards and CPU's from radiation. A lot of the new stuff has just never been put through this process.

In Space, power is king. If a CPU can do every calculation you require from it, the one that takes the least amount of power is the best choice, regardless of age. The older Motorola CPU's fit this bill nicely.

I have been out of the government game for 6 years now, so not sure what they do today. But when I was working on a program just 6 years ago, with a 140 million dollar budget, we used 10 year old CPU's. Not because we didn't have any money or that government moved slow, but because out of all the CPU's on the market, they fit the requirement best.