Given that it would have been possible for both teams to work with whatever units they wanted, as long as they'd agreed on a conversion function between them, it's obviously not the fault of the measurement system.
This was a human error, a tiny glitch in the communications between two programming teams. This happens all the time in software and the only scalable solution is proper testing.
I don't think NASA tested this part of their software.
The physics of modelling a satellite going into orbit aren't that difficult, so why not build a test harness which could simulate all the inputs the satellite would receive (inertial guidance etc), and could take the output from the guidance system (start firing this thruster now, stop firing now)
Since you're in a simulation and the "player" (satellite navigation system) is a computer you can ramp up the rate at which the clock ticks. In this way NASA could have tested that the Mars Climate Orbiter navigation system worked. The level of certainty would be based on how good the model was.
How do you build a good model? Testing of course. E.g. start small, check that when the nav system says fire this thruster, check the engine management subsystem throws the switch, check you can model the body in freespace firing it's thrusters and ending up where it should. Slowly add in more complexity (but keep running all the simple tests too) e.g. gravity, change in rotational inertia as fuel is consumed. Test it can hold an orbit round a model planet, check it can change orbits etc.
Testing this kind of thing would be challenging and fun, there would be parts you'd think were not testable. But if the solution is not testable by a computer how can you hope to solve the problem with a computer.
When the engineers came to install ADSL in my house (BT Engineers (I live in London)) they never looked at the PC.
All the checking of the ADSL hardware was done remotely i.e. they didn't need/want to see my machine using it.
I'd gone to a lot of trouble to borrow a Windows 98 machine for the day, since they said they didn't support linux, especially on laptops as in my case.
So I agree, do it anyway, you could always say that the Windows9X is broken today!
Slashdot Mirror
See http://news.bbc.co.uk/hi/english/uk/newsid_778000/ 778267.stm
"But his plans were dealt a blow in 1987 when the UK extended its territorial waters from 3 to 12 miles" (from that page)"
Given that it would have been possible for both teams to work with whatever units they wanted, as long as they'd agreed on a conversion function between them, it's obviously not the fault of the measurement system.
This was a human error, a tiny glitch in the communications between two programming teams. This happens all the time in software and the only scalable solution is proper testing.
I don't think NASA tested this part of their software.
The physics of modelling a satellite going into orbit aren't that difficult, so why not build a test harness which could simulate all the inputs the satellite would receive (inertial guidance etc), and could take the output from the guidance system (start firing this thruster now, stop firing now)
Since you're in a simulation and the "player" (satellite navigation system) is a computer you can ramp up the rate at which the clock ticks. In this way NASA could have tested that the Mars Climate Orbiter navigation system worked. The level of certainty would be based on how good the model was.
How do you build a good model? Testing of course. E.g. start small, check that when the nav system says fire this thruster, check the engine management subsystem throws the switch, check you can model the body in freespace firing it's thrusters and ending up where it should. Slowly add in more complexity (but keep running all the simple tests too) e.g. gravity, change in rotational inertia as fuel is consumed. Test it can hold an orbit round a model planet, check it can change orbits etc.
Testing this kind of thing would be challenging and fun, there would be parts you'd think were not testable. But if the solution is not testable by a computer how can you hope to solve the problem with a computer.
This has been cross posted Here and Extreme Programming Discussions
What do people think would be hard to test about putting a satellite in orbit around another planet?
When the engineers came to install ADSL in my house (BT Engineers (I live in London)) they never looked at the PC.
All the checking of the ADSL hardware was done remotely i.e. they didn't need/want to see my machine using it.
I'd gone to a lot of trouble to borrow a Windows 98 machine for the day, since they said they didn't support linux, especially on laptops as in my case.
So I agree, do it anyway, you could always say that the Windows9X is broken today!