Python and spacecraft onboard or ground control scripting

[Noah]

Seg faults are the least of your worries for
mission critical applications. Deterministic threading
becomes the real headache. Deterministic garbage collection and 
deterministic thread scheduling; validated compilers; 
strong, static types are all the hallmarks of 
mission critical application languages.
I can't imagine a dynamically typed language like Python 
(in its current form) could ever be suitable for 
real-time embedded systems or life-critical controls.

I think there is an initiative to make a Java VM that
will meet the requirements for real-time programming.
RTJ or JRT or something like that...
Maybe some version of Jython could be created that
will compile class files for that JVM. You would probably
have to give up most of Python's dynamic features to make
it work.

I wonder what those stackless Python people are up to...

Noah

-----Original Message-----
From: python-list-admin at python.org
[mailto:python-list-admin at python.org]On Behalf Of Dave Kuhlman
Sent: Saturday, April 13, 2002 8:51 AM
To: python-list at python.org
Subject: Re: Python and spacecraft onboard or ground control scripting


Cameron Laird wrote:

> Folklore has it that Tcl *did* travel to Mars, and its
> interpretive nature was crucial in responding to some
> mission contingency; the control team needed to upload
> new code during flight.  We ought to document this ...
> 
> While I understand the observations that Python, Tcl, 
> and so on surely aren't safe enough for medical devices,
> nuclear plants, air traffic control, military devices,
> and so on, I have reasonably certain knowledge of instances
> of each of these.
> 


The idea that Python, Tcl, and so on aren't safe enough for medical 
devices sounds like conventional wisdom to me.  Someday a scripting 
language will come along which is so good that it proves this 
conventional wisdom wrong, and does this so conclusively that we are 
forced to give up that idea.  I believe that Python was/is/will be that 
language.

Are there examples and evidence that Python fails when applied to 
long-running, mission critical tasks?

By the way, I write C++ code.  And, the idea that C++ code is safer than 
Python code seems screwy to me.  Can you say "seg fault"?  I thought so.

   - Dave