Ada and ISS

Ada and ISS

[David Michaels]

Hi
Can someone please direct me to a link or a web page that might describe
Ada's use in the International Space Station. I haven't seen much so far
so I figure that I'm looking either in the wrong places or they don't
exist yet. Sorry if this seems an improper question for this group I
know most questions are programing problems and I don't mean to add
noise but... it's driving me nuts not being able to find a article or
two that discuss the relationship. Any help would be greatly appreciated
TIA
dm


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Re: Ada and ISS

[Robert Dewar]

In article <8sb5b0$jo3$1@nnrp1.deja.com>,
  David Michaels <free08@my-deja.com> wrote:
> Sorry if this seems an improper question for this group I
> know most questions are programing problems and I don't mean
to add
> noise but... it's driving me nuts not being able to find a
article or
> two that discuss the relationship. Any help would be greatly
appreciated
> TIA
> dm


This is by no means an improper question, indeed it is a whole
lot more interesting and relevant than most of the messages
here :-)

Remember that there is no separate advocacy group here, so
it is entirely fine to do advocacy posts for Ada here (indeed
they are welcome).

As to the answer, I can provide some partial answers though
I have to check first (a frustrating thing in this business
is that there are several cases where for all sorts of reasons,
a client does not want us to publicize their project, so we
are careful to check whether we have cleared the information
before posting it).

Robert Dewar
Ada Core Technologies


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Before you buy.

Re: Ada and ISS

[Jerry Petrey]

David Michaels wrote:

> Hi
> Can someone please direct me to a link or a web page that might describe
> Ada's use in the International Space Station. I haven't seen much so far
> so I figure that I'm looking either in the wrong places or they don't
> exist yet. Sorry if this seems an improper question for this group I
> know most questions are programing problems and I don't mean to add
> noise but... it's driving me nuts not being able to find a article or
> two that discuss the relationship. Any help would be greatly appreciated
> TIA
> dm
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.

You might want to check with Boeing in Huntsville, AL.  They have done a lot

of Ada work on the ISS.  Here is one example:
http://www.boeing.com/defense-space/space/power/iss.html

Jerry
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-- Jerry Petrey
-- Senior Principal Systems Engineer - Member Team Ada & Team Forth
-- Raytheon Missile Systems  - Please remove NOSPAM from address to reply
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Re: Ada and ISS

[Robert Love]

>>>>> "David" == David Michaels <free08@my-deja.com> writes:

    David> Hi Can someone please direct me to a link or a web page
    David> that might describe Ada's use in the International Space
    David> Station. I haven't seen much so far so I figure that I'm

Web pages on this subject are kind of rare but let me try summarizing.

The software that runs on ISS is distributed thru a 3 tiered network
of computers called MDM's.  They communicate with each other and the
devices they control via 1553 protocol. The software that resides in
these MDMs is written in Ada, almost exclusively.  There is one case,
the Guidance and Nav (GNC) MDMs, written in Ada but designed in a tool
called MatrixX.  Here the designer draws block diagrams of control
algorithms and the program writes the Ada that gets compiled.  Its not
pretty.  In the case of the other MDMs, the code is written by people
and is "human readable".  In all cases I know of, Boeing has written
the software for the MDMs in three locations, Houston, Huntsville and
Huntington Beach.

Now, many of the devices commanded by the MDMs have some type of
firmware controller residing in them.  The ones I'm familiar with were
written in C.  Also used on the Space Station are a series of laptop
computers called PCS that the crew use to interact with the MDMs.
These run Solaris operating system, run X-Windows for displays and are
programmed in C or C++.  As an aside, I recently heard of a laptop
problem where the display for one instrument was not being called up.
Seems the programmer had overloaded some C++ function but at runtime
it was ambiguous what should really be called and it picked the top
entry off of the table which was not the correct function.

Mission Control (MCC) can also command most of the operations on the
station from Houston.  I believe most of the MCC stuff is in C.  There
is a large contingent that wants to go to all C++.

Another large segment devoted to Space Station are the simulators.
There are both part task trainers(PTT) and the full task trainer
(FTT).  The latter is a full up simulator with cockpit mockups and is
used to train both the flight crew and the mission controllers.  The
PTT and FTT are written in Ada by Raytheon in Houston.  Only a very
small portion of the code is in C or assembler.

So, while Ada plays the dominant role in software that goes into orbit
on Station it is by no means the sole player, or even a popular one.
The cry to switch to C++ is heard often.

During the assembly ops that happened Saturday I happened to be
monitoring an audio loop from Mission Control where a "controller" was
conducting part of a formal procedure.  The device being commanded had
a minor glitch and I heard one controller ask another what language
the device had been programmed in.  The answer was C and when the
controller who asked the question got the answer he started off about
how C++ was a way to "organize the code".  These are not programmers
but people who work in space operations.  But they have acquired the
mindset that everything should be in C++.  That attitude seems
prevalent in all aerospace arenas today.  How did we get there?

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