2003 MAPLD International Conference
Ronald Reagan Building and International Trade Center
September 9-11, 2003
Wednesday Evening, September 10, 2003
Last year we discussed "Why is Mars So
and a question that arose was ...
Software So Hard?
A Discussion of the Technical, Programmatic, and Political Factors
That Have Lead To Failures Over the Last 40 Years and Its Impact for Future Systems
Some Examples ...
FGB Launch for ISS Mariner 1 - "Typo" Voyager 2 Software Faults at Launch Gemini V Mars Polar Lander Mars Climate Orbiter Ariane501 Titan CT-2 (Intelsat V6 F3) Titan IV B32/Centaur (MILSTAR II-1) Patriot Missile Sea Launch F3 SOHO Clementine NEAR Phobos 1 Terriers STRV-1c; STRV-1d Windows NT Cripples US Navy Cruiser Collection of Software Bugs Software Horror Stories
Panel Moderator: Dr. Rod Barto (Bio)
Spacecraft Digital Electronics
Dr. James Tomayko, Carnegie Mellon University (bio)
Dr. Paul Cerruzi, Smithsonian National Air and Space Museum (bio)
Opening Case Studies: Magellan and Mars Pathfinder
Tony Spear, Jet Propulsion Laboratory (bio)
Panel Member Organization Dr. Nancy Leveson (bio)
Professor of Aeronautics and Astronautics
Massachusetts Institute of Technology
Jack Garman (bio) Lockheed-Martin (NASA, retired) Fred Martin (bio) Averstar/Intermetrics Steven S. Scott (bio) Chief Engineer, NASA Goddard Space Flight Center John P. Dimtroff (bio) Federal Aviation Administration
Aircraft Certification Engineer - Avionics Systems
Jim Lewis (bio) SynthWorks Design Inc.
Note: All panel members at this time are tentative, as the Panel is in the process of formation.
Two Examples of One Failure Type: Garbage In, Garbage Out
Program A Anomaly
IMU parameters had to be entered just prior to launch
Could not be verified in a test bed
Procedure required a second operator to verify manual entries against factory printout
A supervising engineer copied data from the factory printout and gave it to operators, saying that it was suitable.
Flight was degraded because the engineer wrote down the wrong sign!
Program B Anomaly
A roll rate filter constant, manually entered into the upper stages avionics database missed an exponent - in effect misplaced a decimal point.
Error was not spotted due to data format complication
Flight tape not checked against software test bed thought test bed could only be used for default values
IV&V only used default constants, not the flight database
- Independent simulations deemed not fully capable
- Would have caught the gross error
Modern hardware design is relying on:
Increasingly complex computer aided engineering software
Increasing use of hardware design languages
Is This Hardware or Software?
GC: Process ( Clock, Reset_N )
If ( Reset_N = '0' )
Then IQ <= s0;
Else If Rising_Edge ( Clock )
Then Case IQ Is
When s0 => IQ <= s1;
When s1 => IQ <= s2;
When s2 => IQ <= s3;
When s14 => IQ <= s15;
When s15 => IQ <= s0;
When Others => IQ <= s0;
End Process GC;
Q <= IQ;
End Architecture FSM;
Will hardware design reliability drop to software reliability levels, with "bug rates" of order 1 error per 1,000 lines of code?
"The price of reliability is the pursuit of the utmost simplicity. It is a price which the very rich find most hard to pay." -- Sir Antony Hoare, 1980.
Highlights from the 2002 MAPLD International Conference Panel
"Why Is Mars So Hard?"
A Discussion of the Technical,
Programmatic, and Political Factors
That Have Lead To Failures at Mars over the Last 40 Years
Dr. Rod Barto (Bio)
Spacecraft Digital Electronics
||Dr. Roger Launius (Bio)
Chair, Dept. of Space History, National Air and Space Museum
"A Historical Perspective"
|Dr. Ed Euler
Lockheed Martin Astronautics Operations
|Dr. James Garvin
NASA Headquarters, Mars Exploration Program Office
|Dr. Stamatios M. (Tom) Krimigis (bio)
Head, Space Department
Johns Hopkins University/Applied Physics Lab
|Anthony Spear (bio)
JPL; Chair, NASA Faster, Better, Cheaper (FBC) Task Force;
Mars Pathfinder Project Manager, Magellan Project Manager
|James Oberg (bio)
Soaring Hawk Productions, Inc. (Consultant and Author)
|Ken Ledbetter (bio)
Executive Director for Programs in the Office of Space Science (OSS) at NASA Headquarters
Some reference material:
The end of Computing Science? EW Dijkstra, November 2000
"Go To Statement Considered Harmful," EW Dijkstra, Comm. of the ACM, March 1968.
Dr. Paul Cheng, The Aerospace Corporation
Kevin Willoughby, Sentillion
We invite your participation in our Panel Session.
Richard B. Katz
NASA Goddard Space Flight Center
Home - NASA Office of Logic Design
Last Revised: February 03, 2010
Digital Engineering Institute
Web Grunt: Richard Katz