The Last Cathedral - Democratizing Flight Software

The Last Cathedral Democratizing Flight
Software
Kevin Scharpf
December 11, 2013
The PTR Group
Who are we?
Embedded Systems Consulting Firm
Have supported numerous space missions
including Tacsat-2 (first Linux space mission)
along with IBEX, GLAST, ORBCOMM, OrbitalCygnus, and DARPA F6
Robotic space projects including Phoenix,
SUMO, FREND
Training Provider
Linux, Linux Networking, Multi-core, Linux KVM, and
Android
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Is Linux Viable in Space?
Wide variety of platform support
PREEMPT_RT patchset provides hard realtime guarantees
SpaceX and Tacsat-2
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Why Linux in Space?
Because it is free “as in beer”?
No. The cost of the Operating System is
irrelevant to the overall mission cost.
Because it is free “as in speech”?
No. Possibly relevant to individuals but not to
the organization at-large.
Because it is open source?
Yes and No. Applying known patches to the
kernel is a valid use-case – see PREEMPT_RT.
Applying your own patches may not be wise.
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Why Linux in Space?
Does it have higher quality / more
features / etc?
From the Linux README
Although originally developed first for 32-bit x86-based PCs (386 or higher), today Linux
runs on (at least) the Compaq Alpha AXP, Sun SPARC and UltraSPARC, Motorola 68000,
PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell, IBM S/390, MIPS, HP PA-RISC, Intel IA-64,
DEC VAX, AMD x86-64, AXIS CRIS, Xtensa, Tilera TILE, AVR32 and Renesas M32R
architectures.
Anything else?
Community
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Revisiting Cost
Government (DoD and NASA) budgets are
tightly constrained and will be so for the
foreseeable future
What is the impact of software costs on
program budgets?
Software development costs are almost
entirely labor
Late-stage flexibility up to and including inspace
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Software Labor Cost Drivers
Availability of developers
Indeed.com shows 3343
embedded linux jobs as
of 25 November.
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Labor Drivers – Feedback Cycles
Change
Build
Static
Analysis
Hardware
Test
Feedback
Software
Test
Review
Dynamic
Analysis
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Reducing Feedback Cycles
Goal – achieve the highest quality possible prior
to ever reaching a blocking point in
development
Increase the number of resources
Compilers / Test Articles
People – Strive for an open community
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Feedback – Getting Over Hurdles
A programmer’s best friend –
stackoverflow.com
stackoverflow.com currently has 849 questions
containing the phrase “embedded linux”, 103
questions containing “openembedded”, and 42
questions containing “greenhills”.
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Feedback – Force Multiplier
35 github repositories contain the phrase
“vxworks” containing 340k SLOC*
https://github.com/torvalds/linux shows
3422 contributors as of 14 November
2013*
21098 github repositories contain the
word “linux” containing 155M SLOC. (239
github repositories contain the phrase
“embedded linux”)*
*Source: github.com
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A Flight Software Community
Most flight software isn’t so flightspecific
Developing a common stack
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Summary
Linux is a viable platform for flight
software
Maximize the number of resources
available
It is possible to develop a full stack based
upon Linux that can be carried across
programs
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Questions?
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Embedded Android Job Trends
Embedded Android showing >1000
percent growth since 2010
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GAO NASA 2013
Project
Percentage of new
source lines of code
for mission-critical
software
Reported
number of
critical
technologies
Percentage
cost
growth
JWST
60%
10
140.1%
MMS
46%
2
0
LADEE
29%
1
4.7%
LDCM
8%
3
-1.1%
SMAP
5%
1
0
GPM
5%
1
-8.2%
MAVEN
4%
1
-2.7%
TDRS
4%
1
-11.8%
OCO-2
0
0
49.3%
Source: GAO NASA Assessment of Large Projects - May 2013
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Most projects in
implementation have
undertaken low amounts
of new software
development and have
incorporated a lower
number of critical
technologies, which
indicates a lesscomplex, lower-risk
development effort.
- GAO contrasting
current NASA large
project performance
versus performance in
previous years.