Cover fe ature 47 january 2012 Published by the ieee computer Society 0018-9162/12/$31. 00 2012 ieee

PROGRAMMING TECHNIQUES

I base the discussion here on very simple code ex-

amples, but most current infrastructure software doesn’t 

systematically use the techniques I suggest. Code that did 

so would differ dramatically from what we see today and 

would be much better for it. 

I won’t try to show anything radically new, but I high-

light what I hope to see deployed over the next 10 years. 

My examples are in C++, the programming language  

I know best.

3,4

 Of the languages currently used for infra-

structure programming, C++ most closely approximates 

my ideals, but I hope to see even better language and tool 

support over the next decade. There is clearly much room 

for improvement.

Compute less

On 23 September 1999, NASA lost its US$654 million 

Mars Climate Orbiter

 due to a navigation error. “The root 

cause for the loss of the MCO spacecraft was the failure 

to use metric units in the coding of a ground software 

file, ‘Small Forces,’ used in trajectory models. Specifi-

cally, thruster performance data in English units instead 

of metric units was used.”

5

 The amount of work lost was 

roughly equivalent to the lifetime’s work of 200 good en-

gineers. In reality, the cost is even higher because we’re 

deprived of the mission’s scientific results until (and if) it 

can be repeated. The really galling aspect is that we were 

all taught how to avoid such errors in high school: “Always 

make sure the units are correct in your computations.” 

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