Dr J R Stockton wrote:
In sci.space.tech message
, Wed, 20 May 2009 23:50:28, kevin willoughby .
invalid posted:
Pat Flannery wrote:
kevin willoughby wrote:
If two of three versions agree, that doesn't mean those two are correct.
Though in this case you do get feedback by observing where exactly
the satellite's orbit ended up in reality versus what one or more
programs predicted.
That works, but it can be a *very* expensive way to debug a program...


Not necessarily expensive; it depends on the brightness of the satellite
and the magnitude of the error.

I'll stand by my statement. The test plan for a moderately complex
program will specify several hundred test cases, minimum. Launching
several hundred satellites. Until the cheap-access-to-space miracle
occurs, we're talking a significant chunk of a gigabuck.
--
Kevin Willoughby lid

It doesn't take many trips in Air Force One
to spoil you. -- Ronald Reagan