Hohmann Orbits

[sandcastles]

This may seem trite and trivial...but it's been bugging me for years....I just hadn't gotten around to asking...but, The Handbook of Chemistry and Physics has been giving the Hohmann Transfer Orbits for every combination of pairs of planets from Mercury to Pluto.  I wondered why?  Who is going to use all that information?  If Gregory Benford needed information on one of those orbits, he could probably calculate it himself.  
Not that I'm really complaining.  Maybe there is some value to it.   I haven't looked at the latest edition, and I'm sure the information is online by now...it just seemed like a strange use of hundreds of pages.  I hope you can explain it.  Thanks.

[stevebowers]

I used (pre-calulated) Hohmann transfer orbits from a table to calculate a plausible date for the first manned landing on Mars; they are useful in certain circumstances. In a technologically advanced civilisation like OA, powered transfer would probably be most important for most purposes.