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From: frank@grep.co.uk (Frank Wales)
Newsgroups: comp.software-eng,comp.sys.handhelds
Subject: Re: Astronauts using HP calculators in space
Keywords: astronauts, NASA, HP, calculators, computers
Message-ID: <1991Jan02.193731.5768@grep.co.uk>
Date: 2 Jan 91 19:37:31 GMT
References: <9809@as0c.sei.cmu.edu>
Reply-To: frank@grep.co.uk (Frank Wales)
Followup-To: comp.sys.handhelds
Organization: Grep Limited, LEEDS, UK
Lines: 39

[I've directed follow-ups to comp.sys.handhelds.]

In article <9809@as0c.sei.cmu.edu> mcp@sei.cmu.edu (Mark Paulk) writes:
>HP gave some astronauts calculators as a PR gimmick.
>They included a simple orbital calculation program.
>The calculators were more powerful than the onboard Shuttle computers,
>so the astronauts started carrying them into space as unofficial backups.
>NASA eventually started issuing calculators as offical issue.

This is a somewhat unlikely story based on actual facts.  :-)  For example,
it's hardly likely that HP could write software for NASA as a PR gimmick
that was better than that already in use for the flights.  But anyway...

According to the Jan-Apr 1981 issue of HP Key Notes, the first flight
of Columbia had two HP-41Cs on board, each dedicated to performing a
particular task: 

  + "Acquisition of Signal", which ran continually from launch, displaying
  the name of the next available ground station, when it would be in 
  contact, for how long, and which frequency it used; and

  + "Center of Gravity", which was used to balance the shuttle's fuel
  distribution before re-entry, and was termed flight-critical by NASA.

The article implies that NASA was the prime mover in getting the calculators
on board, and held comparative trials between different models before
deciding on the HP-41, mainly for its large memory capacity and alphanumeric
display.  All the software was written by NASA.

The March-May 1982 issue contains further information, including the
statement that the two machines used on board Columbia were purchased by
NASA over the counter in Houston.  By that time, their use had expanded
somewhat: one was still running the AoS program; the other was being
used as an electronic secretary, reminding the astronauts of chores with
alarms and messages, in addition to being available to compute de-orbit burns,
run the CoG program, and pin-point Earth observation sites.
--
Frank Wales, Grep Limited,             [frank@grep.co.uk<->uunet!grep!frank]
Kirkfields Business Centre, Kirk Lane, LEEDS, UK, LS19 7LX. (+44) 532 500303