CaptainRefsmat

The Apollo program set a requirement for a fourteen day mission from the beginning. None of the missions lasted that long; the longest was Apollo 17 at 12 and a half days.

The Space Shuttle flight software used an interpolating polynomial for the solar ephemeris, with coefficients that were valid 10+ years (I've forgotten the exact number). The solar position was an input to the atmosphere model used to compute on-orbit drag, which itself was itself an interpolating function for data generated by a model with higher fidelity. I could go on. The pattern of using interpolation formulas to save memory and CPU cycles was (is) a common one.

People would be surprised by the amount of data required for on-board guidance and navigation software. Some of it is non-mission specific, but much of it must be generated for each mission. During the Shuttle era, these parameters were called I-Loads (for Initialization, of course) and were a separate memory load from the flight software itself.

My first thought when I saw this was "stocking stuffer". It sounds a little bit pricey for DIY, though. The Python game sounded interesting, but my initial impression was that it would be way too advanced for beginners. Am I missing something?

For those who would like to explore this subject in more detail, it was initially developed by the German Astronomer Karl Stumpff following the second world war. He later worked as a consultant at the Goddard Space Flight Center in the early 1960's. An English translation of his original report is available from the NASA Technical Report Server [1].

These functions were further developed at the MIT Instrumentation Laboratory for use in the Apollo Guidance Computer. This work was published by Richard Battin originally in Astronautical Guidance, which is no longer in print, and later on in his textbook [2].

[1] https://ntrs.nasa.gov/citations/19630000922 [2] https://www.amazon.com/Introduction-Mathematics-Methods-Astr...

Binoculars are a great way to get familiar with finding things in the night sky. I have Nikon Action Extreme 10x50 binoculars, and I couldn't be happier with them. You will have no trouble seeing the Messier objects with them. A good place to start would be with the ones that are visible to the naked eye, such as the Orion nebula (M41), the Andromeda Galaxy (M31), or the Great Globular Cluster in Hercules (M13). The Orion nebula is prominent in the eastern sky early in the evenings right now.

Is there a good definitive guide somewhere on the best workflows for hg?

I don't know about workflows specifically, but there is a very good reference [0] about Mercurial's branching models. Maybe this will help you.

[0] https://stevelosh.com/blog/2009/08/a-guide-to-branching-in-m...

I would caution complete beginners from buying a telescope, because learning to set up and use a telescope might be too frustrating. I would recommend instead starting with a good pair of binoculars (mine are Nikon Action Extreme 10x50), which are powerful enough for you to find Messier objects. Searching for Messier objects will teach you how to identify constellations, read star maps, and how to scan the sky for faint objects. Learning the night sky will go a long ways toward teaching you how to set up and use a telescope.