User talk:Not fred999/CBMsandbox

Overview of the July 2020 Re-write
''Full disclosure: as will be noted from my user page, I had a modest part in developing the CBM. The project started before I got there and continued after I left (shortly before first use). It may be of further interest to know that my background on the project now known as "International Space Station" extended beyond the CBM, having worked several different aspects on several occasions (although not continuously) from 1982 through mid-2001.''

The present organization of the article is my fifth major version. The first four don't warrant much discussion: they all failed to flow. The approach taken here gradually leads the reader from relatively non-technical material of general interest into the proverbial weeds (although not very far). One or more enterprising editors might, if the notion strikes them, be able to generate additional articles from the references and external links that would allow some of the history sections to be down-scoped & referenced to the (new) article. If I'd found articles that adequately addressed those topics, those sections would have been shorter.

Some enterprising editor having the skill and knowledge to archive the talk page prior to this point might wish to do so. I don't have a strongly-held opinion on that topic, but it might be more useful down the road.

The following notes address each major section, in the same order they're found in the re-written article.

Introduction
This section provides a very simplified discussion of the CBM's "what" and "how". To the best of my ability, all of the assertions are substantiated elsewhere in the article so, as suggested by the relevant Help: pages, no citations are included here.

The "Facts" table addresses "specified mass" because several different weights were found in the literature, none of which included any useful description of what was actually included. Actual mass may be different than specified, but the specification's intended complement is unambiguous.

Design Overview
The basic features of the design are addressed for each major type. Little attempt is made to present details in the main body, although some of the explanatory notes provided a glimpse into more detailed material. Essential functions and physical characteristics are introduced and described, along with the terminology used to discuss them. Specifications that dominated the intended capability are introduced, as are the fundamental distinctions between the various types of CBM and the original intent for each type.

No existing graphics (e.g., on-orbit photographs) could be found that provided a common scale and matching perspective for the major CBM types. The graphics for this section were expressly built to do so, albeit originally for a different venue. Detailed substantiation for their construction is included in their discussion pages on Commons.

Operations
Summaries of the basic operations are addressed. In this context, "operation" ("what you do with the dingus") is distinct from "function" ("what the dingus does"). The section relies heavily on flight documentation produced by NASA's Mission Operations Directorate for flights of the Space Shuttle as the ISS was assembled. Overall context is provided by reference to "The International Space Station: Operating an Outpost in the New Frontier", written by NASA's Space Station Flight Directors.

To the extent possible, each subsection provides a brief discussion of contingency operations relevant to the operation. In some cases, extensive contingency operations are available, in which case the notes point to the documentation.

There have been some instances where features of the CBM have been exploited in ways that the specifications did not foresee. I've called them "Opportunities" because I could not come up with a succinct title that better expressed the idea. Some enterprising editor might well improve on that title, and might also undertake to keep an eye on the Bishop Airlock Module to update the sub-section once it becomes operational.

It is entirely possible (perhaps even likely!) that there have been changes in operations since the Space Shuttle program ended. Late in the drafting process, I noticed that the timeline for accessing the vestibule might have been compressed, possibly by minimizing the leak check's dwell time. Some enterprising editor might find a way to determine what happened there, and when it changed...the wall where I've been beating my head was approaching structural failure, and I had to move on before I could really dig into it.

Developmental History
This section addresses the historical and technical contexts of the CBM, with just a slight lift of the veil in both directions.

Astute nerds will notice that the introductory material is a bit "ontological" in nature, providing information about what kinds of abstract topics are relevant to the CBM. The non-nerd will, hopefully, note that there are a couple of nice pictures to look at, and walk away feeling like they've gathered a tiny bit of insight about Engineering the assembly of really big things on orbit.

In effect, the introductory material provides background material for subsequent history sub-sections. Including it as a stand-alone unit allowed a much easier explanation of changes in the design as they came along, consolidating much of the technical referencing into a single location. It walks up to, but sticks no more than a couple of toes over, the line beyond which Engineering education is happening (which would, of course, violate wiki-intent). It is also easy to skip over, if desired.

The introductory material relies heavily on a small number of broadly-structured books, and on NASA's basic description of the environment in which spacecraft operate. It also relies on (but does not much quote) Zipay's mind-boggling description of module pressure structures and their verification.

In general, this section is organized by time frame. Additional sub-sections could easily be inserted, if new information becomes available to some enterprising editor.

The Origin sub-section supplies the "why" of a CBM, building on the rationale that motivated NASA to seek alternatives to docking. A much, much longer treatise on the topic could be written. Such an essay might have been incorporated into the existing Spacecraft docking and berthing mechanism article, but it would force a pretty significant change to the organization thereof. I did not (and do not) wish to entertain that project. Hence, this sub-section's quick turn toward the very specific topic of berthing-as-used-for-NASA-space-station.

The remaining five sub-sections chronologically map to the available documentation, summarizing each body of work and, where useful-but-brief, providing some contemporary context.

Galleries
As is usually the case, it is easier to describe a design with pictures than with words. All of my previous drafts tried to integrate pictures into the text...but that isn't very easy to do with the usual wiki-standards. IMHO, the key to a successful draft was to altogether remove the geometric details from the text, moving them into a set of pictures.

In effect, much of the "Design Gallery" is treated as if it is an old-school photographic drawing, where "find numbers" have been overlayed on a photograph. The technique allowed descriptive text, which might someday be translated, to be in the capture. Doing it off-line allowed my to avoid having to learn using the wiki-tools. All such photographs are available on line; some enterprising editor may wish to re-create each figure using the wiki-methods. The original sources are all available in the original upload pages (most of which are on commons).

In a few cases, "find numbers" were not used. Most of those were uploaded at high enough resolution that some enterprising editor could convert them, if so desired.

More photographs could be added...thousands of them are available online. IMHO, however, these capture the basics with enough overlap (to provide a linking context between them) to suffice.

I orbited endlessly on the subject of where to locate the design gallery. It could easily have gone immediately after the "Design Overview", but forced the reader to wade through the most highly detailed information in the article. It could also have been broken into a separate page with only a small loss in continuity. The location was, to be frank, quasi-arbitrary. Some enterprising editor (more wiki-sensitive than I) may wish to give further consideration to this issue. The same commentary is applicable to the operations gallery.

Missions
The Missions table is a very straight-forward listing of all CBM operations I discovered. Any enterprising editor who adds new berths to the list should carefully note that the referencing scheme will require the matching addition of a new (probably status) source. I noticed that similar pages may have been less than perfectly consistent in doing so.

Like the Galleries, the Missions Table is a good candidate for extraction to a dedicated page.

''N.B.: Earlier versions of this table, which I added quite some time ago, had more columns. Those were artifacts of the table's original purpose, which was to support a scatter plot of the masses on both sides of the CBM/CBM interface. The plot itself supported a discussion about the relative thermal mass, which really isn't pertinent to a venue that emphasizes neutral substantiation. I have, therefore, deleted all extraneous columns for the current iteration.''

Glossary
I saw two distinct problems with terms used in the CBM literature: 1) many of the terms are arcane, even for Engineers and 2) in some cases, more than a single term was used to describe the same topic (sometimes within the same source). The first category required some explanation in order to be of use. The second required a reasonable effort at disambiguation.

Regrettably, the glossary template's tooltip doesn't pop the definition. It seems like that problem should be amenable to solution, since it would be similar to what the harvard templates do. I thought about abusing harvard to give the desired behavior, but decided against it. Some enterprising programmer might be able to make a run at tweaking the glossary template to make the tooltip happen.

Notes and Citations
This section generally follows several of the examples used in the Help: explanations and citations for the main body of the article are integrated into a single set of notes. This approach, which was not my first choice, allowed the notes to deal with differences between sources (which were many) and, where possible, with their resolution. In several cases, no complete resolution was possible; in those cases, the notes indicate which were followed. The approach further allows the main body of the article to be more linear than it would otherwise have been.

The figures depart slightly from that notion: simple citations are incorporated directly into the captions. The captions are essentially used here as a type of note, anyway, and doing it the other seemed unnecessarily complicated when reading. Exceptions to this exception were made when true explanations were necessary.

In all cases, I've used some variant of the harvard templates. I tried other schemes, but that appeared to be the most fully featured.

In many cases, but not all, notes are "bundled" at the end of paragraphs for all the reasons in the Help: pages. In some cases, however, notes were unbundled because it made sense to allow a note to concentrate on a single explanatory topic. That's mostly a matter of style. Other editors may choose to combine them, or further split. As long as the technical content is not corrupted, I don't really "have a dog in that fight".

With a single exception, there is modest re-use of notes. A single note was devised to explain the naming conventions adopted throughout many of the figures. It also observes that several of the figures' discussion pages (mostly on Commons) contain additional substantiation. Other editors may reasonably take exception to allowing any substantiation to be stored with the figure.

Many of the documents contain pagination that does not match that of the pdf. I've tried to clearly indicate which pagination is being used. I think it would be good if some enterprising editor could find time to independently verify that.