Viking '75 Mars Lander Construction, Looking for Viking lander design/construction information Options

[Tom Dahl]

Greetings all! I am searching for detailed construction and design information about the NASA Viking '75 Mars project hardware, particularly for the lander, aeroshell, base cover, and bioshield. Can anyone recommend good sources? I am especially looking for engineering drawings and under-construction photographs.

To set the stage, here is an album of about 100 drawings and photos which I've collected so far.

I have already read the "usual" books, such as NASA RP-1027 "Viking '75 Spacecraft Design and Test", the press kits, the scientific papers produced about the mission, a number of industry papers covering various instruments and subsystems, the major Martin Marietta books, etc. I am hoping to find additional sources. Any ideas?

Also, does anyone know if there are aeroshell, base cover, or bioshield components lurking in a museum or in storage somewhere?

FYI, I have visited three of the best landers still on Earth: The Proof Test Capsule in the Smithsonian NASM, the Flight Capsule 3 (backup) in the Museum of Flight near Seattle, and the Science Test Lander in the Virginia Air and Space Center. I've taken nearly 1,000 photos of the three of them (most of which are publicly available in other Picasa Web albums of mine). I've taken a few measurements, but I would dearly love to find more authoritative drawings of more hardware (interior, exterior, everything). I have begun submitting some Freedom of Information Act requests to NASA/JPL which has started to bear some trivial but kind of fun fruit.
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Update as of March 2017: During the past few years I have been fortunate enough to collect a significant amount of information on the Viking lander hardware. My thanks to a number of organizations for providing me access to their resources:

• Viking Mars Missions Education and Preservation Project
• The Museum of Flight in Seattle
• NASA Langley Research Center
• California Science Center
• Virginia Air and Space Center
• Smithsonian Air and Space Museum

Here is a list of on-line albums with Viking information that I have gathered. Essentially all the photographs - about 3500 currently - were taken by me (with the notable exception of those in the "Misc diagrams" album, which come from historic sources). The photos have descriptions that explain the major subject of each image. To see the descriptions with the current Google Photos web album interface, click on an image and then click the small letter i in circle (i) icon in the upper right corner. This displays an information panel that includes the description. You can also zoom and pan to see the full resolution image detail. Many images in a number of the albums show the 1000 or so measurements I have been able to capture from actual Viking hardware, thanks to the kind cooperation of the above folks.

Flight Capsule 3 in Seattle Museum of Flight (756 photos)
Dimensioned diagrams of the FC3 lander

PTC Lander at Smithsonian NASM 2013 (466 photos)
PTC Lander at Smithsonian NASM 2016 (888 photos)

Lander at Virginia Air and Space Center (622 photos)
Dimensioned diagrams of the VASC’s lander

Lander at California Science Center (456 photos)
Dimensioned diagrams of the CSC's lander

Misc diagrams, unusual photos (over 350 images)
Body assembly blueprints

Collector Head Shroud Unit at NASA LaRC (99 photos)
Biology instrument at Cleveland MoNH (36 photos)
Meteorology Sensor Assembly (60 photos)
Meteorology Electronics Assembly (22 photos)
Tape Recorder (53 photos)
High Gain Antenna photos and measurements (96 images)
XRFS Instrument (42 images)

Viking lander contractor historic scale model (14 images)
My Viking project documents collection

The main focus of my efforts during the past few years has been to create an accurate and high-fidelity digital 3D model of the Viking lander. I've chosen to use the SketchUp software to build the model because a near-full-featured free version is available, allowing other people to use my model. The 3D model itself, as a work-in-progress, is available via DropBox. I update that model file periodically as major elements get added. I've created an album containing numerous renderings of digital model components, and I have a YouTube channel with some videos about the modeling project. I have also uploaded the lander core body and the Surface Sampler Collector Head to the SketchUp 3D Warehouse so that other people can easily access those components (the 3D Warehouse can be accessed from within SketchUp, or via web browser). The file on DropBox lister earlier contains those components and others.
-- Tom

[Tom Dahl]

A few months ago I was delighted to acquire a vintage set of blueprints of the "Viking Lander Body Structure Assembly" by Martin Marietta. With the permission of the UMSF administrators I am making scans of them available to all, hoping they provide useful information or at least enjoyable viewing. Here is a PicasaWeb album.

Overview

I suspect this set of blueprints was intended to guide assembly of the core body and its myriad brackets and fittings, rather than to support the fabrication of the various piece parts. There are extensive dimensions listed on the plans (which is what I find so valuable!), but not enough to fully define the parts. The print set consists of 35 sheets. Sheet 1 is composed of over 100 individual pages, consisting of notes, parts lists, and Design Change Notices. Sheets 2 through 35 are the actual shop drawings (one large page per sheet). In the above album I have shown the drawing sheets first, then the various notes pages. What follows in this message are some of my interpretations and explanations of the contents of this historic blueprint set.

Five Lander Body Variants

Martin Marietta's part number for the core lander body is 837J3100000. The plans show five (5) distinct variants of the body, denoted with tags -009, -010, -019, -020, and -029. All five have unique features (generally quite small). Variants 9 and 29 are fairly close to each other; 10, 19, and 20 have a lot in common. I would love to learn what variants correspond to which manufactured lander body units. There is a table on Sheet 1 page 2.004 which seems to list the five body variants with cryptic nomenclature:

ASSY/PART NO. --- NEXT ASSEMBLY --- TT
837J3100000-009 --- 837K0100000 --- PC (?Proof Test Capsule, PTC?)
837J3100000-010 --- 837J1000200 --- TM (?Thermal Effects Test Model, TETM?)
837J3100000-019 --- 837J2000200 --- SD (?Lander Structural Dynamic-Test Model, LDTM?)
837J3100000-020 --- 837J3000200 --- SS (?Lander Structural Static-Test Model, LSTM?)
837J3100000-029 --- 837K0100000 --- <blank>

I don't know the meaning of the "TT" column, but I'll guess that it represents the purpose or role of the lander units (perhaps Test Type). If so, I wonder if the table's two-letter designations represent the test units who's names I've added to the table in parentheses. For what it's worth, the Flight Capsule 3 (backup) lander body in Seattle's Museum of Flight has stenciling from Martin Marietta on sidebeam 2 which includes the notation "P/X 837K0100000-009" (as well as "S/N 0000003"). This suggests that the FC3 body is of variant type -009; perhaps the two Flight bodies FC1 and FC2 are also this type?

According to the set's revision history information, the initial release of the prints was on 27 June 1972. The revisions incorporated into this set occurred during the interval from 7 March 1973 to 15 January 1975 -- just seven months prior to launch of Viking 1. The last few revisions are mostly re-labeling of part-numbers or changes to fasteners. (Assembly of the Flight landers had been largely completed by late 1974.)

The lander body components are assigned Martin Marietta part numbers generally of the form 837J310xxxx-yyy, where xxxx identifies the component and yyy identifies a specific variant. For example 837J3100053-001 is the Surface Sampler's main mount (which happens to only come in one variant). The drawings often do not identify a specific variant in overview contexts, but all components have a formal variant tag. Sheet 1's parts-list pages include a group for each of the five lander variants (e.g., pages 9.001 to 9.021 contain the parts list for variant 9; pages 19.001 to 19.017 list parts for variant 19). I have collated all parts-lists pages into a spreadsheet showing which component variant belongs to which body variant(s). The spreadsheet also enumerates the drawing sheet(s) on which the given component is notably visible.

Scan Process

My paper copies of the drawing sheets are printed on C-size (17 x 22 inch) sheets, reduced from the master E-size (34 x 44 inch) sheets. The reduction is by a bit over 50%; Martin Marietta's reduction-copy process was a bit casual, yielding some skewed orientations accommodated by wide margins. I suspect this print set came from two different master original printings, because some sheet images are slightly larger with different borders than others. I have rectified the scans to be squared to the image area and of uniform size. I scanned the paper sheets at 600 DPI, which yields an image of about 120 million pixels (nearly 13K by 10K pixels). Google's PicasaWeb service currently allows a maximum image size of 50M pixels, therefore the album contains 300 DPI versions. Each sheet's image caption includes a link to a full-resolution version on DropBox.

A few of the drawing sheets are fairly clear prints, but most have extensive background mottling introduced in Martin Marietta's copy/print process. I have begun digitally cleaning the scans. In order to avoid loss of faint and obscured detail this is largely a manual masking job, which is very tedious. To date I have completed masking the first three drawing sheets (numbers 2, 3, 4). I hope to occasionally replace others with cleaned versions. A few of the sheets have annotations applied by a prior owner of the set. I will be removing such annotations during masking.

Lander Body Size

All linear dimensions are in inches and are usually specified to thousandths. These blueprints confirmed my earlier suspicion that the hexagonal body's long and short side lengths of 43 and 22 inches as stated in some NASA documents are incorrect. The long side length is approximately 43.359 inches; the published figure probably resulted from a simple rounding. However, the short side actual length is approximately 24.566 inches, which is about 10% larger than the published value. The height of the core body (excluding top and bottom covers and some integrally-machined protrusions) is exactly 18.000 inches, which agrees with the published value.

By the way the odd values for the side lengths are not direct design parameters. They are derived from the actual design parameters which are the distances from the body geometric center to the perpendicular midpoints of the sides. The design distance from the body center to the midpoint of a long side is specified as exactly 26.700 inches. From body center to midpoint of a short side is specified as exactly 32.125 inches. Application of some mathematics yields the side length values listed above. (I was pleased to discover that length estimates I had made earlier, based on known Aeroshell data, a scale USGS drawing of the lander, and knowledge of the nine-point interface between Aeroshell and lander, were only off by a few hundredths of an inch.)

The core lander hexagonal body consists of three (3) sidebeams, each machined from a single piece of aluminum. The three sidebeams are broadly similar but differ in numerous details (flanges, holes, stiffeners, etc.). The sidebeams are spliced or butted together with the vertical joints on the centerlines of the three landing legs. Therefore each sidebeam represents one complete long side and the halves of two adjacent short sides (appearing as angled short "wings" seen from above). Here is a rendering I've created of sidebeam 1.

Blueprint Notations

Each of the drawing sheets has a border dividing the sheet into an 8 by 8 grid of 64 zones. Zone coordinates range from 1 to 8 (bottom to top) and A to H (right to left). One portion of a drawing will frequently refer to another view or section on the same or a different sheet. Such zone references are denoted by a square containing number / letter coordinates, with a small sheet-number outside the upper right corner.


Large circles with multi-line text generally represent part numbers (e.g., 837J3101042-009) or fastener types (e.g., ST25D40-5-3).


Small circles containing a dash and three digits denote a simple flat shim part (of which the lander contains dozens). Sometimes the circle is omitted. The three-digit number is the variant tag for the shim's part number, all of which belong to the overall lander part number 837J3100000. For example, a notation of "-075" refers to shim 837J3100000-075. The parts-list pages show the shim's nominal sizes, with width and height larger than final to allow for trimming tolerances. The drawing sheets generally show the final shim sizes (which I've listed in the above spreadsheet when known).


Horizontal triangles containing a number are flags which reference one of the notes listed on pages 2.001 to 2.003 of sheet 1. Such notes detail process operations, assembly instructions, etc.


Small rectangles define construction reference planes, or specify tolerances in relation to a reference plane or point. In the following example the lower rectangle defines the associated feature (not seen in this fragment) to be Plane E. The upper rectangle specifies that this plane must be parallel ("||") to Plane A (defined elsewhere) within 0.020 inches.


A few features on the lander required a particular degree of machined surface finish. These are denoted with a stylized kind of letter J with an adjacent number (representing the roughness average value in microinches).


Anachronism

Most of sheet 18 is devoted to a prominent component which is not present on the final Flight-type lander bodies. It is an earlier design for the lander's Radar Altimeter Antenna mount (described in the parts list as "Support-LAA" and belonging to body variant 10). This photo of the Thermal Effects Test Model (TETM) has such a projecting assembly, visible at the right upper corner of the front of the inverted body (which corresponds to the lower left corner of sidebeam 2). This reinforces the idea that body variant -010 was used for the TETM, and that "TM" in the table I listed near the top of this write-up is the Thermal Model.