I would like to verify the origin of the lander which is on display at the Virginia Air and Space Center (VASC). I believe it is the Science Test Lander (STL) for reasons listed below; however, perhaps it has some other origin. I hope the community can come to a conclusion. I have written to the curator of the VASC but have not received a response in a couple of weeks.
Firstly, here are three certain photos of the STL: one linked near the bottom of
this page by Don Davis (a contributor to this forum), one
from NASA, and a second
similar one. I have been using these photos for identification.
Landers created by Martin MariettaA basic question is what landers were created by Martin Marietta in the first place? There were of course three "Flight Capsule" landers: FC1 and FC2 which are on Mars, and FC3 (backup) which is now in the Museum of Flight near Seattle. I have a large
photo album for FC3 here. What about non-Flight landers? There is a list on page 258 of
NASA SP-4212 "On Mars" which states:
"The major Viking simulators included:
Lander (structural) dynamic-test model (LDTM). A flight-style structure with partial flight-style or equivalent propulsion lines and tanks. Mass (weight) simulators were used for nonstructural hardware. The LDTM was used for structural vibration, acoustic noise, separation tests, and pyrotechnic shock evaluation.
Lander (structural) static-test model (LSTM). A flight-style structure used for qualification of the primary structure under steady-state and low-frequency loads.
Orbiter thermal effects simulator (OTES). A simulator used to study the orbiter's thermal and shadowing effects during the lander-development thermal environmental tests.
Proof-test capsule (PTC). A complete Viking lander capsule assembly assembled from flight-style hardware, used for system-level qualification. [This is at the Smithsonian NASM.]
Structural landing test model (SLTM). A 3/8, geometrically scaled model of the lander, dropped at various velocities and attitudes to determine landing stability boundaries. The 3/8 scale was chosen because the Martian gravity was 3/8 that of Earth's.
Thermal-effects test model (TETM). A full-scale model incorporating developmental thermal control systems and flight cabling test harness. Flight equipment thermal effects were simulated by special equipment. The TETM was used to verify the system developed for controlling the temperature of the lander." [Here is a
photo of the TETM which I scanned from a copy of NASA SP-336 I own.]
One major question in my mind is: which of the above is the STL? I do
not think the JPL-STL is the PTC. The PTC is on display at the Smithsonian NASM, and I've taken a few hundred
photos of the PTC. Many details do not match. However, I do suspect that the lander pictured in the famous photograph with
Carl Sagan in Death Valley is the PTC, not the STL. For example the loose-fitting fabric cover on fuel tank #1, the detail wrinkling of the main fuel-line insulation (especially just above the aeroshell shear fitting near the left end of sidebeam #2), and the gray colors of the large electrical connectors for the aeroshell (along the bottom edge of short side #2 and sidebeam #2) suggests this conclusion.
Clues that the VASC Lander is the JPL-STLHere are some observations which suggest to me that the lander at the VASC is the Science Test Lander. Some of these are pretty obscure; bear with me! For what it's worth the PTC at the Smithsonian does not match these various details.
* Mock-up Terminal Descent Landing Radar box below the lander. The VASC lander has two deep white sheet-metal flanges which represent two sides of the 30-inch square TDLR box. The STL has a white TDLR box which looks similar from the "front."
* There are various survey target "bulls-eye" stickers on the lander, such as near the Load Limiter mounts along the lower corners of sidebeam #2 and near the tops of the primary support fittings for landing legs #2 and #3.
* Details of how insulation is wrapped around the main fuel line which runs across the lower face of sidebeam #2. See the down-pointing triangle bulge near the aeroshell shear fitting near the left end, and the general thickening near the right end. The fuel-line insulation on the PTC and the STL differ considerably, both in the above details and in that the STL insulation has much tighter wrinkles overall.
* The orange electrical cable extending vertically amid the fuel, pressurant, and coolant lines which go up in front of RTG #1's windcover (which were designed to pass through the Base Cover and Bioshield cap). I'll grant that the JPL-STL has two such orange cables, whereas the VASC lander has only one, but I haven't seen even one on other landers.
* The heavily-bolted body panel on the right half of short side #3. Just to the right of the primary support fitting for leg #3 is a panel with four columns of fasteners. This is lacking on the PTC (and Flight lander bodies).
* The hand-inked black serial number lettering on the sides of the leg bipod struts. They each have the numeral 1, 2, or 3 written near the footpad end, and some have "S/N 000000x" written near the Load Limiter end. (Curiously on the VASC lander, the bipod struts for legs #1 and #3 have been swapped!)
* The thick black electrical connector for one of the three aeroshell connections -- the one along the bottom edge of short side #2 -- has a tilted or sloped damaged top. These are black mock-up connectors, different than the functional gray ones on the PTC.
* The stitching (or similar) along the top rim of the protective box for the Meteorology Sensor Assembly when stowed. The PTC has a smooth plastic-looking box. (The Flight landers have yet different boxes, with pressed stiffener ribs.)
* The folding of insulation on the large six-element electrical connection box on the left side of sidebeam #2 below the surface sampler, and the particular arrangement of only three cables.
* The markings on the fixed post of camera #1, in particular the blue NASA property sticker. (I'm not sure how many authentic Itek cameras have such a sticker, but it's lacking on the Flight lander cameras, the PTC cameras, and the development unit camera at the NASM.)
* The fact that Radar Altimeter Electronics #2 (mounted on top of the lander near the High Gain Antenna) is a plain gold-colored mock-up, in contrast to essentially all the other top-mounted components which look very authentic. Don Davis's STL photo is consistent with the VASC lander in this manner.
All of the above strongly suggests to me that the VASC lander is the Science Test Lander from JPL. Also, the other landers on display here and there (e.g., NASM, KSC, Kansas Cosmosphere, and California Science Center) differ from the STL in numerous ways. Thus the STL is not at those institutions.
Mis-matches between VASC Lander and the STLThere are some mis-matches between the VASC and JPL-STL landers, however.
* The American flag marking on RTG #2's windcover is in a different position.
* Camera #2's fixed post is different (though both the VASC and JPL-STL landers have an unusual dark lower half).
* The white fabric contamination fairings which cover the upper primary struts for the landing legs have different "hose clamps" at top and bottom.
* On the side of the Meteorology Boom Assembly's hinge, the VASC lander has a dark-colored blank rectangle in the position where the TRW manufacturer data plate would be. The MBA on the JPL-STL has no data plate of any kind.
* The orange electrical cable which connects to the Meteorology Boom near its mount is covered with thick caulk-like material on the VASC lander, which obscures the shape of the underlying cable connector components. On the JPL-STL it is possible to see the smooth cylindrical orange connector parts.
Perhaps these discrepancies could be explained by swaps of components during the latter stages of the STL's life, but they are puzzling. One definite swap can be found in Terminal Descent Engine #2, near the surface sampler. The overhead image by Don Davis shows a clear mock-up engine (with whitish nozzles, gold-painted thermal side shield and smooth gold top), whereas the NASA side-view photos show metallic nozzles and an authentic-looking very reflective gold-plated thermal shield.
ConclusionSo where did the VASC's lander come from? I think it's the STL. More generally where did the STL come from? Is it a conversion of the LDTM, LSTM, or TETM? I don't know.