Stardust Sample Nomenclature
Aerogel Cell Nomenclature
Sample nomenclature for individual aerogel cells and foils relates to cell number (# 1-132) as illustrated on the tray image, where the tray is mounted in its standard orientation on the Primary Scanning System (PSS). The interface with the deployment arm during cometary exposure is at the top in this orientation. The top is (arbitrarily) assigned N, the bottom S, the left side W, and the right side E. This becomes significant when referring to the locations of various foils.
The prefix C2 for any Stardust sample summarily relates to Cometary Tray 2 (Trays 1 and 3 were relegated as a flight spare prior to launch). Similarly the prefix I1 for any Stardust sample summarily relates to Interstellar Tray 1 (Trays 2 and 3 were relegated as a flight spare prior to launch).
All Level 2 and 3 imagery of individual aerogel tiles and foils consistently utilize the lower-left hand corner as the origin (X=0 and Y=0). Level 3 photography (top views) adopt this orientation as well. All side views of individual cells mandated that the cell be rotated by 90° around the X axis. As a result, the 0/0 point is moved to the upper left-hand corner of the tile/images. The Y axis on the PSS in this orientation becomes a measure of the horizontal or penetration depth from the tile’s surface, while the Z-value on the PSS corresponds to the original Y-value in the top-view situation.
Nomenclature for Impact Features in Aerogel Cell
A sample name begins with the name of the parent aerogel cell, for example C2126, unless the sample derives from a loose aerogel chip with unknown parentage. In the case of loose chips the sample name begins the chip name, for example “FC4”.
The second part of the sample name is the number of the separated aerogel piece that contains the captured particle. The parent aerogel cell “0”, and all subsequent pieces are numbered sequentially beginning with 1.
The third part of a sample number is the “track” number. Impact features (with captured (article residues) are called “tracks”. Tracks are numbered sequentially according to their removal from aerogel cells and/or first sampling.
Following (and meteorite) sample nomenclature, each individual track constitutes the parent of subsequent sub-samples, separated with a comma from its parent. For example, individual grains extracted from a given track are labeled “Track X, 1”, etc. and further subdividing of specific grains (e.g., into potted butts, TEM grids or other sub-splits) would become “Track X,1,1”, etc.
So, for example the number “C2022,1,57,2,3” would be TEM grid “3”, made from grain “2”, from track “57”, which was located in aerogel piece “1” removed from aerogel cell “C2022”.
Because specific track morphology and residue content have no obvious relationship to specific host tile and tray location, the decision was made to not include track location or cell number or coordinates in the identifier. As a consequence each sampled track is assigned a number that simply relates to the chronological sequence in which the individual track was isolated or harvested, regardless of which cell it may have originated from within. The original location or cell is recorded in the Curatorial database and is not lost, but is simply is not part of the identifier.
Aluminum Foil Nomenclature
All aerogel tiles share four Al foils with their neighbors, except those tiles located in cells along the tray’s periphery. By convention and definition, the foils were identified as N and W (i.e., the foils at the top and to the left of each cell were assigned the specific cell number and the prefix N or W, respectively, were used.
In utilizing such a convention, on certain peripheral cells possess S and E foils since there was no cell on the opposite side from which to assign the N or W value from. Each foil draped an individual tray rib in a continuous fashion (i.e., both sides and the exposed top of the rib). The exposed top surface was cut and isolated during foil harvesting and assigned an appropriate sample number (i.e., C2xxx, N1; the wall section facing the parent cell was assigned ,0, while the wall section facing the neighboring cell was assigned ,3 (after harvesting of corresponding cell).
When a given side (N, E, S, or W) possesses more than one foil, the foils are numbered beginning with “1” and continuing clockwise till all are assigned a unique sample number (Ex. N foil above).