The Artemis II Lunar Science Data User Guide, version 1.0 dated October 7, 2026, explains how researchers can locate and interpret the mission’s public science records. The Artemis II Data User Guide covers photographs, video, audio, transcripts, annotations, mission documents, and Orion environmental measurements. Its purpose is practical: a downloaded file needs information about its origin, timing, processing, and limitations before it can support a scientific conclusion.
NASA released the archive after the crew’s April lunar flyby, giving outside investigators access to observations previously held within the mission’s science workflow. The guide does not present a finished scientific interpretation of every product. It describes the records and their organization so that other researchers can identify relevant material, reproduce processing choices, and distinguish a camera image from a calibrated measurement of the lunar surface.
The data user guide was prepared by the lunar science team with several NASA Planetary Data System nodes. These nodes are specialized archive organizations. The Geosciences Node handles mission documentation and Orion environment data; the Cartography and Imaging Sciences Node handles imaging and audio. The Navigation and Ancillary Information Facility supports the geometry information needed to describe spacecraft and target positions.
The archive uses the Planetary Data System’s PDS4 structure. Related records are grouped into collections and larger bundles. Each product has a detached XML label, a separate structured metadata file that explains the associated data. A product can contain more than one data file, but it has one label. This means a file count, product count, and count of distinct observations are not necessarily interchangeable.
Labels matter because they preserve details that may not be visible in a photograph or readable from a filename. They can identify instruments, acquisition information, processing, and references connecting products. Some files also contain embedded metadata, but that does not remove the need for the archive label. Retaining the label with the downloaded data helps later users understand the exact record under examination.
The guide distinguishes original camera material from converted and processed products. Crew-camera records include source files and versions prepared for archiving or viewing. Several files can represent the same exposure in different formats. Counting each version as a separate lunar observation would overstate the evidence. A processed picture may be easier to display, but its appearance also depends on the documented conversion and rendering steps.
One example concerns Nikon Z9 files. The guide explains that available open-source software did not directly preserve the sensor pattern when processing the camera’s high-efficiency raw format for the archive. The team first converted those files to Digital Negative format and then produced the required image products. This documented intermediate step allows researchers to assess a processing path rather than assume that every archived image is an untouched camera output.
Video requires similar attention. During parts of the flyby, communications bandwidth limited transmitted video to five frames per second even though the camera collected imagery at 30 frames per second. Ground recording used a different broadcast frame rate. The guide distinguishes acquisition, intermediate transmission, and recorded-video rates. A higher number in a playback file does not establish that it contains more independently captured moments.
That difference affects investigations of short events such as lunar impact flashes. A researcher needs to know whether a stream preserved enough temporal information to show an event, rather than relying on its nominal playback rate. The guide also describes a short video recorded locally during the eclipse period. Comparisons between these products require their actual observation intervals and processing histories.
Audio and annotations preserve a different kind of evidence. Astronauts recorded descriptions during the flyby, and the archive supplies audio together with transcript products. Annotated images identify features or approximate event locations. These records explain what observers noticed and intended to document. They do not automatically turn a visually perceived color into a measured surface composition or an approximate mark into a precise geographic coordinate.
The mission’s observation practices also have antecedents in space station observation methods. Crew photography depends on target planning, training, and recording conditions as well as camera hardware. For the lunar archive, the relevant information includes how photographs, descriptions, and observation blocks relate. Preserving those relationships supports interpretation after the people who planned and performed the observations are no longer directly involved.
Mission documents provide part of that context. The onboard Lunar Targeting Package was an interactive tool combining planned observations with geographic reference material. The archive preserves a noninteractive, page-by-page PDF representation rather than the original interactive application. That choice retains a view of the instructions and reference content, but researchers should not expect the archived document to reproduce every function of the onboard software.
The environment collection contains measurements from two data loggers placed in Orion storage lockers. Temperature, relative humidity, and dew point were recorded at 60-second intervals from March 26 through April 21, 2026, covering time before and after the flight. Those measurements characterize conditions relevant to planning future lunar sample storage. Artemis II returned no lunar samples, so the records do not demonstrate how actual returned specimens responded to those conditions.
Archive completeness also has a date-specific limit. As of October 8, the archive access page identifies the spacecraft geometry bundle, called SPICE, as delayed. SPICE supplies the position, orientation, and timing information used to reconstruct observation geometry. The guide describes the intended archive structure, but description in the guide does not establish that every planned component was already available in the initial delivery.
The guide’s documented versions and product identifiers support later correction and reuse. Scientific work based on the archive needs to identify the products and processing actually used, account for duplicated formats, and retain qualifications about timing and calibration. Public access permits independent examination; the documentation makes that examination more reproducible. The remaining requirement is to match each research claim to evidence whose observation conditions, processing, and availability are established.
