MEMORANDUM OF UNDERSTANDING

between

NATIONAL SPACE SCIENCE DATA CENTER

and the

PLANETARY DATA SYSTEM


DATED : September 1, 1993


Approved by:




Joe King
Director, National Space Science Data Center



Susan McMahon
Project Manager, Planetary Data System
Jet Propulsion Laboratory



Jay Bergstralh
Program Manager, Planetary Data System
Solar System Exploration Division



Joe Bredekamp
SM/Chief, Information Systems Branch
Office of Space Science and Applications

















I.      PROLOGUE

    Effective data management is necessary to maximize the science output from
NASA missions.  Such data management provides scientists the ability to locate
and access needed data, and to obtain information and software required to
make the data useful.  It has become a precept that data should be managed as
close to the data producing science community as possible.  To this end, NASA
has established a number of Discipline Data Centers (DDC's) to augment the
National Space Science Data Center (NSSDC) to facilitate data access and
utilization in those respective disciplines.  One of these is the Planetary
Data System (PDS).

    NSSDC is responsible for top-level data management functions that span all
OSSA programs and scientific disciplines and for selected discipline-specific
responsibilities to be defined by mutual agreement between the NSSDC and the
relevant OSSA program division.

    As a DDC within the NASA archive environment, the PDS has sole 
responsibility
for the collection of lunar and planetary data (hereafter referred to merely
as planetary data), the definition of its content, its validation and catalog
management.

    This Memorandum of Understanding identifies the roles of NSSDC and 
the PDS in
preserving and facilitating access to data acquired by NASA planetary
missions.

II.     INTRODUCTION

A.      PURPOSE

    The purpose of this document is to describe the roles of the PDS 
and NSSDC in
acquiring, archiving, and distributing planetary data. This document sets the
general constraints on the interfaces between the two organizations.
Additional mission specific details of the interfaces will be developed and
specified in future documents which will govern the details of the interface
between NSSDC and the PDS.

B.      SCOPE

    The scope of this document covers areas of operation  where there is joint
responsibility between the PDS and NSSDC or where, despite possibilities of
ambiguity, there is a sole responsibility of one or the other.  Other
documents exist which describe the full range of operations of each
organization.

C.      AUDIENCE

    The following groups are the intended audience for the document:

    1. Staffs of the PDS and NSSDC.

    2. Those who are preparing planetary science data such as Principal
         Investigators, planetary missions, data restorers.

    3. Those who want to access planetary science data, including NASA planetary
         scientists and other domestic and foreign scientists.

    4. NASA Headquarters personnel who manage and provide the 
operating funds for
         NSSDC and the PDS.

    5. Managers of institutions participating in NSSDC or PDS activities.

    6. Members of other data centers.

    7. PDS and NSSDC advisory groups.

D. SUMMARY

    The following are the key components of this MOU:

    1. The PDS will serve as the point of entry for planetary data into the NASA
archive environment.

    2. The NSSDC shall maintain and coordinate broad data standards for data
management and archiving which are appropriate to most or all disciplines and
recommend, maintain and monitor implementation of minimum NASA data standards
with which all discipline systems must comply.

    3. The PDS shall be responsible for establishing and maintaining data
standards, data structures, and data formats which are appropriate for use by
the Planetary Science community.

    4. The PDS serves as the primary interface with the planetary data 
producers,
obtaining the data and checking them for correctness of format and content.
The data products are then passed on to NSSDC for "deep-archiving" along with
appropriate catalog and ancillary information.

    5. The NSSDC shall maintain and operate the NASA Master Directory (which is
to be inclusive of all NASA Space and Earth science data regardless of the
discipline data system where they reside.) The PDS shall support the
population of the Master Directory. In addition, the PDS shall maintain a
multi-layered catalog residing at the Central Node and Discipline Nodes of the
PDS.

    6. The PDS is intended to serve Code SL-sponsored planetary scientists.

    7. NSSDC serves the non-SL community and, for special needs (e.g., analog
products, large volume distributions, distributions from NSSDC's pre-PDS
holdings, etc.), also the SL-funded community.


F.      MOU REVIEW PROCEDURES
    This MOU will be reviewed periodically by both NSSDC and the PDS 
to determine
each organization's compliance with the MOU as it exists at the time.  Any
statements in the MOU in conflict with the current policy and procedures of
either NSSDC or the PDS will be identified.  The reasons for these
discrepancies will be reviewed and either the MOU or the operational policies
and procedures of NSSDC or the PDS will be changed to reflect a resolution of
this discrepancy.  These changes may be necessary if either organization is
unable to comply with the MOU or the statements in the MOU no longer reflect
current NSSDC and PDS policies and procedures.

III.    ORGANIZATIONAL SCOPE

A. NSSDC

The NSSDC is sponsored by the Technology Office within NASA's Office of Space
Science (Code STI) to have primary responsibility for the multi-disciplinary
Master Directory and underlying information systems at NSSDC, for evolving and
coordinating widely relevant data management and archiving (DMA) standards,
and for providing a DMA infrastructure for use by NASA science divisions in
concert with their Discipline Data Centers (DDCs).  In addition to normal
management reviews, the work and priorities of NSSDC will be reviewed by an
NSSDC User's Group to be constituted by both end-user scientists and by DDC
officials.

B. PDS

The PDS is sponsored by NASA's Solar System Exploration Division (Code SL) to
ensure the long-term usability of data, to stimulate research, to facilitate
data access, and to support correlative analysis.

The PDS will serve as the primary interface to flight projects for product
and catalog definition, standards usage, product generation and product
validation. The PDS will establish a Management Council comprised of planetary
scientists from various disciplines which will advise the PDS on archive
policies and procedures.



IV.     PROJECT INTERFACE

The PDS will serve as the point of entry for planetary data into the NASA
archive environment.  The PDS will maintain a Mission Interface which is
responsible for negotiating individual Project Data Management Plans and
Archive Plans with the projects which at least satisfy the OSSA Policy on
Science Data Management (formerly known as NASA Management Instruction (NMI)
8030.3A).  In most cases, the PDS will have signature authority over the
Project Data Management Plans and Archive Plans. In cases where the PDMP
specifies certain products will be archived at NSSDC, then both NSSDC and PDS
will sign the document.

All active mission data products that enter the NASA archive environment
through the PDS Mission Interface will be validated and  passed on to NSSDC
for long term archive.  These data products shall be specified in pre-launch
PDMPs and Archive Plans signed by NASA Headquarters (Code SL) and may include
raw science data, ancillary data, organized higher level data products agreed
upon  by the Project's Science Steering Group, and individual reduced data
sets deemed important by individual investigators as well as all relevant
documentation.

The PDS will also be the archive entry point for all data restored from past
planetary missions.

PDS and NSSDC will agree on and document the terms covering the transmission
of archive products from PDS to NSSDC such as media type, volume and frequency
of delivery.

V.      CATALOG

The PDS will maintain a catalog of their planetary data holdings.  This
catalog will be multi-layered with the high level catalog residing at the
Central Node and the lower level, more detailed, catalogs residing at the
Discipline Nodes. This multi-layered PDS catalog will be accessible by NSSDC.

NSSDC will maintain and make available to the general community appropriate
information relevant to planetary data in its own information systems. NSSDC
will maintain a multidisciplinary NASA Master Directory which will include
limited information about PDS holdings.  Appropriate descriptive information
from the high level PDS catalog will be sent to NSSDC's Master Directory via
the Directory Interchange Format (DIF).  NSSDC will provide instructions to
PDS in the appropriate use of the DIF Format and will review PDS entries in
the Master Directory. NSSDC will also maintain electronic links into the PDS
catalogs from the Master Directory. For each new data set sent to NSSDC, PDS
will also send a completed AIM level 3 template to be used by NSSDC in
populating the RSIRS/NISE system at the data set level.

The NSSDC shall coordinate the Master Directory design evolution to meet
mutual budget and system scope constraints.

All changes to be made to the Master Directory that will require the PDS to
develop and/or modify their operational system shall first be coordinated with
the PDS.

VI.     DATA

Recognizing PDS budget constraints, the PDS shall strive to coordinate and
share archive tasks with NSSDC and flight projects to do the best possible job
with the available resources. Therefore, the management of planetary data will
be a cooperative effort involving the PDS, NSSDC and flight projects.  Each
organization will have responsibilities concerning the preparation, storage,
and distribution of the data.

A.      DATA PREPARATION

1.      Mission Data:  As described in Section IV, the PDS is responsible for
maintaining the Mission Interface. All NASA mission data will enter the NASA
archive environment through the PDS under the Project Data Management Plans
and Archive Plans negotiated with each of the projects.  The PDS will verify
the correct format, completeness, and continuity of the data and will monitor
the validity and content of the incoming data.  The PDS will also verify the
correct format, completeness, and continuity of the catalog data. Part of the
data preparation process includes  populating the PDS catalog with the new
information.  It will be the responsibility of the PDS to enforce the
negotiated Project Data Management Plans and report cases of non-compliance to
NASA Code SL management as requested.

2.      Restored Data:  The restoration of old planetary data sets will be
coordinated and overseen by the PDS.  The normal procedure for data
restoration will be initiated by a Discipline Node or proposal to the PDS for
the establishment of a Data Node which will exist for a short period ( a year
or two) for the sole purpose of reformatting and documenting the data set.
The restoration process will be sponsored by the appropriate Discipline Node
and the resulting data set will be validated by a peer review process. As with
mission data sets, the restored data sets will result in an update of the PDS
catalog. The data flow will be into the PDS under the appropriate Discipline
Node, even though the pre-restoration location of the data set may be NSSDC.
In cases where NSSDC has the opportunity to restore planetary data sets, it is
important that the PDS be involved in the selection of which data sets are to
be restored, consistent with the priorities set by the PDS.

B.      DATA STORAGE

Most planetary data will be stored in more than one location.  The location
of the deep archive for the long-term preservation of planetary data will be
NSSDC.  The PDS requirements for safety, longevity and reliability in the
archive procedures will be negotiated with NSSDC within the framework of NSSDC
resources.  When practical, affordable and necessary, NSSDC will create a
duplication set from the PDS-provided archive set; this duplication set will
be used in creating data copies for requesters, thereby minimizing use of the
archive set.

The concept for the PDS Discipline Nodes includes the provision for the
maintenance of a working set of all data considered to be relevant to that
particular discipline at the Discipline Node.  The working data sets will be
used to support ongoing research carried out by and through the Discipline
Nodes.  The research effort will, from time to time, result in new, derived
data sets which will be cataloged and submitted to NSSDC for archiving.
Information on data sets which are at Data Nodes and are in the process of
being restored will be available through the PDS.  The data sets themselves
need not be stored elsewhere in the PDS or NSSDC.

A complete set of non-machine-readable planetary data will be archived,
maintained, and distributed by NSSDC.  The PDS will catalog these holdings and
will arrange for the validation, submission, and documentation of these
non-digital products, but it will not store or distribute them.

C.      DATA DISTRIBUTION


The distribution of planetary data will be a function shared by NSSDC and the
PDS. (The only exception to this rule will be the distribution of pre-PDS data
archived at NSSDC. NSSDC shall be primarily responsible for storing and
distributing these products.) NSSDC will be responsible for the distribution
of partial or complete data sets from requests which are considered 'standard'
in the sense that the request may be fulfilled by the straight-forward
duplication of one or more tapes or disks.  Distribution of all
non-machine-readable planetary data products (such as photo products and
videos) will be the sole responsibility of NSSDC. The PDS will have
distribution responsibility for filling requests for small amounts of digital
data (i.e. a single or partial tape or disk volume), or for requests which
require manipulation of the data or the assistance of scientific expertise
within the PDS in the preparation of the distribution.  The distribution of
all data being stored at Data Nodes will be the responsibility of the PDS.

These distribution guidelines hold regardless of the source of the request of
the data, whether from a Code SL-supported scientist (initiated from within
the PDS) or from another individual.  (The non-Code SL-supported scientist
will initiate his request in NSSDC.)  Both the PDS and NSSDC will keep each
other informed of the status of all requests and provide periodic statistical
summaries of all planetary data requests.

Neither NSSDC or the PDS is capable of easily fulfilling requests which
involve large amounts of data or large quantities of expert support for the
manipulation of data.  The NSSDC has well-established charging methods which
will be implemented for large requests of planetary data.  This holds even if
the request is initiated by a scientist supported by NASA Code SL.  The PDS
does not currently have a charging mechanism for requests which involve large
resource expenditures to fulfill. Therefore, it is anticipated that an
exchange of services between NSSDC and the PDS can be arranged to satisfy
occasional resource-intensive requests.

Both the PDS and NSSDC will fulfill requests using NSSDC standard media as
appropriate, including magnetic tape, optical disks, or electronic
distribution under standard protocol.

VII.    USER SUPPORT SERVICES

The PDS is charted to service primarily the planetary scientists supported by
NASA Code SL.  All other users will access planetary data through NSSDC.  As
discussed in Section VI.C, NSSDC will directly handle the large
straightforward data duplication requests for planetary data.

Regardless of the requestor the PDS will service requests which are
non-standard and require manipulation or assistance from the PDS expertise.
When the request is from a non-Code SL supported scientist the 'non-standard'
request will be passed from NSSDC to the PDS.

Both NSSDC and the PDS will supply users access to catalogs of the planetary
data and will support the browse and query of these catalogs.

Planetary data analysis support is the responsibility of the PDS.  As such
the PDS Discipline Nodes will have data, hardware and software tools, and data
management capability to support the analysis of planetary data.  The
Discipline Nodes will provide the technical and scientific expertise required
to use the PDS and to answer questions concerning the data.

VII.    TECHNOLOGY DEVELOPMENT

It is in the interest of both the PDS and NSSDC to continue to develop data
management, storage, presentation, computation, and communication technologies
as well as standards to better serve the scientific community.  Lead roles
should be negotiated by NSSDC and PDS (or other DDC's) for particular types of
developments for which a DDC is especially suited; and these should be put to
use in the overall NASA Distributed Data System as appropriate.
[EOB]