Ulysses Data Coming To NSSDC

Volume 11, Number 1, March 1995
By John Cooper

Ulysses Mission

The Ulysses spacecraft is the first man-made object in a heliocentric orbit with a high enough inclination to allow studies of the polar heliosphere and the solar wind emanating directly out from large dark regions (coronal holes) in the X-ray corona near the solar poles. This mission is providing a unique opportunity to explore the solar wind plasma, magnetic field, and energetic particle processes in interplanetary space over the full range of heliographic latitudes up to about 80 degrees during phases of minimum and maximum solar activity. The Ulysses mission is jointly managed by NASA and the European Space Agency (ESA). Click here for the most recent report from the Ulysses Project Office at the Jet Propulsion Laboratory on the mission status.

After launch by Space Shuttle Discovery STS-41 on October 6, 1990, the Ulysses spacecraft was boosted on a path towards a flyby of Jupiter on February 8, 1992. The Jupiter encounter swung the spacecraft out of the ecliptic into a heliocentric orbit inclined about 80 degrees to the ecliptic and with a period of about six years. In June 1993, Ulysses passed beyond the maximum heliographic latitude (32 degrees south) reached by any other heliospheric spacecraft (Voyager 1), afterwards, traversing the south polar region (above 70 degrees) of the Sun from June through November 1994 and the north polar region from June through September of the next year. An approved extension of mission operations into the next solar maximum will provide further solar polar science from polar traversals from September 2000 through January 2001 (south pole) and from August through December 2001 (north pole).

The Ulysses science experiments were described in the Ulysses Instruments Special Issue of Astronomy and Astrophysics (Astron. Astrophys. Suppl. Ser., 92(2), Jan. 1992). These instruments are listed in Table 1, and their layout on the spacecraft body is shown in a Web-accessible NSSDC) has been specified in a project data management plan and agreed upon by the Ulysses Project, NASA Headquarters, and NSSDC. This plan was formally approved in November 1994 and specifies that reduced (experimenter unit) and analyzed (scientific unit) data, along with associated documentation and software, will be submitted to NSSDC within two years of original data receipt by the Ulysses experimenters. NSSDC will serve as the primary archive for interplanetary cruise data and as the deep archive for all Ulysses data. Jupiter-related data will first be submitted to the Planetary Data System (PDS) and then subsequently transferred to NSSDC after PDS processing and peer review. NSSDC will further receive and hold in proprietary status all Ulysses CD-ROM data in Experimenter Data Record (EDR) format. One exception to the proprietary status of the CD-ROM data is that NSSDC can extract Ulysses ephemeris data in the Supplementary Experiment Data Record (SEDR) format for public distribution. (Note that most PI-provided data sets will have some included ephemeris data.)

Much Ulysses data will be electronically acquired by NSSDC from ESA's Ulysses Data System (UDS), or from individual investigator sites on the Internet. UDS was originally implemented as a prototype online archive for distribution of proprietary Ulysses data among the experiment investigators and now also serves as a primary distribution point for data acquisition by the NASA archives. An average of 0.1 gigabytes per month of nonproprietary Ulysses data is presently expected to be ingested by NSSDC, usually via the Internet, and made available to users. Table 2 shows most of the data sets presently expected at NSSDC by the time of this article. Some Ulysses data sets, including solar wind plasma, magnetic field, and energetic particle data, will be staged through NSSDC's Coordinated Heliospheric Observations (COHO) data base which will provide immediate online accessibility via anonymous ftp ( access at account anonymous@nssdca.gsfc.nasa.gov, directory anon_dir:[000000.coho] ) and the World Wide Web (note that it's still partially under construction.) Eventually, all digital data sets, whether initially ingested on line or off line (e.g., on CD-ROMs or high density tapes) will be migrated to NSSDC's near-line archive environment, the NSSDC Data Archive and Distribution System NDADS. Graphical browse and display accessibilities are planned for selected Ulysses data parameters in the future through a Web-based service to be called COHOWeb, similar to NSSDC's new OMNIWeb service for near-Earth interplanetary data.

NSSDC staff will continue discussions with the Ulysses investigators on identification and acquisition of new data sets through official presentations and negotiations at periodic meetings of the Ulysses Science Working Team and through individual contacts with the investigators. These discussions have recently included an NSSDC briefing of representatives from the URAP team on new automated software for production of Standard Formatted Data Unit (SFDU) metadata in accordance with NASA's increasing emphasis on usage of evolving data standards technology. This briefing was supported by staff from the NASA/OSSA Office of Standards and Technology (NOST) in the Interoperable Systems Office at NSSDC. Space physics expertise related to Ulysses science and data is provided by acquisition scientists associated with the NASA Space Physics Data Facility (SPDF), co-located with NSSDC in the NASA Goddard's Space Sciences Directorate. Continuing technical collaboration between NSSDC/SPDF, PDS, UDS, and the investigators will ensure the expeditious and comprehensive archiving and public accessibility of Ulysses data during the prime and extended mission phases.

Questions about Ulysses data archiving and access at NSSDC should be directed by E-mail to Dr. John F. Cooper, the Ulysses Acquisition Scientist, at the Internet address: jcooper@nssdca.gsfc.nasa.gov.

Table 2: Ulysses Data Sets at NSSDC

Exp.          PI               Brief Data Set Description     Start Date   End Date

SEDR    Ulysses Project        Spacecraft Ephemeris Data      1990-11-01   1991-02-28
                                                              1993-12-01   1994-11-30
GRB     K. C. Hurley           Integral 0.5-s Counting Rates  1990-10-29   1994-09-17
HISCALE L. J. Lanzerotti       Full Resolution Particle Data  1990-11-14   1991-12-31 
                               Hourly Average Data            1990-11-14   1991-12-31
                               Particle Anisotropy Plots      1990-11-15   1991-12-31
SWICS   G. Gloeckler/J. Geiss  3.5-Hour Averaged Cruise Data  1990-12-07   1993-12-31
SWOOPS  J. Phillips            High-Resolution & 1-Hr SW Ions 1990-11-18   1993-12-31
                               High-Resolution SW Electrons   1990-11-18   1992-12-31
URAP    R. G. Stone            3-Hour Summary Plots           1990-11-05   1994-09-26
                               Daily Summary Plots            1990-11-05   1994-03-31
                               10-Min Average/Peak Intensity  1990-11-05   1994-03-31
DUST    E. Gruen               Dust Particle Event Listing    1990-10-28   1992-12-29
MAG     A. Balogh              1-Hour RTN Vectors & Magnitude 1990-10-25   1992-02-02

URL List for document construction:

JHU/APL Ulysses Spacecraft & ESA Emblem

JPL Ulysses Mission Profile Plot

JPL Ulysses Mission Status Rep. No. 5, July 1994

STS-41 Shuttle Mission

ESA/ESTEC: Ulysses Scientific Instruments



The NSSDC Data Archive and Distribution System

COHO Home Page

PDS Home Page

PDS/PPI Home Page

NASA/Goddard Space Flight Center

NASA/GSFC Space Sciences Directorate


Space Physics Data Facility

Ulysses Project Home Page at NSSDC/SPDF

Return to NSSDC News Table of Contents

NASA home page GSFC home page GSFC organizational page

Author:Miranda Beall
Curators: Erin Gardner and Miranda Beall
Responsible Official: Dr. Joseph H. King, Code 633
Last Revised: 04 Dec 1996 [EDG]