AndreaBozzo/ceres-open-data-index huggingface dataset:
ROSETTA-ORBITER 67P OSIWAC 4 ESC1-MTP012 RDR-STRLIGHT V1.0

This CODMAC level 4 data set contains solar stray light corrected, radiometric calibrated and geometric distortion corrected (resampled) image data in W/m^2/sr/nm, acquired by the OSIRIS Wide Angle Camera on the Rosetta spacecraft during the COMET ESCORT 1 mission phase, covering the period from 2015-01-13T23:25:00.000 to 2015-02-10T23:24:59.000. The prime target is comet 67P/Churyumov-Gerasimenko 1 (1969 R1). This version V1.0 is the first version of this dataset: Lien corrected dataset after October 2018 PSA/PDS external peer review.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission, vega
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     COMET ESCORT 2 0770 V1.0

This is a Rosetta Radio Science data set, collected during the COMET ESCORT 2 phase 2015-03-11 to 2015-06-30. It is a Global Gravity measurement at the comet 67P and covers the time 2015-05-12T21:04:00.000 to 2015-05-12T23:12:10.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     COMET ESCORT 2 0643 V1.0

This is a Rosetta Radio Science data set, collected during the COMET ESCORT 2 phase 2015-03-11 to 2015-06-30. It is a Global Gravity measurement at the comet 67P and covers the time 2015-03-14T02:03:15.000 to 2015-03-14T03:06:58.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     ROSETTA EXTENSION 1 1427 V1.0

This is a Rosetta Radio Science data set, collected during the ROSETTA EXTENSION 1 phase 2016-01-01 to 2016-04-05. It is a Global Gravity measurement at the comet 67P and covers the time 2016-02-16T14:07:05.000 to 2016-02-16T22:13:22.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     PRELANDING 0395 V1.0

This is a Rosetta Radio Science data set, collected during the PRELANDING phase 2014-01-21 to 2014-11-18. It is a Global Gravity measurement at the comet 67P and covers the time 2014-10-30T09:53:05.000 to 2014-10-30T14:25:44.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     COMET ESCORT 1 0451 V1.0

This is a Rosetta Radio Science data set, collected during the COMET ESCORT 1 phase 2014-11-20 to 2015-03-10. It is a Global Gravity measurement at the comet 67P and covers the time 2014-11-22T13:42:25.000 to 2014-11-22T20:15:09.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
MARS EXPRESS MARS MRS 1/2/3
                                     EXTENDED MISSION 3 3340 V1.0

This is a Mars Express Radio Science data set, collected during the extended mission phase 2010-01-01 to 2012-12-31. It is a Global Gravity measurement and covers the time 2012-07-07T06:43:24.000 to 2012-07-07T10:30:04.500.

Tags: mars, mars-express
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     COMET ESCORT 4 1164 V1.0

This is a Rosetta Radio Science data set, collected during the COMET ESCORT 4 phase 2015-10-22 to 2015-12-31. It is a Global Gravity measurement at the comet 67P and covers the time 2015-11-08T08:15:40.000 to 2015-11-08T17:03:28.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
DAWN FC2 DERIVED CERES LAMO DTM SPG V1.0

Abstract ======== This data set contains a Ceres regional digital terrain models and associated clear filter mosaics based on the Dawn Low Altitude Mapping orbit (LAMO) Framing Camera 2 (FC2) images and derived by using the stereo photo-grametric (SPG) method. The LAMO DTMs/mosaics covers the regions around the following features: Ahuna Mons and the Occator, Ernutet, Haulani, Ikapati, Kupalo/Juling, and Yalode craters. The DTM has a lateral spacing of 32 m/pixel (256 pixel/degree) and a vertical accuracy of about 1.5 m.

Tags: 1-ceres, dawn-mission-to-vesta-and-ceres
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P OSIWAC 4 EXT2-MTP030 RDR V2.0

This CODMAC level 4 data set contains radiometric calibrated and geometric distortion corrected (resampled) image data in W/m^2/sr/nm, acquired by the OSIRIS Wide Angle Camera on the Rosetta spacecraft during the ROSETTA EXTENSION 2 mission phase, covering the period from 2016-05-31T23:25:00.000 to 2016-06-28T23:24:59.000. The prime target is comet 67P/Churyumov-Gerasimenko 1 (1969 R1). This version V2.0 supersedes previous deliveries of the same dataset with the following changes since the last version: Lien corrected dataset after October 2018 PSA/PDS external peer review. Updated documentation and ancillary files, added document on bandpass filter. Updated SCIENCE_USER_GUIDE_V03.PDF to include one section about FAQ and one section about image data quality. Added shutter backtravel and readout issues to image quality map. Updated DATA_QUALITY_ID keyword in image header. Improved handling of images with missing packets.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission, vega, zeta-cas
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER SW RPCMAG 3 CR2 CALIBRATED V9.0

This dataset contains CALIBRATED (CODMAC LEVEL 3) DATA of the CRUISE 2 (CR2)
phase of the ROSETTA orbiter magnetometer RPCMAG.
Included are data from the time interval June 1, 2005 until July 8, 2006.
The current version of the dataset is V9.0.
The difference to the datasets of earlier versions is mainly a significantly
improved sensor temperature model, more detailed documentation about magnetic
disturbance sources, more data handling information for the user and
also an improved quality flagging system.

Tags: checkout, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RPCLAP 2
ESC2 MTP015 V2.0

This data set contains
EDITED data from Rosetta RPC-LAP, acquired during the COMET ESCORT 2
MTP015 mission phase. Comet C-G/67P was the primary target.
This data set supersedes RO-C-RPCLAP-2-ESC2-MTP015-V1.0.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P NAVCAM 2 ROSETTA EXTENSION 3 MTP032 V1.0

This dataset contains ROSETTA NAVCAM RAW DATA of the Extension 3 phase from 26th July 2016 to 9th Aug 2016 when at the vicinity of target 67P/CG.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, alpha-lyr, international-rosetta-mission, zeta-cas
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P OSINAC 4 EXT3-MTP035 RDR V1.0

This CODMAC level 4 data set contains radiometric calibrated and geometric distortion corrected (resampled) image data in W/m^2/sr/nm acquired by the OSIRIS Narrow Angle Camera during the ROSETTA EXTENSION 3 phase of the Rosetta mission, covering the period from 2016-09-26T06:40:00.000 to 2016-10-01T00:00:00.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P OSINAC 4 PRL-MTP005 RDR-INFLDSTR V1.0

This CODMAC level 4 data set contains solar stray-light corrected, in-field stray-light corrected,  radiometric calibrated and geometric distortion corrected  (resampled) image data in W/m^2/sr/nm,  acquired by the OSIRIS Narrow Angle Camera on the Rosetta spacecraft  during the PRELANDING mission phase, covering the period  from 2014-07-02T08:35:00.000 to 2014-08-01T09:59:59.000. The prime target is comet 67P/Churyumov-Gerasimenko 1 (1969 R1). This version V1.0 is the first version of this dataset: Lien corrected dataset after September 2019 PSA/PDS external peer review.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
TROPESS Chemical Reanalysis Ozone Increment Monthly 3-dimensional Product V1 (TRPSCRO3IM3D) at GES DISC

The TROPESS Chemical Reanalysis O3 Increment Monthly 3-dimensional Product contains the ozone increment by data assimilation. The data are part of the Tropospheric Chemical Reanalysis v2 (TCR-2) for the period 2005-2021. TCR-2 uses JPL's Multi-mOdel Multi-cOnstituent Chemical (MOMO-Chem) data assimilation framework that simultaneously optimizes both concentrations and emissions of multiple species from multiple satellite sensors.

The data files are written in the netCDF version 4 file format, and each file contains a year of data at monthly resolution, and a spatial resolution of 1.125 x 1.125 degrees at 27 pressure levels between 1000 and 60 hPa. The principal investigator for the TCR-2 data is Miyazaki, Kazuyuki.

Tags: atmosphere, atmospheric-chemistry, earth-science
Organization: National Aeronautics and Space Administration
NEAR GRS SPECTRA FOR EROS/ORBIT

The GRS Level 2 data products in this archive include daily time series of spectra collected by the instrument along with selected spacecraft engineering and instrument configuration and orbital ephemerides. Supporting documentation includes as to the specifics of how these data were generated. Selected ephemerides and engineering parameters are averaged for the composite set of information.

Tags: eros, near-earth-asteroid-rendezvous
Organization: National Aeronautics and Space Administration
MSU Ch 4 Daily Lower Stratosphere Temps with Limb93 Correction L3 1 day 2.5 degree x 2.5 degree V001 (MSULST) at GES DISC

The Microwave Sounding Unit (MSU) Lower Stratosphere Deep Layer Mean Temperature product (MSULST) provides gridded lower stratospheric temperatures for each day derived from MSU instruments on several different platforms. The temperatures are derived from MSU channel 4 using the method of Spencer and Christy (1990) with the LIMB 93 limb correction based on latitude, longitude,  month, and scan angle. The MSU instruments measure the thermal emission of radiation by molecular oxygen at four frequencies near 60 GHz.  North (south) of 66.7N (S) the footprint data are assigned to grid boxes in a weighted method depending on footprint latitude.  Horizontal averaging is used
to fill some of the empty grid boxes.

Tags: atmosphere, atmospheric-temperature, earth-science, microwave, spectral-engineering
Organization: National Aeronautics and Space Administration
VG2 J PLASMA WAVE SPECTROMETER DENSITY 1S V1.0

Electron plasma density data set for Jupiter's outer magnetosphere derived from high-resolution wideband measurements of low-frequency radio and plasma waves obtained by Voyagers 1 and 2 during their 1979 flybys.  Density data were measured at 1-second intervals.

Tags: jupiter, voyager
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P MIRO 3 ESC2 67P V1.0

This data set contains Spectroscopic, Continuum, and Geometry level 3 data, in the form of table files, taken during the COMET ESCORT 2 phase of the Rosetta mission to comet 67P/CHURYUMOV-GERASIMENKO by the MIRO instrument.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
PHOENIX MARS ROBOTIC ARM CAMERA 
                                      5 ROUGHNESS OPS V1.0

The Robotic Arm Camera (RAC)  experiment on the Mars Phoenix Lander consists of one instrument  component plus command electronics. This RAC Imaging Operations RDR  data set contains roughness data from the Robotic Arm Camera (RAC).

Tags: mars, phoenix
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     ROSETTA EXTENSION 1 1370 V1.0

This is a Rosetta Radio Science data set, collected during the ROSETTA EXTENSION 1 phase 2016-01-01 to 2016-04-05. It is a Global Gravity measurement at the comet 67P and covers the time 2016-01-25T16:23:40.000 to 2016-01-25T18:41:48.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RPCLAP 3
ESC1 CALIB2 V1.0

This data set contains
CALIBRATED data from Rosetta RPC-LAP, acquired during the COMET ESCORT 1
mission phase where the primary target was the comet
67P/CHURYUMOV-GERASIMENKO 1 (1969 R1). It contains instrument outputs in
volts and amperes, calibrated and corrected for instrument offsets. This
version reorganizes the data into fewer files with longer time series
and sorted by type of measurement. The version number starts over from
V1.0 due to a change in naming convention.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER EARTH RPCMAG 2 EAR1 RAW V3.0

2010-07-30 SBN:T.Barnes Updated and DATA_SET_DESCThis dataset contains EDITED RAW DATA of the first Earth Flyby (EAR1). Included are the data of the very Flyby from March 1 until March 7 and the data of the Passive Checkout (PC0) at March 29. (Version 3.0 is the first version archived.)

Tags: earth, international-rosetta-mission, unknown
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P VIRTIS 3 ESCORT 2 MTP016 V2.0

This release contains the calibrated data of the VIRTIS instrument on board of the spacecraft Rosetta. This volume contains data from the ESCORT 2 MTP016 phase, which occurred from 2015-05-06 to 2015-06-03 when at the vicinity of comet 67P. This data set V2.0 supersedes V1.0. It includes major updates on the data and documentation.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
GO A PWS REFORMATTED GASPRA SPECTRUM ANALYZER FULL V1.0

This data set includes full resolution electric and magnetic wave spectra obtained during a ~ 2-hour period of contiguous observations near the closest approach to Gaspra and a number of non-contiguous spectra taken prior and subsequent to closest approach.  In addition waveform survey data (uncalibrated) and all instrument housekeeping data are included.

Tags: galileo, gaspra
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     COMET ESCORT 4 1162 V1.0

This is a Rosetta Radio Science data set, collected during the COMET ESCORT 4 phase 2015-10-22 to 2015-12-31. It is a Global Gravity measurement at the comet 67P and covers the time 2015-11-07T08:18:10.000 to 2015-11-07T12:29:07.000.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER COMET PRELANDING OSINAC 2 EDR MTP 007 V1.0

This data set contains raw EDR images acquired by the OSIRIS Narrow Angle
Camera during the prelanding phase of the Rosetta mission at the comet 67P,
covering the period from 2014-09-02 to 2014-09-16.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
SnowEx17 Boise State University Raw Terrestrial Laser Scanner (TLS) Point Cloud V001

This data set contains raw, unprocessed terrestrial laser scanner (TLS) point cloud data collected as part of the 2017 SnowEx campaign in Grand Mesa, Colorado. Data were collected in the fall (September 2016) and winter (February 2017). Multiple scans were conducted at each site and registered together using common targets. Each point contains X, Y, and Z coordinates (Easting, Northing, and Elevation), as well as intensity (i).

Tags: earth-science, lidar, spectral-engineering
Organization: National Aeronautics and Space Administration
NEW HORIZONS                            
      PEPSSI PLUTO ENCOUNTER                                                  
      CALIBRATED V1.0

This data set contains Calibrated data taken by the New Horizons         Pluto Energetic Particle Spectrometer Science Investigation            instrument during the                                                    Pluto encounter                                                        mission phase.  This is VERSION 1.0 of this data set.

Tags: new-horizons
Organization: National Aeronautics and Space Administration
VG1 SAT MAG RESAMPLED KRONOGRAPHIC (L1)
                                      COORDS 9.6SEC V1.0

This data set includes calibrated magnetic field data acquired by the Voyager 1 Low Field Magnetometer (LFM) during the Saturn encounter. Coverage begins in the solar wind inbound to Saturn and continues past the last outbound bowshock crossing. The data are in Kronographic (L1) coordinates and have been averaged from the 1.92 second summary rate to a 9.6 second sample rate. All magnetic field measurements are given in nanoTesla (nT). The magnetic field data are calibrated (see the calibration description included in the Voyager 1 Magnetometer instrument catalog file for details).

Tags: saturn, voyager
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P RSI 1/2/3
                                     COMET ESCORT 3 1051 V1.0

This is a Rosetta Radio Science data set, collected during the COMET ESCORT 3 phase 2015-07-01 to 2015-10-21. It is a Global Gravity measurement at the comet 67P and covers the time 2015-09-23T09:47:45.000 to 2015-09-23T17:32:52.500.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
DAWN CERES RAW GRAVITY SCIENCE V1.0

This data set contains archival raw, partially processed, and              ancillary/supporting gravity science data acquired during the Dawn         mission while the spacecraft was in orbit around the asteroid Ceres.       The radio observations were carried out using the Dawn spacecraft and      Earth-based receiving stations of the NASA Deep Space Network (DSN).       The data set was designed primarily to support generation of               high-resolution gravity field models for Ceres. Of most interest are       likely to be the Orbit Data Files in the ODF directory, which provided     the raw input to gravity investigations, as well as the ionospheric and    tropospheric media calibration files in the ION and TRO directories,       respectively.

Tags: 1-ceres, dawn-mission-to-vesta-and-ceres
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P NAVCAM 2 ROSETTA EXTENSION 3 MTP033 V1.1

This dataset contains ROSETTA NAVCAM RAW DATA of the Extension 3 Phase from 9th Aug 2016 to 2nd Sep 2016 when at the vicinity of target 67P/CG. This data set V1.1 supersedes the V1.0. It includes document updates and resolve other outstanding errata.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission
Organization: National Aeronautics and Space Administration
SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Analysis Update V007

SMAP Level-4 (L4) surface and root zone soil moisture data are provided in three products:
<ul> 
  <li>SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data (SPL4SMGP, DOI: 10.5067/EVKPQZ4AFC4D)</li>
  <li>SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Analysis Update (SPL4SMAU, DOI: 10.5067/LWJ6TF5SZRG3)</li>
  <li>SMAP L4 Global 9 km EASE-Grid Surface and Root Zone Soil Moisture Land Model Constants (SPL4SMLM, DOI: 10.5067/KN96XNPZM4EG).</li>
</ul>
For each product, SMAP L-band brightness temperature data from descending and ascending half-orbit satellite passes (approximately 6:00 a.m. and 6:00 p.m. local solar time, respectively) are assimilated into a land surface model that is gridded using an Earth-fixed, global cylindrical 9 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) projection.

Tags: earth-science, land-surface, soils
Organization: National Aeronautics and Space Administration
ROSETTA-ORBITER 67P OSIWAC 4 EXT3-MTP032 RDR V2.0

This CODMAC level 4 data set contains radiometric calibrated and geometric distortion corrected (resampled) image data in W/m^2/sr/nm, acquired by the OSIRIS Wide Angle Camera on the Rosetta spacecraft during the ROSETTA EXTENSION 3 mission phase, covering the period from 2016-07-26T23:25:00.000 to 2016-08-09T23:24:59.000. The prime target is comet 67P/Churyumov-Gerasimenko 1 (1969 R1). This version V2.0 supersedes previous deliveries of the same dataset with the following changes since the last version: Lien corrected dataset after October 2018 PSA/PDS external peer review. Updated documentation and ancillary files, added document on bandpass filter. Updated SCIENCE_USER_GUIDE_V03.PDF to include one section about FAQ and one section about image data quality. Added shutter backtravel and readout issues to image quality map. Updated DATA_QUALITY_ID keyword in image header. Improved handling of images with missing packets.

Tags: 67p-churyumov-gerasimenko-1-1969-r1, international-rosetta-mission, vega
Organization: National Aeronautics and Space Administration
VOYAGER 2 SATURN PLASMA DERIVED ELECTRON PARAMETERS 96 SEC

THIS DATA SET CONTAINS ELECTRON PARAMETERS IN THE PLS ENERGY RANGE (10-5950 EV) AT SATURN DURING THE VOYAGER 2 ENCOUNTER. PARAMETERS ARE CALCULATED IN SEVERAL WAYS. TOTAL MOMENT DENSITY AND TEMPERATURE ARE GIVEN. EACH ELECTRON SPECTRUM IS ALSO FIT WITH A THERMAL COMPONENT AND 1-3 HOT COMPONENTS DEPENDING ON HOW MANY MAXWELLIANS ARE NEEDED TO FIT THE ENTIRE DISTRIBUTION. THE MOMENT DENSITY AND TEMPERATURE OF THE HOT COMPONENT IS CALCULATED AFTER THE THERMAL COMPONENT IS SUBTRACTED FROM THE SPECTRUM. THE CHI-SQUARE VALUE FOR EACH FIT IS GIVEN. THE SPACECRAFT CHARGE IS NOT CALCULATED CONSISTENTLY, AND MAY RESULT IN FACTOR OF 2-3 ERRORS IN THE THERMAL ELECTRON DENSITY. DATA IS UNRELIABLE INSIDE 6 RS AND IN THE OCCULTATION REGIONS. A COMPLETE DESCRIPTION OF THIS DATA SET IS IN SITTLER ET AL. (1983). DATA FORMAT: THE DATA SET IS IN ASC FORMAT AND CAN BE READ USING THE FOLLOWING FORTRAN STATEMENT:\n

Tags: comet-sl9-jupiter-collision, saturn, voyager
Organization: National Aeronautics and Space Administration
USGS Global Forest Observations Initiative (GFOI) Costa Rica

The Global Forest Observations Initiative (GFOI) is an initiative of the inter-governmental Group on Earth Observations (GEO) that aims to:

foster the sustained availability of observations for national forest monitoring systems; support governments that are establishing national systems by providing a platform for coordinating observations, providing assistance and guidance on utilizing observations, developing accepted methods and protocols, and promoting ongoing research and development; and work with national governments that report into international forest assessments (such as the global Forest Resources Assessment (FRA) of the Food and Agriculture Organization, FAO) and the national greenhouse gas inventories reported to the UN Framework Convention on Climate Change (UNFCCC) using methods of the Intergovernmental Panel on Climate Change (IPCC).

Tags: agriculture, biosphere, earth-science, forest-science, habitat-conversion-fragmentation, human-dimensions, terrestrial-ecosystems, vegetation
Organization: National Aeronautics and Space Administration