Version: 1.0 (2021 July)
change log
This API provides access to JPL’s Horizons system. An input file must be created containing settings appropriate for the desired ephemeris results. Please see the Horizons batch example/instructions for details on possible settings. An alternate Horizons API is available that uses the HTTP GET method to send Horizons parameters as query parameters via the URL.
POST
https://ssd.jpl.nasa.gov/api/horizons_file.api
Given the following input file called my_input_file.txt which requests an observer ephemeris of Mars:
!$$SOF
COMMAND='499'
OBJ_DATA='YES'
MAKE_EPHEM='YES'
TABLE_TYPE='OBSERVER'
CENTER='500@399'
START_TIME='2006-01-01'
STOP_TIME='2006-01-20'
STEP_SIZE='1 d'
QUANTITIES='1,9,20,23,24,29'
Using curl, send the POST request to the API and save the output in file results.txt:
curl -s -F format=text -F input=@my_input_file.txt https://ssd.jpl.nasa.gov/api/horizons_file.api > results.txt
Using python, send the input file and save the output in results.txt:
python horizons.py my_input_file.txt > results.txt
where horizons.py is as follows:
import sys
import requests
f = open(sys.argv[1])
url = 'https://ssd.jpl.nasa.gov/api/horizons_file.api'
r = requests.post(url, data={'format':'text'}, files={'input': f})
print(r.text)
f.close()
Using perl, send the input file and save the output in results.txt:
perl horizons.pl my_input_file.txt > results.txt
where horizons.pl is as follows:
use strict;
use LWP::UserAgent;
my $file = shift;
my $ua = LWP::UserAgent->new;
my $url = 'https://ssd.jpl.nasa.gov/api/horizons_file.api';
my $res = $ua->post($url,
Content_Type=>'form-data',
Content=>[
'format' => 'text',
'input' => [ $file ],
],
);
print $res->content;
| Parameter | Type | Default | Allowable Values/Format |
Description |
|---|---|---|---|---|
| input | string | none | see description below | Horizons input file content, encoded as appropriate |
| format | string | json |
json, text |
output format: json for JSON or text for plain-text |
Please always check the JSON payload “signature” object for the API “version”. If the version does not match the version in this document (at the top), there is no guarantee that the format has not changed.
Example "signature" object with "version" value "1.0":
"signature":{"version":"1.0","source":"NASA/JPL ... API"}
Successful query requests result in a data payload.
The format is controlled by the format parameter.
text-format OutputThe first two lines are added by the API. It is important to note the
API VERSION value when programmatically processing results to ensure the
version is what you expect.
The number of blank lines following API SOURCE may vary by will be at least one.
If you request the body information page (OBJ_DATA='YES'), there will be
an additional block of text output after the blank lines following API SOURCE.
The remainder of the output is formatted as provided by the Horizons system.
API VERSION: 0.2
API SOURCE: NASA/JPL Horizons API
*******************************************************************************
Ephemeris / WWW_USER Thu May 14 07:39:14 2020 Pasadena, USA / Horizons
*******************************************************************************
Target body name: Mars (499) {source: mar097}
Center body name: Earth (399) {source: mar097}
Center-site name: GEOCENTRIC
*******************************************************************************
Start time : A.D. 1998-Jan-01 10:00:00.0000 UT
Stop time : A.D. 1998-Jan-02 00:00:00.0000 UT
Step-size : 60 minutes
*******************************************************************************
Target pole/equ : IAU_MARS {West-longitude positive}
Target radii : 3396.2 x 3396.2 x 3376.2 km {Equator, meridian, pole}
Center geodetic : 0.00000000,0.00000000,0.0000000 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 0.00000000,0.00000000,0.0000000 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : High-precision EOP model {East-longitude positive}
Center radii : 6378.1 x 6378.1 x 6356.8 km {Equator, meridian, pole}
Target primary : Sun
Vis. interferer : MOON (R_eq= 1737.400) km {source: mar097}
Rel. light bend : Sun, EARTH {source: mar097}
Rel. lght bnd GM: 1.3271E+11, 3.9860E+05 km^3/s^2
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
EOP file : eop.200513.p200804
EOP coverage : DATA-BASED 1962-JAN-20 TO 2020-MAY-13. PREDICTS-> 2020-AUG-03
Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO )
Table cut-offs 2: Solar elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO )
Table cut-offs 3: RA/DEC angular rate ( 0.0=NO )
*****************************************************************************************
Date__(UT)__HR:MN R.A._____(ICRF)_____DEC APmag S-brt delta deldot
*****************************************************************************************
$$SOE
1998-Jan-01 10:00 20 55 41.20 -18 33 23.0 1.17 4.08 2.13799045474771 5.6049390
1998-Jan-01 11:00 20 55 49.17 -18 32 49.7 1.17 4.08 2.13812533287512 5.6044117
1998-Jan-01 12:00 20 55 57.13 -18 32 16.5 1.17 4.08 2.13826019831403 5.6038846
1998-Jan-01 13:00 20 56 05.09 -18 31 43.1 1.17 4.08 2.13839505107206 5.6033579
1998-Jan-01 14:00 20 56 13.05 -18 31 09.8 1.17 4.08 2.13852989115697 5.6028315
1998-Jan-01 15:00 20 56 21.01 -18 30 36.5 1.17 4.08 2.13866471857652 5.6023055
1998-Jan-01 16:00 20 56 28.97 -18 30 03.1 1.17 4.08 2.13879953333835 5.6017797
1998-Jan-01 17:00 20 56 36.93 -18 29 29.7 1.17 4.08 2.13893433545018 5.6012543
1998-Jan-01 18:00 20 56 44.89 -18 28 56.3 1.17 4.08 2.13906912492008 5.6007292
1998-Jan-01 19:00 20 56 52.85 -18 28 22.9 1.17 4.08 2.13920390175678 5.6002045
1998-Jan-01 20:00 20 57 00.81 -18 27 49.4 1.17 4.08 2.13933866596968 5.5996802
1998-Jan-01 21:00 20 57 08.76 -18 27 15.9 1.17 4.08 2.13947341756857 5.5991564
1998-Jan-01 22:00 20 57 16.72 -18 26 42.5 1.17 4.08 2.13960815656331 5.5986329
1998-Jan-01 23:00 20 57 24.67 -18 26 08.9 1.17 4.08 2.13974288296371 5.5981098
1998-Jan-02 00:00 20 57 32.63 -18 25 35.4 1.17 4.08 2.13987759677950 5.5975872
$$EOE
*****************************************************************************************
Column meaning:
... [some content excluded here for brevity] ...
Computations by ...
Solar System Dynamics Group, Horizons On-Line Ephemeris System
4800 Oak Grove Drive, Jet Propulsion Laboratory
Pasadena, CA 91109 USA
Information: http://ssd.jpl.nasa.gov/
Connect : telnet://ssd.jpl.nasa.gov:6775 (via browser)
telnet ssd.jpl.nasa.gov 6775 (via command-line)
Author : Jon.D.Giorgini@jpl.nasa.gov
*****************************************************************************************
If there are any errors in your input file (such as requesting ephemeris output times outside the range available), they will be shown at the end of the normal output. Thus, such error detection is the responsibility of the user.
In some cases, error messages will provide suggestions that are only
applicable to the command-line interface. For example, when specifying
an observatory code that does not exist, the message suggests ..., ?! for help.
In such cases, if the error is not obvious, please check the Horizons system documentation.
json-format OutputWhen json-format is requested, the API attempts to detect any Horizon error
message(s), capture them, and report them in the error field.
Thus, if the error field is present in the output, an appropriate programmatic
response can be issued.
In the following successful request, the content of interest will be in the
JSON result field.
{
"signature" : {
"source" : "NASA/JPL Horizons API",
"version" : "0.2"
},
"result" : " \n \n*******************************************************************************\nEphemeris / WWW_USER Thu May 14 08:06:02 2020 Pasadena, USA / Horizons \n*******************************************************************************\nTarget body name: Mars (499) {source: mar097}\nCenter body name: Earth (399) {source: mar097}\nCenter-site name: GEOCENTRIC\n*******************************************************************************\nStart time : A.D. 1998-Jan-01 10:00:00.0000 UT \nStop time : A.D. 1998-Jan-02 00:00:00.0000 UT \nStep-size : 60 minutes\n*******************************************************************************\nTarget pole/equ : IAU_MARS {West-longitude positive}\nTarget radii : 3396.2 x 3396.2 x 3376.2 km {Equator, meridian, pole} \nCenter geodetic : 0.00000000,0.00000000,0.0000000 {E-lon(deg),Lat(deg),Alt(km)}\nCenter cylindric: 0.00000000,0.00000000,0.0000000 {E-lon(deg),Dxy(km),Dz(km)}\nCenter pole/equ : High-precision EOP model {East-longitude positive}\nCenter radii : 6378.1 x 6378.1 x 6356.8 km {Equator, meridian, pole} \nTarget primary : Sun\nVis. interferer : MOON (R_eq= 1737.400) km {source: mar097}\nRel. light bend : Sun, EARTH {source: mar097}\nRel. lght bnd GM: 1.3271E+11, 3.9860E+05 km^3/s^2 \nAtmos refraction: NO (AIRLESS)\nRA format : HMS\nTime format : CAL \nEOP file : eop.200513.p200804 \nEOP coverage : DATA-BASED 1962-JAN-20 TO 2020-MAY-13. PREDICTS-> 2020-AUG-03\nUnits conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s \nTable cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO )\nTable cut-offs 2: Solar elongation ( 0.0,180.0=NO ),Local Hour Angle( 0.0=NO )\nTable cut-offs 3: RA/DEC angular rate ( 0.0=NO ) \n*****************************************************************************************\n Date__(UT)__HR:MN R.A._____(ICRF)_____DEC APmag S-brt delta deldot\n*****************************************************************************************\n$$SOE\n 1998-Jan-01 10:00 20 55 41.20 -18 33 23.0 1.17 4.08 2.13799045474771 5.6049390\n 1998-Jan-01 11:00 20 55 49.17 -18 32 49.7 1.17 4.08 2.13812533287512 5.6044117\n 1998-Jan-01 12:00 20 55 57.13 -18 32 16.5 1.17 4.08 2.13826019831403 5.6038846\n 1998-Jan-01 13:00 20 56 05.09 -18 31 43.1 1.17 4.08 2.13839505107206 5.6033579\n 1998-Jan-01 14:00 20 56 13.05 -18 31 09.8 1.17 4.08 2.13852989115697 5.6028315\n 1998-Jan-01 15:00 20 56 21.01 -18 30 36.5 1.17 4.08 2.13866471857652 5.6023055\n 1998-Jan-01 16:00 20 56 28.97 -18 30 03.1 1.17 4.08 2.13879953333835 5.6017797\n 1998-Jan-01 17:00 20 56 36.93 -18 29 29.7 1.17 4.08 2.13893433545018 5.6012543\n 1998-Jan-01 18:00 20 56 44.89 -18 28 56.3 1.17 4.08 2.13906912492008 5.6007292\n 1998-Jan-01 19:00 20 56 52.85 -18 28 22.9 1.17 4.08 2.13920390175678 5.6002045\n 1998-Jan-01 20:00 20 57 00.81 -18 27 49.4 1.17 4.08 2.13933866596968 5.5996802\n 1998-Jan-01 21:00 20 57 08.76 -18 27 15.9 1.17 4.08 2.13947341756857 5.5991564\n 1998-Jan-01 22:00 20 57 16.72 -18 26 42.5 1.17 4.08 2.13960815656331 5.5986329\n 1998-Jan-01 23:00 20 57 24.67 -18 26 08.9 1.17 4.08 2.13974288296371 5.5981098\n 1998-Jan-02 00:00 20 57 32.63 -18 25 35.4 1.17 4.08 2.13987759677950 5.5975872\n$$EOE\n*****************************************************************************************\nColumn meaning:\n \nTIME\n\n Times PRIOR to 1962 are UT1, a mean-solar time closely related to the\nprior but now-deprecated GMT. Times AFTER 1962 are in UTC, the current\ncivil or \"wall-clock\" time-scale. UTC is kept within 0.9 seconds of UT1\nusing integer leap-seconds for 1972 and later years.\n\n Conversion from the internal Barycentric Dynamical Time (TDB) of solar\nsystem dynamics to the non-uniform civil UT time-scale requested for output\nhas not been determined for UTC times after the next July or January 1st.\nTherefore, the last known leap-second is used as a constant over future\nintervals.\n\n Time tags refer to the UT time-scale conversion from TDB on Earth\nregardless of observer location within the solar system, although clock\nrates may differ due to the local gravity field and no analog to \"UT\"\nmay be defined for that location.\n\n Any 'b' symbol in the 1st-column denotes a B.C. date. First-column blank\n(\" \") denotes an A.D. date. Calendar dates prior to 1582-Oct-15 are in the\nJulian calendar system. Later calendar dates are in the Gregorian system.\n\n NOTE: \"n.a.\" in output means quantity \"not available\" at the print-time.\n \n R.A._____(ICRF)_____DEC =\n Astrometric right ascension and declination of the target center with\nrespect to the observing site (coordinate origin) in the reference frame of\nthe planetary ephemeris (ICRF). Compensated for down-leg light-time delay\naberration.\n\n Units: RA in hours-minutes-seconds of time (HH MM SS.ff)\n DEC in degrees-minutes-seconds of arc (sDD MN SC.f)\n \n APmag S-brt =\n Target's approximate apparent visual magnitude & surface brightness. For\nplanets and satellites, values are available only for solar phase angles in the\nrange generally visible from Earth. This is to avoid extrapolation of models\nbeyond their valid (data-based) limits.\n Units: MAGNITUDE & VISUAL MAGNITUDES PER SQUARE ARCSECOND\n \n delta deldot =\n Range (\"delta\") and range-rate (\"delta-dot\") of target center with respect\nto the observer at the instant light seen by the observer at print-time would\nhave left the target center (print-time minus down-leg light-time); the\ndistance traveled by a light ray emanating from the center of the target and\nrecorded by the observer at print-time. \"deldot\" is a projection of the\nvelocity vector along this ray, the light-time-corrected line-of-sight from\nthe coordinate center, and indicates relative motion. A positive \"deldot\"\nmeans the target center is moving away from the observer (coordinate center).\nA negative \"deldot\" means the target center is moving toward the observer.\nUnits: AU and KM/S\n\n\n Computations by ...\n Solar System Dynamics Group, Horizons On-Line Ephemeris System\n 4800 Oak Grove Drive, Jet Propulsion Laboratory\n Pasadena, CA 91109 USA\n Information: http://ssd.jpl.nasa.gov/\n Connect : telnet://ssd.jpl.nasa.gov:6775 (via browser)\n telnet ssd.jpl.nasa.gov 6775 (via command-line)\n Author : Jon.D.Giorgini@jpl.nasa.gov\n\n*****************************************************************************************\n"
}
If the object specified via the COMMAND variable in the input file is not
unique to the Horizons system, you will get a list of matching objects.
Below is an example (text-format) output where COMMAND='DES=141P;'.
API VERSION: 0.2
API SOURCE: NASA/JPL Horizons API
*******************************************************************************
JPL/DASTCOM Small-body Index Search Results 2021-May-11 07:53:26
Comet AND asteroid index search:
DES = 141P;
Matching small-bodies:
Record # Epoch-yr >MATCH DESIG< Primary Desig Name
-------- -------- ------------- ------------- -------------------------
90001032 2011 141P 141P Machholz 2
90001033 2019 141P 141P Machholz 2
90001034 1994 141P-A 141P-A Machholz 2
90001035 1997 141P-A 141P-A Machholz 2
90001036 1999 141P-A 141P-A Machholz 2
90001037 1994 141P-D 141P-D Machholz 2
90001038 1999 141P-D 141P-D Machholz 2
(7 matches. To SELECT, enter record # (integer), followed by semi-colon.)
*******************************************************************************
In the above example, there are three bodies represented: the parent comet 141P,
fragment A 141P-A, and fragment D 141P-D.
There are also multiple orbits for each of these comets represented by the Epoch-yr
field in the results table.
To select the object and orbit of interest, you must specify the Horizons
record number listed in the Record # column.
For example, to select the orbit for the parent comet with epoch 2019,
specify COMMAND='90001033;' in your input file.
However, be warned that for small bodies (comets and asteroids)
these record numbers are subject to change without notice.
For unique comet selection without using Horizons record numbers,
there are additional flags that can be used in the COMMAND specification.
For example, if you know there are fragments for comet 141P and you want the
parent comet, you can add the NOFRAG flag to the COMMAND specification
such as COMMAND='DES=141P;NOFRAG'.
Similarly, if you know you always want the orbit with the latest epoch,
you can add the CAP flag to the COMMAND specification such as
COMMAND='DES=141P;CAP'.
In this example, combining CAP and NOFRAG will result in a unique match for
the parent comet 141P as in COMMAND='DES=141P;CAP;NOFRAG'.
For fragments, the designation is already unique so you’d only need the CAP flag
as in COMMAND='DES=141P-A;CAP'.
See the Horizons documentation for more details.
The binary SPK file is base-64 encoded on return and, for text-format output,
begins after the API header text with the base-64 string REFGL1NQ...
in the following example.
API VERSION: 0.2
API SOURCE: NASA/JPL Horizons API
SPK Binary Data Follows -- base64 encoded:
REFGL1NQSyACAAAABgAAAFNNQl9TUEtfRklMRSAgICAgICAgICAgICAgICAgICAgICAgICAgICAg
ICAgICAgICAgICAgICAgICAgID4AAAA+AAAAULQAAExUTC1JRUVFAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
...
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAA==
To convert the base-64 encoded content to a usable binary SPK file,
extract the encoded portion to a file and use a base-64 decoder.
On most Linux systems this is done with the command
base64 --decode {extracted_file_content},
where {extacted_file_content} is the name of the file containing
the encoded content from the API.
The following input file requests an SPK file spanning from 2020-01-01 through 2030-12-31 (TDB) for asteroids 1 Ceres.
!$$SOF
COMMAND='1;'
EPHEM_TYPE='S'
START_TIME='2020-01-01'
STOP_TIME='2030-12-31'
OBJ_DATA='NO'
The following input file requests an SPK file spanning from 2030-01-01 through 2031-01-01 (TDB) for the small-body specified with user-supplied osculating elements and non-gravitational parameters
!$$SOF
COMMAND = ';' ! Input asteroid/comet NOT in JPL database
MAKE_EPHEM = 'YES' ! Make an ephemeris
EPHEM_TYPE = 'S' ! Set ephemeris type to SPK
OBJ_DATA = 'NO' ! Suppress object data-sheet
START_TIME = '2030-Jan-1' ! Start time (TDB)
STOP_TIME = '2031-Jan-1' ! Stop time (TDB)
!
OBJECT = 'User Apophis'
EPOCH = '2459311.5'
FRAME = 'J2000'
EC = '0.1915350975906659'
QR = '0.7458351838564465'
TP = '2459424.5839352785'
OM = '203.9782743995174'
W = '126.6377455281965'
IN = '3.33973556589891'
MA =
A =
N =
RAD =
! Next two (H and G) for asteroids only
H =
G =
! Next group for comets only
M1 =
M2 =
K1 =
K2 =
PHCOF =
DT =
! Next group for asteroids or comets
A1 = '3.869431020576E-13'
A2 = '-2.898628963521E-14'
A3 =
R0 = '1.'
ALN = '1.'
NM = '2.'
NN = '5.093'
NK = '0.'
AMRAT =
!$$EOF
An example Linux command-line to extract the binary SPK file content
for asteroid 1 Ceres from a successful text-format output is shown below.
However, be advised that such usage will not easily catch errors returned from the API.
curl -s -F format=text -F input=@my_input_file.txt https://ssd.jpl.nasa.gov/api/horizons_file.api | awk '/REFGL1NQ/,0' | base64 --decode > object.bsp
Similarly, for the json-format output, the SPK encoded content is contained
in the spk: object as in the following example:
{
"signature" : {
"source" : "NASA/JPL Horizons API",
"version" : "0.2"
},
"spk_file_id" : "2000001",
"spk" : "REFGL1NQSyACAAAABgAAAFNNQl9TUEtfRklMRSAgICAgICAgICAgICAgICAgICAgICAgICAgICAg\nICAgICAgICAgICAgICAgICAgID4AAAA+AAA ... AAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAA==\n"
}
Extract the content from the JSON spk object excluding the surrounding quotes
and then decode to produce the corresponding binary SPK file.
The spk_file_id can be used as the SPK file’s basename
(e.g., 20000001.bsp in the above example).
The following scripts expect the Horizons input file as an argument on the command-line. Assuming that input file see example script above requests an SPK file for a specific object, the resulting SPK file is decoded and written to a binary file in the current working directory.
use strict;
use LWP::UserAgent;
use JSON;
use MIME::Base64;
# Define API URL and SPK filename:
my $url = 'https://ssd.jpl.nasa.gov/api/horizons_file.api';
my $spk_filename = 'spk_file.bsp';
# Get the Horizons API input file from the command-line:
my $file = shift;
die unless ( defined $file and -e $file );
# Build and submit the API request and decode the JSON-response:
my $ua = LWP::UserAgent->new;
my $response = $ua->post($url,
Content_Type=>'form-data',
Content=>[ 'format'=>'json', 'input'=>[$file] ],
);
my $data = decode_json($response->content);
# If the request was valid...
if ( $response->code eq '200' ) {
#
# If the SPK file was generated, decode it and write it to the output file:
if ( defined $data->{spk} ) {
#
# If a suggested SPK file basename was provided, use it:
if ( defined $data->{spk_file_id} ) { $spk_filename = "$data->{spk_file_id}.bsp"; }
open (my $fh, ">", $spk_filename) or die "unable to open $spk_filename: $!\n";
#
# Decode and write the binary SPK file content:
print $fh decode_base64($data->{spk});
close $fh;
print "wrote SPK content to $spk_filename\n";
exit;
}
#
# Otherwise, the SPK file was not generated so output an error:
print "ERROR: SPK file not generated\n";
if ( defined $data->{result} ) { print $data->{result}; }
else { print $response->content; }
exit 1;
}
# If the request was invalid, extract error content and display it:
if ( $response->code eq '400' ) {
print "ERROR in API call: HTTPS response: ", $response->status_line, "\n";
if ( defined $data->{message} ) { print $data->{message}, "\n"; }
else { print $response->content; }
exit 1;
}
# Otherwise, some other error occurred:
print "ERROR in API call: HTTPS response: ", $response->status_line, "\n";
exit 1;
import sys
import json
import base64
import requests
# Define API URL and SPK filename:
url = 'https://ssd.jpl.nasa.gov/api/horizons_file.api'
spk_filename = 'spk_file.bsp'
# Get the Horizons API input file from the command-line:
try:
f = open(sys.argv[1])
except OSError as err:
print("Unable to open input file '{0}': {1}".format(sys.argv[1], err))
# Build and submit the API request and decode the JSON-response:
response = requests.post(url, data={'format':'json'}, files={'input': f})
f.close()
try:
data = json.loads(response.text)
except ValueError:
print("Unable to decode JSON results")
# If the request was valid...
if (response.status_code == 200):
#
# If the SPK file was generated, decode it and write it to the output file:
if "spk" in data:
#
# If a suggested SPK file basename was provided, use it:
if "spk_file_id" in data:
spk_filename = data["spk_file_id"] + ".bsp"
try:
f = open(spk_filename, "wb")
except OSError as err:
print("Unable to open SPK file '{0}': {1}".format(spk_filename, err))
#
# Decode and write the binary SPK file content:
f.write(base64.b64decode(data["spk"]))
f.close()
print("wrote SPK content to {0}".format(spk_filename))
sys.exit()
#
# Otherwise, the SPK file was not generated so output an error:
print("ERROR: SPK file not generated")
if "result" in data:
print(data["result"])
else:
print(response.text)
sys.exit(1)
# If the request was invalid, extract error content and display it:
if (response.status_code == 400):
data = json.loads(response.text)
if "message" in data:
print("MESSAGE: {}".format(data["message"]))
else:
print(json.dumps(data, indent=2))
# Otherwise, some other error occurred:
print("response code: {0}".format(response.status_code))
sys.exit(2)
Most errors are returned via appropriate HTTP response codes.
However, it is possible to submit Horizons input data
(e.g., a bad START_TIME value) resulting in Horizons-generated errors.
In such cases, a non-error code of 200 is returned so the user is responsible
for checking the payload if they wish to detect a such errors.
| HTTP Code | Description | Typical Usage |
|---|---|---|
| 200 | OK | normal successful result |
| 400 | Bad Request | the request contained invalid keywords and/or content or used a request-method other than GET or POST (details returned in the JSON or text payload) |
| 405 | Method Not Allowed | the request used an incorrect method (see the HTTP Request section) |
| 500 | Internal Server Error | the database is not available at the time of the request |
| 503 | Service Unavailable | the server is currently unable to handle the request due to a temporary overloading or maintenance of the server, which will likely be alleviated after some delay |