Updated Ephemeris for ISEE-3 at JPL Horizons 23 June 2014

Source: JPL Horizons
Ephemeris Type: OBSERVER
Target Body: ICE Spacecraft (ISEE-3) [-111]
Observer Location: Geocentric [500]
Time Span: Start=2014-06-05, Stop=2014-07-05, Step=1 d
Table Settings: defaults
Object Data Page

Revised: Jun 23, 2014 ISEE-3/ICE Spacecraft (Heliocentric)

UPDATE (2014-Jun-23): Trajectory updated to JPL solution #32 (s32), based on 42 coarse Arecibo plane-of-sky angular measurements spanning May 22 - Jun 23 ... (not delay/Doppler).

Because uncertainties for s32 are large, predicts are currently available for tracking purposes only through Aug 01 and have these 3-sigma formal pointing uncertainties:

 Date__(UT)__HR:MN SMAA_3sig SMIA_3sig    Theta Area_3sig RNG_3sigma RNGRT_3sig
 2014-Jun-26 00:00    25.479    18.350  -20.976   2937.68 1750231.72  0.7111276
 2014-Jul-02 00:00    74.750    31.532  -28.205  14809.47 1393898.99  0.6646599
 2014-Jul-08 00:00   257.387    49.377  -30.025  79852.67 1060614.78  0.6230800
 2014-Jul-14 00:00   765.304    72.640  -28.892 349295.05 747517.969  0.5882362
 2014-Jul-20 00:00  1903.641   113.185  -29.562 1353802.1 451303.150  0.5611801
 2014-Jul-26 00:00  4758.720   198.706  -31.926 5941282.7 170902.357  0.5419842
 2014-Aug-01 00:00 15735.292   422.982  -35.515 41819255. 113684.526  0.5325829
NOTE: s32 statistical uncertainties are larger than s27's despite additional data because an a-priori constraint has been dropped, no longer being necessary to the solution.

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Ephemeris / WWW_USER Mon Jun 23 17:48:14 2014 Pasadena, USA      / Horizons    
*******************************************************************************
Target body name: ICE Spacecraft (-111)           {source: Horizons_SPK:user_input_}
Center body name: Earth (399)                     {source: DE-0431LE-0431}
Center-site name: GEOCENTRIC
*******************************************************************************
Start time      : A.D. 2014-Jun-05 00:00:00.0000 UT      
Stop  time      : A.D. 2014-Jul-05 00:00:00.0000 UT      
Step-size       : 1440 minutes
*******************************************************************************
Target pole/equ : No model available
Target radii    : (unavailable)                                                
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 +}
Center radii    : 6378.1 x 6378.1 x 6356.8 km     {Equator, meridian, pole}    
Target primary  : Earth
Vis. interferer : MOON (R_eq= 1737.400) km        {source: DE-0431LE-0431}
Rel. light bend : Sun, EARTH                      {source: DE-0431LE-0431}
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.140623.p140914                                           
EOP coverage    : DATA-BASED 1962-JAN-20 TO 2014-JUN-23. PREDICTS-> 2014-SEP-13
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 )
**************************************************************************************************************
 Date__(UT)__HR:MN     R.A._(ICRF/J2000.0)_DEC  APmag  S-brt            delta      deldot    S-O-T /r    S-T-O
**************************************************************************************************************
$$SOE
 2014-Jun-05 00:00     07 59 38.85 +20 47 23.3   n.a.   n.a. 0.09418503596650  -3.5244538  43.7079 /T 132.3583
 2014-Jun-06 00:00     08 01 31.44 +20 41 35.5   n.a.   n.a. 0.09215854869112  -3.4924224  43.1997 /T 132.9908
 2014-Jun-07 00:00     08 03 21.83 +20 35 47.9   n.a.   n.a. 0.09015076956714  -3.4596712  42.6836 /T 133.6294
 2014-Jun-08 00:00     08 05 09.95 +20 30 00.8   n.a.   n.a. 0.08816212920225  -3.4261484  42.1596 /T 134.2743
 2014-Jun-09 00:00     08 06 55.78 +20 24 14.5   n.a.   n.a. 0.08619308850090  -3.3918015  41.6273 /T 134.9257
 2014-Jun-10 00:00     08 08 39.26 +20 18 29.3   n.a.   n.a. 0.08424413745582  -3.3565838  41.0865 /T 135.5837
 2014-Jun-11 00:00     08 10 20.36 +20 12 45.3   n.a.   n.a. 0.08231578866786  -3.3204662  40.5371 /T 136.2485
 2014-Jun-12 00:00     08 11 59.08 +20 07 02.7   n.a.   n.a. 0.08040856255584  -3.2834537  39.9791 /T 136.9202
 2014-Jun-13 00:00     08 13 35.40 +20 01 21.6   n.a.   n.a. 0.07852296243393  -3.2456032  39.4122 /T 137.5986
 2014-Jun-14 00:00     08 15 09.36 +19 55 41.9   n.a.   n.a. 0.07665944066187  -3.2070353  38.8368 /T 138.2839
 2014-Jun-15 00:00     08 16 41.00 +19 50 03.5   n.a.   n.a. 0.07481836126424  -3.1679339  38.2527 /T 138.9757
 2014-Jun-16 00:00     08 18 10.40 +19 44 26.3   n.a.   n.a. 0.07299996763014  -3.1285288  37.6604 /T 139.6737
 2014-Jun-17 00:00     08 19 37.63 +19 38 50.1   n.a.   n.a. 0.07120436366527  -3.0890678  37.0602 /T 140.3777
 2014-Jun-18 00:00     08 21 02.79 +19 33 14.7   n.a.   n.a. 0.06943151253288  -3.0497859  36.4522 /T 141.0873
 2014-Jun-19 00:00     08 22 25.98 +19 27 39.8   n.a.   n.a. 0.06768125123817  -3.0108819  35.8370 /T 141.8021
 2014-Jun-20 00:00     08 23 47.27 +19 22 05.2   n.a.   n.a. 0.06595331515854  -2.9725081  35.2148 /T 142.5217
 2014-Jun-21 00:00     08 25 06.77 +19 16 30.8   n.a.   n.a. 0.06424736584797  -2.9347684  34.5859 /T 143.2458
 2014-Jun-22 00:00     08 26 24.52 +19 10 56.4   n.a.   n.a. 0.06256301724630  -2.8977248  33.9507 /T 143.9741
 2014-Jun-23 00:00     08 27 40.60 +19 05 21.8   n.a.   n.a. 0.06089985795577  -2.8614045  33.3094 /T 144.7065
 2014-Jun-24 00:00     08 28 55.06 +18 59 47.0   n.a.   n.a. 0.05925746915855  -2.8258070  32.6620 /T 145.4427
 2014-Jun-25 00:00     08 30 07.92 +18 54 11.8   n.a.   n.a. 0.05763543864964  -2.7909109  32.0089 /T 146.1825
 2014-Jun-26 00:00     08 31 19.21 +18 48 36.2   n.a.   n.a. 0.05603337159339  -2.7566783  31.3501 /T 146.9259
 2014-Jun-27 00:00     08 32 28.95 +18 43 00.1   n.a.   n.a. 0.05445089840763  -2.7230603  30.6857 /T 147.6728
 2014-Jun-28 00:00     08 33 37.15 +18 37 23.2   n.a.   n.a. 0.05288767997657  -2.6900012  30.0157 /T 148.4231
 2014-Jun-29 00:00     08 34 43.80 +18 31 45.7   n.a.   n.a. 0.05134341036439  -2.6574423  29.3401 /T 149.1769
 2014-Jun-30 00:00     08 35 48.91 +18 26 07.1   n.a.   n.a. 0.04981781735077  -2.6253261  28.6589 /T 149.9342
 2014-Jul-01 00:00     08 36 52.46 +18 20 27.5   n.a.   n.a. 0.04831066134413  -2.5935974  27.9722 /T 150.6949
 2014-Jul-02 00:00     08 37 54.44 +18 14 46.4   n.a.   n.a. 0.04682173342072  -2.5622051  27.2799 /T 151.4592
 2014-Jul-03 00:00     08 38 54.86 +18 09 03.7   n.a.   n.a. 0.04535085329403  -2.5311010  26.5820 /T 152.2269
 2014-Jul-04 00:00     08 39 53.70 +18 03 18.8   n.a.   n.a. 0.04389786789557  -2.5002388  25.8786 /T 152.9980
 2014-Jul-05 00:00     08 40 50.96 +17 57 31.4   n.a.   n.a. 0.04246265093787  -2.4695718  25.1696 /T 153.7727
$$EOE
**************************************************************************************************************

Column meaning:

TIME

Prior to 1962, times are UT1. Dates thereafter are UTC. Any 'b' symbol in the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D. date. Calendar dates prior to 1582-Oct-15 are in the Julian calendar system. Later calendar dates are in the Gregorian system.

Time tags refer to the same instant throughout the universe, regardless of where the observer is located.

The dynamical Coordinate Time scale is used internally. It is equivalent to the current IAU definition of "TDB". Conversion between CT and the selected non-uniform UT output scale has not been determined for UTC times after the next July or January 1st. The last known leap-second is used over any future interval.

NOTE: "n.a." in output means quantity "not available" at the print-time.

R.A._(ICRF/J2000.0)_DEC = J2000.0 astrometric right ascension and declination of target center. Adjusted for light-time. Units: HMS (HH MM SS.ff) and DMS (DD MM SS.f)

APmag S-brt = Target's approximate apparent visual magnitude & surface brightness. For planets and satellites, values are available only for solar phase angles in the range generally visible from Earth. This is to avoid extrapolation of models beyond their valid (data-based) limits. Units: MAGNITUDE & VISUAL MAGNITUDES PER SQUARE ARCSECOND

delta deldot = Range ("delta") and range-rate ("delta-dot") of target center with respect to the observer at the instant light seen by the observer at print-time would have left the target center (print-time minus down-leg light-time); the distance traveled by a light ray emanating from the center of the target and recorded by the observer at print-time. "deldot" is a projection of the velocity vector along this ray, the light-time-corrected line-of-sight from the coordinate center, and indicates relative motion. A positive "deldot" means the target center is moving away from the observer (coordinate center). A negative "deldot" means the target center is moving toward the observer. Units: AU and KM/S

S-O-T /r = Sun-Observer-Target angle; target's apparent solar elongation seen from observer location at print-time. If negative, the target center is behind the Sun. Angular units: DEGREES.

The '/r' column is a Sun-relative code, output for observing sites with defined rotation models only.

/T indicates target trails Sun (evening sky)

/L indicates target leads Sun (morning sky)

NOTE: The S-O-T solar elongation angle is the total separation in any direction. It does not indicate the angle of Sun leading or trailing.

S-T-O = "S-T-O" is the Sun->Target->Observer angle; the interior vertex angle at target center formed by a vector to the apparent center of the Sun at reflection time on the target and the apparent vector to the observer at print-time. Slightly different from true PHASE ANGLE (requestable separately) at the few arcsecond level in that it includes stellar aberration on the
down-leg from target to observer. Units: DEGREES


UPDATE (2014-Jun-13): Trajectory updated to JPL solution #27 (s27), based on coarse Arecibo plane-of-sky angular measurements (not delay/Doppler).

UPDATE (2014-Jun-09): Trajectory updated to JPL solution #24 (s24), based on coarse Arecibo plane-of-sky angular measurements (not delay/Doppler).

UPDATE (2014-Jun-05): Trajectory updated to JPL solution #21 (s21), based on coarse Arecibo plane-of-sky angular measurements (not delay/Doppler).

UPDATE (2014-Jun-03): Trajectory updated to JPL solution #17 (s17), based on coarse Arecibo plane-of-sky angular measurements (not delay/Doppler).

UPDATE (2014-Jun-01): The trajectory has been updated to JPL solution #6 (s6), based on coarse Arecibo plane-of-sky angular measurements (not delay/Doppler).

UPDATE (2014-May-23): While too distant/small for radar echos, Arecibo obtained one plane-of-sky measurement about 0.39 deg (RSS) from this trajectory. A full, three dimensional orbit solution update is not yet possible, but will be made available here if/when it is.

UPDATE (2014-Mar-10): Reacquired carrier signal by AMSAT-DL/Bochum: http://www.amsat-dl.org/index.php/news-mainmenu-97/199-ice-satellite-received-in-bochum

SPACECRAFT TRAJECTORY

  Trajectory name               Start        Stop      
  ----------------------------  -----------  -----------
  JPL s27                       2014-May-16  2014-Aug-01

BACKGROUND:

Launched 1978-Aug-12 15:12 UTC on a Delta 2914, the International Sun-Earth Explorer 3 was the third of a trio of spacecraft launched to study interplanetary space; Earth's magnetosphere and its interaction with the solar wind. ISEE-1 and 2 were Earth-orbiters. ISEE-3 was the first spacecraft to orbit a libration point (Earth-Sun L1, about 1.5 million km from Earth) beginning 1978-Nov-20. The mission was managed by NASA/GSFC.

After completion of its primary mission, it was renamed International Cometary Explorer (ICE) and sent to study comet Giacobini-Zinner and comet Halley. Fifteen maneuvers and five lunar passes (the last on 1983-Dec-22, at an altitude of 119.4 km, not far from the Apollo 11 landing site on the surface) were used to maneuver it to the heliocentric escape orbit achieved 1983-Dec-22.

It was the first spacecraft to fly past a comet, being initially maneuvered to a point 26550 km behind comet Giacobini-Zinner on 1985-Jun-05 so as to sample the tail, then approached the nucleus to within 7862 km on 1985-Sep-11 with a relative velocity of 20.7 km/s, confirming for the first time theories that comets are 'dirty snowballs' of ice and rock. The spacecraft later flew between the Sun and comet Halley on 1986-Mar-28, 31 million km from the comet.

NASA headquarters approved an update to the ICE mission in 1991: a heliospheric mission consisting of investigations of coronal mass ejections in coordination with ground-based observations, continued cosmic ray studies, and special-period observations such as when ICE and Ulysses were on the same solar radial line. By May 1995, ICE was being operated with only a low duty cycle, with some support being provided by the Ulysses project for data analysis. Two years later, on May 5, 1997, NASA authorized termination of operations.

Twelve of its thirteen instruments were working and the spacecraft retained a 150 m/s delta-V fuel capacity.

At 20:49 UTC on September 18, 2008, the 70-meter Goldstone antenna DSS-14 locked onto the carrier signal of the ISEE-3/ICE spacecraft, still transmitting and relatively close to the position based on predictions from several years earlier. The remainder of the 3-hour track was then used to gather Doppler tracking data for future use.

When last contacted, the spacecraft was on a trajectory that will bring it close to Earth in August 2014.

Current transmitter hardware of the Deep Space Network no longer includes the equipment needed to transmit commands to ISEE-3 without some modification, but the spacecraft's transmitter signal could still be detected and down-linked data understood.

PHYSICAL DATA:

Cylindrical: 1.7-m diameter x 1.6-m height
Mass : 390 kg (478 kg at launch)
Spin rate : 20 rpm
Solar power: 160 watts (cells cover body surface)
Two 3-meter booms carrier magnetometer and plasma wave sensors.
Four antennas span 91-meters for radio and plasma wave studies.

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.Giorgini@jpl.nasa.gov

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