Updated Ephemeris for ISEE-3 at JPL Horizons 3 July 2014

Source: JPL HORIZONS
Ephemeris Type: OBSERVER
Target Body: ICE Spacecraft (ISEE-3)
Observer Location: Geocentric [500]
Time Span : Start=2014-07-04, Stop=2014-08-03, Step=1 d
Table Settings: defaults
Object Data Page

UPDATE (2014-Jul-03): Trajectory update from ISEE-3 Reboot based on Arecibo angular data and DSN two-way Doppler.

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Ephemeris / WWW_USER Fri Jul  4 15:33:03 2014 Pasadena, USA      / Horizons    
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Target body name: ICE Spacecraft (-111)           {source: STK created (pnts= 9953,}
Center body name: Earth (399)                     {source: DE-0431LE-0431}
Center-site name: GEOCENTRIC
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Start time      : A.D. 2014-Jul-04 00:00:00.0000 UT      
Stop  time      : A.D. 2014-Aug-03 00:00:00.0000 UT      
Step-size       : 1440 minutes
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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.140703.p140924                                           
EOP coverage    : DATA-BASED 1962-JAN-20 TO 2014-JUL-03. PREDICTS-> 2014-SEP-23
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-Jul-04 00:00     08 40 02.08 +18 01 13.6   n.a.   n.a. 0.04102209634767  -2.3055020  25.9199 /T 153.0316
 2014-Jul-05 00:00     08 40 59.98 +17 55 20.2   n.a.   n.a. 0.03969866749291  -2.2772117  25.2139 /T 153.7982
 2014-Jul-06 00:00     08 41 56.28 +17 49 23.7   n.a.   n.a. 0.03839154673226  -2.2490284  24.5023 /T 154.5684
 2014-Jul-07 00:00     08 42 50.99 +17 43 23.3   n.a.   n.a. 0.03710068668829  -2.2209024  23.7854 /T 155.3421
 2014-Jul-08 00:00     08 43 44.15 +17 37 18.1   n.a.   n.a. 0.03582606763871  -2.1927889  23.0633 /T 156.1192
 2014-Jul-09 00:00     08 44 35.80 +17 31 06.9   n.a.   n.a. 0.03456769169879  -2.1646593  22.3362 /T 156.8993
 2014-Jul-10 00:00     08 45 26.05 +17 24 48.4   n.a.   n.a. 0.03332556914011  -2.1365172  21.6048 /T 157.6819
 2014-Jul-11 00:00     08 46 15.05 +17 18 20.8   n.a.   n.a. 0.03209969392201  -2.1084188  20.8697 /T 158.4661
 2014-Jul-12 00:00     08 47 03.02 +17 11 41.8   n.a.   n.a. 0.03089000807953  -2.0804898  20.1321 /T 159.2510
 2014-Jul-13 00:00     08 47 50.26 +17 04 48.8   n.a.   n.a. 0.02969635943504  -2.0529299  19.3933 /T 160.0351
 2014-Jul-14 00:00     08 48 37.18 +16 57 38.7   n.a.   n.a. 0.02851846232881  -2.0259973  18.6553 /T 160.8164
 2014-Jul-15 00:00     08 49 24.23 +16 50 07.8   n.a.   n.a. 0.02735587301288  -1.9999746  17.9202 /T 161.5928
 2014-Jul-16 00:00     08 50 11.94 +16 42 12.1   n.a.   n.a. 0.02620798735264  -1.9751280  17.1904 /T 162.3618
 2014-Jul-17 00:00     08 51 00.89 +16 33 46.9   n.a.   n.a. 0.02507406017583  -1.9516756  16.4689 /T 163.1206
 2014-Jul-18 00:00     08 51 51.68 +16 24 47.1   n.a.   n.a. 0.02395323823008  -1.9297728  15.7586 /T 163.8661
 2014-Jul-19 00:00     08 52 44.99 +16 15 06.9   n.a.   n.a. 0.02284459636980  -1.9095147  15.0630 /T 164.5948
 2014-Jul-20 00:00     08 53 41.52 +16 04 39.6   n.a.   n.a. 0.02174716911183  -1.8909482  14.3857 /T 165.3032
 2014-Jul-21 00:00     08 54 42.02 +15 53 17.4   n.a.   n.a. 0.02065997404612  -1.8740874  13.7310 /T 165.9869
 2014-Jul-22 00:00     08 55 47.37 +15 40 51.1   n.a.   n.a. 0.01958202706568  -1.8589261  13.1038 /T 166.6410
 2014-Jul-23 00:00     08 56 58.53 +15 27 09.6   n.a.   n.a. 0.01851235105670  -1.8454475  12.5098 /T 167.2600
 2014-Jul-24 00:00     08 58 16.65 +15 11 59.4   n.a.   n.a. 0.01744997991973  -1.8336311  11.9559 /T 167.8368
 2014-Jul-25 00:00     08 59 43.11 +14 55 03.4   n.a.   n.a. 0.01639395928940  -1.8234576  11.4504 /T 168.3630
 2014-Jul-26 00:00     09 01 19.59 +14 36 00.3   n.a.   n.a. 0.01534334464658  -1.8149128  11.0040 /T 168.8283
 2014-Jul-27 00:00     09 03 08.20 +14 14 22.5   n.a.   n.a. 0.01429719698428  -1.8079925  10.6297 /T 169.2194
 2014-Jul-28 00:00     09 05 11.68 +13 49 33.8   n.a.   n.a. 0.01325457593049  -1.8027064  10.3446 /T 169.5194
 2014-Jul-29 00:00     09 07 33.62 +13 20 45.6   n.a.   n.a. 0.01221453027351  -1.7990829  10.1707 /T 169.7062
 2014-Jul-30 00:00     09 10 18.94 +12 46 51.0   n.a.   n.a. 0.01117608618761  -1.7971722  10.1374 /T 169.7504
 2014-Jul-31 00:00     09 13 34.50 +12 06 15.2   n.a.   n.a. 0.01013823426724  -1.7970466  10.2850 /T 169.6118
 2014-Aug-01 00:00     09 17 30.26 +11 16 39.4   n.a.   n.a. 0.00909991847470  -1.7987924  10.6706 /T 169.2334
 2014-Aug-02 00:00     09 22 21.29 +10 14 31.4   n.a.   n.a. 0.00806003574095  -1.8024766  11.3796 /T 168.5300
 2014-Aug-03 00:00     09 28 31.62 +08 54 10.4   n.a.   n.a. 0.00701747177841  -1.8080415  12.5472 /T 167.3662
$$EOE
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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-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).

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
(provided by ISEE-3 Reboot project 2014-Jul-01, predicts after that date)

  Trajectory name                                         Start        Stop    
  --------------------------------------------------   -----------  -----------
  ISEE-3_from_20140610_to_20140901_20140701.bsp_V0.2   2014-Jun-10  2014-Sep-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.

Results

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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