Updated Ephemeris for ISEE-3 at JPL Horizons

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 05, 2014 ISEE-3/ICE Spacecraft -111 (Heliocentric)

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

Because uncertainties for s21 are large, predicts are currently available for tracking purposes only through Aug 01 and have these 3-sigma pointing uncertainties:

  Date__(UT)__HR:MN  POS_3sigma (in arcseconds)
  2014-Jun-05 00:00      19.122 
  2014-Jun-08 00:00      30.658 
  2014-Jun-11 00:00      56.265 
  2014-Jun-14 00:00      90.015 
  2014-Jun-17 00:00     133.165 
  2014-Jun-20 00:00     191.945 
  2014-Jun-23 00:00     273.486 
  2014-Jun-26 00:00     382.333 
  2014-Jun-29 00:00     519.251 
  2014-Jul-02 00:00     681.771 
  2014-Jul-11 00:00    1278.962 
  2014-Jul-20 00:00    2102.522 
  2014-Jul-29 00:00    3625.306 
  2014-Aug-01 00:00    4471.727 

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 s21                       2014-May-16  2014-Aug-01


Results


*******************************************************************************
Ephemeris / WWW_USER Fri Jun 6 09:14:34 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.140605.p140827
EOP coverage : DATA-BASED 1962-JAN-20 TO 2014-JUN-05. PREDICTS-> 2014-AUG-26
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 38.87 +20 47 20.5 n.a. n.a. 0.08874655570056 -3.3071738 43.7081 /T 132.5999
2014-Jun-06 00:00 08 01 31.53 +20 41 32.4 n.a. n.a. 0.08684504658965 -3.2769596 43.2002 /T 133.2239
2014-Jun-07 00:00 08 03 21.98 +20 35 44.4 n.a. n.a. 0.08496118477196 -3.2460638 42.6845 /T 133.8541
2014-Jun-08 00:00 08 05 10.19 +20 29 57.0 n.a. n.a. 0.08309537947010 -3.2144322 42.1607 /T 134.4908
2014-Jun-09 00:00 08 06 56.11 +20 24 10.3 n.a. n.a. 0.08124807158890 -3.1820099 41.6288 /T 135.1340
2014-Jun-10 00:00 08 08 39.68 +20 18 24.6 n.a. n.a. 0.07941973252663 -3.1487478 41.0884 /T 135.7839
2014-Jun-11 00:00 08 10 20.87 +20 12 40.2 n.a. n.a. 0.07761085771471 -3.1146142 40.5394 /T 136.4408
2014-Jun-12 00:00 08 11 59.68 +20 06 57.2 n.a. n.a. 0.07582195184748 -3.0796118 39.9817 /T 137.1046
2014-Jun-13 00:00 08 13 36.10 +20 01 15.6 n.a. n.a. 0.07405350397937 -3.0437947 39.4153 /T 137.7754
2014-Jun-14 00:00 08 15 10.16 +19 55 35.4 n.a. n.a. 0.07230595369374 -3.0072811 38.8402 /T 138.4531
2014-Jun-15 00:00 08 16 41.91 +19 49 56.5 n.a. n.a. 0.07057965373921 -2.9702521 38.2566 /T 139.1374
2014-Jun-16 00:00 08 18 11.41 +19 44 18.8 n.a. n.a. 0.06887483774377 -2.9329351 37.6648 /T 139.8281
2014-Jun-17 00:00 08 19 38.77 +19 38 41.9 n.a. n.a. 0.06719160137893 -2.8955751 37.0650 /T 140.5248
2014-Jun-18 00:00 08 21 04.08 +19 33 05.7 n.a. n.a. 0.06552990111014 -2.8584044 36.4577 /T 141.2272
2014-Jun-19 00:00 08 22 27.43 +19 27 30.0 n.a. n.a. 0.06388956878823 -2.8216194 35.8432 /T 141.9348
2014-Jun-20 00:00 08 23 48.92 +19 21 54.5 n.a. n.a. 0.06227033618423 -2.7853692 35.2218 /T 142.6472
2014-Jun-21 00:00 08 25 08.64 +19 16 19.0 n.a. n.a. 0.06067186279537 -2.7497555 34.5939 /T 143.3642
2014-Jun-22 00:00 08 26 26.65 +19 10 43.5 n.a. n.a. 0.05909376205246 -2.7148375 33.9597 /T 144.0855
2014-Jun-23 00:00 08 27 43.03 +19 05 07.6 n.a. n.a. 0.05753562359065 -2.6806395 33.3196 /T 144.8108
2014-Jun-24 00:00 08 28 57.80 +18 59 31.4 n.a. n.a. 0.05599703115702 -2.6471587 32.6736 /T 145.5398
2014-Jun-25 00:00 08 30 11.02 +18 53 54.8 n.a. n.a. 0.05447757662946 -2.6143708 32.0220 /T 146.2726
2014-Jun-26 00:00 08 31 22.70 +18 48 17.7 n.a. n.a. 0.05297687075552 -2.5822356 31.3647 /T 147.0090
2014-Jun-27 00:00 08 32 32.86 +18 42 39.9 n.a. n.a. 0.05149455101562 -2.5507014 30.7020 /T 147.7488
2014-Jun-28 00:00 08 33 41.50 +18 37 01.5 n.a. n.a. 0.05003028681260 -2.5197101 30.0338 /T 148.4923
2014-Jun-29 00:00 08 34 48.61 +18 31 22.3 n.a. n.a. 0.04858378215972 -2.4892007 29.3601 /T 149.2392
2014-Jun-30 00:00 08 35 54.20 +18 25 42.2 n.a. n.a. 0.04715477618897 -2.4591129 28.6809 /T 149.9897
2014-Jul-01 00:00 08 36 58.23 +18 20 01.1 n.a. n.a. 0.04574304203500 -2.4293896 27.9961 /T 150.7438
2014-Jul-02 00:00 08 38 00.71 +18 14 18.6 n.a. n.a. 0.04434838484290 -2.3999771 27.3058 /T 151.5015
2014-Jul-03 00:00 08 39 01.61 +18 08 34.6 n.a. n.a. 0.04297063970371 -2.3708252 26.6099 /T 152.2628
2014-Jul-04 00:00 08 40 00.93 +18 02 48.6 n.a. n.a. 0.04160967019844 -2.3418852 25.9084 /T 153.0279
2014-Jul-05 00:00 08 40 58.64 +17 57 00.3 n.a. n.a. 0.04026536792114 -2.3131084 25.2013 /T 153.7966
$$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


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

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.

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