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Revised: Dec 26, 2021 James Webb Space Telescope / (E-S L2) -170
https://www.jwst.nasa.gov/index.html
https://www.youtube.com/watch?v=bTxLAGchWnA
The James Webb Space Telescope (JWST or Webb) is a space-based infrared
observatory and NASA's successor to the Hubble Space Telescope.
Launched by Ariane 5 booster on 2021-Dec-25 @ 12:20 UTC from the ELA-3
launch complex near Korou, French Guiana.
After launch, the telescope will deploy during its 30-day, 1.5 million km
journey to Halo orbit at the second Earth-Sun Lagrange point (E-S L2).
Mission duration is nominally 5-10 years.
GOALS
- Search for the first galaxies or luminous objects formed after the Big Bang
- Determine how galaxies evolved from their formation until now
- Observe the formation of stars from the first stages to the formation of
planetary systems
- Measure the physical and chemical properties of planetary systems,
including our own Solar System, investigating the potential for life
in those systems.
TELESCOPE
* total launch mass : ~6200 kg (observatory, fuel, launch adaptor)
* primary mirror : 25 m^2
mass : 705 kg
material : beryllium coated w/48.25 grams gold (golf-ball size)
segment mass : 20.1 kg, 39.48 kg for entire segment assembly
No. of segments : 18
* focal length : 131.4 meters
* optical resolution: 0.1 arcseconds
* wavelength : 0.6 - 28.5 microns
* size of sun shield: 21.197 m x 14.162 m
* Sun shield layers : 1: Max temp 283K, 231 deg. F.
5: Max temp 221K, -80 F
Min temp 36K, -394 F
* Operating temp : < 50K (-370 deg. F)
INSTRUMENTS
- Near Infrared Camera (NIRCam)
- Near Infrared Spectrograph (NIRSpec)
- Mid Infrared Instrument (MIRI)
- Fine Guidance Sensors/Near Infrared Imager & Slitless Spectrograph
(FGS/NIRISS)
TRAJECTORY
Post-launch trajectory, data through ~16:00 UTC Dec 26, predicts thereafter.
Trajectory files Start (TDB) End (TDB)
-------------------------------------- ----------------- -----------------
BURN_TTF_01_2021359124800_02U.OEM.V0.3 2021-Dec-25 12:50 2021-Dec-25 20:01
BURN_MCC_1A_2021359200000_04U.OEM.V0.1 2021-Dec-25 20:01 2021-Dec-26 15:01
BURN_MCC_1B_2021360150000_01U.OEM.V0.1 2021-Dec-26 15:01 2022-Jan-23 15:01
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Ephemeris / WWW_USER Sun Dec 26 23:15:38 2021 Pasadena, USA / Horizons
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Target body name: James Webb Space Telescope (spacecraft) (-170) {source: JWST_merged}
Center body name: Earth (399) {source: DE441}
Center-site name: GEOCENTRIC
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Start time : A.D. 2021-Dec-27 00:00:00.0000 UT
Stop time : A.D. 2022-Jan-06 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 : ITRF93 {East-longitude positive}
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: DE441}
Rel. light bend : Sun, EARTH {source: DE441}
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.211223.p220318
EOP coverage : DATA-BASED 1962-JAN-20 TO 2021-DEC-23. PREDICTS-> 2022-MAR-17
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 S-O-T /r S-T-O Sky_motion Sky_mot_PA RelVel-ANG Lun_Sky_Brt sky_SNR
******************************************************************************************************************************************************************************
$$SOE
2021-Dec-27 00:00 05 42 56.05 -00 14 08.9 n.a. n.a. 0.00189650825362 1.4329090 154.5580 /T 25.3947 11.270798 85.786121 79.778541 n.a. n.a.
2021-Dec-28 00:00 05 55 42.00 +00 00 53.3 n.a. n.a. 0.00263108791411 1.1421249 155.5285 /T 24.4082 5.8167451 85.383588 80.799510 n.a. n.a.
2021-Dec-29 00:00 06 03 10.35 +00 10 47.7 n.a. n.a. 0.00323933913676 0.9735787 155.9536 /T 23.9697 3.8092629 84.638866 81.289811 n.a. n.a.
2021-Dec-30 00:00 06 08 20.68 +00 18 56.5 n.a. n.a. 0.00376557033050 0.8549440 156.1911 /T 23.7206 2.7907352 83.482081 81.548935 n.a. n.a.
2021-Dec-31 00:00 06 12 15.68 +00 26 32.2 n.a. n.a. 0.00423247214568 0.7656768 156.3416 /T 23.5598 2.1938176 81.892340 81.660644 n.a. n.a.
2022-Jan-01 00:00 06 15 24.37 +00 34 08.6 n.a. n.a. 0.00465356508162 0.6950406 156.4432 /T 23.4490 1.8150387 79.908666 81.643353 n.a. n.a.
2022-Jan-02 00:00 06 18 02.68 +00 42 03.0 n.a. n.a. 0.00503775953544 0.6371579 156.5128 /T 23.3708 1.5653284 77.644898 81.491514 n.a. n.a.
2022-Jan-03 00:00 06 20 20.43 +00 50 24.3 n.a. n.a. 0.00539130042008 0.5884046 156.5590 /T 23.3167 1.3988900 75.272915 81.193020 n.a. n.a.
2022-Jan-04 00:00 06 22 24.10 +00 59 15.9 n.a. n.a. 0.00571872660429 0.5463952 156.5863 /T 23.2820 1.2887235 72.978480 80.739962 n.a. n.a.
2022-Jan-05 00:00 06 24 18.14 +01 08 37.9 n.a. n.a. 0.00602341794849 0.5094458 156.5973 /T 23.2641 1.2171913 70.911712 80.131656 n.a. n.a.
2022-Jan-06 00:00 06 26 05.69 +01 18 28.4 n.a. n.a. 0.00630793626558 0.4763691 156.5933 /T 23.2616 1.1720598 69.154412 79.374752 n.a. n.a.
$$EOE
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Column meaning:
TIME
Times PRIOR to 1962 are UT1, a mean-solar time closely related to the
prior but now-deprecated GMT. Times AFTER 1962 are in UTC, the current
civil or "wall-clock" time-scale. UTC is kept within 0.9 seconds of UT1
using integer leap-seconds for 1972 and later years.
Conversion from the internal Barycentric Dynamical Time (TDB) of solar
system dynamics to the non-uniform civil UT time-scale requested for output
has not been determined for UTC times after the next July or January 1st.
Therefore, the last known leap-second is used as a constant over future
intervals.
Time tags refer to the UT time-scale conversion from TDB on Earth
regardless of observer location within the solar system, although clock
rates may differ due to the local gravity field and no analog to "UT"
may be defined for that location.
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.
NOTE: "n.a." in output means quantity "not available" at the print-time.
'R.A._____(ICRF)_____DEC' =
Astrometric right ascension and declination of the target center with
respect to the observing site (coordinate origin) in the reference frame of
the planetary ephemeris (ICRF). Compensated for down-leg light-time delay
aberration.
Units: RA in hours-minutes-seconds of time, HH MM SS.ff{ffff}
DEC in degrees-minutes-seconds of arc, sDD MN SC.f{ffff}
'APmag S-brt' =
The targets' approximate apparent visual magnitude and surface brightness.
For planets and natural satellites, output is restricted to solar phase angles
covered by observational data. Outside the observed phase angle range, "n.a."
may be output to avoid extrapolation beyond the limit of model validity.
For Earth-based observers, the estimated dimming due to atmospheric
absorption (extinction) is available as a separate, requestable quantity.
Surface brightness is the average airless visual magnitude of a
square-arcsecond of the illuminated portion of the apparent disk. It is
computed only if the target radius is known.
Units: MAGNITUDES & MAGNITUDES PER SQUARE ARCSECOND
'delta deldot' =
Apparent range ("delta", light-time aberrated) and range-rate ("delta-dot")
of the target center relative to the observer. A positive "deldot" means the
target center is moving away from the observer, negative indicates movement
toward the observer. Units: AU and KM/S
'S-O-T /r' =
Sun-Observer-Target apparent SOLAR ELONGATION ANGLE seen from the observers'
location at print-time.
The '/r' column provides a code indicating the targets' apparent position
relative to the Sun in the observers' sky, as described below:
Case A: For an observing location on the surface of a rotating body, that
body rotational sense is considered:
/T indicates target TRAILS Sun (evening sky: rises and sets AFTER Sun)
/L indicates target LEADS Sun (morning sky: rises and sets BEFORE Sun)
Case B: For an observing point that does not have a rotational model (such
as a spacecraft), the "leading" and "trailing" condition is defined by the
observers' heliocentric ORBITAL motion:
* If continuing in the observers' current direction of heliocentric
motion would encounter the targets' apparent longitude first, followed
by the Sun's, the target LEADS the Sun as seen by the observer.
* If the Sun's apparent longitude would be encountered first, followed
by the targets', the target TRAILS the Sun.
Two other codes can be output:
/* indicates observer is Sun-centered (undefined)
/? Target is aligned with Sun center (no lead or trail)
The S-O-T solar elongation angle is numerically the minimum separation
angle of the Sun and target in the sky in any direction. It does NOT indicate
the amount of separation in the leading or trailing directions, which would
be defined along the equator of a spherical coordinate system.
Units: DEGREES
'S-T-O' =
The Sun-Target-Observer angle; the interior vertex angle at target center
formed by a vector from the target to the apparent center of the Sun (at
reflection time on the target) and the apparent vector from target 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
'Sky_motion Sky_mot_PA RelVel-ANG' =
Total apparent angular rate of the target in the plane-of-sky. "Sky_mot_PA"
is the position angle of the target's direction of motion in the plane-of-sky,
measured counter-clockwise from the apparent of-date north pole direction.
"RelVel-ANG" is the flight path angle of the target's relative motion with
respect to the observer's line-of-sight, in the range [-90,+90], where positive
values indicate motion away from the observer, negative values are toward the
observer:
-90 = target is moving directly toward the observer
0 = target is moving at right angles to the observer's line-of-sight
+90 = target is moving directly away from the observer
UNITS: ARCSECONDS/MINUTE, DEGREES, DEGREES
'Lun_Sky_Brt sky_SNR' =
Sky brightness due to moonlight scattered by Earth's atmosphere at the
target's position in the sky. "sky_SNR" is the visual signal-to-noise ratio
(SNR) of the target's surface brightness relative to background sky. Output
only for topocentric Earth observers when both the Moon and target are above
the local horizon and the Sun is in astronomical twilight (or further) below
the horizon, and the target is not the Moon or Sun. If all conditions are
not met, "n.a." is output. Galactic brightness, local sky light-pollution
and weather are NOT considered. Lunar opposition surge is considered. The
value returned is accurate under ideal conditions at the approximately 8-23%
level, so is a useful but not definitive value.
If the target-body radius is also known, "sky_SNR" is output. This is the
approximate visual signal-to-noise ratio of the target's brightness divided
by lunar sky brightness. When sky_SNR < 1, the target is dimmer than the
ideal moonlight-scattering background sky, so unlikely to be detectable at
visual wavelengths. In practice, visibility requires sky_SNR > 1 and a
detector sensitive enough to reach the target's magnitude, even if it isn't
washed out by moonlight. When relating magnitudes and brightness values,
keep in mind their logarithmic relationship m2-m1 = -2.5*log_10(b2/b1).
UNITS: VISUAL MAGNITUDES / ARCSECOND^2, and unitless ratio
Computations by ...
Solar System Dynamics Group, Horizons On-Line Ephemeris System
4800 Oak Grove Drive, Jet Propulsion Laboratory
Pasadena, CA 91109 USA
General site: https://ssd.jpl.nasa.gov/
Mailing list: https://ssd.jpl.nasa.gov/email_list.html
System news : https://ssd.jpl.nasa.gov/horizons/news.html
User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html
Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/
API https://ssd-api.jpl.nasa.gov/doc/horizons.html
command-line telnet ssd.jpl.nasa.gov 6775
e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/hrzn_batch.txt
scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS
Author : Jon.D.Giorgini@jpl.nasa.gov
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