Updates James Webb Space Telescope updates

GLS

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Better quality video from the separation (the reflection of the upper stage thruster firings is visible in the back of JWST):



Next steps: https://www.nasa.gov/press-release/nasa-plans-coverage-of-webb-space-telescope-deployments

Webb’s deployment sequence is a human-controlled process that provides the team with the flexibility to pause, assess data, and adjust as needed. The timing and order of all milestones may therefore change. NASA will host live broadcast coverage to mark the following milestones, with specific times and dates updated as they approach:
  • Sunshield tensioning: The full deployment of the sunshield, the most challenging element for Webb, will mark a critical milestone for the mission. This step is scheduled for completion about eight days after launch, no earlier than Sunday, Jan. 2.
  • Secondary mirror support structure deployment: The support structure that holds the secondary mirror in position to focus light collected by the primary mirror is set for deployment about 10 days after launch, no earlier than Tuesday, Jan. 4.
  • Webb deployments complete: With the unfolding of the second of Webb’s primary mirror wings, the Webb team will have completed all observatory deployments. This is scheduled to take place about 13 days after launch, no earlier than Friday, Jan. 7.
 

BEEP

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Does anyone know whether this main part of the trajectory is an eliptical transfer to a point near L2? I'd think they designed it for a minimum apogee speed (all tangential at this point), therefore it is a transfer with an eccentricity very close to 1.
 
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Ajaja

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@BEEP
Check it yourself :)
Data from https://ssd.jpl.nasa.gov/horizons/app.html#/ :
Code:
BEGIN_ENVIRONMENT
  System Sol
  Date MJD 59579
END_ENVIRONMENT

BEGIN_FOCUS
  Ship JWST
END_FOCUS

BEGIN_SHIPS
JWST:Deltaglider
  STATUS Orbiting Sun
  RPOS -2.358205523858005E+10 -2.539440950672254E+08  1.457949526099925E+11
  RVEL -3.005237777583948E+04 -2.800497262752064E+02 -4.170954502893305E+03
END
END_SHIPS
 

Gerdih

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Smh that came to my mind, since Webb will stay in L2 and the shield will reflect sun's light. Does anyone know if it can be spotted with amateur telescopes at night?
 

Ajaja

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Interesting.
It's heading slightly (or even not so slightly) off L2.
There are scenarios with L2 (the data is from Horizons System too):
Code:
BEGIN_ENVIRONMENT
  System Sol
  Date MJD 59579
END_ENVIRONMENT

BEGIN_FOCUS
  Ship JWST
END_FOCUS

BEGIN_SHIPS
JWST:DeltaGlider
  STATUS Orbiting Sun
  RPOS -2.358205523858005E+10 -2.539440950672254E+08  1.457949526099925E+11
  RVEL -3.005237777583948E+04 -2.800497262752064E+02 -4.170954502893305E+03
END
L2:DeltaGlider
  STATUS Orbiting Sun
  RPOS -2.378767009328692E+10 -7.017005133420229E+06  1.466726354919139E+11
  RVEL -3.019001592077677E+04  3.472894011289362E-01 -4.930955897640987E+03
END
END_SHIPS
Code:
BEGIN_ENVIRONMENT
  System Sol
  Date MJD 59606
END_ENVIRONMENT

BEGIN_FOCUS
  Ship JWST
END_FOCUS

BEGIN_SHIPS
JWST:DeltaGlider
  STATUS Orbiting Sun
  RPOS -8.841122009338984E+10 -4.110513190204427E+08  1.193916624458967E+11
  RVEL -2.451326365942533E+04  5.840172101138918E+01 -1.781472102455762E+04
END
L2:DeltaGlider
  STATUS Orbiting Sun
  RPOS -8.893764621154593E+10 -5.411322143010795E+06  1.192796024391203E+11
  RVEL -2.461084036537315E+04  1.005411282567259E+00 -1.810033297525489E+04
END
END_SHIPS
 

BrianJ

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Interesting.
It's heading slightly (or even not so slightly) off L2.
There are scenarios with L2 (the data is from Horizons System too):
Hi,
I have a hunch those predicted state vectors don't include the two MCC's that have been made already, and that JPL Horizons has been updated since then to include them, but possibly not future MCC's. Not sure. I just grabbed the vectors for MJD59606 (27 Jan 2022) and I have different numbers.

BTW my back-of-envelope calcs give JWST max.acceleration of 0.0115m/s^2 using 2 x 8lbf thrusters.
Which equates roughly to MCC's of ~40m/s and ~7m/s so far.

Cheers,
BrianJ
 

Ajaja

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I have a hunch those predicted state vectors don't include the two MCC's that have been made already, and that JPL Horizons has been updated since then to include them, but possibly not future MCC's. Not sure. I just grabbed the vectors for MJD59606 (27 Jan 2022) and I have different numbers.
Yes, mayby.
The data is based on:
Code:
 TRAJECTORY
 MCC1A (65-minute engine burn) began 2021-Dec-26 12:50 UTC, completed 01:55 UTC.
 MCC1B (09:27 engine burn) began 2021-Dec-28 12:20 UTC, completed 12:29:27 UTC.

 Post-launch trajectory from Goddard Flight Dynamics Facility (FDF), based on
 data through ~20:00 UTC Dec 30, 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  2021-Dec-27 14:01
 BURN_MCC_1B_2021361140000_02U.OEM.V0.1   2021-Dec-27 14:01  2021-Dec-29 00:01
 NOBURN_2021363000000_01U.OEM.V0.1        2021-Dec-29 00:01  2021-Dec-30 18:29
 NOBURN_2021364182800_01U.OEM.V0.1        2021-Dec-30 18:29  2022-Jan-27 18:29
*******************************************************************************
Initially I took vectors for 2021-Dec-31 and saw in Orbter that Webb is heading to a huge halo orbit >600Mm from L2. Then I took vectors for 2022-Jan-27 and they confirmed the calculation in Orbiter.
The halo orbit doesn't seem right. But halo orbits are not very intuitive things. I wonder what the final orbit will be.
 
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