ESA - JUICE updates

[Josh_from_Canada]

Launch window 5-25 April 2023
Earth-Moon flyby August 2024
Venus flyby August 2025
Earth flyby September 2026
Earth flyby January 2029
Arrival at Jupiter July 2031
Ganymede orbit insertion December 2034
Mission end late 2035

Flybys of Jupiter's Moons:
2 of Europa
12 of Ganymede
21 of Calisto

[Blackstar]

Launch window 5-25 April 2023
Earth-Moon flyby August 2024
Venus flyby August 2025
Earth flyby September 2026
Earth flyby January 2029
Arrival at Jupiter July 2031
Ganymede orbit insertion December 2034
Mission end late 2035

It's been a long time since I paid attention to this mission, but why does it take 8 years to get to Jupiter? Why did they have to do so many flybys? Galileo did it in 6 years with a Venus and Earth flyby. Cassini-Huygens reached Saturn in 7 years with two Venus, one Earth-Moon, and one Jupiter flyby.

[vjkane]

It's been a long time since I paid attention to this mission, but why does it take 8 years to get to Jupiter? Why did they have to do so many flybys? Galileo did it in 6 years with a Venus and Earth flyby. Cassini-Huygens reached Saturn in 7 years with two Venus, one Earth-Moon, and one Jupiter flyby.

I seem to remember reading on this forum or another that JUICE is massive (heavy) for the launch vehicle. This is an EVEE gravity assist trajectory. I seem to remember that outer planets usually have only three or fewer inner planet assists.

I'm sure there are others with more expertise on this on this forum

[redliox]

It's been a long time since I paid attention to this mission, but why does it take 8 years to get to Jupiter? Why did they have to do so many flybys? Galileo did it in 6 years with a Venus and Earth flyby. Cassini-Huygens reached Saturn in 7 years with two Venus, one Earth-Moon, and one Jupiter flyby.

For starters ESA seems to be patient.  Second, I think it's in part due to them having to settle for smaller rockets than their NASA counterparts.  However I'm likewise not fond of these extra-long trajectories; I tend to forgive single-Earth flybys ala Juno and Europa Clipper since their routes are at least simpler.  I have not forgotten the grief poor Galileo endured, although much of the issues it had was from long-term storage and people forgetting to lube the antenna or check the integrity of it's VHS-esque hard drive.

[redliox]

Flybys of Jupiter's Moons:
2 of Europa
12 of Ganymede
21 of Calisto

I'm glad Callisto will still get some attention out of this mission.  Although it's been a while and I presume some details have changed, one thing I recall from flight plans about JUICE's Galilean flybys was how, as a side-effect of the high-inclination phase, alot of the Callisto flybys are going to end up concentrated in a few bands of the moon.  Those regions, as a perk, will get some very great science and imagery that'll be akin to the attention Europa and Ganymede will get, but the cost was that the rest of Callisto might only end up with global imaging; probably will still end up overall better than Galileo's coverage but that was the price ESA had to compromise on to ensure JUICE did decent science while achieving both the high-inclination system science and ultimately reaching Ganymede.

[spacexplorer]

ESA JUICE software, (I think, bohemian villages for me  )
https://www.cosmos.esa.int/web/spice/spice-for-juice

5.0   New Baseline trajectory, launch September 2022

same link updated:

5.0b23.1    New Baseline trajectory, launch April 2023

https://spiftp.esac.esa.int/data/SPICE/JUICE/kernels/mk/juice_crema_5_0b23_1.tm

- Launch on April, 5th 2023

Using ESA version of WebGeoCalc (I can't yet find JUICE kernels on NASA sites) you can plot JUICE trajectory  w.r.t. Sun, Earth, Jupiter,...

http://spice.esac.esa.int/webgeocalc/#StateVector

Kernels to use:
1) STUDY -- JUICE -- CReMA 5.0 Consolidated Trajectory for launch 2022 (150l0a) kernel set (from list)
2) data/SPICE/JUICE/kernels/fk/juice_v26.tf (*)

1) Target: JUICE
2) Observer name: JUPITER or other (This is the center of reference frame)
3) Observer frame: (as above)
4) Input times: Single interval
5) Start/stop time: yyyy/mm/dd (choose between 2023-04-30 and 2035-10-22)
6) Timestep:  input 30 and select days from listbox (***)
7) Time series plots: nothing
X-Y plots: add Y vs X (**)
9 ) Click CALCULATE button

Check top of page for errors, or scroll down for plot.

------------

Configuration for usage with http://spice.esac.esa.int/webgeocalc/example/perform-calculation.html :


{
  "kernels": [
    {
      "type": "KERNEL",
      "path": "data/SPICE/JUICE/kernels/mk/juice_crema_5_0b23_1.tm"
    },

    {
      "type": "KERNEL",
      "path": "data/SPICE/JUICE/kernels/fk/juice_v26.tf"
    },

    {
      "type": "KERNEL",
      "path": "pds/wgc/mk/latest_lsk_v0004.tm"
    },

    {
      "type": "KERNEL",
      "path": "pds/wgc/mk/solar_system_v0043.tm"
    }
  ],
  "timeSystem": "UTC",
  "timeFormat": "CALENDAR",
  "intervals": [
    {
      "startTime": "2023-04-30T00:00:00",
      "endTime": "2023-05-30T00:00:00"
    }
  ],
  "timeStep": 1,
  "timeStepUnits": "DAYS",
  "calculationType": "STATE_VECTOR",
  "target": "-28000",
  "targetType": "OBJECT",
  "observer": "JUPITER",
  "observerType": "OBJECT",
  "referenceFrame": "IAU_JUPITER",
  "frameLocus": "OBSERVER",
  "aberrationCorrection": "NONE",
  "stateRepresentation": "RECTANGULAR"
}


(*) manually: scroll "Kernel selection" list down to last item, click MANUAL and then press button CHOOSE KERNEL
(**): Click on "X:" listbox , then select Y; click "Y:" listbox and select "X"; click ADD PLOT button
(***) if timespan is on multiple years; not that small step and big timespan will cause a very long calculation delay; maximum allowed points: 25000; select "equal intervals" from listbox to split the selected timespan into the specified number of steps

[LouScheffer]

It's been a long time since I paid attention to this mission, but why does it take 8 years to get to Jupiter? Why did they have to do so many flybys? Galileo did it in 6 years with a Venus and Earth flyby. Cassini-Huygens reached Saturn in 7 years with two Venus, one Earth-Moon, and one Jupiter flyby.

Most interplanetary missions launched by Ariane 5 take an extra year, even if the launcher performance is sufficient.  The reason is that Ariane does not have a restartable second stage, as restarts are not needed for GTO launches from their near-equatorial site.  Most interplanetary launches require a very specific DLA (the latitude over Earth where the escape firing needs to be to hit the target).  Because the Earth's axis is tilted, and the solar system is not flat, this typically falls anywhere from +- 30 degrees from the equator.

For a rocket that can re-start, this is no big deal.  You launch into a parking orbit, wait until it's at the right latitude, then fire to escape velocity.  But if your second stage cannot re-start, then the orbits you can achieve are limited to those where the latitude is quite close to that of your launch site.  So what Ariane does is fire into an Earth-return orbit (which is accessible) a year early, and then do an flyby at the right latitude.  This flyby adds no energy, but can reach orbits that direct ascent cannot.  This is why Ariane 5 interplanetary missions almost always start with an Earth flyby one year after launch, where most other launchers go straight to their first flyby planet.

I *think* something similar, but less serious, happened on one of the Chinese Mars missions.  The launcher could reach the latitude they needed, but was not qualified for the length of coast required.  So they could not quite aim straight at Mars, and had to do an extra maneuver on the way to reach it.

[Star One]

It's been a long time since I paid attention to this mission, but why does it take 8 years to get to Jupiter? Why did they have to do so many flybys? Galileo did it in 6 years with a Venus and Earth flyby. Cassini-Huygens reached Saturn in 7 years with two Venus, one Earth-Moon, and one Jupiter flyby.

Most interplanetary missions launched by Ariane 5 take an extra year, even if the launcher performance is sufficient.  The reason is that Ariane does not have a restartable second stage, as restarts are not needed for GTO launches from their near-equatorial site.  Most interplanetary launches require a very specific DLA (the latitude over Earth where the escape firing needs to be to hit the target).  Because the Earth's axis is tilted, and the solar system is not flat, this typically falls anywhere from +- 30 degrees from the equator.

For a rocket that can re-start, this is no big deal.  You launch into a parking orbit, wait until it's at the right latitude, then fire to escape velocity.  But if your second stage cannot re-start, then the orbits you can achieve are limited to those where the latitude is quite close to that of your launch site.  So what Ariane does is fire into an Earth-return orbit (which is accessible) a year early, and then do an flyby at the right latitude.  This flyby adds no energy, but can reach orbits that direct ascent cannot.  This is why Ariane 5 interplanetary missions almost always start with an Earth flyby one year after launch, where most other launchers go straight to their first flyby planet.

I *think* something similar, but less serious, happened on one of the Chinese Mars missions.  The launcher could reach the latitude they needed, but was not qualified for the length of coast required.  So they could not quite aim straight at Mars, and had to do an extra maneuver on the way to reach it.

Will Ariane 6 have a restartable upper stage?

[Alpha_Centauri]

Yes, the new Vinci engine on the Ariane 6 is restartable.

[bolun]

https://twitter.com/esa/status/1508818305414541332

Our Jupiter Icy Moons Explorer @ESA_JUICE has a new launch window!

Liftoff on an @ariane5 from Europe's Spaceport in Kourou during a 5-25 April 2023 window, starting an 8-year interplanetary cruise to the Jupiter system.

Explore #Juice's journey 👉

[leovinus]

The Register gets up close and personal with ESA's JUICE spacecraft

And JUICE? "We will use the last Ariane 5 before the handover to Ariane 6," says Pham. "It will be launched from Kourou on the fifth of April 2023."
Shipment to the launch facility is expected during January 2023

https://www.theregister.com/2022/04/11/esa_juice_visit/?td=rt-3a

[catdlr]

SA JUICE mission's flight plan to Jupiter & its moons

ESA's Jupiter Icy Moons Explorer (JUICE) mission will arrive at the gas giant planet in 2031 and make flybys of its moons Europa, Callisto and Ganymede. See highlights of the flight in this animation.

Credit: ESA

[skizzo]

I wish it reached Jupiter sooner, but alas. Guess we'll have to wait patiently

[Blackstar]

I wish it reached Jupiter sooner, but alas. Guess we'll have to wait patiently

Physics will get its due...

[Welsh Dragon]

Is this the first interplanetary mission to use a lunar gravity assist? I know the STEREO spacecraft used lunar flybys to get into their different solar orbits, but any others that used it as part of a trajectory for a planetary target?

[deadman1204]

Is this the first interplanetary mission to use a lunar gravity assist? I know the STEREO spacecraft used lunar flybys to get into their different solar orbits, but any others that used it as part of a trajectory for a planetary target?

Stereo certainly qualifies as an interplanetary mission, even if it never orbited a different planet.

[LouScheffer]

Is this the first interplanetary mission to use a lunar gravity assist? I know the STEREO spacecraft used lunar flybys to get into their different solar orbits, but any others that used it as part of a trajectory for a planetary target?

After extensive research (typing "lunar gravity assist" into google) I found the Nozomi Mars mission used lunar gravity assists on its way to Mars.  Unfortunately the mission ultimately failed due to electrical problems.

[Rondaz]

#JUICE, the Jupiter Icy Moons Explorer of @esa, has passed a series of electromagnetic compatibility tests in the anechoic chamber.
Next step: solar array deployment and mechanical tests...

https://twitter.com/AirbusSpace/status/1517121741084110848

[Rondaz]

#JUICE is fully integrated and going through extensive testing. A good summary of this important milestone in the preparation for launch next year !

https://twitter.com/ESA_JUICE/status/1528654717038956544

[lrk]

Is this the first interplanetary mission to use a lunar gravity assist? I know the STEREO spacecraft used lunar flybys to get into their different solar orbits, but any others that used it as part of a trajectory for a planetary target?

ISEE-3 / ICE did a series of lunar flybys when it was redirected from its original mission in an L1 halo orbit to flyby Comet 21P/Giacobini-Zinner.

https://solarsystem.nasa.gov/missions/isee-3-ice/in-depth/