Discussion
Loading...

Discussion

  • About
  • Code of conduct
  • Privacy
  • Users
  • Instances
  • About Bonfire
AkaSci 🛰️
@AkaSci@fosstodon.org  ·  activity timestamp 2 months ago

According to ESA, "the root cause was traced to a software timing bug. The function that switches the signal amplifier on and off uses an internal timer, which increments and restarts from zero every 16 months. If the function happens to be using the timer at the exact moment it restarts, the amp remains switched off."

Sounds like an unsigned 32-bit counter that counts every 10 ms and rolls over in 497.1 days (~16 months) and some faulty logic like t1 > t0 + delta?

https://www.esa.int/Enabling_Support/Operations/Juice_team_resolves_anomaly_on_approach_to_Venus
2/n

ESA’s Jupiter Icy Moons Explorer, Juice, being installed on a ‘multi-purpose trolley’ in the Rosetta clean room at the European Space Research and Technology Centre, ESTEC in the Netherlands on 30 April.
ESA’s Jupiter Icy Moons Explorer, Juice, being installed on a ‘multi-purpose trolley’ in the Rosetta clean room at the European Space Research and Technology Centre, ESTEC in the Netherlands on 30 April.
ESA’s Jupiter Icy Moons Explorer, Juice, being installed on a ‘multi-purpose trolley’ in the Rosetta clean room at the European Space Research and Technology Centre, ESTEC in the Netherlands on 30 April.
  • Copy link
  • Flag this post
  • Block
AkaSci 🛰️
@AkaSci@fosstodon.org replied  ·  activity timestamp 2 months ago

Note that the 32-bit counter ticking every 10 ms rolls over in 2^32/100/3600/24 = 497.1 days = ~16 months.

Juice was launched on 14 Apr 2023. The counter was probably reset in Jan 2023; this must be the 2nd rollover.

The #ESA Jupiter Icy Moons Explorer (Juice) is on its way to orbit and study 3 icy moons of Jupiter: Ganymede, Callisto, and Europa. ETA: Jul 2031.

Check out these threads for some more info -
https://fosstodon.org/@AkaSci/110196855592852020
https://fosstodon.org/@AkaSci/112984391598098464
https://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Explorer
3/n

Graphic showing timeline of events for the JUICE mission to Jupiter and its icy moons.
Graphic showing timeline of events for the JUICE mission to Jupiter and its icy moons.
Graphic showing timeline of events for the JUICE mission to Jupiter and its icy moons.
  • Copy link
  • Flag this comment
  • Block
AkaSci 🛰️
@AkaSci@fosstodon.org replied  ·  activity timestamp 2 months ago

FYI - during this Venus flyby, Juice is using its steerable medium-gain antenna for communication with earth. The larger high-gain antenna will remain pointed towards the Sun to act as a heat shield.

This also implies that the imaging systems of Juice will not take any pictures during this flyby.

https://www.esa.int/Enabling_Support/Operations/Juice_team_resolves_anomaly_on_approach_to_Venus4/n
#ESA#Juice
4/n

1. Still from video of medium-gain antenna installation
https://www.esa.int/esatv/Videos/2022/10/Juice_mission_clips/Medium_Gain_Antenna_deployment

2. Pic showing both antennas.
https://www.esa.int/ESA_Multimedia/Images/2021/06/Juice_antenna
1. Still from video of medium-gain antenna installation https://www.esa.int/esatv/Videos/2022/10/Juice_mission_clips/Medium_Gain_Antenna_deployment 2. Pic showing both antennas. https://www.esa.int/ESA_Multimedia/Images/2021/06/Juice_antenna
1. Still from video of medium-gain antenna installation https://www.esa.int/esatv/Videos/2022/10/Juice_mission_clips/Medium_Gain_Antenna_deployment 2. Pic showing both antennas. https://www.esa.int/ESA_Multimedia/Images/2021/06/Juice_antenna
  • Copy link
  • Flag this comment
  • Block
AkaSci 🛰️
@AkaSci@fosstodon.org replied  ·  activity timestamp last month

The ESA Juice (Jupiter Icy Moons Explorer) spacecraft gravity-assist flyby of Venus was successfully executed at 05:28 UTC earlier this morning. No pics are expected.

Juice’s next planetary flybys will be at Earth in Sept 2026 and Jan 2029.

Congratulations to the team.
👏
https://bsky.app/profile/operations.esa.int/post/3lxrcin7z522v
5/n
#ESA#ESAJuice

1. Bsky post by ESA Operations ‪@operations.esa.int‬
Flyby success! ESA's Juice spacecraft passed Venus at 07:28 CEST on 31 August.

This photo shows our deep-space antenna in Spain in communication with Juice during the flyby.

Juice’s current location, Venus, and its destination, Jupiter, are both visible in the sky ❤️

2. Bsky post by ESA Operations ‪@operations.esa.int‬
Congratulations to the Juice operations team at ESA mission control in Germany for the smooth gravity assist that helped Juice pick up the speed required to get to Jupiter. 👏

Juice’s next planetary flyby will be at Earth in September 2026.

On, on, onwards, up the gravity well!
1. Bsky post by ESA Operations ‪@operations.esa.int‬ Flyby success! ESA's Juice spacecraft passed Venus at 07:28 CEST on 31 August. This photo shows our deep-space antenna in Spain in communication with Juice during the flyby. Juice’s current location, Venus, and its destination, Jupiter, are both visible in the sky ❤️ 2. Bsky post by ESA Operations ‪@operations.esa.int‬ Congratulations to the Juice operations team at ESA mission control in Germany for the smooth gravity assist that helped Juice pick up the speed required to get to Jupiter. 👏 Juice’s next planetary flyby will be at Earth in September 2026. On, on, onwards, up the gravity well!
1. Bsky post by ESA Operations ‪@operations.esa.int‬ Flyby success! ESA's Juice spacecraft passed Venus at 07:28 CEST on 31 August. This photo shows our deep-space antenna in Spain in communication with Juice during the flyby. Juice’s current location, Venus, and its destination, Jupiter, are both visible in the sky ❤️ 2. Bsky post by ESA Operations ‪@operations.esa.int‬ Congratulations to the Juice operations team at ESA mission control in Germany for the smooth gravity assist that helped Juice pick up the speed required to get to Jupiter. 👏 Juice’s next planetary flyby will be at Earth in September 2026. On, on, onwards, up the gravity well!
  • Copy link
  • Flag this comment
  • Block
Log in

bonfire.cafe

A space for Bonfire maintainers and contributors to communicate

bonfire.cafe: About · Code of conduct · Privacy · Users · Instances
Bonfire social · 1.0.0-rc.3.13 no JS en
Automatic federation enabled
  • Explore
  • About
  • Members
  • Code of Conduct
Home
Login