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ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

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Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#21

Post by randallsquared »

twic wrote: post #19
eep_social wrote: post #17

Earlier quoted context omitted.

This was an intentional choice for efficiency and to allow more science at the destination, “the final flyby.. will be 3700 km from Earth in November 2026” [1] Really disappointing that this is top comment tbh. [1] https://sci.esa.int/web/juice/-/58815-juices-journey-to-jupi...

What? How does getting there more slowly mean more science at the destination? And if so, why is Europa Clipper going to get there much faster?

The trade-off for a given rocket is more spacecraft (and instruments to do science with) vs getting there faster.

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#22

Post by beebeepka »

twic wrote: post #19
eep_social wrote: post #17

Earlier quoted context omitted.

This was an intentional choice for efficiency and to allow more science at the destination, “the final flyby.. will be 3700 km from Earth in November 2026” [1] Really disappointing that this is top comment tbh. [1] https://sci.esa.int/web/juice/-/58815-juices-journey-to-jupi...

What? How does getting there more slowly mean more science at the destination? And if so, why is Europa Clipper going to get there much faster?

Maybe slower speed means more time spent in close proximity. Moving things don't exactly stop on their own in space. Or maybe they wanted more stuff on there

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#23

Post by [deleted] »

twic wrote: post #19
eep_social wrote: post #17

Earlier quoted context omitted.

This was an intentional choice for efficiency and to allow more science at the destination, “the final flyby.. will be 3700 km from Earth in November 2026” [1] Really disappointing that this is top comment tbh. [1] https://sci.esa.int/web/juice/-/58815-juices-journey-to-jupi...

What? How does getting there more slowly mean more science at the destination? And if so, why is Europa Clipper going to get there much faster?

[deleted]

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#24

Post by JumpCrisscross »

twic wrote: post #19
eep_social wrote: post #17

Earlier quoted context omitted.

This was an intentional choice for efficiency and to allow more science at the destination, “the final flyby.. will be 3700 km from Earth in November 2026” [1] Really disappointing that this is top comment tbh. [1] https://sci.esa.int/web/juice/-/58815-juices-journey-to-jupi...

What? How does getting there more slowly mean more science at the destination? And if so, why is Europa Clipper going to get there much faster?

> How does getting there more slowly mean more science at the destination?

Mass. Small payload fast. Or large payload slower. (Also flyby vs. orbital insertion. If you’re going fast, you don’t get to loiter.)

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#26

Post by dang »

macintux wrote: post #11

Previous discussions over the last two days: * https://news.ycombinator.com/item?id=35568388 * https://news.ycombinator.com/item?id=35551870

Thanks! Macroexpanded:

Juice launch to Jupiter – Live [video] - https://news.ycombinator.com/item?id=35568388 - April 2023 (29 comments)

ESA – Jupiter Icy Moons Explorer: Live Launch - https://news.ycombinator.com/item?id=35551870 - April 2023 (70 comments)

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#27

Post by sfifs »

867-5309 wrote: post #8
swarnie wrote: post #7

Earlier quoted context omitted.

Nasa are supposedly working on it but that hasn't meant much since the 60s. Maybe inequality will breed a billionaire with a hard-on for nuclear propulsion?

it's a shame nuclear detonations in space are banned (for obvious reasons)

What is actually the obvious reason to ban nuclear detonation in space (Not planetside) other than proliferation & security concerns?

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#28

Post by z3t4 »

dmix wrote: post #2

Has there ever been a major unmanned project like this that blew up on takeoff/failed in orbit in recent years? I was listening to the huge list of gear they put on this thing by a project lead and the years of hard work by scientists and it would have been heartbreaking if it failed catastrophically. https://youtu.be/Ljh2BKdjpmE

For some missions I think there's an exact copy left on earth for easier debugging/testing

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#29

Post by TaylorAlexander »

drewg123 wrote: post #6

Wow, 11 years to Jupiter. I wish we had better propulsion systems. EDIT: This wasn't meant to disrespect the ESA mission. I'm just sad that the outer planets are years away, rather than the hours, days, weeks or months of science fiction.

I think the very big rocket planned for launch in a few days will, if successful, help a lot with this. Chemical rockets aren't the best but if we can launch much larger payloads, we can design deep space rockets that consume a lot more fuel to get there faster. Imagine a multi stage rocket which is assembled in orbit from multiple Starship launches, and then blasts off to the outer worlds.

Re: ESA’s Juice lifts off on quest to discover secrets of Jupiter’s icy moons

#30

Post by overthrow »

sfifs wrote: post #27
867-5309 wrote: post #8

Earlier quoted context omitted.

it's a shame nuclear detonations in space are banned (for obvious reasons)

What is actually the obvious reason to ban nuclear detonation in space (Not planetside) other than proliferation & security concerns?

Your question got me curious so I did some googling.

The current international agreement is (best I can tell) UNITED NATlONS: GENERAL ASSEMBLY RESOLUTION AND PRINCIPLES RELEVANT TO THE USE OF NUCLEAR POWER SOURCES IN OUTER SPACE [December 14, 1992]

https://csps.aerospace.org/sites/default/files/2021-08/Princ...

I only skimmed, but it says this:

> In order to mlnlmlze the quantity of radioactLve materzal in space and the risks Involved, the use of nuclear power sources in outer space shall be restrxcted to those space mLssions which cannot be operated by non-nuclear energy sources in a reasonable way.

and

> (a) Nuclear reactors may be operated: (i) On interplanetary missions; (ii) In sufficiently high orbits as defined in paragraph 2 (h); (iii) In low-Earth orbits if they are stored in sufficiently high orbits after the operational part of their mission.

So it seems like nuclear reactors are restricted, but not completely banned. For an interplanetary mission to Jupiter, it would probably be allowed.

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