https://www.telegraph.co.uk/news/2023/03/18/jupiter-juice-mission-icy-moons-explorer-space-solar-system/

I see potential for disaster here.

--
Davey.

Davey <davey@example.invalid> wrote:
> https://www.telegraph.co.uk/news/2023/03/18/jupiter-juice-mission-icy-moons-explorer-space-solar-system/
>
> I see potential for disaster here.
>

The one-second window that could make or break mission to Jupiter
Experts working on the Juice project reveal the short timeframe its craft
has to get into orbit – or it could go wrong
By
Sarah Knapton,
SCIENCE EDITOR
18 March 2023 • 4:10pm
Jupiter Icy Moons Explorer Juice space Solar System mission European Space
Agency
The Jupiter Icy Moons Explorer (Juice) mission will look for signs of
extra-terrestrial life on the Solar System’s largest planet CREDIT:
Reuters/Nasa/ESA/AOES/Handout
All space missions require split-second precision, but Europe’s ambitious
journey to Jupiter has a tighter schedule than usual.

The Juice mission, which is looking for signs of extra-terrestrial life on
the Jovian moons Europa, Ganymede and Callisto, has a miniscule one-second
window to get into orbit when it launches in April.

The European Space Agency orbiter needs to harness the gravitational forces
of Earth, Mars and Venus to slingshot it towards its target, and the
planets must align perfectly, or the spacecraft could end up way off
course.

In comparison, when the Artemis I mission launched to the Moon last
November, it had a leisurely two hours to get off the ground.

Juice, which stands for Jupiter Icy Moons Explorer, is due for launch on
April 13 from the European spaceport in Kourou, French Guiana, onboard an
Ariane 5 rocket.

1903
Justin Byrne, the head of science and Earth exploration missions at Airbus
Defence and Space UK, which built the spacecraft, said: “The rocket is not
powerful enough to send the mission straight to Jupiter, so we have to use
energy from elsewhere, so we steal it from the planets.

“Those planets are only going to line up twice a year, in April and at the
end of the summer. But when that lines up with the rotation of the Earth,
we only have a one-second launch window each day where the physics of the
whole universe lines up, so it’s quite a tricky thing.”

Jupiter lies around 391 million miles from Earth, on average, and it will
take eight years for the spacecraft to reach its destination.

The system is believed to be one of the best places to look for
extraterrestrial life because its ice moons are believed to contain vast
icy oceans.

Once there, the orbiter will fly 125 miles above Callisto, observing the
oldest moon in the Solar System, before making two flybys of Europa.

Beneath the ice crust of Europa is thought to lie a huge ocean of liquid
water or slushy ice, that contains twice as much water as Earth's oceans
combined.

Jupiter Icy Moons Explorer Juice space Solar System mission European Space
Agency
Engineers preparing the spacecraft for the Juice mission CREDIT: Charly
Triballeau/AFP via Getty Images
This vast and deep body of water is widely considered to be the most
promising place to look for life in the Solar System, and instruments on
board Juice will be hunting for biosignatures like methane, which could
hint that life is thriving beneath the icy surface.

On Earth, extremophile lifeforms have been found thriving near subterranean
volcanoes and deep-sea vents, raising hopes that it could also exist in the
underground oceans of Jupiter's moons.

After Europa, the mission will spend eight months circling Ganymede, the
first time a spacecraft has orbited any moon other than our own.

Ganymede is the only moon in the Solar System known to generate its own
magnetic field, so scientists are keen to work out how that is being
achieved.

Just like Europa and Callisto, it harbours a hidden ocean, so researchers
will also be looking for signs of habitability.

“Ganymede is the one that everyone is really interested in, because it has
a magnetic field and it must have a molten core, but the other two have
liquid under the surfaces an there is potentially life on all three,” added
Mr Byrne.

“There are definitely signatures that we may be able to see. When the data
starts coming back it will be really intensive, with bang, bang, bang new
results. We will be swamped with new information.”

Jupiter Icy Moons Explorer Juice space Solar System mission European Space
Agency
An artist’s impression of how the Juice spacecraft will orbit Jupiter’s
moons CREDIT: Nasa/ESA Hubble Space Telescope
The magnetic field surrounding Ganymede has proved challenging to
spacecraft engineers who had to construct a lead-lined centre to protect
the electronics.

Mr Byrne added: “It has a massive magnetic field, 10,000 times stronger
than the Earth, so it’s really the worst place to be putting a spacecraft.
If you wanted to kill it, this is what you'd do.”

In all, Juice will make 35 fly-bys of the three moons, before finally
carrying out a controlled crash into Ganymede. The team also wants to learn
more about Jupiter, in particular why its famous Red Spot is shrinking.

Experts believe that the one-second window is achievable, but are worried
that weather could scupper the launch. Too much wind or storms could cause
delays and would mean waiting for the next time the planets align.

If the first window is missed there are several more opportunities in
April, but after that the team would need to wait until August.

Tim

--
Please don't feed the trolls

Well, most missions tend to use gravity assist to get them where they are
going. Its not new. I would have said that this is a false quote, in that
course corrections en route are nearly always required as the Solar system
is not clockwork and indeed the strength of the solar wind over the years
will vary and hence corrections are needed. The current Nasa probe Juno had
several course corrections, and even now with such large solar panels is
purtibated by it as it orbits.

It may be that the ability to have enough fuel for a full mission might be
compromised if its off by more than the quoted time, but without more info,
its hard to say. Nobody would fund a project if it was expected to revolve
around such a small error.
If they needed a bigger rocket then I'm sure these exist. Also you would
expect the spacecraft cruise stage to have a surplus of fuel.
Brian

--

--:
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The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Tim+" <tim.downie@gmail.com> wrote in message
news:1858495154.700947040.833799.tim.downie-gmail.com@news.individual.net...
> Davey <davey@example.invalid> wrote:
>> https://www.telegraph.co.uk/news/2023/03/18/jupiter-juice-mission-icy-moons-explorer-space-solar-system/
>>
>> I see potential for disaster here.
>>
>
> The one-second window that could make or break mission to Jupiter
> Experts working on the Juice project reveal the short timeframe its craft
> has to get into orbit - or it could go wrong
> By
> Sarah Knapton,
> SCIENCE EDITOR
> 18 March 2023 . 4:10pm
> Jupiter Icy Moons Explorer Juice space Solar System mission European Space
> Agency
> The Jupiter Icy Moons Explorer (Juice) mission will look for signs of
> extra-terrestrial life on the Solar System's largest planet CREDIT:
> Reuters/Nasa/ESA/AOES/Handout
> All space missions require split-second precision, but Europe's ambitious
> journey to Jupiter has a tighter schedule than usual.
>
> The Juice mission, which is looking for signs of extra-terrestrial life on
> the Jovian moons Europa, Ganymede and Callisto, has a miniscule one-second
> window to get into orbit when it launches in April.
>
> The European Space Agency orbiter needs to harness the gravitational
> forces
> of Earth, Mars and Venus to slingshot it towards its target, and the
> planets must align perfectly, or the spacecraft could end up way off
> course.
>
> In comparison, when the Artemis I mission launched to the Moon last
> November, it had a leisurely two hours to get off the ground.
>
> Juice, which stands for Jupiter Icy Moons Explorer, is due for launch on
> April 13 from the European spaceport in Kourou, French Guiana, onboard an
> Ariane 5 rocket.
>
> 1903
> Justin Byrne, the head of science and Earth exploration missions at Airbus
> Defence and Space UK, which built the spacecraft, said: "The rocket is not
> powerful enough to send the mission straight to Jupiter, so we have to use
> energy from elsewhere, so we steal it from the planets.
>
> "Those planets are only going to line up twice a year, in April and at the
> end of the summer. But when that lines up with the rotation of the Earth,
> we only have a one-second launch window each day where the physics of the
> whole universe lines up, so it's quite a tricky thing."
>
> Jupiter lies around 391 million miles from Earth, on average, and it will
> take eight years for the spacecraft to reach its destination.
>
> The system is believed to be one of the best places to look for
> extraterrestrial life because its ice moons are believed to contain vast
> icy oceans.
>
> Once there, the orbiter will fly 125 miles above Callisto, observing the
> oldest moon in the Solar System, before making two flybys of Europa.
>
> Beneath the ice crust of Europa is thought to lie a huge ocean of liquid
> water or slushy ice, that contains twice as much water as Earth's oceans
> combined.
>
> Jupiter Icy Moons Explorer Juice space Solar System mission European Space
> Agency
> Engineers preparing the spacecraft for the Juice mission CREDIT: Charly
> Triballeau/AFP via Getty Images
> This vast and deep body of water is widely considered to be the most
> promising place to look for life in the Solar System, and instruments on
> board Juice will be hunting for biosignatures like methane, which could
> hint that life is thriving beneath the icy surface.
>
> On Earth, extremophile lifeforms have been found thriving near
> subterranean
> volcanoes and deep-sea vents, raising hopes that it could also exist in
> the
> underground oceans of Jupiter's moons.
>
> After Europa, the mission will spend eight months circling Ganymede, the
> first time a spacecraft has orbited any moon other than our own.
>
> Ganymede is the only moon in the Solar System known to generate its own
> magnetic field, so scientists are keen to work out how that is being
> achieved.
>
> Just like Europa and Callisto, it harbours a hidden ocean, so researchers
> will also be looking for signs of habitability.
>
> "Ganymede is the one that everyone is really interested in, because it has
> a magnetic field and it must have a molten core, but the other two have
> liquid under the surfaces an there is potentially life on all three,"
> added
> Mr Byrne.
>
> "There are definitely signatures that we may be able to see. When the data
> starts coming back it will be really intensive, with bang, bang, bang new
> results. We will be swamped with new information."
>
> Jupiter Icy Moons Explorer Juice space Solar System mission European Space
> Agency
> An artist's impression of how the Juice spacecraft will orbit Jupiter's
> moons CREDIT: Nasa/ESA Hubble Space Telescope
> The magnetic field surrounding Ganymede has proved challenging to
> spacecraft engineers who had to construct a lead-lined centre to protect
> the electronics.
>
> Mr Byrne added: "It has a massive magnetic field, 10,000 times stronger
> than the Earth, so it's really the worst place to be putting a spacecraft.
> If you wanted to kill it, this is what you'd do."
>
> In all, Juice will make 35 fly-bys of the three moons, before finally
> carrying out a controlled crash into Ganymede. The team also wants to
> learn
> more about Jupiter, in particular why its famous Red Spot is shrinking.
>
> Experts believe that the one-second window is achievable, but are worried
> that weather could scupper the launch. Too much wind or storms could cause
> delays and would mean waiting for the next time the planets align.
>
> If the first window is missed there are several more opportunities in
> April, but after that the team would need to wait until August.
>
> Tim
>
> --
> Please don't feed the trolls

On Monday, 20 March 2023 at 11:33:37 UTC, Brian Gaff wrote:
> Well, most missions tend to use gravity assist to get them where they are
> going. Its not new. I would have said that this is a false quote,

Otr the journalist got the wrong end of the stick which happens quite a lot.

I doubt NASA would risk the cost of such a project if it relied on a 1 second accuracy for success or failure.

whisky-dave wrote:

> Otr the journalist got the wrong end of the stick which happens quite a lot.

I thought it was a bit odd that the story started by saying "all space
travel depends on split second timing" and then went on to say that this
mission "had a 1 second window", as though that was tighter than split
second ...

The question is why? I mean, unless it was subsidised as a show case, no
education authority would go anywhere near that sort of cost.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Andy Burns" <usenet@andyburns.uk> wrote in message
news:k7r48iFjcuU1@mid.individual.net...
> whisky-dave wrote:
>
>> Otr the journalist got the wrong end of the stick which happens quite a
>> lot.
>
> I thought it was a bit odd that the story started by saying "all space
> travel depends on split second timing" and then went on to say that this
> mission "had a 1 second window", as though that was tighter than split
> second ...

On 3/20/2023 8:23 AM, whisky-dave wrote:
> On Monday, 20 March 2023 at 11:33:37 UTC, Brian Gaff wrote:
>> Well, most missions tend to use gravity assist to get them where they are
>> going. Its not new. I would have said that this is a false quote,
>
>
> Otr the journalist got the wrong end of the stick which happens quite a lot.
>
> I doubt NASA would risk the cost of such a project if it relied on a 1 second accuracy for success or failure.

That is the width of the launch window.

For a couple days in a row, at a certain time of the
day, the window for multiple slingshots will open. With
minimal fuel burns needed, to tune the slingshots.

If you miss the window, then the satellite does not have
the fuel, to correct for the error.

On the James Webb mission, Ariane 5 demonstrated what a
precise puppy it could be. So I can see why they're doing this.
On James Webb, Ariane had to put the vehicle in just the right
orbital path, and then it took very little fuel by Webb, to complete
the trip to Lagrange.

*******

Now, this is a different kind of mission, and they provided
the satellite with a piss-weak engine. The ion engine on
this thing, ran for a total of 5.9 years. And you can see
the spiffy lane changes it did. But that adds a lot of
weight to the satellite, to pack enough Xenon to run an
engine for 5.9 years. The launch window for a satellite
with a piss-weak engine like this, could be a lot wider.
If you leave the engine running long enough, you can make
quite large corrections.

https://en.wikipedia.org/wiki/Dawn_%28spacecraft%29

Paul

On Sun, 19 Mar 2023 18:57:20 +0000
Davey <davey@example.invalid> wrote:

> https://www.telegraph.co.uk/news/2023/03/18/jupiter-juice-mission-icy-moons-explorer-space-solar-system/
>
> I see potential for disaster here.
>

It launches today at 12:30, streamed live on iPlayer. If it misses
today's 1 second window, then it tries again tomorrow, and the day
after, etc.
--
Davey.

On 19/03/2023 in message <tv7lug$2vsnv$8@dont-email.me> Davey wrote:

>https://www.telegraph.co.uk/news/2023/03/18/jupiter-juice-mission-icy-moons-explorer-space-solar-system/
>
>I see potential for disaster here.

ALL THESE WORLDS ARE YOURS – EXCEPT EUROPA.
ATTEMPT NO LANDING THERE.

--
Jeff Gaines Dorset UK
George Washington was a British subject until well after his 40th birthday.
(Margaret Thatcher, speech at the White House 17 December 1979)

On 13/04/2023 09:39, Jeff Gaines wrote:
> On 19/03/2023 in message <tv7lug$2vsnv$8@dont-email.me> Davey wrote:
>
>> https://www.telegraph.co.uk/news/2023/03/18/jupiter-juice-mission-icy-moons-explorer-space-solar-system/
>>
>> I see potential for disaster here.
>
> ALL THESE WORLDS ARE YOURS – EXCEPT EUROPA.
> ATTEMPT NO LANDING THERE.
>
It's funny, I was looking at the viewing figures (under 200k) and
remembering another Clarke quote, in response to the comment "Earth is
decadent"

"Oh no, we're not decadent. But our children will be"

(Ghost from the Grand Banks, and I'm quoting from memory).

Andy

Davey wrote:

> It launches today at 12:30, streamed live on iPlayer. If it misses
> today's 1 second window, then it tries again tomorrow, and the day
> after, etc.

Seems it got away on day 2. Can't figure out how it only has a 1 second
window, yet this 1 second window repeats every day for a fortnight?
Surely the rest of the solar system just ploughs on, regardless of
earth's rotational speed?

On 14/04/2023 18:16, Andy Burns wrote:
> Davey wrote:
>
>> It launches today at 12:30, streamed live on iPlayer. If it misses
>> today's 1 second window, then it tries again tomorrow, and the day
>> after, etc.
>
> Seems it got away on day 2.  Can't figure out how it only has a 1 second
> window, yet this 1 second window repeats every day for a fortnight?
> Surely the rest of the solar system just ploughs on, regardless of
> earth's rotational speed?
>

it's a /different/ 1 second?
--
Robin
reply-to address is (intended to be) valid

On 14 Apr 2023 at 18:16:52 BST, "Andy Burns" <usenet@andyburns.uk> wrote:

> Davey wrote:
>
>> It launches today at 12:30, streamed live on iPlayer. If it misses
>> today's 1 second window, then it tries again tomorrow, and the day
>> after, etc.
>
> Seems it got away on day 2. Can't figure out how it only has a 1 second
> window, yet this 1 second window repeats every day for a fortnight?
> Surely the rest of the solar system just ploughs on, regardless of
> earth's rotational speed?

One second seems a bit tight, but it's prolly to do with the number of
slingshots they need to do to reach Jupiter. It's what happens when you use a
sixpenny rocket instead of a shilling one.

--
"Please stop telling us what you feel. Please stop telling us what your intuition is. Your intuitive feelings are of no interest whatsoever, and nor are mine. I don't give a bugger what you feel, or what I feel. I want to know what the evidence shows." -- Richard Dawkins

On 14/04/2023 22:04, Tim Streater wrote:
> On 14 Apr 2023 at 18:16:52 BST, "Andy Burns" <usenet@andyburns.uk> wrote:
>
>> Davey wrote:
>>
>>> It launches today at 12:30, streamed live on iPlayer. If it misses
>>> today's 1 second window, then it tries again tomorrow, and the day
>>> after, etc.
>>
>> Seems it got away on day 2. Can't figure out how it only has a 1 second
>> window, yet this 1 second window repeats every day for a fortnight?
>> Surely the rest of the solar system just ploughs on, regardless of
>> earth's rotational speed?
>
> One second seems a bit tight, but it's prolly to do with the number of
> slingshots they need to do to reach Jupiter. It's what happens when you use a
> sixpenny rocket instead of a shilling one.
>

I v much doubt they are 1 second windows in the sense that the mission
fails if launched outside them. I could never cope with the maths of
mission design but I suspect it's more that the fuel required for the
mission /to/ Jupiter increases rapidly if an optimum launch time is
missed and they want to keep as much fuel as possible for manoeuvres
after it gets there.
--
Robin
reply-to address is (intended to be) valid

On 14 Apr 2023 21:04:57 GMT
Tim Streater <tim@streater.me.uk> wrote:

> On 14 Apr 2023 at 18:16:52 BST, "Andy Burns" <usenet@andyburns.uk>
> wrote:
>
> > Davey wrote:
> >
> >> It launches today at 12:30, streamed live on iPlayer. If it misses
> >> today's 1 second window, then it tries again tomorrow, and the day
> >> after, etc.
> >
> > Seems it got away on day 2. Can't figure out how it only has a 1
> > second window, yet this 1 second window repeats every day for a
> > fortnight? Surely the rest of the solar system just ploughs on,
> > regardless of earth's rotational speed?
>
> One second seems a bit tight, but it's prolly to do with the number of
> slingshots they need to do to reach Jupiter. It's what happens when
> you use a sixpenny rocket instead of a shilling one.
>

Whatever the detail of the 1 second window, at least the Juice project
managed to squeeze its way through the window yesterday (Sorry!).

--
Davey.