Tangentially related, but if you haven't read 17776: What Football Will Look Like in the Future, it's an excellent example of using hypermedia to tell a story (and isn't really about football): https://www.sbnation.com/a/17776-football
Jon Bois is a genius, and this is the main example I return to when tempted to think that hypermedia is just a gimmick. It takes a special type of creativity to not just make it feel "tacked on." Perhaps the light jazz and dated look of the google maps visuals just meld well with the nostalgia evoked by the content of the story. The text alone would probably work as a good scifi short, but the additional material makes it so much more dramatic.
I'd really like to read this, but for some reason the font size keeps increasing, which eventually crashes the page. It happens on Firefox and Chromium, on Linux and Android. Strange.
Has there been any word on the third part of the series? 20020 came out then allegedly 20021 was coming out "soon", but didn't seem to ever materialize.
This is almost certainly due to the fact that a full rotation of the Earth is shorter than a day. As the Earth moves around the sun, it has to turn slightly further than a full rotation to bring the sun back to the same position in the sky. Additionally, Earth's position relative to Jupiter will have changed slightly.
Off the top of my head I'd have to say the planetary ephemerides are more of a factor than the earth's rotation. That much we have pretty down pat, otherwise they'd just announce it's at (Day+23.6h)
I like this theory better than mine. My jaded view of bureaucracy has me thinking that there are additional fees for delaying the launch 24 hours or more.
That mission features a complex trajectory that will use a lot of gravity assist to get to Jupiter. It will actually take eight years to get there, while Juno needed five and the Voyagers only two. Why do recent missions choose to do that? Is that a cost saving measure?
The Voyagers took advantage of a special constellation that doesn't happen often:
"In the 1960s, mission designers at JPL noted that the next occurrence of a once-every-175-year alignment of the outer planets would happen in the late 1970s. A spacecraft could take advantage of this opportunity to fly by Jupiter and use its gravity to bend its trajectory to visit Saturn, and repeat the process to also visit Uranus, Neptune, and Pluto."
If I'm reading the specs correctly the Titan IIIE was a significantly more powerful vehicle than the Ariane 5 while launching a much smaller payload. JUICE also has to be going slow enough to enter orbit without carrying an insane amount of fuel for braking while Voyager just did a flyby.
- "Titan IIIE was a significantly more powerful vehicle than the Ariane 5 while launching a much smaller payload"
Yes, with a fourth stage. (I don't think it's particularly that modern rockets can't integrate such a solid-rocket boost stage, but rather there's no payload that needs this).
- "JUICE also has to be going slow enough to enter orbit without carrying an insane amount of fuel for braking while Voyager just did a flyby"
The flyby speeds are similar; but JUICE takes a time to get to that speed.
It's not really that difficult to capture into Jupiter. Parent's link [3] says it's only 900 m/s for JUICE. Part of the reason is the extremely deep gravity well; and another is that the moons are large enough to give you effective gravity assists, within the orbit of Jupiter.
- "The mass injected into the Earth escape trajectory would be 4800 kg (without launch adapter), with a hyperbolic escape velocity of 3.15 km/s, which increases to 9.5 km/s after the last Earth swing-by"
The Voyagers were launched directly to hyperbolic excess of >10 km/s — comparable to the speed JUICE will reach on its third flyby, of Earth, in 2029.
[1]: "From Earth to Jupiter...JUICE trajectory is designed by ESOC Mission Analysis team. It is the result of an optimization, iterated with
ESA project and Airbus teams, aiming at maximizing the dry mass at launch, keeping the total mass within the launcher capabilities and minimizing the transfer duration, while respecting other mission constraints, like total
radiation dose, minimum Sun distance and maximum eclipse duration..."
JUICE has a launch mass of 5,963 kg while Juno had 3,625 kg and Voyager only 721.9 kg. I guess it may be a limit of the launch vehicle and the mass the spacecrafts have.
Indeed. The same rocket will give a light probe a much higher velocity than a large probe. The launch vehicle for JUICE is the Ariane 5 ECA which can launch 16 tonnes to low earth orbit[1], while the Titan IIIE that launched the Voyagers had a capability of 15.4 tonnes to a (lower) low earth orbit[2]. So the current launch vehicle is a bit more powerful, but not 8 times as much. There are some more powerful (and more expensive) rockets active at the time, but nothing 8 times as powerful as the Titan IIIE.
So NASA has the choice of 1) launching a lighter/smaller probe with less scientific capabilities and endurance, 2) spend $$$ and time developing a much more powerful launch vehicle, or 3) have a few years of patience waiting for JUICE to get to Jupiter on a slower trajectory.
Jupiter has already been visited by multiple probes so sending a small and not very capable probe would not gain us much scientifically. (But this option was taken with the New Horizons probe to Pluto some years ago.) (2) Wouldn't actually be faster and much much much more expensive (see how long the SLS rocket is taking to get done. But mr. Musk is taking this route too with SpaceX's Starship, so this will be an option in the future if all goes well). So that leaves option 3, which NASA has taken. They could probably have opted for an existing more powerful and expensive launcher to shave some years off the transit, but they preferred to wait a bit longer and not spend that money.
The Voyager missions were able to use a rare and convenient alignment of the planets that would slingshot them into deep space. Juno is orbiting Jupiter itself, which is not a hard thing to do in our solar system. JUICE is attempting flybys of several of Jupiter moons, to end up orbiting around Ganymede. This is a much more delicate orbital insertion and has much stricter requirements for the gravity assists on its way there.
The Voyagers, besides their much lower mass, were flyby missions. They could afford to be fast because they didn’t need to slow down for orbit insertion.
NASA’s Europa Clipper, due to launch in Oct 2024 on a Falcon 9, will take 5.5 years to get to Jupiter. The Congress directed NASA to investigate the option to launch it on an SLS, should one be available (it won’t, and it would be ridiculously expensive) – it would have been able to send the probe on a direct ~1.5 year Hohmann transfer to Jupiter without gravity assists, but no other existing launch vehicle could do that.
It's always a tradeoff. For every kilogram of propellant you save on the trip, you get one extra kilogram for the payload.
Also, you may end up bumping into payload limits of the launcher itself, so you can get there, but you'll need to take the scenic route with fewer delta-v tolls.
It's cost saving, but the cost saved is really weight (mass) of the fuel. Using the gravity assists means you can save on fuel and use that mass for the spacecraft and its instruments instead. JUICE masses 2400 kg, where Juno is 1600 and the Voyagers were 700.
The voyagers were launched within very specific window iirc which is why they managed to get to the outer planets so quickly. Also the voyagers only did a flyby so they could afford to go as fast as they want as they didn’t needed to enter orbit.
The length of time to get to Jupiter is pretty much dictated by orbital mechanics. As well as your ability to slow down and actually get into orbit instead of just doing a flyby.
So the longer journey is likely a combination of the launch vehicle, the cruise stage vehicle and how much fuel they want to dedicate into getting into orbit vs the mission since the probe is expected to visit multiple moons it’s likely that they prioritize the fuel for in mission orbit corrections so they are taking a longer and slower approach.
Well, sure, the window was very specific to visit multiple planets, but Jupiter was the first stop. Similar Earth-Jupiter configuration happens every year.
I wonder what the predictions are like. When it finally gets to Jupiter, eight years from now, do we know now where the moons will be ? To what accuracy ?
I believe orbits are chaotic over a timespan of many millions of years (due to weak interactions with multiple other bodies), but accurately predictable over a human lifespan.
I just wonder whether they can say that, on date&time X1 (98% sure to be accurate within E1 hours) we know satellite Z will be X2 thousands of km away (98% sure to be accurate within E2 km).
We designed and built the RIME antenna for this craft. It deploys to 16 meters long and weighs only 1.5 kg! See [1] for some more info.
If you are already in, or are willing to relocate to southern Germany, I'm looking for flexible, multi-domain software engineers to build out our small team here at SpaceTech. Check my profile if you are interested.
I had a brief look at the open positions listed on your website. The only (pure) SWE role that doesn't require a degree in electrical or aerospace engineering seems to be this one:
Yes, that's the role I'm looking to fill at the moment, but it's a small company, and the horizontal coupling is tight. A SWE here will be confronted with many hands-on EE and ME challenges as well (hence the on-site requirement). People who thrive in such environments are a good fit.
Lol, that neutral buoncy, super light material nervousness in the video for the deployment.
Dont touch it, but also do not break it, its machined from electrically carrying carbon fog.
You could argue that the last two sentences were removed in the book version, since the book and film were written simultaneously and the book came out later.
Now that you mention that...The mission will conclude with a crash on Ganymede. I guess from then on a bunch of Tardigrades will be the new population. Surprised they went with this decision.
> Category II missions are flyby or orbiter missions that venture to worlds where there may be some possibility of life, but the chances of contamination are slim. Then there's category III, where the chances of contamination are deemed greater.
> The planetary protection classification for Ganymede is driven by the likelihood that living organisms from Earth, brought to Ganymede by the spacecraft, can make their way down to the ice-ocean interface [...] In turn, this likelihood is deemed so low for Ganymede that it justifies a category II protection level, allowing for the spacecraft to be disposed on Ganymede's surface.
If tardigrades can survive launch, deep space, Jovian orbital conditions for years, and a crash on Ganymede, and then be able to reproduce, maybe they deserve to be there.
Why would there be a bunch of tardigrades sitting on the probe? Unless they walk out to their nearest moss pile and smear it all over I think the chances are remarkably, incredibly slim.
You know they go to every length to sterilize the probe before launch?
Let me remind you of when we sent a probe to Earth, thinking it was sterile, and a few billions of years later our RNA-based lifeforms had spread everywhere.
What, are you saying that it is expected that the probe will actually be inadvertently carrying Tardigrades that might actually survive to the surface? Hidden in little corners of the probe? Why didn't we sterilize it?
That is a bizarre decision. Have we learned nothing from the hundreds or thousands of examples of humans inadvertently messing with ecosystems by introducing new organisms?
