NASASpaceFlight.com Forum
Robotic Spacecraft (Astronomy, Planetary, Earth, Solar/Heliophysics) => Space Science Coverage => Topic started by: skizzo on 06/12/2021 04:32 pm
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ESA’s large-class science missions for the timeframe 2035-2050 will focus on moons of the giant Solar System planets, temperate exoplanets or the galactic ecosystem, and new physical probes of the early Universe.
“The selection of the Voyage 2050 themes is a pivotal moment for ESA’s science programme, and for the future generation of space scientists and engineers,” says Günther Hasinger, ESA Director of Science.
“Now that Cosmic Vision has taken shape with a clear plan for our missions until the mid 2030s, we must start planning the science and the technology we’ll need for the missions we want to launch decades from now, and that is why we are defining the top-level science themes of the Voyage 2050 plan today.”
A call for ideas for Voyage 2050 was issued in March 2019, generating close to 100 diverse and ambitious ideas, which were subsequently distilled into a number of science themes. Topical teams, comprising many early career through early scientists from a broad range of space science expertise areas, carried out an initial assessment of the themes and reported their findings to a senior science committee. This committee was tasked by the Director to recommend not only science themes for the next three large-class missions following the Jupiter Icy Moons Explorer, Athena and LISA, but also to identify potential themes for future medium-class missions, and recommend areas for long-term technology development beyond the scope of Voyage 2050. The science themes were selected by ESA’s Science Programme Committee at a meeting on 10 June 2021. The specific missions themselves will be selected in due course when ESA issues individual calls for mission proposals.
“The Voyage 2050 plan is the result of a significant effort of the science community, of the topical teams, and of the senior committee who contributed to such a lively and productive debate to arrive at this outstanding proposal,” says Fabio Favata, Head of the Strategy, Planning and Coordination Office. “Voyage 2050 is setting sail, and will keep Europe at the forefront of space science for decades to come.”
Mission themes
The top three priorities for future large-class missions are identified as:
Moons of the giant planets
Investigating the habitability potential of worlds in our Solar System is essential for understanding the emergence of life, and is of particular relevance in the search for Earth-like planets beyond our Solar System. Building on the legacy of the international Cassini-Huygens mission to Saturn and ESA’s upcoming Jupiter Icy Moons Explorer, a future outer Solar System mission with advanced instrumentation would focus on the study of the connection of ocean-bearing moon interiors with their near-surface environments, also attempting to search for possible biosignatures. The mission profile might include an in-situ unit, such as a lander or a drone.
From temperate exoplanets to the Milky Way
Our Milky Way contains hundreds of millions of stars and planets along with dark matter and interstellar matter but our understanding of this ecosystem, a stepping-stone for understanding the workings of galaxies in general, is limited. A detailed understanding of our Galaxy’s formation history, including its “hidden regions”, is key to our understanding of galaxies in general. At the same time, the characterisation of temperate exoplanets in the mid-infrared, through a first spectrum of direct thermal emission from exoplanet atmospheres to better understand if they harbour truly habitable surface conditions, would be an outstanding breakthrough.
While the exoplanet topic is considered to have a high scientific priority, solidifying Europe’s leadership in the field of exoplanets beyond the lifetime of Cheops, Plato and Ariel, an informed choice between a study of the less accessible regions of our Galaxy and the study of temperate exoplanets needs to be made involving the interested scientific community to assess the likelihood of success and feasibility of missions within the large mission boundary conditions.
New physical probes of the early Universe
How did the Universe begin? How did the first cosmic structures and black holes form and evolve? These are outstanding questions in fundamental physics and astrophysics that could be addressed by missions exploiting new physical probes, such as detecting gravitational waves with high precision or in a new spectral window, or by high-precision spectroscopy of the cosmic microwave background – the relic radiation left over from the Big Bang. This theme follows the breakthrough science from Planckand the expected scientific return from LISA, and would leverage advances made in instrumentation to open a huge discovery space. Additional study and interaction with the scientific community will be needed to converge on a mission addressing this theme.
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A bright future for medium-class missions
Medium-class missions are a key component of ESA’s Science Programme and enable Europe to conduct stand-alone missions that answer important scientific questions with relatively modest cost envelopes. Venus Express, Mars Express and the upcoming Euclid, Plato, and Ariel missions are examples of ESA’s past, current and future medium-class missions.
The Voyage 2050 committee identified themes across all domains of space science, from solar system science to astrometry, astronomy, astrophysics and fundamental physics, showing that breakthrough science can continue to be achieved within the medium-class mission cost-cap. Medium missions will continue to be selected through future open 'Calls for missions'.
Medium-class missions also provide a route for Europe’s participation in ambitious missions with international partners. This could include contributing to NASA’s next-generation astronomy observatories – much like the current James Webb Space Telescope partnership – or to future outer Solar System missions, for example.
Technology development for the next century
In discussing the possible large mission themes, the Voyage 2050 committee identified several areas where the science return would be outstanding but the technology would not reach maturity by the timeframe of Voyage 2050. The committee therefore recommended investment in a number of technologies so that these themes could become a reality in the second half of this century. This covers topics such as cold atom interferometry for atomic clock development, enabling X-ray interferometry for the future study of compact objects like black holes, and developments for future planetary missions: in particular better power sources to enable the exploration of the outer Solar System, and advances in collecting and storing cryogenic samples of cometary ices for a future sample return mission.
Why plan now?
Long-term planning is essential to ensure success in future space science endeavours. Cosmic Vision 2015-2025 is the current planning cycle for ESA’s space science missions. It was created in 2005, and is predated by the Horizon 2000 plan prepared in 1984, and Horizon 2000 Plus, which was drawn up in 1994–95. To put these plans in context, comet-chasing Rosetta and its lander Philae, and ‘time-machine’ Planck and astronomy observatory Herschel all began life in Horizon 2000. Gaia, Lisa Pathfinder and BepiColombo were all conceived in Horizon 2000 Plus. Cosmic Vision missions are just being realised today: the exoplanet mission Cheops launched in 2019, and Solar Orbiter in 2020. Jupiter Icy Moons Explorer, Athena and LISA are all large-class missions in the Cosmic Vision plan. Large missions in particular require significant technology development, which often takes a number of years. Therefore, it is important to start defining the necessary technology well in advance, to ensure that ESA’s Science Programme can secure a world-class, forward-looking series of missions for future generations.
Thus, it is time to look beyond Cosmic Vision, to the period 2035-2050 – and even beyond – with the Voyage 2050 plan.
VOYAGE 2050
LONG-TERM PLANNING OF THE ESA SCIENCE PROGRAMME
WHITE PAPERS
https://www.cosmos.esa.int/web/voyage-2050/white-papers (https://www.cosmos.esa.int/web/voyage-2050/white-papers)
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Just mentioned this in the 2020 decadal thread and realised there hasn't been much discussion on the candidate missions being developed for these opportunities.
Anyway, this is the full Voyage 2050 report for those interested;
https://www.cosmos.esa.int/documents/1866264/1866292/Voyage2050-Senior-Committee-report-public.pdf/e2b2631e-5348-5d2d-60c1-437225981b6b?t=1623427287109
While this has technically only selected the science themes for the next three large missions, the stated recommendations heavily hint towards particular mission architectures. Typically for strategic ESA missions a science community will rally round one or two concepts for their field, so while the missions haven't been chosen yet, there'll end up being only a handful of viable options at most to downselect for these opportunities. From the wording we can already have a decent guess at which missions will go ahead.
Moons of the giant planets
2.1.1 Recommendation
The Voyage 2050 Senior Committee recommends that ESA pursue efforts leading to exploration of the outer Solar System by considering a “Moons of the Giant Planets” theme that will continue and extend the characterisation era in Voyage 2050. An ESA mission to the moons of the giant planets will build on the agency’s expertise for exploration of the outer Solar System after Cassini-Huygens and (the soon to fly) JUICE. One possible profile for an ESA-led Large mission would involve obtaining a global perspective on these moons via a spacecraft, or a possible dual-spacecraft mission in a mother-daughter configuration, performing multiple flybys and/or orbit insertions. Alternatively, a mission profile might include a significant in situ element to characterise the local surface and subsurface environments, for example via a lander, drones or sample return
The JUICE mission at Ganymede and Europa Clipper at Europa will address some of these challenges. In Voyage 2050, a dedicated mission to other icy moons, especially Titan or Enceladus in the Saturnian system or a new mission in the Jovian system focused on key aspects of the Europa and/or Io science will be critical for further progress.
A mission to the moons of the gas giants will likely be developed first, leveraging the fact many of the engineers/scientists on the JUICE team will be available shortly due to that mission's launch. This is probably going to be the most competitive selection because it's target rich, but we can guess given the report's emphasis on the habitability of ocean worlds that means Enceladus, Titan and Europa are the most likely targets.
One of these concepts is POSEIDON to Titan;
https://forum.nasaspaceflight.com/index.php?topic=55108.msg2304755#msg2304755
https://arxiv.org/abs/2110.10466
Another may be something like JEM for Europa;
https://www.cosmos.esa.int/documents/1866264/3219248/BlancM_JEM-WP_050819_final.pdf/40ee9893-ab2a-771a-4576-7a9434ec06eb?t=1565184623389
And another could be Exploration of Enceladus and Titan (a previous M-class submission IIRC);
https://www.cosmos.esa.int/documents/1866264/3219248/MitriG_Mitri_Enceladus_Titan_Exploration.pdf/ee07fff9-ae5d-e2b3-ae27-10edc92fbafb?t=1565184647615
I'm sure more will come out in due course.
Note that while the science theme is titled Moons of the Giant Planets, it seems very orientated towards the ocean worlds of the gas giant moons. The report separately discusses an ice giant mission as an ESA medium-class contribution to an international project, and states it would be over the L-class cost cap for an ESA-led mission. The principal stumbling block is no RTGs. And here's Leigh Fletcher, perennially involved in ice giants proposals, talking about how that mission may be a NASA-led collaboration, depending on the US planetary science decadal;
https://twitter.com/LeighFletcher/status/1404722557933260800
https://twitter.com/LeighFletcher/status/1440697537661308946
There is a group pushing a Neptune L-class using Starship, but I agree with Leigh's interpretation, I don't think this is what ESA has in mind.
https://arxiv.org/abs/2110.10808
https://arxiv.org/abs/2106.09409
From Temperate Exoplanets to the Milky Way
The second theme is a mini competition between two themes, but potentially-habitable exoplanets is the higher priority; it will be selected if it can demonstrate enough atmospheric spectra can be obtained.
2.2.3 Recommendation
In conclusion, the Senior Committee finds that the science themes focusing on the “Characterisation of Temperate Exoplanets” and the “Galactic Ecosystem with Astrometry in the Near-infrared” are both compelling and offer the potential for a high science return in the 2050 timeframe. The “Characterisation of Temperate Exoplanets” is considered as having the highest scientific priority, but an informed downselection is currently not possible with the available information.
The committee recommends that ESA launch a detailed study involving the scientific community for the exoplanet theme to assess its likelihood of success and feasibility within the Large mission cost-cap. Specifically, such a study should assess what molecules could be detected, to what precision, and for how many targets. If it is found that at least 10 temperate exoplanets (within some reasonable bound of uncertainty) can be characterised and thus that a scientific breakthrough can be achieved in a feasible and affordable mission, then the committee recommends such a theme be selected for the third Large mission in the Voyage 2050 timeframe. If this is not the case, the committee instead recommends that ESA select the “Galactic Ecosystem with Astrometry in the Near-infrared” for a Large mission. The compelling nature of the astrometry theme is also highlighted by its inclusion in the Medium mission recommendations.
These themes are pretty easy to tie to particular mission concepts, given the report's recommendations.
“Characterisation of Temperate Exoplanets” = mid-infrared nulling interferometer for direct imaging cool terrestrial planets in thermal emission (as opposed to reflected light like HabEx/LUVOIR). The community seems to be coalescing around the Large Interferometer for Exoplanets (LIFE) https://www.life-space-mission.com/ (new website due shortly afaik), a formation-flying array of 4 ~2m telescopes. This leverages ESA's developments in formation-flying with Proba-3 and LISA, as well as mid-infrared spectrometer technology like MIRI.
(https://image.jimcdn.com/app/cms/image/transf/dimension=561x1024:format=jpg/path/s8821592646f4f949/image/i65be01b2a8a62110/version/1613511347/image.jpg)
This is essentially the spawn of Darwin, https://www.esa.int/Science_Exploration/Space_Science/Darwin_overview, and similar to TPF-I.
"Galactic Ecosystem with Astrometry in the Near-infrared" = Infrared Gaia, generally called 'GaiaNIR' . So this will only happen as an L-class if LIFE is technically/financially infeasible. Otherwise it's an M-class, or someone else wants to lead it and ESA joins as an M-class.
Finally,
New Physical Probes of the Early Universe
2.3.4 Recommendation
The Senior Committee recommend that ESA should develop a Large mission capable of deploying new instrumental techniques such as gravitational wave detectors or precision microwave spectrometers to explore the early Universe (say 𝑧 > 8 ). Such a mission would shed light on outstanding questions in fundamental physics and astrophysics, such as how inflation occurred and the Universe became hot and then transparent, how the initial cosmic structures grew, how the first black holes formed and how supermassive black holes came to exist less than a billion years after the Big Bang.
While the focus of this Large mission is on the early Universe and the exciting new insights into the physics and astrophysics of that era, it is expected that the space observatories proposed to meet these objectives will also accomplish significant science at lower redshifts by the nature of their survey and new spectroscopic capabilities.
This theme largely looks towards pursuing two different architectures.
One is a LISA-like gravitational wave mission, but probably in the relatively rich decihertz and microhertz frequency ranges;
E.g.;
https://www.cosmos.esa.int/documents/1866264/3219248/BerryC_High_frequency_Voyage_2050_white_paper_submit.pdf/d68ddea0-15f4-5fd2-7fb7-9bdeeb28abbf?t=1565184622145
The other is a super-Planck CMB mission utilising modern technology, with improved absolutely-calibrated microwave spectrometers.
Please add more proposed missions if you can find them.
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I would love to see new missions to Neptune and Uranus' systems in my lifetime, but I'm starting to doubt that
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I wonder when the decadal surveys will begin to seriously consider the benefits of the bigger, cheaper rockets coming from SpaceX and Blue Origin?
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I wonder when the decadal surveys will begin to seriously consider the benefits of the bigger, cheaper rockets coming from SpaceX and Blue Origin?
There is the bad example of the space shuttle, when everyone banked on mass cost savings coming from reuse and they never materialized. NASA Science has a costing structure where the cost of the launch vehicle is somewhat irrelevant to the mission; once upon a time one of the Pluto missions was shot down from Discovery by HQ because it required a Titan IV but otherwise the idea has always been something in the class of Delta II/Atlas V without being said explicitly. Atlas V likely to turn into in the class of Falcon 9, but the launch vehicle cost will remain irrelevant to the mission for the proposers unless we are talking something flagship, which is a whole other ballgame. ESA has now adopted a "buy European" policy which means in practice, as news reports of the time put it, put it on an Ariane and not on the cheaper Soyuz if you want to be considered.
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I would love to see new missions to Neptune and Uranus' systems in my lifetime, but I'm starting to doubt that
Yeah, it's time to go back. Hopefully it'll get a start in the planetary decadal and ESA can join in.
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I wonder when the decadal surveys will begin to seriously consider the benefits of the bigger, cheaper rockets coming from SpaceX and Blue Origin?
There is the bad example of the space shuttle, when everyone banked on mass cost savings coming from reuse and they never materialized.
Everybody was *told* that STS would be better, faster and cheaper so they *had* to factor it in to proposals, especially longer-term ones. Today is a bit different, with several LVs on the near horizon where lower overall costs and higher masses should be the norm. This is the sort of thing that might shorten travel times and/or turn flyby missions into orbiters at relatively little cost/risk. And hopefully more missions as a result. In particular, Starship in fully expendable mode is a beast - imagine one of those, an IUS-style solid orbital insertion stage and a 30foot diameter hi-gain antenna for the Ice Giants...
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Guys, not really seeing what this has to do with ESA's Voyage 2050. Take it elsewhere.
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I'm going to guess Triton can't be on the gas giant moon list since that'd be more along the lines of flagship needs. On top of that ESA would have a hard time picking between Europa, Titan, and Enceladus; deciding factor likely to be what 'Clipper, JUICE, and Dragonfly come across in their respective missions. Exciting they chose this category with or without Triton in the ranks.
Could a medium telescope mission do both the Milky Way or Universal studies, or would that diminish the results by using a bad compromise of an instrument versus one very good specialized one?
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I'm going to guess Triton can't be on the gas giant moon list since that'd be more along the lines of flagship needs. On top of that ESA would have a hard time picking between Europa, Titan, and Enceladus; deciding factor likely to be what 'Clipper, JUICE, and Dragonfly come across in their respective missions. Exciting they chose this category with or without Triton in the ranks.
Could a medium telescope mission do both the Milky Way or Universal studies, or would that diminish the results by using a bad compromise of an instrument versus one very good specialized one?
Yeah, one of the killers for ESA-led missions to the ice giants (and makes Saturn difficult too) is a lack of RTGs; wish ESA would get a move on with this (and to be fair the committee makes the same recommendation). Not been paying close attention but from what I've read there's some promising results from still using Am-241 but with small quantities of other fissile elements like plutonium which enhances the performance. Still seems a long way off though sadly.
Personally I think I'd prefer the moons mission to go to Enceladus, just because breakthrough science in ocean habitability will probably be easier there. I don't rate Titan in terms of the potential emergence of life.
Regarding "Milky Way", or GaiaNIR, here's some comments from David Hobbs who is leading that effort;
Dear all,
The full report is available here, https://www.cosmos.esa.int/documents/1866264/1866292/Voyage2050-Senior-Committeereport-public.pdf/e2b2631e-5348-5d2d-60c1-437225981b6b?t=1623427287109 and it clarifies a lot.
For L-class missions we are in competition with LIFE which is given higher scientific priority. https://www.life-space-mission.com However LIFE requires more challenging technological developments as a formation flying nulling interferometer. The report recommends that studies be conducted to see if it can fit in an L-class mission budget. I presume this is similar to the CDF study we have already undergone.
We are mentioned explicitly in the report as "The Galactic Ecosystem with Astrometry in the Near-infrared”. I see our inclusion as an L-class concept as a major success - our proposal was effectively as an M-class mission with international collaboration to make it affordable.
For M-class missions we are also mentioned under “High Precision Astrometry” and here we seem to have a higher priority than pointed relative astrometry.
“Global astrometry in the near IR as described in Section 2.2.2 would have a much broader
impact…”
This reflects our original proposal as an M-class mission with international collaboration.
For the immediate future we have to follow up the detector developments as they are critical to achieving the science goals. US NIR detectors are still mentioned as an example which means the rotating mirror concept is still being pushed by ESA even though it gives a weaker scientific return. I still feel the NIR-APD detectors show greater promise but let us see.
In summary we have a shot at both M- and L-class missions. It is clear we must now embark on a long proposal process and make ourselves very visible to sell our ideas.
In the end I hope that both LIFE and our NIR mission will fly as both have compelling scientific goals.
All the best
David
David Hobbs
Associate Professor (Universitetslektor)
Lund Observatory, Sweden
This is the GaiaNIR CDF report mentioned, https://sci.esa.int/web/future-missions-department/-/60028-cdf-study-report-gaianir
I can see what you mean by combining GaiaNIR and a CMB mission, though I suspect the technicalities mean this would be suboptimal for both, and I think that would still end up as an L-class. GaiaNIR alone is probably only just about feasible as an M-class with NASA help. From the Voyage 2050 report on an M-class GaiaNIR;
Global astrometry in the near IR as described in Section 2.2.2 would have a much broader impact as it would
tackle various aspects of the above questions, as well as additional important open questions regarding the
whole Milky Way ecosystem. Such a mission, which is of Large class given its scientific breadth, will be
difficult to scale down to fit the Medium mission cost cap given the technological developments required for
the near-IR detectors. However, all of its science objectives could be achieved with a Medium mission led by
ESA with a substantial contribution from other partners. Among other possibilities, the US could contribute
with the near-IR detector following a similar scheme as in the Euclid mission.
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I'm going to guess Triton can't be on the gas giant moon list since that'd be more along the lines of flagship needs. On top of that ESA would have a hard time picking between Europa, Titan, and Enceladus; deciding factor likely to be what 'Clipper, JUICE, and Dragonfly come across in their respective missions. Exciting they chose this category with or without Triton in the ranks.
Could a medium telescope mission do both the Milky Way or Universal studies, or would that diminish the results by using a bad compromise of an instrument versus one very good specialized one?
Yeah, one of the killers for ESA-led missions to the ice giants (and makes Saturn difficult too) is a lack of RTGs; wish ESA would get a move on with this (and to be fair the committee makes the same recommendation). Not been paying close attention but from what I've read there's some promising results from still using Am-241 but with small quantities of other fissile elements like plutonium which enhances the performance. Still seems a long way off though sadly.
Personally I think I'd prefer the moons mission to go to Enceladus, just because breakthrough science in ocean habitability will probably be easier there. I don't rate Titan in terms of the potential emergence of life.
Regarding "Milky Way", or GaiaNIR, here's some comments from David Hobbs who is leading that effort;
Dear all,
The full report is available here, https://www.cosmos.esa.int/documents/1866264/1866292/Voyage2050-Senior-Committeereport-public.pdf/e2b2631e-5348-5d2d-60c1-437225981b6b?t=1623427287109 and it clarifies a lot.
For L-class missions we are in competition with LIFE which is given higher scientific priority. https://www.life-space-mission.com However LIFE requires more challenging technological developments as a formation flying nulling interferometer. The report recommends that studies be conducted to see if it can fit in an L-class mission budget. I presume this is similar to the CDF study we have already undergone.
We are mentioned explicitly in the report as "The Galactic Ecosystem with Astrometry in the Near-infrared”. I see our inclusion as an L-class concept as a major success - our proposal was effectively as an M-class mission with international collaboration to make it affordable.
For M-class missions we are also mentioned under “High Precision Astrometry” and here we seem to have a higher priority than pointed relative astrometry.
“Global astrometry in the near IR as described in Section 2.2.2 would have a much broader
impact…”
This reflects our original proposal as an M-class mission with international collaboration.
For the immediate future we have to follow up the detector developments as they are critical to achieving the science goals. US NIR detectors are still mentioned as an example which means the rotating mirror concept is still being pushed by ESA even though it gives a weaker scientific return. I still feel the NIR-APD detectors show greater promise but let us see.
In summary we have a shot at both M- and L-class missions. It is clear we must now embark on a long proposal process and make ourselves very visible to sell our ideas.
In the end I hope that both LIFE and our NIR mission will fly as both have compelling scientific goals.
All the best
David
David Hobbs
Associate Professor (Universitetslektor)
Lund Observatory, Sweden
This is the GaiaNIR CDF report mentioned, https://sci.esa.int/web/future-missions-department/-/60028-cdf-study-report-gaianir
I can see what you mean by combining GaiaNIR and a CMB mission, though I suspect the technicalities mean this would be suboptimal for both, and I think that would still end up as an L-class. GaiaNIR alone is probably only just about feasible as an M-class with NASA help. From the Voyage 2050 report on an M-class GaiaNIR;
Global astrometry in the near IR as described in Section 2.2.2 would have a much broader impact as it would
tackle various aspects of the above questions, as well as additional important open questions regarding the
whole Milky Way ecosystem. Such a mission, which is of Large class given its scientific breadth, will be
difficult to scale down to fit the Medium mission cost cap given the technological developments required for
the near-IR detectors. However, all of its science objectives could be achieved with a Medium mission led by
ESA with a substantial contribution from other partners. Among other possibilities, the US could contribute
with the near-IR detector following a similar scheme as in the Euclid mission.
Isn’t that rather presumptive of you to dismiss Titan like that. TBH it seems to me to be a better target than some other possible targets.
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I'm not going to go into too much detail here but bluntly, no.
There are two main ways to view how organic chemistry (complex carbons) became ubiquitous to life. One is the top-down "organic soup", the other is the bottom-up metabolic pathway.
In the top-down model, the theory goes that a soup of abiotically-produced organic molecules + energy + time somehow leads to RNA/DNA and all the other molecules of life as we know it. Scientists interested in studying, for instance, amino acids on comets supposedly "seeding" the early Earth with this organic soup are generally following this model. Or in the case of Titan, the idea that the organic haze perhaps somehow led to rainout of RNA etc is another. These ideas have an ancestor in things such as the famous Miller–Urey experiment (https://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experiment). While this is a long-established and commonly-held view, in part perhaps because it is relatively easier to propose studying, IMO it is unlikely to be an accurate genesis story.
In the bottom-up model, the fundamental unit of life is not organic molecules but metabolic pathways (think Krebs cycle (https://en.wikipedia.org/wiki/Citric_acid_cycle) etc), and that the organic molecules life uses were a by-product of the metabolic pathways present in the very earliest life. E.g. Evidence from genetics suggests the early lifeforms on Earth were Methanogens or Acetogens, i.e. organics are a natural by-product of the chemical reactions that sustained them. This model is the basis of the connection between underwater hydrothermal vents and the emergence of life, because one plausible way to create primitive acetogenic or methanogenic cycles abiotically is through serpentinization in hydrothermal systems. (This also may explain life's affinity for aqueous chemical reactions) Scientists who are interested in Europa and Enceladus as potential sites where life has emerged are implicitly viewing the emergence of life through this model. In my opinion this is a far more sophisticated view, and one considerably more plausible than the top-down model.
I don't believe Titan can tell us much about how life really got started on Earth because the model used to imply life has any potential to begin there is flimsy at best. Studying hydrothermal systems has the potential to tell us so much more. Titan is a fascinating place where lots of cool science can be done, I just don't see a huge relevance to the question of life. It is a bit of a red herring in that regard.
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I don't believe Titan can tell us much about how life really got started on Earth because the model used to imply life has any potential to begin there is flimsy at best. Studying hydrothermal systems has the potential to tell us so much more. Titan is a fascinating place where lots of cool science can be done, I just don't see a huge relevance to the question of life. It is a bit of a red herring in that regard.
If I'm not mistaken, a critical question is hat's the depth of Europa and Enceladus oceans. IIRC, once you went past 150km in Europa, water becomes Ice VII due to pressure and you can't have any life. But my calculation might have been off.
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I don't believe Titan can tell us much about how life really got started on Earth because the model used to imply life has any potential to begin there is flimsy at best. Studying hydrothermal systems has the potential to tell us so much more. Titan is a fascinating place where lots of cool science can be done, I just don't see a huge relevance to the question of life. It is a bit of a red herring in that regard.
If I'm not mistaken, a critical question is hat's the depth of Europa and Enceladus oceans. IIRC, once you went past 150km in Europa, water becomes Ice VII due to pressure and you can't have any life. But my calculation might have been off.
Enceladus' ocean appears to be in contact with the rocky mantle, based on Cassini's mass spectrometer data. Europa's is as well in theory, although we are less certain about the conditions.
Titan is thought to have an H2O ocean too, but that is unlikely to be in contact with rock but instead sandwiched between ices, same for others like Ganymede.
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https://www.bbc.co.uk/news/science-environment-59353504
Manifesto seeks to re-invigorate Europe in space
...It proposes also two inspirational goals - for Europe to launch its own astronauts, and for a mission to return ice samples from the outer planets....
...The manifesto's two "inspirators" are really quite long term and would also be very expensive to implement. The icy moons of Jupiter and Saturn intrigue scientists because the observational data suggests they might be good places for life to take hold. Bringing samples back of their frozen terrains, or even their subsurface oceans, would certainly be an exciting endeavour.
This sounds interesting in the context of Voyage 2050. The agency has already been directed to have an icy moons mission for the fourth L-class. I'm guessing, but now it sounds like ESA may be asking for more money to "pimp my ride" and add a sample return capability to this mission, I can't see them doing two.
A European space summit will be held in February in Toulouse, France, where the issues will be discussed further. Dr Aschbacher is hoping momentum will build up behind a transformational increase in Esa's budget come the next ministerial council meeting in 12 months' time.
I'll believe that when I see it, but hopefully something will come of it.
Edit: In fact I just spotted an ESA webpage with slightly more detail, which seems to be pushing Enceladus in particular;
https://vision.esa.int/prepare-the-future-of-space/
The icy moons of the giant planets in the outer Solar System could also host life. This makes them an exciting destination for space missions. A sample return mission to Saturn’s moon Enceladus will exploit synergies with the Mars sample return mission.
Many of the ingredients needed for life appear to exist in the Enceladus’s subsurface ocean. Studying a sample from the moon will provide crucial evidence for the origin of the Solar System and its ability to host life...
...What’s the next step?
ESA will take preparatory steps towards a sample return mission from the icy moons of giant planets...
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Yeah, one of the killers for ESA-led missions to the ice giants (and makes Saturn difficult too) is a lack of RTGs;
Would it be feasible to have NASA contribute the RTG on an ESA-led mission?
I'm thinking of JWST, where ESA contributed one of the instruments and the launch to a NASA-led mission.
Or would you run into ITAR or nuclear-related legal issues exporting an RTG?
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Yeah, one of the killers for ESA-led missions to the ice giants (and makes Saturn difficult too) is a lack of RTGs;
Would it be feasible to have NASA contribute the RTG on an ESA-led mission?
I'm thinking of JWST, where ESA contributed one of the instruments and the launch to a NASA-led mission.
Or would you run into ITAR or nuclear-related legal issues exporting an RTG?
Of course they've already done this pre-ITAR with Ulysses. Post-ITAR, If they wanted to make it work they probably could do, e.g. integrate and launch in the US. The problem is NASA doesn't have enough RTGs to hand out like candy right now, there'll probably be pressure to save them for US-led projects.
If ESA wants an RTG mission it's going to need to start building its own.
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Yeah, one of the killers for ESA-led missions to the ice giants (and makes Saturn difficult too) is a lack of RTGs;
Would it be feasible to have NASA contribute the RTG on an ESA-led mission?
I'm thinking of JWST, where ESA contributed one of the instruments and the launch to a NASA-led mission.
Or would you run into ITAR or nuclear-related legal issues exporting an RTG?
Of course they've already done this pre-ITAR with Ulysses. Post-ITAR, If they wanted to make it work they probably could do, e.g. integrate and launch in the US. The problem is NASA doesn't have enough RTGs to hand out like candy right now, there'll probably be pressure to save them for US-led projects.
If ESA wants an RTG mission it's going to need to start building its own.
ESA has been looking into developing their own RTGs. I think they've been looking at using Americium. You can probably find information on that with a search. I'm somewhat dubious, because the US experience has demonstrated that this technology is expensive and has expensive infrastructure requirements. But the few people I've talked to about this in the past few years (and my data is by no means current or extensive) indicates that the Europeans appear to be serious about developing their own RTGs.
I think they would look for some kind of cooperative agreement with NASA to bring the US in as a joint sponsor and provide the RTG. If the two sides have similar high priorities for the mission, that's possible.
Update: a quick search "ESA Americium" turned up some relevant hits. I don't know where you would find good information on the current state of the development program, however.
https://www.nnl.co.uk/customer-solutions/case-studies/developing-new-nuclear-fuel-for-space-missions/
https://inis.iaea.org/collection/NCLCollectionStore/_Public/45/066/45066049.pdf
https://www.sciencedirect.com/science/article/abs/pii/S2468896721001038
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Yeah, I've been following developments. Americium is preferred since we have large stockpiles from reprocessed civil nuclear reactor fuel in the UK and France, I don't think that's true in the US. It's also commercial (used in smoke alarms IIRC), so overall it's theoretically significantly cheaper to produce than plutonium.
It's far lower specific power than plutonium, though much longer life, so more stable in output. And while not as harmful to humans it produces neutron radiation that can embrittle materials. They are testing ways to moderate the neutron radiation though.
ESA's RTG design so far has a poor specific power of about 1W/Kg though, to my knowledge that somewhat undershot what they were initially hoping for. A full-scale RTG useable on for instance an Ice Giants mission is still probably decades away. An Am241 RHU is easier and may fly as a tech demo on ESA's planned EL3 moon mission IIRC.
There's been some interesting initial studies into mixed-isotope fuels which could create vastly higher powered/lower weight systems. For instance one looking at adding uranium or curium isotopes to the Am241. The current baselined Am241 fuel is already stabilised with plain old uranium to stop it cracking anyway. This seems very low TRL right now though as they'd have to repeat a lot of the fuel testing they've already done.
E. g. https://www.tandfonline.com/doi/full/10.1080/00295450.2021.1888616
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ESA's RTG design so far has a poor specific power of about 1W/Kg though, to my knowledge that somewhat undershot what they were initially hoping for.
I used to talk to Ralph McNutt about RTGs a lot. He became an expert after getting involved in a study we did in the late 2000s and then he would talk anybody's ear off about RTGs, Pu-238 and all the related stuff (I actually liked talking to him about this).
One of the things he told me was that pretty much every American RTG program produced less power than planned. That has certainly been true of the work done in the past few decades. The MMRTGs had lower power, for example, and there was a technology program around 2013-2016 that was going to increase the thermoelectric efficiency that also fell below target. In each case there have been different reasons why, but when you step back and look at the full picture, it's clear that for all aspects of this technology there are always problems that result in lower performance than planned.
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Yeah, one of the killers for ESA-led missions to the ice giants (and makes Saturn difficult too) is a lack of RTGs;
Would it be feasible to have NASA contribute the RTG on an ESA-led mission?
I'm thinking of JWST, where ESA contributed one of the instruments and the launch to a NASA-led mission.
Or would you run into ITAR or nuclear-related legal issues exporting an RTG?
This would never happen. The US doesn't have enough plutonium and has to be very stingy about what missions get an RTG. They would never give a full RTG to ESA.
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I'm puzzled by the choice of words in the Moons of the giant planets theme
"Investigating the habitability potential of worlds in our Solar System is essential for understanding the emergence of life..."
To me the term "habitability" suggests astronaut encampments in the far future. Jupiter's Galilean moons are bathed in heavy radiation from the planet, even as far out as Callisto. Maybe I'm misinterpreting this.
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To me the term "habitability" suggests astronaut encampments in the far future. Jupiter's Galilean moons are bathed in heavy radiation from the planet, even as far out as Callisto. Maybe I'm misinterpreting this.
You are misinterpreting it. The scientific definition of habitability means its ability to support life, not astronauts. So amoebas are fine, shrimp are great, and fish are bleeping wonderful.
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Of course water is a pretty decent shield against most radiation. If you could get below the ice into the ocean on Europa an aquatic artificial habitat would be fairly well protected.
But yes, habitability in this context means for potential extraterrestrial life.
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If there was a lead time of more than 10 years, then I don't see why the US couldn't supply an RTG to ESA. Investments could be made to increase Pu-238 production by debottlenecking the current production process, which would also tend to decrease the unit cost.
One of the missions being studied for the decadal is an astrobiology mission to Enceladus. If the Europeans wanted to go to Enceladus, then NASA might supply an RTG if the Europeans agreed to host an American instrument on their mission. The Europeans could also make a generous contribution to a US lead Ice Giant mission, which they might be happy to do because some European scientists are interested in Ice Giants.
There is another aspect to this. I think that a lot of the science from the atmosphere probe on an Ice Giant mission will come from comparing the results to Jupiter. Having atmosphere probe data from Saturn as well would probably be very valuable when modeling solar system formation scenarios. Perhaps the Europeans could supply two probes, one for their own Saturn mission and one for a US Ice Giants mission. They could also host a US astrobiology instrument on their Saturn mission and in return would get a US RTG to power it.
However, it is possible that solar panel technology has advanced to the point where RTGs are not really needed for Saturn. The Voyage 2050 report states on page 10 :
Technology developments on higher efficiency solar cells have been ongoing at ESA making a solar-powered mission in the Saturnian system not only feasible but also operationally flexible and capable of hosting advanced instrumentation.
The Europeans are clearly very interested in the Ice Giants. On page 28 they say:
A mission towards Uranus and/or Neptune is a necessary step in the exploration of the Solar System, filling the current, huge, knowledge gap,...
... A partnership with another agency is an absolute necessity. One possibility would be a Medium class contribution in a mission led by an international partner. It could for instance consist of an atmospheric entry probe, a Triton lander, or some key instrumentation....
...it is strongly recommended that every effort is made to pursue this theme in order to set up a cooperation scheme on a future mission to the Ice Giants.
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Thanks to the mess of Nasa pulling out of Exomars, L-class missions must now be explicitly ESA-led, so there will be an ESA-led Jupiter/Saturn moons mission regardless of what Nasa does. ESA could also join a separate Nasa-led moons mission with an M-class, though it would be in competition with lots of other priorities.
Yes as you note, ESA now considers solar array technology mature enough for capable large Jupiter and Saturn missions. That's why conspicuously the 'giant planet' moons mission focuses on those to the exclusion of the ice giants, it's just implicitly assuming sufficient RTG technology won't be available.
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If there was a lead time of more than 10 years, then I don't see why the US couldn't supply an RTG to ESA. Investments could be made to increase Pu-238 production by debottlenecking the current production process, which would also tend to decrease the unit cost.
Note that doing so would require some kind of joint mission. In other words, in return for the US supplying the RTG, the US also gets to supply instruments and have participation on the science team. Yes, this is possible. But all of this requires coordination. (I don't see the US ever "trading" an RTG for something not related to the mission that it is on. In other words, we would not give ESA an RTG in return for a launch on an Ariane 5.)
There is a possibility of increasing US Pu-238 production, but that's not the only thing that has to be increased. There are other limits along the supply chain, particularly how many fuel clads can be produced per year. Just increasing Pu-238 supply would mean that it would pile up, like pumping a lot of oil out of the ground but not having capacity at the refinery to process it.
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Depending on when this European mission flies, it might not be necessary to expand Pu-238 and RTG production. I noticed that the LISA mission won't fly until 2037, so perhaps the Jupiter/Saturn moons mission won't fly until the early 2040s.
I think there are two great opportunities in the outer solar system. Both astrobiology at Enceladus and an Ice Giant mission will be prestigious, high profile missions. I think that ESA should jump on whichever one the Decadal does not pick as #1 and try to make it happen even if it requires making a deal with the US for an RTG.
The US will eventually do both so if the Europeans want to be first they will need to launch by the mid-2030s.
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If there was a lead time of more than 10 years, then I don't see why the US couldn't supply an RTG to ESA. Investments could be made to increase Pu-238 production by debottlenecking the current production process, which would also tend to decrease the unit cost.
The US is very limited in how much Pu-238 it can produce. Lead time is irrelevant when there isn't enough as is. Increasing the production rate is a multi billion dollar decade long proposition. We are incredibly risk adverse to anything with the word nuclear in it.
If there is a joint NASA-ESA mission, an RTG could be possible, but there is no near future scenario where NASA sells/gives away an RTG.
Consider the Juno orbiter and Lucy. Going out of our way to try and do solar 5 AU out and all that work BECAUSE there isn't enough plutonium to go around.
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Increasing the production rate is a multi billion dollar decade long proposition.
It's not "multi billion dollars" to increase Pu-238 production. The numbers are not public, but the planetary decadal survey asked about it. There's a path to increasing production, but cost depends upon how much and there's a step function where you have to build new equipment and so on--for instance, increasing production by 25% might not cost that much, but 50% would cost a lot more.
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EPSC2022
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https://universemagazine.com/en/finding-extraterrestrial-life-europe-begins-to-develop-a-mission-to-enceladus/
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The report:
https://cosmos.esa.int/documents/1866264/1866292/ESA_L4_Expert_Committee_report_Voyage_2050_Moons_of_the_Giant_Planets.pdf
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The report:
https://cosmos.esa.int/documents/1866264/1866292/ESA_L4_Expert_Committee_report_Voyage_2050_Moons_of_the_Giant_Planets.pdf
These quotes still seem counterproductive to me: "the L4 mission concepts considered in this study, with launch in the early 2040s" and "During the CDF studies, the scenario considered was a single A64 launcher. Only after the conclusion of the CDF studies was a double launch scenario introduced for the Enceladus mission, (see paragraph below)."
I realize this is a national prestige matter, but I'd think the prestige attaches to the science, not the launcher. And talking *18 years* in advance, surely some advance in launcher technology can be assumed. And at some point, launch will become a commodity. Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
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Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
I'm not sure that's a great example, considering that the vast majority (all?) of NSF flights to the South Pole are done with US military aircraft. "More and Better Science in Antarctica through Increased Logistical Effectiveness" https://www.nsf.gov/geo/opp/usap_special_review/usap_brp/rpt/antarctica_07232012.pdf
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I realize this is a national prestige matter, but I'd think the prestige attaches to the science, not the launcher. And talking *18 years* in advance, surely some advance in launcher technology can be assumed. And at some point, launch will become a commodity. Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
In other words, you want to discuss Starship in this thread.
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I realize this is a national prestige matter, but I'd think the prestige attaches to the science, not the launcher. And talking *18 years* in advance, surely some advance in launcher technology can be assumed. And at some point, launch will become a commodity. Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
In other words, you want to discuss Starship in this thread.
I didn't think there were any Starship free threads on this site once a thread passes 20 comments. But it does bring up a point. How do you realistically start planning for missions fifteen to twenty years out knowing that there is potential for massive technology advancements in a number of areas that could significantly change the mission architecture for the the better?
I had this discussion with my congressman at the time Jim Sensenbrenner (former chair of the House Science Committee). We were discussing the ITER nuclear fusion project. He thought, and I agreed, that committing to a design thirty years to complete was completely ridiculous and a big waste of money because it ignores potential breakthroughs along the way. I think it is reasonable to come up with general goals for twenty years out, but not specific designs to accomplish them.
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I realize this is a national prestige matter, but I'd think the prestige attaches to the science, not the launcher. And talking *18 years* in advance, surely some advance in launcher technology can be assumed. And at some point, launch will become a commodity. Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
In other words, you want to discuss Starship in this thread.
More likely to be Ariane Next, isn’t it ??
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I think it’s best to design for what exists. Europa Clipper was going to launch on SLS, a cheaper gentler ride came along, it’s going to go on FH. No need to clog up all the threads with future launchers.
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I had this discussion with my congressman at the time Jim Sensenbrenner (former chair of the House Science Committee). We were discussing the ITER nuclear fusion project. He thought, and I agreed, that committing to a design thirty years to complete was completely ridiculous and a big waste of money because it ignores potential breakthroughs along the way. I think it is reasonable to come up with general goals for twenty years out, but not specific designs to accomplish them.
We're at a point where projects as complicated as ITER take 20 years to build. The start of that build is when you should freeze the design, otherwise you'll be restarting construction and adding years to the build over and over again.
Before that, there's going to be years of designing, and before that, there's going to be years of R&D before you can settle on a design. We could speed that up by increasing funding, but as we've seen with ITER, that's not happening. So we end up with having to freeze the design 30 years before the reactor becomes operational.
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Unless we discover a new way to get to these places much faster, we are never really gonna see a faster turnout for these type of missions
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Unless we discover a new way to get to these places much faster, we are never really gonna see a faster turnout for these type of missions
Isn't it the money more than the speed through space? They simply cannot afford more missions
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Unless we discover a new way to get to these places much faster, we are never really gonna see a faster turnout for these type of missions
Isn't it the money more than the speed through space? They simply cannot afford more missions
ESA has a smaller science budget than NASA (you can look up the numbers, although the member nation's individual space science budgets also contribute to ESA, for example to provide instruments or analyze data).
As a treaty organization, ESA has to operate based on consensus and well articulated - and followed - long term plans.
They also plan missions differently. They select a destination/concept and that becomes part of the approved plan for the agency. Then they do the preliminary architecture and design work that leads to a definitive mission plan that can then be formally approved. That leads to a long time between selection of the concept, formal mission approval, design/testing/construction, and then launch.
NASA doesn't have quite the equivalent. NASA will state it has a goal to fly a particular kind of mission, but that's not a formal approval of the concept. Approval comes when the mission architecture is well along and there's a mission team. ESA selects the team well after approving the concept
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I had this discussion with my congressman at the time Jim Sensenbrenner (former chair of the House Science Committee). We were discussing the ITER nuclear fusion project. He thought, and I agreed, that committing to a design thirty years to complete was completely ridiculous and a big waste of money because it ignores potential breakthroughs along the way. I think it is reasonable to come up with general goals for twenty years out, but not specific designs to accomplish them.
We're at a point where projects as complicated as ITER take 20 years to build. The start of that build is when you should freeze the design, otherwise you'll be restarting construction and adding years to the build over and over again.
Before that, there's going to be years of designing, and before that, there's going to be years of R&D before you can settle on a design. We could speed that up by increasing funding, but as we've seen with ITER, that's not happening. So we end up with having to freeze the design 30 years before the reactor becomes operational.
And since then there was the breakthrough in REBCO superconductors that allows a much stronger magnetic field than they had anticipated being available for ITER rendering the design obsolete and yet they keep building it. That is my problem with such long term projects. They become white elephants that no one has the guts to kill.
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ESA's article: Saturn's moon Enceladus top target for ESA (https://www.esa.int/Science_Exploration/Space_Science/Saturn_s_moon_Enceladus_top_target_for_ESA)
The report:
https://cosmos.esa.int/documents/1866264/1866292/ESA_L4_Expert_Committee_report_Voyage_2050_Moons_of_the_Giant_Planets.pdf
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That is my problem with such long term projects. They become white elephants that no one has the guts to kill.
ESA has settled on Enceladus (and if you read the report, the other moons of Saturn) as the target for its large mission.
Design work may not start for another decade.
This is a programmatic decision, not a design decision. ESA settles on its scientific targets much further in advance than NASA does, possibly because they are an international agency that has to build and maintain consensus for programs that last decades.
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The report:
https://cosmos.esa.int/documents/1866264/1866292/ESA_L4_Expert_Committee_report_Voyage_2050_Moons_of_the_Giant_Planets.pdf
Interesting from the exec summary:
An Enceladus south polar lander with an orbiter and plume sampling system would be the optimum candidate for the L4 mission. According to the analyses performed, this would be enabled by a dual launch configuration (A64+A64), with Near-Earth rendezvous prior to escape.
Ambitious…
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I realize this is a national prestige matter, but I'd think the prestige attaches to the science, not the launcher. And talking *18 years* in advance, surely some advance in launcher technology can be assumed. And at some point, launch will become a commodity. Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
In other words, you want to discuss Starship in this thread.
I completely get your frustration with Starship poking up everywhere.
On the other hand, I worked for 30 years in the semiconductor industry, where you based next year's plan (not to mention plans 18 years out) on technology that was not available yet, but you could see coming. Failure to take future advances into account was a disaster that led quickly to uncompetitive products and likely corporate demise. Space launch technology is not advancing as quickly or reliably as semiconductor technology, but the same idea holds. If you want a mission that will be state of the art in 2042, you need to think of what advances may occur.
As far as launch as a commodity, again I think the semiconductor industry might provide a good example. In the 1980's, semiconductor fabs were thought to be a corporate and national jewel. Every company, and every country, had to have its own fab for control and prestige. But as fabs grew more expensive, this objective was quietly dropped. Now just a few fabs serve almost all companies, and almost all (western) countries. And the glory attaches to the end design, not who fabs the chip. Take, for example, NVidea, a super hot company. Do you know off the top of your head who does their fab? Is it TSMC, Samsung, Chartered, or other? Admiration and valuation of these companies are almost completely independent of fab companies. The same may well happen in launch.
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The report:
https://cosmos.esa.int/documents/1866264/1866292/ESA_L4_Expert_Committee_report_Voyage_2050_Moons_of_the_Giant_Planets.pdf
Technically, these proposals seem extremely marginal due to the lack of RTGs. They are proposing, for example, to send 331 kg of batteries to Titan's surface, to support 33 kg of science, and that for only 16 days. Likewise for Enceladeus, 250 kg of batteries to support 23 kg of instruments, again for a few days. If these missions had RTGs, the science return could be hugely greater, with both more mass for instruments and a much longer lifetime. And on the pessimistic side, if these battery missions have some initial problems that require a few days of debugging, the science could be lost completely.
From the viewpoint of science alone, it seems crazy to go to the enormous trouble, expense, and time of an outer planets lander mission leaving out perhaps the most enabling technology. I know there are huge political obstacles, but if a solution to this dilemma could be found (cooperative mission? ESA pays to increase USA plutonium production?) the science return would be enormously greater.
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Technically, these proposals seem extremely marginal due to the lack of RTGs.
ESA has been working on Am241 RTGs for some time, strange that they wouldn't use them here.
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Technically, these proposals seem extremely marginal due to the lack of RTGs.
ESA has been working on Am241 RTGs for some time, strange that they wouldn't use them here.
Agreed, and this February 2022 course summary on the current status of Am241 RTG technology would seem to buttress your point: http://large.stanford.edu/courses/2022/ph241/spaugh1/
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I realize this is a national prestige matter, but I'd think the prestige attaches to the science, not the launcher. And talking *18 years* in advance, surely some advance in launcher technology can be assumed. And at some point, launch will become a commodity. Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
In other words, you want to discuss Starship in this thread.
ESA decides on its science targets decades ahead of launch. I expect that serious design work won't start for another decade. At that time, the design team will be able to evaluate launcher opportunities. Even I expect Starship or perhaps multiple equivalents to be available. However, ESA may have a policy to use use only it's own launch vehicles in its science missions.
Let's circle back to this in a decade.
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Technically, these proposals seem extremely marginal due to the lack of RTGs.
ESA has been working on Am241 RTGs for some time, strange that they wouldn't use them here.
Agreed, and this February 2022 course summary on the current status of Am241 RTG technology would seem to buttress your point: http://large.stanford.edu/courses/2022/ph241/spaugh1/
I expect that only very high level concept designs were considered. They likely had some rules on what level of technological readiness and which launch vehicles could be used. am241 RTGs may not have made that list.
ESA also has been open to collaborations, so RTGs from NASA may be a possibility once they get into serious design.
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I realize this is a national prestige matter, but I'd think the prestige attaches to the science, not the launcher. And talking *18 years* in advance, surely some advance in launcher technology can be assumed. And at some point, launch will become a commodity. Perhaps an analogy is research at the South Pole - no one cares what ship brought the equipment, just what the research reveals.
In other words, you want to discuss Starship in this thread.
I completely get your frustration with Starship poking up everywhere.
On the other hand, I worked for 30 years in the semiconductor industry, where you based next year's plan (not to mention plans 18 years out) on technology that was not available yet, but you could see coming. Failure to take future advances into account was a disaster that led quickly to uncompetitive products and likely corporate demise. Space launch technology is not advancing as quickly or reliably as semiconductor technology, but the same idea holds. If you want a mission that will be state of the art in 2042, you need to think of what advances may occur.
As far as launch as a commodity, again I think the semiconductor industry might provide a good example. In the 1980's, semiconductor fabs were thought to be a corporate and national jewel. Every company, and every country, had to have its own fab for control and prestige. But as fabs grew more expensive, this objective was quietly dropped. Now just a few fabs serve almost all companies, and almost all (western) countries. And the glory attaches to the end design, not who fabs the chip. Take, for example, NVidea, a super hot company. Do you know off the top of your head who does their fab? Is it TSMC, Samsung, Chartered, or other? Admiration and valuation of these companies are almost completely independent of fab companies. The same may well happen in launch.
the issue is that starship is designed for lots of mass to leo, its the frame that starlink is hung on. It may be able to do HLS in the next 10 years. Maybe, but no garuntee. All the starship discussions make far reaching assumptions that starship will be able to do literally anything people want it to do. It can do any mission of any type better, and also make julien fries. Long term space flight, land on multiple planets, land on boulder fields and hills, refuel itself, literally anything. All will happen in the next couple years and for basically free as well.
Starship is a bad discusson subject because its a place holder for some magic thing that will solve all problems. It sucks all the oxygen out of the room and leaves you trying to deal with opinions and dreams instead of engineering and facts. Will starhip be cool? Of course. Will it do 5% of what the internet thinks it will? HIGHLY doubtful. Starship is not a serious discussion, all posts about it in the science forums are simply rocket fan fiction.
Starship inevitably ends all current and legitimate discusson about stuff, because it doesn't exist in any form that people invoke. They just say it could do X, and it'll be cheaper/faster/better/whateverer to use starship for it. It derails literally every conversation.
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ESA won't plan missions around Starship since it's not European. So there's no point discussing Starship or Starship fans in this thread.
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Technically, these proposals seem extremely marginal due to the lack of RTGs.
ESA has been working on Am241 RTGs for some time, strange that they wouldn't use them here.
Agreed, and this February 2022 course summary on the current status of Am241 RTG technology would seem to buttress your point: http://large.stanford.edu/courses/2022/ph241/spaugh1/
I expect that only very high level concept designs were considered. They likely had some rules on what level of technological readiness and which launch vehicles could be used. am241 RTGs may not have made that list.
The only way this report makes sense to me is as an engineering response to management obstinacy. I could see management saying "Do we REALLY need RTGs? It's an expensive development program..." and engineering saying "OK, we've taken our best shot at designing a mission without RTGs. The best we can do is to spend 2 billion Euros and 15 years to send a mission that's nine-tenths batteries to an outer planet moon, and have it work for only 16 days. We REALLY need RTGs if you want to tackle this science."
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The only way this report makes sense to me is as an engineering response to management obstinacy. I could see management saying "Do we REALLY need RTGs? It's an expensive development program..." and engineering saying "OK, we've taken our best shot at designing a mission without RTGs. The best we can do is to spend 2 billion Euros and 15 years to send a mission that's nine-tenths batteries to an outer planet moon, and have it work for only 16 days. We REALLY need RTGs if you want to tackle this science."
This was an assessment of scientific destinations with a very limited assessment of conceivable mission architectures. The goal was to decide on the target, not a mission architecture.
I have not seen the ground rules for the architecture assessment; perhaps you have?
Launch is conceived for the early 2040s, which means serious design and considerations of collaborations is a decade away.
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ESA also has been open to collaborations, so RTGs from NASA may be a possibility once they get into serious design.
I'm not sure I see this happening. The US cannot produce enough PU for its own basic needs. I've a hard time seeing us cancel our own missions to sell PU to ESA
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ESA also has been open to collaborations, so RTGs from NASA may be a possibility once they get into serious design.
I'm not sure I see this happening. The US cannot produce enough PU for its own basic needs. I've a hard time seeing us cancel our own missions to sell PU to ESA
Enceladus is a high US Decadal Survey priority. The evaluated Decadal Survey concept mission used RTGs.
We are talking about a mission that wouldn't launch for 15+ years, so lots of time to produce PU for either a NASA or a joint NASA/ESA mission.
BTW, US law requires that NASA provide PU in the form of a finished RTG, and I believe that it also requires that the RTG (and the spacecraft attached to it) be launched by the US.
ESA and NASA have a long history of collaboration, generally pretty successful. Do a search on 'NASA ESA collaboration' and you'll get lots of hits for past, current, and potential mission collaborations. Since Enceladus is a high priority target for both ESA and NASA, collaboration almost certainly will be considered. But again, we are many years away from anything resembling start of design.
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I'm not sure I see this happening. The US cannot produce enough PU for its own basic needs. I've a hard time seeing us cancel our own missions to sell PU to ESA
BTW, Lori Glaze has stated repeatedly that the production facilities are not limiting the rate of RTGs, which can be ramped up or down with mission demand.
The lack of funding for missions that would use RTGs is the limiting factor on RTG production.
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I'm not sure I see this happening. The US cannot produce enough PU for its own basic needs. I've a hard time seeing us cancel our own missions to sell PU to ESA
BTW, Lori Glaze has stated repeatedly that the production facilities are not limiting the rate of RTGs, which can be ramped up or down with mission demand.
The lack of funding for missions that would use RTGs is the limiting factor on RTG production.
Ehh... isn't that the long way of saying we don't/won't have all the PU we need? Sure it can be "ramped up", not only will that ALWAYS go slower and cost WAY MORE than expected, but it requires the money to begin with.
Instead, we simply won't start missions that require a significant increase, because everyone knows the budget won't exist for it.
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I'm not sure I see this happening. The US cannot produce enough PU for its own basic needs. I've a hard time seeing us cancel our own missions to sell PU to ESA
BTW, Lori Glaze has stated repeatedly that the production facilities are not limiting the rate of RTGs, which can be ramped up or down with mission demand.
The lack of funding for missions that would use RTGs is the limiting factor on RTG production.
No, it's not the long way. If more RTGs were produced, NASA doesn't have the money to design, build, launch, and manage the missions that would use them.
RTG production rate is limiting the missions NASA flies. It's sort of like the price of gas - you care, but it is secondary to whether or not you can afford to buy a car in the first place. NASA can't afford the car.
Ehh... isn't that the long way of saying we don't/won't have all the PU we need? Sure it can be "ramped up", not only will that ALWAYS go slower and cost WAY MORE than expected, but it requires the money to begin with.
Instead, we simply won't start missions that require a significant increase, because everyone knows the budget won't exist for it.
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Ehh... isn't that the long way of saying we don't/won't have all the PU we need? Sure it can be "ramped up", not only will that ALWAYS go slower and cost WAY MORE than expected, but it requires the money to begin with.
Instead, we simply won't start missions that require a significant increase, because everyone knows the budget won't exist for it.
Compared to the rest of the cost of a mission, RTGs and the RTG program are cheap.
NASA can't afford new planetary missions to any destination, whether solar or radioisotope powered. If RTGs were free, NASA still doesn't have the funding to start the new underlying missions.
It's like with launch vehicles. If launch were free, NASA still doesn't have the money to start new planetary missions.
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There's been a discussion of whether RTG production rate is hindering mission selection. I had time this morning to go back to the OPAG presentations from last fall. I've attached a key slide from Lori Glaze's presentation.
Another point is that for a mission to launch in the early 2040's, you'd want to use RTGs produced in the mid-2030s. There is the nuclear decay, but it turns out that the decay of other components in the package is the driving force on lifetime power. The production rate today likely has little relevance to the potential use of ESA's 2040's mission.
https://www.hou.usra.edu/meetings/opagnov2023/presentations/Tuesday/0915_Glaze.pdf (https://www.hou.usra.edu/meetings/opagnov2023/presentations/Tuesday/0915_Glaze.pdf)
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if ESA does indeed go with an Enceladus orbilander as their flagship mission, what do you think NASA will choose are their top priority mission after Uranus, since for them it was also Enceladus? Not sure if there was another mission in the ranking just below that one?
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if ESA does indeed go with an Enceladus orbilander as their flagship mission, what do you think NASA will choose are their top priority mission after Uranus, since for them it was also Enceladus? Not sure if there was another mission in the ranking just below that one?
I think that question will be answered by the next Decadal Survey, which should start about 2030 and be published about 2032. There seems to be more priorities than budget remaining from the last one for that question to be formally answered before then.
For Enceladus and NASA, NASA could select a New Frontiers Enceladus multi-flyby mission that would arrive approximately a decade before the European mission. While it might seem like competition, the European mission would benefit from learning more about Enceladus.
I also expect that ESA and NASA will talk about collaboration on the ESA Voyage 2050 mission. They have done so on possible Uranus missions and are collaborating on many. The ideas in the ESA document for an Enceladus mission are ambitious. They may be far more doable with collaboration.
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if ESA does indeed go with an Enceladus orbilander as their flagship mission, what do you think NASA will choose are their top priority mission after Uranus, since for them it was also Enceladus? Not sure if there was another mission in the ranking just below that one?
I think that question will be answered by the next Decadal Survey, which should start about 2030 and be published about 2032. There seems to be more priorities than budget remaining from the last one for that question to be formally answered before then.
For Enceladus and NASA, NASA could select a New Frontiers Enceladus multi-flyby mission that would arrive approximately a decade before the European mission. While it might seem like competition, the European mission would benefit from learning more about Enceladus.
I also expect that ESA and NASA will talk about collaboration on the ESA Voyage 2050 mission. They have done so on possible Uranus missions and are collaborating on many. The ideas in the ESA document for an Enceladus mission are ambitious. They may be far more doable with collaboration.
Oh I agree they would collaborate on both missions, but if Enceladus is ESA led, I think NASA will want their own flagship mission too, assuming this comes after Uranus.