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A spacecraft that can provide the propulsion necessary to reach other planets while also being reproducible, relatively light, and inexpensive would be a great boon to larger missions in the inner solar system. Micocosm, Inc., based in Hawthorne, California, proposed just such a system via a NASA Small Business Innovation Research (SBIR) grant. Its Hummingbird spacecraft would have provided a platform to visit nearby planets and asteroids and a payload to do some basic scouting of them.

Large space missions are expensive, so using a much less expensive spacecraft to collect preliminary data on the mission target could potentially help save money on the larger mission’s final design. That is the role that Hummingbird would play. It is designed essentially as a propulsion system, with slots for radiation-hardened CubeSat components as well as a larger exchangeable payload, such as a telescope.

The key component of the Hummingbird is its propulsion system. It uses a rocket engine that runs on hydrazine fuel. More importantly, it holds a lot of that fuel. A fully assembled system is expected to weigh 25 kg “Dry”—meaning without propellant installed—whereas a fully fueled “Wet” system would weigh an estimated 80 kg. 

Travelling to a Lagrange Point is one of the things Hummingbird could do – Fraser explains why this points in space are important.

That would give Hummingbird plenty of “oomph” – enough to bring its orbital speed up to an estimated 3.5 km/s delta-V, which is required for getting to hard-to-reach objects like some near-Earth asteroids. However, it could also reach other, larger places, like Mars or even Venus, the various Lagrange points, or even Mars’ moons.

When it got there, the prototype of Hummingbird described in a paper presented back in 2013 would take images of its target world using an Exelis telescope. The manufacturer of this telescope has since been bought by Harris Systems, which was then rolled into L3Harris Technologies, the owner of Aerojet Rocketdyne. However, the authors stress that the payload itself was interchangeable and could be tailored to the mission that it was meant to scout.

The Hummingbird bus was also the fuel tank, and it had additional slots for CubeSat components. These components could be used for further data collection or data analysis. However, the paper doesn’t necessarily mention how Hummingbird would handle standard CubeSat operations, like attitude control or communications back to a ground station.

A CubeSat has already made its way to Mars – as described in the JPL video.
Credit – NASA Jet Propulsion Laboratory YouTube Channel

Those could likely have been worked out in future iterations. Additionally, the final design was published before the dramatically reduced cost of getting to orbit, which is now available – the authors don’t even mention a “Falcon” as a potential launch service. A lot has changed in the space industry in the last 11 years. Still, the idea behind Hummingbird, an inexpensive, adaptable platform for preliminary scouting missions to interesting places in the inner solar system, has yet to see its day in the Sun – the project did not appear to receive a Phase II SBIR grant, which could have continued its development. But maybe, someday, it or a similar system will see the light of interplanetary space.

Learn More:
C. Taylor et al – Hummingbird: Versatile Interplanetary Mission Architecture
UT – What Happened to those CubeSats that were Launched with Artemis I?
UT – A CubeSat Mission to Phobos Could Map Staging Bases for a Mars Landing
UT – We Could SCATTER CubeSats Around Uranus To Track How It Changes

Lead Image:
Computer-generated mockup of the Hummingbird spacecraft
Credit – C. Taylor et al.

The post A Cheap Satellite with Large Fuel Tank Could Scout For Interplanetary Missions appeared first on Universe Today.

Many ancient board games have been discovered, but there are no rulebooks so we don't know how to play them. Now AI is bringing these games back to life by working out likely rules

Google has unveiled a new quantum computer called Willow that excels at a benchmarking problem, but it still isn't clear whether these machines can serve a practical purpose

Google has unveiled a new quantum computer that excels at a benchmarking problem, but it still isn't clear whether these machines can serve a practical purpose

Higher or lower levels of certain proteins in your blood appear to indicate if your brain's age is older than your actual age

Don’t let the bright Moon deter you from seeing the one of the best meteor showers of the year.

One of the best meteor showers of 2024 closes out the year this coming weekend. If skies are clear, watch for the Geminid meteors, peaking on the night of Friday into Saturday, December 13-14th.

The Geminids in 2024

To be sure, the Geminids have a few strikes against them this year. Not only is it cold outside, but the Moon is near Full, 98% illuminated waxing gibbous at the shower’s max. But don’t despair: the shower hits its maximum at 3:00 Universal Time (UT) on December 14th (10:00 PM EST on the 13th) with a max Zenithal Hourly Rate of 120 meteors per hour. This means the shower will favor western Europe and North America, a plus. The radiant in Gemini near the bright star Castor (Alpha Geminorum) also means that the shower starts to be active in the late evening before local midnight.

The Geminid radiant, looking east on the evening of December 13th. Credit: Stellarium.

The source of the Geminids is none other than prolific ‘rock-comet’ 3200 Phaethon. Clearly, something intriguing is going on with this object. On a short 1.4 year orbit, 3200 Phaethon seems to blur the line between asteroid and semi-dormant comet nucleus. Japan wants to send its DESTINY+ mission to 3200 Phaethon in 2028 to get a closer look.

A radio animation of 3200 Phaethon. Credit: Arecibo/NASA/NSF

The Geminids have put on a show since 1862, though they seem to have really taken off in recent decades, surpassing the August Perseids as the best annual meteor shower of the year.

Fighting the Moon

The key to seeing any meteor shower at its best is to find dark skies and a clear, unobstructed horizon. The December Moon sits just a constellation away in Taurus at the shower’s peak… but keep in mind, the shower is also active on the evenings prior to and after the 14th. I plan to select my observing site with this in mind, and block the Moon behind a hill or tree. Early morning predawn observing will put the Moon lower to the horizon.

A sequence of Geminid meteors from 2014. Credit: Mary McIntyre.

There’s a reason the Moon is currently so high in the sky: not only is the Moon near the December Solstice and occupying the slot that the Sun will hold in June, but we’re headed towards a once every 18.6-year Major Lunar Standstill of the Moon in 2025.

A Geminid meteor all-sky camera view. Credit: Eliot Herman.

Observing and contributing to meteor shower science is as easy as watching, recording what you’re seeing at a designated interval, and reporting that count to the International Meteor Organization (IMO). Keep in mind, several other meteor showers are still active in mid-December, including the November Taurid fireballs and the Ursids, peaking on December 22nd. For imaging, I like to simply automate the process, and set a wide-field DSLR camera running on a tripod with an intervalometer to take timed exposure shots and see what turns up later in post processing. Aim the camera off to one side of the radiant by about 45 to 90 degrees to catch the Geminid meteors in profile.

Don’t miss the 2024 Geminids, as a fine way to round out sky-watching in 2024.

The post Our Strategy to Catch the 2024 Geminid Meteors appeared first on Universe Today.

The moving sofa problem, which involves negotiating furniture around an awkward hallway, has puzzled mathematicians for decades – but now we have an answer

As I predicted the controversy over whether or not we have achieved general AI will likely exist for a long time before there is a consensus that we have. The latest round of this controversy comes from Vahid Kazemi from OpenAI. He posted on X:

“In my opinion we have already achieved AGI and it’s even more clear with O1. We have not achieved “better than any human at any task” but what we have is “better than most humans at most tasks”. Some say LLMs only know how to follow a recipe. Firstly, no one can really explain what a trillion parameter deep neural net can learn. But even if you believe that, the whole scientific method can be summarized as a recipe: observe, hypothesize, and verify. Good scientists can produce better hypothesis based on their intuition, but that intuition itself was built by many trial and errors. There’s nothing that can’t be learned with examples.”

I will set aside the possibility that this is all for publicity of OpenAI’s newest O1 platform. Taken at face value – what is the claim being made here? I actually am not sure (part of the problem of short form venues like X). In order to say whether or not OpenAI O1 platform qualified as an artificial general intelligence (AGI) we need to operationally define what an AGI is. Right away, we get deep into the weeds, but here is a basic definition: “Artificial general intelligence (AGI) is a type of artificial intelligence (AI) that matches or surpasses human cognitive capabilities across a wide range of cognitive tasks. This contrasts with narrow AI, which is limited to specific tasks.”

That may seem straightforward, but it is highly problematic for many reasons. Scientific American has a good discussion of the issues here. But at it’s core two features pop up regularly in various definitions of general AI – the AI has to have wide-ranging abilities, and it has to equal or surpass human level cognitive function. There is a discussion about whether or not how the AI achieves its ends matters or should matter. Does it matter if the AI is truly thinking or understanding? Does it matter if the AI is self-aware or sentient? Does the output have to represent true originality or creativity?

Kazemi puts his nickel down on how he operationally defines general AI – “better than most humans at most tasks”. As if often the case, one has to frame such claims as “If you define X this way, then this is X.” So, if you define AGI as being better than most humans at most tasks, then Kazemi’s claims are somewhat reasonable. There is still a lot to debate, but at least we have some clear parameters. This definition also eliminated the thorny question of understanding and awareness.

But not everyone agrees with this definition. There are still many experts who contend that the modern LLM’s are still just really good autocompletes. They are language prediction algorithms that simulate thought through simulating language, but are not capable of true thought, understanding, or creativity. What they are great at is sifting through massive amounts of data and finding patterns, and then regenerating those patterns.

This is not a mere discussion of “how” LLMs function but gets to the core of whether or not they are “better” than humans at what they do. I think the primary argument against LLMs being better than humans is that they function by using the output of humans. Kazemi essentially says this is just how they learn, they are following a recipe like people do. But I think that dodges the key question.

Let’s take art as an example. Humans create art, and some artists are truly creative and can bring into existence new and unique works. There are always influences and context, but there is also true creativity. AI art does not do this. It sifts through the work of humans, learns the patterns, and then generates imitations from those patterns. Since AI does not experience existence, it cannot draw upon experience or emotions or the feeling of what it is to be a human in order to manifest artistic creativity. It just regurgitates the work of humans. So how can we say that AI is better than humans at art when it is completely dependent on humans for what it does? The same is true for everything LLMs do, but it is just more obvious when it comes to art.

I am not denigrating LLMs or any modern AI as extremely useful tools. They are powerful, and fast, and can accomplish many great tasks. They are accelerating the rate of scientific research in many areas. They can improve the practice of medicine. They can help us control the tsunami of data that we are drowning ourselves in. And yes, they can do a lot of different tasks.

Perhaps it is easier to define what is not AGI. A chess-playing computer is not AGI, as it is programmed to do one task. In fact, the term AGI was developed by programmers to distinguish this effort from the crop of narrow AI applications that were popping up, like Chess and Go players. But is everything that is not a very narrow AI an AGI? Seems like we need more highly specific terms.

OpenAI and other LLMs are more than just the narrow AIs of old. But they are not thinking machines, nor do they have human-level intelligence. They are also certainly not self-aware. I think Kazemi’s point about a trillion parameter deep neural net misses the point. Sure, we don’t know exactly what it is doing, but we know what it is not doing, and we can infer from it’s output and also how it’s programmed the general way that it is accomplishing its outcome. There is also the fact that LLMs are still “brittle” – a term that refers to the fact that narrow AIs can be easily “broken” when they are pushed beyond their parameters. It’s not hard to throw an LLM off its game and push the limits of it’s ability. It still has not true thinking or understanding, and this makes it brittle.

For that reason I don’t think that LLMs have achieved AGI. But I could be wrong, and even if we are not there yet we may be really close. But regardless, I think we need to go back to the drawing board, look at what we currently have in terms of AI, and experts need to come up with perhaps new more specific operational definitions. We do this in medicine all the time – as our knowledge evolves, sometimes we need for experts to get together and revamp diagnostic definitions and make up new diagnoses to reflect that knowledge. Perhaps ANI and AGI are not enough.

To me LLMs seems like a multi-purpose ANI, and perhaps that is a good definition. Either “AGI” needs to be reserved for an AI that can truly derive new knowledge from a general understanding of the world, or we “downgrade” the term “AGI” to refer to what LLMs currently are (multi-purpose but otherwise narrow) and come up with a new term for true human-level thinking and understanding.

What’s exciting (and for some scary) is that AIs are advancing quickly enough to force a reconsideration of our definitions of what AIs actually are.

The post Have We Achieved General AI first appeared on NeuroLogica Blog.

You might expect a child's belief in Santa Claus – with his ability to discern whether children have been naughty or nice – would have an impact on their behaviour. But it turns out other festive trappings like Christmas jumpers and carols may play a more important role

A technology that packs more optical fibre connections onto chips could let them transmit 80 times as much information, speeding up AI training and slashing data centre energy costs

Meanwhile, in Dobrzyn, Hili is on the alert:

Hili: The Chinese are coming!
A: You must be confused.
Hili: So maybe it’s somebody else.

Hili: Chińczycy idą!
Ja: Chyba ci się coś pomyliło.
Hili: To może jacyś inni.

On BlueSky, Jack Ashby is continuing his observations of the duckbilled platypus:

Perfect #platypus – you can see how they change from swimming to waddling to slithering depending on how deep the water is.#MonotremeMonday #fieldwork #Tasmania #MammalWatching #platypuses #WildOz

— Jack Ashby (@jackdashby.bsky.social) 2024-12-09T08:22:33.461Z

And Ze Frank is exploring how species are named:

Since the nomination of Dr. Jay Bhattacharya for NIH Director, I've been seeing a suggestion from certain contrarian doctors for a a "randomized trial" of study sections vs. a "modified lottery" to determine which grant applications are funded by the NIH. Just what the heck is Dr. Vinay Prasad talking about?

The post Are NIH study sections a waste of time? first appeared on Science-Based Medicine.

A new vortex electric field with the potential to enhance future electronic, magnetic and optical devices has been observed by researchers.

The standard theory of cosmology is based upon four things: the structure of space and time, matter, dark matter, and dark energy. Of these, dark energy is the one we currently understand the least. Within the standard model, dark energy is part of the structure of space and time as described by general relativity. It is uniform throughout the cosmos and expressed as a parameter known as the cosmological constant. But initial observations from the Dark Energy Spectroscopic Instrument (DESI) suggest the rate of comic expansion may vary over time. If further observations reinforce this, it could open up cosmological models to alternatives to general relativity known as modified gravity.

In a recent paper on the arXiv, the authors look at one version of modified gravity known as Horndeski’s theory. The theory is based upon a generalization of general relativity. Einstein’s original theory was based upon the principle of equivalence, from which he derived a generalized description of spacetime through what is known as a metric tensor. From this, you can derive the equations of motion for objects in a gravitation field, just as Newton’s laws lead to equations of motion for objects under physical and gravitational forces.

General relativity is the simplest model with a metric tensor. Horndeski’s theory is the most general model with a metric tensor and allows for the presence of a uniform scalar field. There are special cases of Horndeski’s theory, such as the Brans-Dicke model and the model of quintessence. Both of these models have been used to describe dark energy in a more general way, as well as dark matter in some cases. While observations of gravitational waves, galactic clustering and cosmic expansion constrain these models to some degree, they don’t entirely rule them out. So far, our data on dark energy isn’t rich enough to distinguish between alternatives.

Comparison between standard model and modified gravity. Credit: Chudaykin and Kunz

This latest work looks at the DESI results in the context of Horndeski models, specifically looking at how it might address the time-evolution of cosmic expansion suggested by the DESI data. It found that if the time evolution is taken to be correct, then a modified gravity is a better fit than the standard model. The study goes on to show that Horndeski models only work where the time evolution of the scalar field correlates to the proposed time evolution of dark matter. This rules out some Horndeski models that have been used to explain dark matter.

Overall, the authors argue that the DESI observations make Horndeski’s theory a viable alternative to general relativity. That is, if the data holds up. The Dark Energy Spectroscopic Instrument is still in its early stages, and we don’t yet know what the final results will be. But it is clear that Einstein’s seat on the theoretical throne isn’t entirely assured, and Horndeski’s theory might just be the one to steal the crown.

Reference: Chudaykin, Anton, and Martin Kunz. “Modified gravity interpretation of the evolving dark energy in light of DESI data.” arXiv preprint arXiv:2407.02558 (2024).

The post Observations by DESI Open the Door to Modified Gravity Models appeared first on Universe Today.

Meanwhile, in Dobrzyn, Hili is coming to terms with the inevitable.

Hili: I’m thinking whether to go for a walk.
A: And what is your conclusion?
Hili: It’s not the right season.

Hili: Zastanawiam się, czy iść na spacer.
Ja: I jaki wniosek?
Hili: Niewłaściwa pora roku.

The nature of dark matter has been a hotly debated topic for decades. If it’s a heavy, slow moving particle then it’s just possible that neutrinos may be emitted during interactions with normal matter. A new paper proposes that Jupiter may be the place to watch this happen. It has enough gravity to capture dark matter particles which may be detectable using a water Cherenkov detector. The researchers suggest using a water Cherenkov detector to watch for excess neutrinos coming from the direction of Jupiter with energies between 100 MeV and 5 GeV.

Jupiter is the largest planet in the solar system, large enough to swallow up all the planets and have a little room to spare. It’s composed mainly of hydrogen and helium and  is devoid of a solid surface. Of all the planets, Jupiter has a powerful magnetic field and a strong gravitational field. It’s gravitational field is so powerful that, over the years, it has attracted, and even destroyed comets like Shoemaker-Levy 9 back in 1994. Of all the features visible in the planet’s atmosphere, the giant storm known as the Great Red Spot is by far the most prominent. 

Image of Jupiter taken by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) in July 2022 displays striking features of the largest planet in the solar system in infrared light, with brightness indicating high altitudes. One of these features is a jet stream within the large bright band just above Jupiter’s equator, which was the focus of this study. (Credit: NASA, ESA, CSA, STScI, R. Hueso (University of the Basque Country), I. de Pater (University of California, Berkeley), T. Fouchet (Observatory of Paris), L. Fletcher (University of Leicester), M. Wong (University of California, Berkeley), J. DePasquale (STScI))

Planets in the solar system would, until now, be the last place to go hunting for dark matter. This mysterious stuff is invisible to all normal detection methods but is thought to make up 27% of the universe, outweighing visible matter at 5% (the majority of remainder made up of dark energy.) As its name suggests, dark matter doesn’t emit, absorb or reflect light making it hard to observe. It’s existence has been inferred from the gravitational effects on galaxies, galaxy clusters and the largest scale structures of the universe. Despite its prominence in the universe, the nature of it remains largely unknown. 

Researchers are making progress mapping dark matter, but they don’t know what it is. This is a 3D density map of dark matter in the local universe, with the Milky Way marked by an X. Dots are galaxies, and the arrows indicate the directions of motion derived from the reconstructed gravitational potential of dark matter. Image Credit: Hong et al., doi: 10.3847/1538-4357/abf040.

Dark matter is measured in GeV because this is a standard method in high energy physics to express the mass of particles. Until recently attempts to detect dark matter have relied upon experiments where dark matter is scattered with electrons, protons or neutrons in a detector. The interactions cause energy transfers which then reveal he presence of dark matter. 

A view of the Large Underground Xenon (LUX) dark matter detector. Shown are photomultiplier tubes that can ferret out single photons of light. Signals from these photons told physicists that they had not yet found Weakly Interacting Massive Particles (WIMPs) Credit: Matthew Kapust / South Dakota Science and Technology Authority

In a paper by Sandra Robles from Kings College London and Stephan Meighen-Berger from the University of Melbourne, they propose and calculate the level of annihilating dark matter neutrinos within Jupiter and whether they could be detected using existing neutrino observatories. The team also propose a way to use of water Cherenkov detectors which are designed to detect high-energy particles such as neutrinos or cosmic rays. This is achieved by capturing Cherenkov radiation emitted while they travel through water. To give context to the process, the radiation is optical and occurs when a charged particle moves through a medium like water producing a faint flash of blue light. 

The team suggest Jupiter is an ideal location to hunt for dark matter using Cherenkov radiation detectors. It’s low core temperature and significant gravitational attraction will mean it could capture dark matter and retain it.  The presence of neutrinos in the direction of Jupiter reveals the capture and annihilation of dark matter. A similar technique is used by observing the Sun. 

Source : Extending the Dark Matter Reach of Water Cherenkov Detectors using Jupiter

The post Using Jupiter as a Dark Matter Detector appeared first on Universe Today.

Doctors who profit in any way by normalizing RFK Jr. should be calmly and politely reminded of this at every opportunity for the rest of their careers. They are not entitled to a safe space.

The post Actually Dr. Adam Cifu, It’s Fine to “Attack” Doctors Who Profit By Spreading Pro-RFK Jr. Propaganda first appeared on Science-Based Medicine.

Through the Artemis Program, NASA hopes to lay the foundations for a program of “sustained lunar exploration and development.” This will include regular missions to the surface, the creation of infrastructure and habitats, and a long-term human presence. To facilitate this, NASA is teaming up with industry and international partners to develop Human Landing Systems (HLS) that can transport crews to and from the lunar surface and landers that can deliver payloads of equipment, vehicles, and supplies to the lunar surface.

In a recent statement, NASA indicated that it intends to award Blue Origin and SpaceX additional work under their existing contracts to develop landers that will deliver equipment and infrastructure to the lunar surface. NASA also plans to assign demonstration missions to these companies, in addition to design certification reviews, which will validate their concepts. This decision builds on NASA’s earlier request, made in 2023, that the two companies develop cargo versions of their HLS concepts, which are currently in development for the Artemis III, Artemis IV, and Artemis V missions.

Stephen D. Creech, the Assistant Deputy Associate Administrator (Technical) for the Moon to Mars Program Office, explained in the NASA statement:

“NASA is planning for both crewed missions and future services missions to the Moon beyond Artemis V. The Artemis campaign is a collaborative effort with international and industry partners. Having two lunar lander providers with different approaches for crew and cargo landing capability provides mission flexibility while ensuring a regular cadence of Moon landings for continued discovery and scientific opportunity.”

In previous statements issued in April and September of this year, NASA has emphasized the need for vehicles that can accommodate heavy payload deliveries – between 2,000 and 6,000 kg (4,400 and 13,000 pounds) to the Moon to accommodate the Artemis missions. Per the latest, NASA indicates that it plans for at least two heavy payload missions that will deliver elements of the Artemis Base Camp to the Moon. These large cargo landers must have the capacity and capability of landing approximately 12 to 15 metric tons (13 to 16.5 U.S. tons) of heavy cargo on the lunar surface.

The two missions will see SpaceX using a cargo lander version of their Starship to deliver the Habitable Mobility Platform (HMP) – a pressurized rover currently being developed by the Japan Aerospace Exploration Agency (JAXA) – no earlier than 2032 in support of Artemis VII and later missions. Meanwhile, the agency expects Blue Origin to deliver the Lunar Surface Habitat (LSH) element using its Blue Moon lander no earlier than 2033. Said Dr. Lisa Watson-Morgan, program manager for NASA’s Human Landing System:

“Based on current design and development progress for both crew and cargo landers and the Artemis mission schedules for the crew lander versions, NASA assigned a pressurized rover mission for SpaceX and a lunar habitat delivery for Blue Origin. These large cargo lander demonstration missions aim to optimize our NASA and industry technical expertise, resources, and funding as we prepare for the future of deep space exploration.”

SpaceX and Blue Origin will continue to develop their cargo lander concepts and prepare for demonstration missions as part of their NextSTEP Appendix H (Option B) and NextSTEP Appendix P contracts (respectively). NASA plans to issue an initial request for both proposals by early 2025.

Further Reading: NASA

The post NASA has Plans for More Cargo Deliveries to the Moon appeared first on Universe Today.

Telescopes in space have a huge advantage over those on the ground: they can see the universe more clearly. The Earth’s atmosphere, weather conditions, and low-flying satellites don’t obscure their view. But space telescopes have a disadvantage too. They can’t be repaired, at least not since NASA’s Space Shuttle program ended in 2011.

But next-generation telescopes are being planned with robotic servicing missions in mind. And not just in low earth orbit, where the Hubble Space Telescope received repairs and upgrades five times during its lifespan from space shuttle crews. Today’s engineers are preparing for ways to repair telescopes in deep space, including at the Sun-Earth Lagrange point L2.

L2 is the current home of the James Webb Space Telescope (JWST) and ESA’s Gaia mission. In this position, the Earth is kept between the Sun and the telescopes, giving them pristine conditions for observing the universe.

“While neither Gaia nor JWST were explicitly designed to be serviceable, next-generation space telescopes now in development include serviceability in their baseline designs,” write the authors of a new paper from a team at the Grainger College of Engineering, University of Illinois Urbana-Champaign.

Service spacecraft could attach themselves to derelict telescopes, bringing extra fuel, working reaction wheels, or even repairing damaged mirrors and other key components.

But it isn’t an easy task.

Artist’s illustration showing the location of the Sun-Earth Lagrange Points. Credit: NASA

The University of Illinois team, including Professor Siegfried Eggl and Ruthvik Bommena, used Gaia and JWST as test subjects to design a feasible service mission.

“Gaia is like a rotating cylinder with a solar panel. It is encapsulated, so it hasn’t been damaged, but after a decade out there it’s running low on fuel,” said Eggl in a press release. “Ruthvik Bommena designed a novel concept to add a sort of spider-looking attachment that can extend its life without impeding its data collection. Gaia will be decommissioned soon, so there isn’t enough time to reach it, but the James Webb might still be a possibility because it will be operating for several more years and they may decide to prolong its mission.”

JWST’s exposed mirrors have already been struck by micrometeorites multiple times, affecting the quality of its observations.

“We’re trying to stay a step ahead so there is a plan to replace broken mirrors, for example. If we don’t, it’s like buying an expensive sports car, then like throwing it away when it runs out of gas,” says Eggl.

One of the most significant barriers to long-distance servicing missions is designing a trajectory for rendezvous with the target.

“A spacecraft sent to repair or refuel a telescope needs to brake when it reaches it,” Bommena said. “Using the thrusters to slow down would be like pointing a blowtorch at the telescope. You don’t want to do that to a delicate structure like a telescopic mirror. How do we get there without torching the whole thing?”

In addition, the team is working to optimize both fuel efficiency and cost for such a mission.

As Professor Robyn Wollands, another author on the paper explains, “getting there is doable because of some hidden highways in our solar system. We have a trajectory that is optimal for the size of spacecraft needed to repair the JWST,” she said.

These ‘hidden highway’s are geometrically optimal paths that take advantage of orbital mechanics to make rendezvous safe and cost-efficient. The team have developed a new way to calculate and evaluate these optimal paths.

“After we create a map of initial solutions, we use optimal control theory to generate optimal end-to-end trajectories,” said PhD student Alex Pascarella. “Optimal control allows us to find trajectories that depart near Earth, and rendezvous with our space telescope in the least amount of time. The initial sampling of the solution space is fundamental—optimal control problems are notoriously difficult to solve, so we need a decent initial guess to work with.

“The novelty is in how we brought together two separate approaches to trajectory design: dynamical systems theory and optimal control theory,” Pascarella added.

With teams like this one laying the groundwork, the lifespan of space telescopes might be extended long past their original best-before date, and that’s good news for astrophysicists and space programs worldwide.

Learn More:

Alex Pascarella, Ruthvik Bommena, Siegfried Eggl, Robyn Woollands, “Mission design for space telescope servicing at Sun–Earth L2.” Acta Astronautica.

“A mission design for servicing telescopes in space.” EurekAlert.

The post Space Telescopes Could See a Second Life With a Servicing Mission appeared first on Universe Today.

It’s a mere 18 days until Christmas and, of course, the First Day of Coynezaa.  Both festivities are marked by an overconsumption of food, and Coynezaa enjoys the advantage of having no religious overtones save encomiums for Professor Ceiling Cat (Emeritus).

Here in Katowice, in southern Poland, the Christmas Market is already in full swing in the town square, and I happened upon it walking back from the Silesian Science Festival (today I registered, tomorrow and Monday I speak). It was exactly what I’d expect a Polish Christmas market to be: full of fun, food, and just a bit of religion in the form of singing angels (not shown). Here are a few holiday snaps I took while crossing the town square.

Yep, here’s where we are:

Katowice has an ancient history, but lacks the charm of other Polish cities for two reasons: it was an industrial hub for mining coal and steel, and, under German occupation, many of its landmarks were wrecked, including the Great Synagogue, shown below next to the City Baths. It was completed in 1900 and razed by the Germans in 1939.  And of course most of the Jews were killed or sent away to be murdered.

Photo from public domain, Wikipedia.

An old building that remains in the city square:

Here is a monument that I take to be in honor of the local miners. Note the flowers and miner’s lamp at the base:

And everywhere people were having fun and laughing, expecially the kids. This one got a big soap bubble:

But the adults were also having a great time. There are various plastic status behind which you can stick your face to get a photograph. Like these people:

A penguin:

And a train chugging the kids through the market:

But of course people were there to get stuff, too: mostly food. Like these roasted chestnuts:

And look at this inventive and mouth-watering display of lollipops:

And, of curse, gingerbread, a Polish speciality for the holidays:

Very fancy gingerbread. These say “Happy Christmas” in Polish:

Various candies (caramels?), some of them flavored with booze (“piwo” is beer):

And what is a Polish market without sausages?

There were stalls selling non-comestibles, too. This one carried a variety of soaps, including these cat soaps in lavender and lily-of-the-valley (“kot” is “cat” in Polish):

Walking back to my hotel on the shopping street, I saw a big line in front of one shop. It was selling a variety of soft pretzels, and I would have joined the line had it been shorter:

There was a variety, including non-twisted pretzels filled with Nutella. The cinnamon pretzels were nearly sold out:

But below is a store selling the quintessence of Polish baked treats: pączki.  Wikipedia describes them:

A pączek is a deep-fried piece of dough shaped into a flattened ball and filled with confiture or other sweet filling. Pączki are usually covered with powdered sugar, icing, glaze, or bits of dried orange zest. A small amount of grain alcohol (traditionally rectified spirit) is added to the dough before cooking; as it evaporates, it prevents the absorption of oil deep into the dough.  Pączki are commonly thought of as fluffy but somewhat collapsed, with a bright stripe around them; these features are seen as evidence that the dough was fried in fresh oil.

Although they look like German berliners (bismarcks in North America) or jelly doughnuts, pączki are made from especially rich dough containing eggs, fats, sugar, yeast, and sometimes milk.

(Note that when JFK proclaimed himself “Ich bin ein Berliner” in Germany in June, 1963, his attempt to forge solidarity with the divided people of that city actually meant, in German, “I am a jelly donut.”  He should have said “Ich bin Berliner.”)

Believe me; these pastries are superb! The only thing preventing me from trying one or three was that I was full from the ample spread of goodies in the Science Festival’s VIP room, to which I have access as a speaker. But have a look at these puppies! There are four zloty to the dollar, so each large filled pastry is about two bucks.

Happy Christmas from Poland!