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James Kerman
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Posts posted by James Kerman
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Both MarCO cubesats (EVE and WALL-E) have ceased communicating with NASA.
QuoteNow well past Mars, the daring twins seem to have reached their limit. It's been over a month since engineers have heard from MarCO, which followed NASA's InSight to the Red Planet. At this time, the mission team considers it unlikely they'll be heard from again.
MarCO, short for Mars Cube One, was the first interplanetary mission to use a class of mini-spacecraft called CubeSats. The MarCOs - nicknamed EVE and WALL-E, after characters from a Pixar film - served as communications relays during InSight's landing, beaming back data at each stage of its descent to the Martian surface in near-real time, along with InSight's first image. WALL-E sent back stunning images of Mars as well, while EVE performed some simple radio science.
All of this was achieved with experimental technology that cost a fraction of what most space missions do: $18.5 million provided by NASA's Jet Propulsion Laboratory in Pasadena, California, which built the CubeSats.
WALL-E was last heard from on Dec. 29; EVE, on Jan. 4. Based on trajectory calculations, WALL-E is currently more than 1 million miles (1.6 million kilometers) past Mars; EVE is farther, almost 2 million miles (3.2 million kilometers) past Mars.
The mission team has several theories for why they haven't been able to contact the pair. WALL-E has a leaky thruster. Attitude-control issues could be causing them to wobble and lose the ability to send and receive commands. The brightness sensors that allow the CubeSats to stay pointed at the Sun and recharge their batteries could be another factor. The MarCOs are in orbit around the Sun and will only get farther away as February wears on. The farther they are, the more precisely they need to point their antennas to communicate with Earth.
The MarCOs won't start moving toward the Sun again until this summer. The team will reattempt to contact the CubeSats at that time, though it's anyone's guess whether their batteries and other parts will last that long.
Even if they're never revived, the team considers MarCO a spectacular success.
"This mission was always about pushing the limits of miniaturized technology and seeing just how far it could take us," said Andy Klesh, the mission's chief engineer at JPL. "We've put a stake in the ground. Future CubeSats might go even farther."
A number of the critical spare parts for each MarCO will be used in other CubeSat missions. That includes their experimental radios, antennas and propulsion systems. Several of these systems were provided by commercial vendors, making it easier for other CubeSats to use them as well.
More small spacecraft are on the way. NASA is set to launch a variety of new CubeSats in coming years.
"There's big potential in these small packages," said John Baker, the MarCO program manager at JPL. "CubeSats - part of a larger group of spacecraft called SmallSats - are a new platform for space exploration that is affordable to more than just government agencies."
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My understanding of the outer space treaty means that host nations are responsible for approving rocket launches. I'd imagine this means NASA would still be the responsible body to approve or deny launches and I can't really see them allowing a crewed mission to fly without robust failure modes, even if they are not a customer.
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Insight has now made adjustments to its seismic sensor and has deployed its wind and thermal shield.
Image Credit: NASA/JPL-CaltechQuoteFor the past several weeks, NASA's InSight lander has been making adjustments to the seismometer it set on the Martian surface on Dec. 19. Now it's reached another milestone by placing a domed shield over the seismometer to help the instrument collect accurate data. The seismometer will give scientists their first look at the deep interior of the Red Planet, helping them understand how it and other rocky planets are formed.
The Wind and Thermal Shield helps protect the supersensitive instrument from being shaken by passing winds, which can add "noise" to its data. The dome's aerodynamic shape causes the wind to press it toward the planet's surface, ensuring it won't flip over. A skirt made of chain mail and thermal blankets rings the bottom, allowing it to settle easily over any rocks, though there are few at InSight's location.
An even bigger concern for InSight's seismometer - called the Seismic Experiment for Interior Structure (SEIS) - is temperature change, which can expand and contract metal springs and other parts inside the seismometer. Where InSight landed, temperatures fluctuate by about 170 degrees Fahrenheit (94 degrees Celsius) over the course of a Martian day, or sol.
"Temperature is one of our biggest bugaboos," said InSight Principal Investigator Bruce Banerdt of NASA's Jet Propulsion Laboratory in Pasadena, California. JPL leads the InSight mission and built the Wind and Thermal Shield. "Think of the shield as putting a cozy over your food on a table. It keeps SEIS from warming up too much during the day or cooling off too much at night. In general, we want to keep the temperature as steady as possible."
On Earth, seismometers are often buried about four feet (1.2 meters) underground in vaults, which helps keep the temperature stable. InSight can't build a vault on Mars, so the mission relies on several measures to protect its seismometer. The shield is the first line of defense.
A second line of defense is SEIS itself, which is specially engineered to correct for wild temperature swings on the Martian surface. The seismometer was built so that as some parts expand and contract, others do so in the opposite direction to partially cancel those effects. Additionally, the instrument is vacuum-sealed in a titanium sphere that insulates its sensitive insides and reduces the influence of temperature.
But even that isn't quite enough. The sphere is enclosed within yet another insulating container - a copper-colored hexagonal box visible during SEIS's deployment. The walls of this box are honeycombed with cells that trap air and keep it from moving. Mars provides an excellent gas for this insulation: Its thin atmosphere is primarily composed of carbon dioxide, which at low pressure is especially slow to conduct heat.
With these three insulating barriers, SEIS is well-protected from thermal "noise" seeping into the data and masking the seismic waves that InSight's team wants to study. Finally, most additional interference from the Martian environment can be detected by InSight's weather sensors, then filtered out by mission scientists.
With the seismometer on the ground and covered, InSight's team is readying for its next step: deploying the heat flow probe, called the Heat Flow and Physical Properties Package (HP3), onto the Martian surface. That's expected to happen next week.
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1 hour ago, RubyPetersen said:
I simply want to know which platform do you use to play this game?
I think the majority of players are using windows/Linux because of the ability to add mods and the speed of updates.
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The Statospheric Observatory For Infrared Astronomy (SOFIA) , a modified 747SP carrying 2.7-meter (106-inch) reflecting telescope will attempt to image Titans atmosphere as it flies through the moons shadow, cast on earth this evening.
Image Credit: NASA
The Australian Broadcasting Corporation has posted an article explaining the mission here:
https://www.abc.net.au/news/2019-02-01/sofia-flying-telescope-occultation-chasing-shadow-titan/10635802
Update: The mission was successful and the results will be compared with Cassini data to see if Titans atmosphere has changed over time.
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Sorry, posted in the wrong thread.
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45 minutes ago, Scorpion14 said:
I have done this multiple times, unfortunately nothing changes every time that I do it. And I am back with the same issue.
Sorry about that - maybe @bewing has more insight into the problem.
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“There is a distinct difference between having an open mind and having a hole in your head from which your brain leaks out.” James Randi
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Further research by Professor Jan Kramers, Dr Georgy Belyanin, PhD candidate Tebogo Makhubela and their team of the University of Johannesburg suggests the Hypatia stone may have a pre solar origin.
QuoteHypatia is thought to be a fragment of an extraterrestrial rock originally several meters long, which segmented into numerous pieces during its journey to Earth. It has a mineral composition unlike that of any meteorite we’ve seen. A chondritic meteorite’s chemical composition, for example, is similar to Earth’s, with high amounts of silicon and low amounts of carbon. (Chondritic meteorites are extremely common, making up about 86 percent of known meteorites.) Hypatia’s composition, however, is just the opposite, with unusually high amounts carbon and low amounts of silicon.
"Even more unusual, the matrix (the stone, inside which dust grains are embedded) contains a high amount of very specific carbon compounds, called polyaromatic hydrocarbons, or PAH, a major component of interstellar dust, which existed even before our solar system was formed,” said Prof. Jan Kramers, who led the study, in a press release.“Interstellar dust is also found in comets and meteorites that have not been heated up for a prolonged period in their history.”
Oddly enough, the majority of PAH in the matrix turned into tiny diamonds, no larger than one micrometer, likely due to the immense heat and pressure when Hypatia made contact with Earth’s atmosphere or surface. However, the diamonds weren’t the only surprise that researchers came across when they analyzed the mysterious stone. Geologist Georgy Belyanin also found unexpected chemical elements in the interstellar dust grains embedded throughout the stone, including a rare form of aluminum.
"The aluminum occurs in pure metallic form, on its own, not in a chemical compound with other elements. As a comparison, gold occurs in nuggets, but aluminum never does. This occurrence is extremely rare on Earth and the rest of our solar system, as far as is known in science," said Belyanin. "We also found silver iodine phosphide and moissanite (silicon carbide) grains, again in highly unexpected forms. The grains are the first documented to be found in situ (as is) without having to first dissolve the surrounding rock with acid," adds Belyanin. "There are also grains of a compound consisting of mainly nickel and phosphorus, with very little iron; a mineral composition never observed before on Earth or in meteorites."
A pre-solar origin
Hypatia’s abnormal composition implies that it’s made up of material that existed prior to the formation of the Sun and the planets in our solar system. But then, based on its composition, the question of how and where the iron, nickel, and phosphorus within Hypatia were formed arises.
These elements reside in the class of chemical heavier than carbon and nitrogen, which make up the majority of our rocky planets. "In the grains within Hypatia the ratios of these three elements to each other are completely different from that calculated for the planet Earth or measured in known types of meteorites. As such these inclusions are unique within our solar system," said Belyanin. "We think the nickel-phosphorus-iron grains formed pre-solar... and are unlikely to have been modified by shock such as collision with the Earth's atmosphere or surface, and also because their composition is so alien to our solar system."
The nickel-phosphorus-iron grains are likely dust that became embedded in the matrix of the stone, just as nuts and fruit are embedded in dough to make fruitcake. However, unlike the grains, Belyanin says that the matrix itself probably wasn’t pre-solar, as it would have needed a cloud of dense interstellar dust to form.
It’s believed that the solar nebula, a massive cloud of dust and gas, produced the Sun and the planets in our solar system. Planet formation likely began with concentration of the nebula’s solar dust, which has long been believed to be homogenous (the same throughout). However, Hypatia casts doubt on the homogenous theory.
"For starters, there are no silicate minerals in Hypatia's matrix, in contrast to chondritic meteorites (and planets like the Earth, Mars and Venus), where silicates are dominant. Then there are the exotic mineral inclusions. If Hypatia itself is not pre-solar, both features indicate that the solar nebula wasn't the same kind of dust everywhere — which starts tugging at the generally accepted view of the formation of our solar system," said Kramers.
Despite the shroud of mystery that hangs over Hypatia’s existence, we do know that it formed in an environment with temperatures colder than that of liquid nitrogen, which is about -384° Fahrenheit (-196° Celsius). We also know that it came from an area beyond the asteroid belt, which produces the majority of our meteorites, and the Kuiper Belt, where most of our comets come from. However, very little is known about the chemical compositions of deeper space objects.
Researchers continue to question the origin of this mysterious stone, and its clues only cast doubt over the distribution of elements inside the nebula that we believe formed our solar system.
Paper: https://www.sciencedirect.com/science/article/pii/S0016703717307962?via%3Dihub
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Welcome to the forum, @RoyCreditor.
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Spoiler38 minutes ago, kerbiloid said:
They did it... No more Planet Nine.
I believe 'It's either Alderaan debris or the Death Star is planet 9' was the alternate title of the paper. (just kidding)
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Another great video, Mate, Subscribed.
Understanding the source of these signals, even if they prove not to be communications but cosmic events, will improve our knowledge of the Universe.
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Welcome to our 'collective' @RockKrawler. I'd love to see an IVA created by a pilot.
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Welcome @Moostic. I'm glad you have found your path in life and I hope you go on to make great discoveries (and also post about them in the science and spaceflight subforum
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Welcome @MrSystems. Your spreadsheet surely beats my "Slap it on in the VAB and see" technique. Can't wait to try it.
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As at December 2017, there are around 2400 observed trans Neptunian objects. Modeling predicts billions to trillions of these objects so, as per the GB mantra, I think we need moar data.
Core region (38–49 AU): inclination (left) and eccentricity (right) vs. semi-major axis (a)
Full region on a logarithmic scale from 30 to 1000 AU: inclination (left) and eccentricity (right).
Images: https://commons.wikimedia.org/wiki/User:Rfassbind
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Researchers at the University of Cambridge and the American University of Beirut have proposed an alternate theory for the orbital anomalies that do not require a massive trans-Neptunian object.
Quote“The Planet Nine hypothesis is a fascinating one, but if the hypothesised ninth planet exists, it has so far avoided detection,” said co-author Antranik Sefilian, a PhD student in Cambridge’s Department of Applied Mathematics and Theoretical Physics. “We wanted to see whether there could be another, less dramatic and perhaps more natural, cause for the unusual orbits we see in some TNOs. We thought, rather than allowing for a ninth planet, and then worry about its formation and unusual orbit, why not simply account for the gravity of small objects constituting a disc beyond the orbit of Neptune and see what it does for us?”
Professor Jihad Touma, from the American University of Beirut, and his former student Sefilian modelled the full spatial dynamics of TNOs with the combined action of the giant outer planets and a massive, extended disc beyond Neptune. The duo’s calculations, which grew out of a seminar at the American University of Beirut, revealed that such a model can explain the perplexing spatially clustered orbits of some TNOs. In the process, they were able to identify ranges in the disc’s mass, its ‘roundness’ (or eccentricity), and forced gradual shifts in its orientations (or precession rate), which faithfully reproduced the outlier TNO orbits.
“If you remove planet nine from the model and instead allow for lots of small objects scattered across a wide area, collective attractions between those objects could just as easily account for the eccentric orbits we see in some TNOs,” said Sefilian, who is a Gates Cambridge Scholar and a member of Darwin College.
Earlier attempts to estimate the total mass of objects beyond Neptune have only added up to around one-tenth the mass of the Earth. However, in order for the TNOs to have the observed orbits and for there to be no Planet Nine, the model put forward by Sefilian and Touma requires the combined mass of the Kuiper Belt to be between a few to ten times the mass of the Earth.
“When observing other systems, we often study the disc surrounding the host star to infer the properties of any planets in orbit around it,” said Sefilian. “The problem is when you’re observing the disc from inside the system, it’s almost impossible to see the whole thing at once. While we don’t have direct observational evidence for the disc, neither do we have it for Planet Nine, which is why we’re investigating other possibilities. Nevertheless, it is interesting to note that observations of Kuiper belt analogues around other stars, as well as planet formation models, reveal massive remnant populations of debris.
“It’s also possible that both things could be true – there could be a massive disc and a ninth planet. With the discovery of each new TNO, we gather more evidence that might help explain their behaviour.”
The Paper: Shepherding in a Self-Gravitating Disk of Trans-Neptunian Objects
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JPL has released an update on Opportunity.
QuoteEngineers at NASA's Jet Propulsion Laboratory in Pasadena, California, have begun transmitting a new set of commands to the Opportunity rover in an attempt to compel the 15-year-old Martian explorer to contact Earth. The new commands, which will be beamed to the rover during the next several weeks, address low-likelihood events that could have occurred aboard Opportunity, preventing it from transmitting.
The rover's last communication with Earth was received June 10, 2018, as a planet-wide dust storm blanketed the solar-powered rover's location on Mars.
"We have and will continue to use multiple techniques in our attempts to contact the rover," said John Callas, project manager for Opportunity at JPL. "These new command strategies are in addition to the 'sweep and beep' commands we have been transmitting up to the rover since September." With "sweep and beep," instead of just listening for Opportunity, the project sends commands to the rover to respond back with a beep.
The new transmission strategies are expected to go on for several weeks. They address three possible scenarios: that the rover's primary X-band radio - which Opportunity uses to communicate with Earth - has failed; that both its primary and secondary X-band radios have failed; or that the rover's internal clock, which provides a timeframe for its computer brain, is offset. A series of unlikely events would need to have transpired for any one of these faults to occur. The potential remedies being beamed up to address these unlikely events include a command for the rover to switch to its backup X-band radio and commands directed to reset the clock and respond via UHF.
"Over the past seven months we have attempted to contact Opportunity over 600 times," said Callas. "While we have not heard back from the rover and the probability that we ever will is decreasing each day, we plan to continue to pursue every logical solution that could put us back in touch."
Time is of the essence for the Opportunity team. The "dust-clearing season" - the time of year on Mars when increased winds could clear the rover's solar panels of dust that might be preventing it from charging its batteries - is drawing to a close. Meanwhile, Mars is heading into southern winter, which brings with it extremely low temperatures that are likely to cause irreparable harm to an unpowered rover's batteries, internal wiring and/or computer systems.
If either these additional transmission strategies or "sweep and beep" generates a response from the rover, engineers could attempt a recovery. If Opportunity does not respond, the project team would again consult with the Mars Program Office at JPL and NASA Headquarters to determine the path forward.
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Welcome to the forum, @Plebeian.
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Welcome to the forum, @Kerbal Madness. Cool channel you've got there, Mate.
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1 hour ago, Xd the great said:
I can do it for free. On ksp. With kerbals.
I also originally thought it was a cool but silly idea however after reading further, it is probable ALE-1 will be deployed for the 2020 Tokyo Olympic games.
Image Credit: ALE Co Ltd
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One of the secondary payloads on this launch was from a Japanese company, ALE Co. Ltd, who intend to provide artificial meteor showers on demand.
Quote"I was too moved for words," Lena Okajima, president of the company behind the artificial meteor showers, told the Jiji Press agency. "I feel like now the hard work is ahead."
The company ALE Co. Ltd plans to deliver its first out-of-this-world show over Hiroshima in the spring of 2020. The satellite launched Friday carries 400 tiny balls whose chemical formula is a closely-guarded secret. That should be enough for 20-30 events, as one shower will involve up to 20 stars, according to the company. ALE's satellite, released 500 kilometres (310 miles) above the Earth, will gradually descend to 400 kilometres over the coming year as it orbits the Earth.
Worldwide meteor shower shows
The company plans to launch a second satellite on a private-sector rocket in mid-2019. ALE says it is targeting "the whole world" with its products and plans to build a stockpile of shooting stars in space that can be delivered across the world. When its two satellites are in orbit, they can be used separately or in tandem, and will be programmed to eject the balls at the right location, speed and direction to put on a show for viewers on the ground. Tinkering with the ingredients in the balls should mean that it is possible to change the colours they glow, offering the possibility of a multi-coloured flotilla of shooting stars. Each star is expected to shine for several seconds before being completely burned up—well before they fall low enough to pose any danger to anything on Earth. They would glow brightly enough to be seen even over the light-polluted metropolis of Tokyo, ALE says. If all goes well, and the skies are clear, the 2020 event could be visible to millions of people, it says. Okajima has said her company chose Hiroshima for its first display because of its good weather, landscape and cultural assets. ALE is working in collaboration with scientists and engineers at Japanese universities as well as local government officials and corporate sponsors.
It has not disclosed the price for an artificial meteor shower.
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4 hours ago, The Aziz said:
Actually, KER can tell you when to launch at the an/dn if you set a target.
Under the RDZV tab in KER you see relative inclination and times to An/Dn in a landed vessel.
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It's going to be huge!
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Hello and Welcome!
in Welcome Aboard
Posted
Welcome to the forum, @Lankspace. I love the game too and it is responsible for my interest in science and spaceflight. The forum is host to some great amateur astronomers, lots of STEM members and If you enjoy coding, the game has a vibrant modding community. I'm sure you'll fit right in.