It will be here next month!

Ok, now that the shameless self-promotion is out of the way, we can get on to Lucy.

There has been a lot of buzz surrounding the launch of the LUCY spacecraft to explore “Trojan” asteroids that orbit with Jupiter.

The L4 swarm, which is located about 60 degrees ahead of Jupiter in its orbit, and the L5 swarm, is found at the same distance behind the giant planet.

Usually when NASA/JPL launches deep space probes with long missions such as this one the spacecraft is powered primarily by a plutonium generator to keep things moving and reliable. In our present era, those have been ruled politically incorrect, so LUCY will be solar powered even though the Sun looks like a dim flashlight from Jupiter.

Read more on the solar array glitch here.

Finding a solution that may work required that much more money be spent on the project than would otherwise be the case. $981 million. And who knows if it will work? (more here) We should have stuck with plutonium generators.

No probe has flown by these smallish Trojan asteroids, which are clustered at stable LaGrange points trailing and ahead of Jupiter’s orbit 5.2 astronomical units from the Sun. The asteroids are mostly dark but may be covered with tholins, which are organic compounds that could provide raw materials for the basic chemicals of life.

This diagram illustrates Lucy’s orbital path. The spacecraft’s path (green) is shown in a frame of reference where Jupiter remains stationary, giving the trajectory its pretzel-like shape.

 

White Dwarf Star

(Link) Astronomers have observed a white dwarf star ‘switching on and off’ in less than 30 minutes. The researchers, led by Durham University in the United Kingdom, announced on October 18 that they used NASA’s Transiting Exoplanet Survey Satellite (TESS) to observe the unusual phenomenon, which had previously only been observed over a period of days and months. The British university team observed the phenomenon in the solar system TW Pictoris, which is 1,400 light-years away from Earth, using TESS data.

University of Durham researchers said that the particular white dwarf which showed the phenomena is known to be “accreting or feeding from an orbiting companion star. Our astronomers saw it lose brightness in 30 minutes, a process only previously seen in accreting white dwarfs over a period of several days to months.”

The researchers also noted in the statement that when the system ‘abruptly’ turns ‘off,’ the magnetic field of the white dwarf star spins so fast that it hinders the amount of ‘food’ that the white dwarf star can receive. According to astronomers, this is known as magnetic gating. The shortage of ‘food’ for the star leads to “semi-regular small increases in brightness seen by the astronomers. After some time, the system sporadically turns “on” again, and the brightness increases back to its original level.”

18 COMMENTS

    • …and failing power.

      Incidentally, ours is out for the entire day here….“line upgrades”, which should help reduce intermittent outages this Winter. Should be a test for the unprepared despite preemptive texts, emails, and robo-calls. Going wind and solar will have this occur every other week. Embrace crappy power.

      • There’s a LOT of electrical system upgrades going on around here. In the first two wweeks of my son’s new job, he’s been on five locations where new power poles are being put in, along with additional cabling on the poles to support higher capacity electric service.

        One of the places was to replace burned out stuff from the fires last year, and he said the homeowners in the area were ecstatic that things were getting repaired and upgraded.

        • Us too. REA does a good job and planned this out as best one could. A tiny inconvenience. I once asked the service guy to leave me the breaker reset pole as it was always the same one on the main North-South line when snow or ice would pop it. Now they upgraded them to blink when they are in a fault condition.

    • I’m mighty proud that we have our first tranny four-star. It shows how the Navy will reach down to the very dregs of humanity, raise them and shower them with gold and power. What a country.

  1. I’m all for solar when it works, and in certain applications it actually is a good thing. But it always must be supplemented by backup systems.

    The radio-isotope generator? None have ever gone wrong. And a smaller footprint for the satellite, the mass could be used for more instruments, better armoring, more reaction mass.

    But no. Radioactive power systems are a big no-no because butthurt environmentalists and watermelons.

    Screw it. If I was in charge, nothing would lift with just solar power (and solar power panels have led to at least one satellite failing spectacularly, and I also remember Skylab that was screwed up due to solar panels (and the huge sail area contributed to the degradation of Skylab’s orbit.) If only we had radio-isotope generators on Skylab, probably could have rescued her, maybe.

    • Nuclear power is safe and effective for deep space probes where sunlight is oh, so dim. But sadly, it’s not “progressive”.

    • Boeing had some “issues” with a new design solar panel they were using on their satellites. The first two birds for XM Radio had defective panels, and Boeing wound up selling them XM-3 and XM-4 for something like half-price.

      Loral also had some serious issues their panels. They weren’t properly evacuated when they were sealed together, causing the glass covers to blow apart during ascent. The tried to sue Sea Launch, claiming that we damaged the spacecraft during launch, and then the same exact thing happened when they launched on Ariane.

      OOOPS! The data from both launches showed the exact same thing happening, and Loral had a very red face.

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