A propeller in Saturn’s A ring

A propeller in Saturn's A ring

Cool image time! The image on the right, cropped and reduced to show here, captures the same propeller feature in Saturn’s A ring, with the top image showing the sunlight side and the bottom image the side away from the Sun.

Cassini scientists have been tracking the orbit of this object for the past decade, tracing the effect that the ring has upon it. Now, as Cassini has moved in close to the ring as part of its ring-grazing orbits, it was able to obtain this extreme close-up view of the propeller, enabling researchers to examine its effects on the ring. These views, and others like them, will inform models and studies in new ways going forward.

…The propeller’s central moonlet would only be a couple of pixels across in these images, and may not actually be resolved here. The lit-side image shows that a bright, narrow band of material connects the moonlet directly to the larger ring, in agreement with dynamical models. That same thin band of material may also be obscuring the moonlet from view.

Lengthwise along the propeller is a gap in the ring that the moonlet has pried open. The gap appears dark on both the lit and unlit sides. Flanking the gap near the moonlet are regions of enhanced density, which appear bright on the lit side and more mottled on the unlit side.

The scale of the two images is slightly different, 0.33 and 0.44 miles, as they were taken as Cassini was zipping past during one of its ring-grazing orbits on February 21.

To my eye, the effect here faintly resembles a wake produced by a boat in water, except that the wake moves in opposite directions on opposite sides of the tiny moonlet as it plows through the A ring.

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Fascist protesters attack professor and speaker at Vermont college

Brownshirts: While leaving a speaking event at Middlebury College in Vermont, both political scientist Charles Murray and the college professor escorting him were attacked by protesters, causing injuries to the professor.

As Stanger, Murray and a college administrator left McCullough Student Center last evening following the event, they were “physically and violently confronted by a group of protestors,” according to Bill Burger, the college’s vice president for communications and marketing. Burger said college public safety officers managed to get Stanger and Murray into the administrator’s car.

“The protestors then violently set upon the car, rocking it, pounding on it, jumping on and try to prevent it from leaving campus,” he said. “At one point a large traffic sign was thrown in front of the car. Public Safety officers were able, finally, to clear the way to allow the vehicle to leave campus. “During this confrontation outside McCullough, one of the demonstrators pulled Prof. Stanger’s hair and twisted her neck,” Burger continued. “She was attended to at Porter Hospital later and (on Friday) is wearing a neck brace.”

I am willing to bet that these protesters would heartily agree with you if you proposed throwing all conservatives in prison camps.

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Two of five cameras on Japan’s Venus orbiter Akatsuki shut down

Japan has been forced to shut down operation on two of the five cameras on its Venus orbiter Akatsuki.

They think the problem has been caused by the additional five years required to get into Venus orbit when its main engine failed to fire during the first orbital attempt in 2010. During those five years the spacecraft was exposed to more radiation that expected, possibly damaging its equipment.

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College Republicans at Berkeley-UC continue to be threatened

Fascists: One day after a Berkeley student was filmed destroying property belonging to the College Republicans group at Berkeley-UC, the campus was plastered with posters calling its members “baby fascists”.

The posters included pictures of six members of the College Republicans group.

The college today issued a condemnation of the harassment, but as yet has not done anything about the students who have been doing the harassment, even though they have been videotaped in the act and have apparently been identified.

The Berkeley campus, much like most of urban California, has begun to resemble the Soviet Union. You better not dare to express any dissent against the liberal, Democratic Party agenda, or else you face harassment, violence, and outright hatred.

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Police arrest former journalist for bomb threats against Jewish centers

The police today arrested a former journalist, fired for making up quotes, for making some of the recent bomb threats nationwide against Jewish community centers.

Juan Thompson, 31, of St. Louis, was arrested in connection with the menacing messages sent by phone or email to Jewish organizations from coast to coast, authorities said. He invoked his girlfriend’s name in making four of the bomb threats, the FBI said in court papers. “Thompson appears to have made some of the … threats as part of a sustained campaign to harass and intimidate” the former girlfriend, according to an FBI complaint.

While this arrest is a good thing, it appears that there were others who made other bomb threats against Jewish sites in the past year or so that still remain at large.

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Blue Origin proposes unmanned lunar mission

The competition heats up: Blue Origin has proposed building for NASA an unmanned lunar mission to visit Shackleton Crater at the Moon’s south pole by 2020.

The Post says the company’s seven-page proposal, dated Jan. 4, has been circulating among NASA’s leadership and President Donald Trump’s transition team. It’s only one of several proposals aimed at turning the focus of exploration beyond Earth orbit to the moon and its environs during Trump’s term.

As described by the Post, the proposal seeks NASA’s support for sending a “Blue Moon” lander to Shackleton Crater near the moon’s south pole. The lander would be designed to carry up to 10,000 pounds of payload. It could be launched by Blue Origin’s New Glenn rocket, which is currently under development, or by other vehicles including NASA’s Space Launch System or United Launch Alliance’s Atlas 5. [emphasis mine]

The important take-away from this story is not the proposal to go to the Moon, but the proposal, as highlighted, that other rockets could do it instead of SLS. Though the proposal includes SLS as a possible launch vehicle, NASA’s giant rocket simply won’t be ready by 2020. That New Glenn might be illustrates again how much better private space does things, as this rocket is only now beginning development. If it is ready by 2020, which is what Blue Origin has been promising, it will have taken the company only about four years to build it, one fourth the time it is taking NASA to build SLS.

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Virgin Galactic spins off LauncherOne into its own division

The competition heats up: Virgin Galactic this week spun off its LauncherOne smallsat orbital rocket to form a new company called Virgin Orbit.

This split highlights the competition that actually existed within Virgin Galactic. Virgin Galactic’s SpaceShipTwo remains a very questionable design. Rather than have its problems suck the profits from LauncherOne, which has contracts and I firmly believe will fly first, the Virgin corporation has pulled it from Virgin Galactic so that the two rockets can succeed or fail on their own. In the end, I suspect now that Virgin Galactic will die and Virgin Orbit will succeed.

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China launches smallsat on new rocket

The competition heats up: China yesterday launched a small experimental satellite on new rocket, Kaituozhe-2 (KT-2).

The Xinhua news agency is identifying the new launch vehicle simply as ‘KT-2’. Other sources identify the new launcher as the Kaituo-2. Previously rumors expected that the new launch vehicle was the Kaituozhe-2A. The Kaituozhe-2/Kaituo-2 launch vehicle is a three-stage solid propellant launch vehicle developed by the “CASIC Forth Bureau”. The new launcher is capable of orbiting a 350 kg cargo to LEO or a 250 kg cargo to a 700 km high SSO.

KT-2 has similar capabilities to the Kuaizhou-1A launch vehicle, that was used for the first time on January 9, 2017. The KZ-1A is capable of orbiting a 300 kg satellite to LEO or a 200 kg payload to a 700km SSO. The other Chinese solid fuel launcher, the Long March 11 (Chang Zheng-11) rocket, is capable of orbiting a 750 kg to LEO or 350kg to a 700 km SSO.

With this fleet of small rockets, Chinese is now well positioned to grab market share in the emerging smallsat launch market. Their biggest problem remains the legal restrictions that prevent any American space technology from launching on Chinese rockets.

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SpaceX loses 89 smallsats due to delays

Spaceflight, a company that specializing in scheduling secondary payload launches for smallsat companies, this week pulled 89 satellites from SpaceX because of that company’s launch delays.

For more than a year, Seattle-based Spaceflight has been waiting to launch an array of 89 miniaturized satellites aboard a SpaceX Falcon 9 rocket and deploy them in orbit from its innovative SHERPA carrier.

Now the launch logistics company isn’t waiting any longer. All 89 satellites have been rebooked due to schedule concerns, Spaceflight’s president, Curt Blake, reported today in a blog posting. “We found each of our customers an alternative launch that was within the same time frame,” Blake wrote. “It took a huge effort, but within two weeks, the team hustled to have all customers who wanted to be rebooked confirmed on other launches!”

The SHERPA carrier had been slated as a secondary payload on the launch of Taiwan’s Formosat-5 satellite. It was put on SpaceX’s manifest since 2015, but the launch has been repeatedly delayed, in part due to the Falcon 9 rocket mishaps that occurred in mid-2015 and last September.

What is good about this is that the competition in the launch industry is now robust enough that these smallsats can find alternatives, and do it quickly. As good as SpaceX might be at some things, if the company doesn’s start fulfilling its promised launch schedule it will start to bleed customers more and more.

Unfortunately, the article doesn’t say which launch companies have now gotten this business. If I had to guess, I would bet that India got the contracts, based on their recent PSLV launch that put 103 smallsats into orbit. In arranging that launch ISRO had been very mobile, adding new smallsats to it quickly and very late in the launch schedule.

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China completes construction of space station core module

The competition heats up: China has completed the construction of the core module of its full size space station, now set to launch in 2018.

Tianhe-1, the first of three 20-tonne space station modules, was completed by the end of 2016 and has entered a testing phase, according to Bao Weimin of the China Aerospace Science and Technology Corporation (CASC). Tianhe-1 will launch from Wenchang on a new Long March 5 heavy-lift rocket sometime in 2018, which was developed specifically to allow China to put large space station modules into low Earth orbit.

The image of the module at the link is remarkable in its resemblance to the core module of Russia’s Mir station, launched in 1986.

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