Author: Robert Zimmerman

Astronomers discover white dwarf stars still burning hydrogen

9:50 am

The uncertainty of science: Using Hubble observations of the white dwarfs in two different globular clusters, astronomers have discovered that — contrary to the consensus opinion — some white dwarf stars are not slowly cooling embers of a dead star, but are still generating nuclear fusion by burning hydrogen in their outer layers.

Using Hubble’s Wide Field Camera 3 the team observed [globular clusters] M3 and M13 at near-ultraviolet wavelengths, allowing them to compare more than 700 white dwarfs in the two clusters. They found that M3 contains standard white dwarfs, which are simply cooling stellar cores. M13, on the other hand, contains two populations of white dwarfs: standard white dwarfs and those which have managed to hold on to an outer envelope of hydrogen, allowing them to burn for longer and hence cool more slowly.

Comparing their results with computer simulations of stellar evolution in M13, the researchers were able to show that roughly 70% of the white dwarfs in M13 are burning hydrogen on their surfaces, slowing down the rate at which they are cooling.

This discovery could have consequences for how astronomers measure the ages of stars in the Milky Way galaxy. The evolution of white dwarfs has previously been modeled as a predictable cooling process. This relatively straightforward relationship between age and temperature has led astronomers to use the white dwarf cooling rate as a natural clock to determine the ages of star clusters, particularly globular and open clusters. However, white dwarfs burning hydrogen could cause these age estimates to be inaccurate by as much as 1 billion years.

In other words, many past age estimates for star clusters could be very wrong, which in turn could mean the general understanding of the evolution of these objects could be very wrong as well.

These results also illustrate a fact that astronomers seem to always forget. The stars in any one category (white dwarfs, red super giants, yellow stars like the Sun, etc.) are not all identical, and thus their life and death processes will not all follow the predicted stages, like clockwork. Things are always far more complicated. Though the predictions might be broadly right, there will be many variations, so many that it will often be difficult to draw a generalized conclusion.

It seems that with white dwarfs astronomers have made this mistake, and now must rethink many of their conclusions.

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Firefly confirms launch failure due to the premature shutdown of one engine

9:33 am

Capitalism in space: Firefly this past weekend confirmed that its September 2nd launch failure was caused when one of the Alpha rocket’s first stage engines shut down almost immediately after liftoff.

On Sunday (Sept. 5), the company announced the proximate cause of the failure: One of Alpha’s four first-stage Reaver engines shut down unexpectedly about 15 seconds after liftoff. “The vehicle continued to climb and maintain control for a total of about 145 seconds, whereas nominal first-stage burn duration is about 165 seconds. However, due to missing the thrust of 1 of 4 engines, the climb rate was slow, and the vehicle was challenged to maintain control without the thrust vectoring of engine 2,” Alpha representatives wrote in a Twitter thread on Sunday.

“Alpha was able to compensate at subsonic speeds, but as it moved through transonic and into supersonic flight, where control is most challenging, the three-engine thrust vector control was insufficient and the vehicle tumbled out of control. The range terminated the flight using the explosive Flight Termination System (FTS). The rocket did not explode on its own,” they added.

The engine apparently did not fail or explode, it merely closed its main propellant valves so the engine was no longer being fed fuel. Though they obviously they need to find out why this happened, the nature of the failure is actually encouraging. It suggests a relatively easy fix (with a strong emphasis on the word “relatively”).

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Debris from Firefly launch rains down near launch spectators

12:38 pm

Alpha rocket exploding
Screen capture of explosion from Everyday Astronaut live stream.

When the range officer was forced to terminate the first launch of Firefly’s Alpha rocket on September 2, 2021, the subsequent explosion caused some of the debris to apparently fall near the spectators who had come out to see the launch.

Spectators who gathered across the Central Coast to watch the launch of Firefly Aerospace’s Alpha rocket — a privately designed, unmanned rocket built to carry satellites — instead saw it explode midair and debris rain down on nearby areas.

“I saw this thing floating down from the sky … then another piece, then another, and then hundreds of pieces varying in size were falling,” said Mike Hecker, a resident of Solvang who was out mountain biking in the Orcutt Hills with a large group of friends. “It was surreal to have rocket debris raining down on you,” he said.

According to all reports, it appears no one was injured or even came close to getting hurt.

We need to accept such things if we wish to do great things. The range officer destroyed the rocket to make sure it did not fly in one piece into anything on the ground, something that would have certainly caused great harm. Blowing it up prevented that, though it resulted in a small risk that smaller pieces might hit something.

Once, a story like this would have been intriguing but would have bothered no one. In today’s culture — which attempts to give everyone a “safe space” even from dissenting opinions — I fear that we shall find greater restrictions soon placed on launches.

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Today’s blacklisted American: The National Archives blacklists the Constitution and Declaration of Independence

12:18 pm

The National Archives

The intolerance sweeping through our country has become so mindless that it repeatedly ends up being completely insane. It now appears that the website of the National Archives, which is also tasked with preserving the originals of the Declaration of Independence, the Constitution, and the Bill of Rights, automatically places a “harmful language alert” on all three.

The screen capture to the right shows the National Archives webpage for viewing the first page of the Constitution. The red box indicates the alert. That alert also appears at the top for every other page of the Constitution. It also appears if you view the Declaration of Independence and the Bill of Rights. (You can see screen captures of these additional alerts here and here.)

According to the National Archives, this “harmful language alert” exists because it is tasked with preserving all past documents, and thus must also make available to the public documents that:
» Read more

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China’s Chang’e-5 orbiter returning to lunar space

9:25 am

The new colonial movement: In a somewhat bold move, Chinese engineers appear to now be shifting the Chang’e-5 orbiter so that it will be able to return to lunar space to fly past the Moon.

The orbiter, one of four distinct Chang’e-5 mission spacecraft, delivered a return module containing 1.731 kilograms of lunar samples to Earth Dec. 16 before firing its engines to deep space for an extended mission.

The Chang’e-5 orbiter later successfully entered an intended orbit around Sun-Earth Lagrange point 1, roughly 1.5 million kilometers, in March. There it carried out tests related to orbit control and observations of the Earth and Sun.

New data from satellite trackers now suggests Chang’e-5 has left its orbit around Sun-Earth L1 and is destined for a lunar flyby early September 9 Eastern time.

This data comes not from China but from amateur astronomers who specialize in tracking satellites.

The fly-by could provide the spacecraft the velocity it needs to reach near Earth asteroid Kamo’oalewa, which China has said it is targeting for a 2024 sample return mission. Such a reconnaissance will help them design the sample return mission.

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Ingenuity completes 13th flight

9:15 am

Ingenuity landing on September 5, 2021
Click for full image.

Though the full slate of images taken has not yet been released, it appears from the five images available that the thirteenth flight of Ingenuity on September 5, 2021 ended successfully. The photo to the right is the last available, and shows the helicopter’s shadow on the ground mere seconds before touch down. The landing legs’ shadows suggest it is oriented properly for that landing.

No word yet on how successful the flight itself was. The goal had been to fly back over the South Seitah area from a different angle and lower altitude, getting different perspectives of the ridges there to help plan Perseverance’s coming travels across that terrain.

The second picture below, cropped, reduced, and enhanced to post here, was taken about forty minutes before take-off by Perseverance and captures Ingenuity in the lower left, as indicated by the arrow.
» Read more

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China Long March 4C rocket launches satellite

8:33 am

According to China’s state-run press, the country launched an “earth observation” satellite today using its Long March 4C rocket.

The satellite is part of a series of similar satellites launched by civilian agencies ostensibly for civilian use. The rocket was launched from an interior spaceport. No word on whether its first stage carried grid fins or parachutes to control its landing in the interior of China, or whether it crashed near habitable areas.

The leaders in the 2021 launch race:

30 China
21 SpaceX
13 Russia
4 Northrop Grumman

The U.S. lead over China in the national rankings has now narrowed to 32 to 30.

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House NASA budget cuts all funding for lunar lander but adds billions for “infrastructure”

10:13 pm

The House science committee is about to propose a NASA budget that would cut all funding for a lunar lander but add $4 billion so that NASA can build new buildings and facilities.

An updated draft of the bill, dated Sept. 4, offers good and bad news for NASA. It includes $4 billion for “repair, recapitalization, and modernization of physical infrastructure and facilities” across the agency. The bill does not assign amounts to specific projects or centers.

NASA Administrator Bill Nelson had made funding for agency infrastructure a priority in any budget reconciliation package, seeking more than $5 billion earlier this year. “There’s aging infrastructure that is dilapidated,” he told House appropriators in May. “They’ve got holes in the roof where they’re putting together the core of the SLS” at the Michoud Assembly Facility in New Orleans. Michoud suffered additional damage from Hurricane Ida last month.

However, the draft bill includes nothing for the other priority identified by Nelson, the agency’s Human Landing System (HLS) program. Nelson said in May he wanted $5.4 billion for HLS to allow NASA to select a second company alongside SpaceX to develop and demonstrate a lander capable of transporting astronauts to and from the lunar surface.

Congratulations America! This is the Congress we have voted for. They want a space agency tasked with finding ways to explore the solar system but will only fund the “repair, recapitalization, and modernization of physical infrastructure and facilities” on Earth.

In other words, NASA will have gold-plated buildings in which they will be able to do nothing but shuffle paper because Congress has given them no funding to fly anything in space.

What a joke. But then, as I said, this is the Congress Americans have chosen, so that means not only is Congress a joke, so are the American people.

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Righteous Brothers – You’ve Lost That Loving Feeling

6:01 pm

An evening pause: Performed live on television, c1966. The sound on this video has been remastered using the studio recording, in a manner that really enhances the live performance in every way. (The original is available, but the sound was not great, and was partly drowned out by the audience.)

Hat tip Dan Steele.

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