Category: Points of Information

Very brief descriptions, with appropriate links, of current or recent news items.

Shells of dust surrounding massive binary star

10:07 am

Webb infrared image of dust shells surrounding binary star system
Click for full image.

Cool image time! Using the Webb telescope, astronomers have detected a series of concentric shells surrounding the massive binary star dubbed Wolf-Rayet 140.

The infrared image to the right shows these shells quite clearly. As noted by astronomer Ryan Lau:

“On the night that my team’s Early Release Science observations of the dust-forming massive binary star Wolf-Rayet (WR) 140 were taken, I was puzzled by what I saw in the preview images from the Mid-Infrared Instrument (MIRI). There seemed to be a strange-looking diffraction pattern, and I worried that it was a visual effect created by the stars’ extreme brightness. However, as soon as I downloaded the final data I realized that I was not looking at a diffraction pattern, but instead rings of dust surrounding WR 140 – at least 17 of them.

“I was amazed. Although they resemble rings in the image, the true 3D geometry of those semi-circular features is better described as a shell. The shells of dust are formed each time the stars reach a point in their orbit where they are closest to each other and their stellar winds interact. The even spacing between the shells indicates that dust formation events are occurring like clockwork, once in each eight-year orbit. In this case, the 17 shells can be counted like tree rings, showing more than 130 years of dust formation. Our confidence in this interpretation of the image was strengthened by comparing our findings to the geometric dust models by Yinuo Han, a doctoral student at the University of Cambridge, which showed a near-perfect match to our observations.

Furthermore, the spectroscopy from Webb says these dust shells are carbon-enriched, showing that the dust released by these aged massive stars is a significant source of the carbon in the universe, the fundamental atom needed for life.

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SpaceX fully stacks Starship/Superheavy in preparation for launch

9:53 am

Starship about to be stacked on Superheavy
Starship about to be stacked on Superheavy, using
the launch tower’s chopstick arms. Click for full image.

For the first time in six months SpaceX engineers have stacked Starship prototype #24 on top of Superheavy prototype #7, with the intention of running a dress rehearsal countdown and a full static fire test of Superheavy’s 33 engines, all in preparation for the first orbital test flight before the end of this year.

According to CEO Elon Musk, Booster 7 and Ship 24 will attempt Starship’s first full-stack wet dress rehearsal (WDR) once all is in order. The prototypes will be simultaneously loaded with around 5000 tons (~11M lb) of liquid oxygen and methane propellant and then run through a launch countdown. Diverging just before ignition and liftoff, a WDR is meant to be more or less identical to a launch attempt.

…If the wet dress rehearsal goes to plan, SpaceX will then attempt to simultaneously ignite all 33 of the Raptor engines installed on Super Heavy B7, almost certainly making it the most powerful liquid rocket ever tested. Even if all 33 engines never reach more than 60% of their maximum thrust of 230 tons (~510,000 lbf), they will likely break the Soviet N-1 rocket’s record of 4500 tons of thrust (~10M lbf) at sea level. It would also be the most rocket engines ever simultaneously ignited on one vehicle. SpaceX will be pushing the envelope by several measures, and success is far from guaranteed.

Depending on the results of these tests, the stacked rocket will either require further modifications, or could even proceed directly to launch.

We are thus seeing a true race between SpaceX’s privately developed and funded rocket and NASA’s government developed and funded SLS rocket. Which will launch first? Right now the race is neck-and-neck, though that is deceiving since SpaceX began development twelve years after NASA started work on SLS. Even if SLS launches first, SpaceX will have clearly shown that private enterprise does things faster (7 years vs 18 years) and for far less money (about $9 billion vs $46 billion).

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NASA sets November 14th as next SLS launch date

9:38 am

NASA today announced that it will make its next attempt to launch its SLS rocket just past midnight on November 14, 2022.

NASA is targeting the next launch attempt of the Artemis I mission for Monday, Nov. 14 with liftoff of the Space Launch System (SLS) rocket carrying the Orion spacecraft planned during a 69-minute launch window that opens at 12:07 a.m. EST. Artemis I is an uncrewed flight test to launch SLS and send Orion around the Moon and back to Earth to thoroughly test its system before flights with astronauts.

This is the second launch opportunity in the November launch window, as shown in this graph [pdf]. It will result in a 26-day mission for the Orion capsule to and from lunar orbit, returning on December 9th.

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Russia’s Proton rocket successfully launches communications satellite

9:32 am

Russia today used its Proton rocket to successfully place an Angolan communications satellite into orbit.

The satellite’s launch had been delayed for several years, first because of the Wuhan panic and second because the sanctions against Russia over its invasion of the Ukraine prevented delivery of American components (eventually “resolved”, whatever that means).

Proton, developed in the 1960s, is winding down operations, and will soon be replaced by Russia’s Angara rocket.

The leaders in the 2022 launch race:

46 SpaceX
43 China
14 Russia
8 Rocket Lab
7 ULA

American private enterprise still leads China 66 to 43 in the national rankings, and the entire world combined 66 to 65.

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Japan’s Epsilon rocket fails during launch

9:24 am

Early this morning Japan’s Epsilon rocket failed during a launch intended to put eight satellites into orbit.

Live coverage by JAXA of the launch showed what appeared to be a stage 3 ignition failure, followed by a callout that the flight termination system (FTS) was activated. It’s the first Epsilon launch not to reach orbit.

This rocket was developed by Japan to offer a lower cost option to his H2 and new H3 rockets. The first launch of the H3 is set for March 2023 after several long delays due to problems with the rocket’s engine.

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DART’s impact shortened Dimorphus’s orbit around Didymos by 32 minutes

5:51 pm

LICIACube Explorer image of DART impact
LICIACube Explorer image just after the DART
impact. Dimorphus is the blob near the top.

After two weeks of analyzing the orbit of Dimorphus around its parent asteroid Didymos, astronomers have determined that the impact of DART on Dimorphus shortened its orbit by 32 minutes.

Prior to DART’s impact, it took Dimorphos 11 hours and 55 minutes to orbit its larger parent asteroid, Didymos. Since DART’s intentional collision with Dimorphos on Sept. 26, astronomers have been using telescopes on Earth to measure how much that time has changed. Now, the investigation team has confirmed the spacecraft’s impact altered Dimorphos’ orbit around Didymos by 32 minutes, shortening the 11 hour and 55-minute orbit to 11 hours and 23 minutes. This measurement has a margin of uncertainty of approximately plus or minus 2 minutes.

Before its encounter, NASA had defined a minimum successful orbit period change of Dimorphos as change of 73 seconds or more. This early data show DART surpassed this minimum benchmark by more than 25 times.

It also appears the ejecta from the impact — much greater than expected — helped propel Dimorphus, a result that I think was also not expected.

Researchers are now shifting to studying the debris and asteroid itself, to better understand what happened as well as the nature of Dimorphus itself. This will also include a European probe dubbed Hera that will launch in 2024 an dvisit both asteroids in 2026.

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October 11, 2022 Quick space links

4:31 pm

Courtesy of Jay, BtB’s stringer.

 

 

 

  • Upcoming schedule of launches to Tiangong-3

    • Mengtian on a Long March 5B on October 31st, Tianzhou-5 freighter on a Long March 7 on November 6th, and the next manned mission on Shenzhou-15 on a Long March 2F on November 26th.

 

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Webb gets first direct infrared image of exoplanet

10:21 am

Exoplanet as seen in the infrared by Webb

Using the Webb Space Telescope, scientists have obtained that telescope’s first direct infrared image of an exoplanet, covering four different wavelengths.

The image to the right is from the wavelength image with the least distortion (formed by Webb’s own optics and the shape of its mirror and indicated by the faint ring surrounding the planet). The star indicates the masked location of the star itself.

The planet is about seven times the mass of Jupiter and lies more than 100 times farther from its star than Earth sits from the sun, direct observations of exoplanet HIP 65426 b show. It’s also young, about 10 million or 20 million years old, compared with the more than 4-billion-year-old Earth.

You can download the full research paper here.

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Volcano on the Moon

10:08 am

Wide shot of lunar volcano

Close-up of lunar volcano
Click for full image.

Cool image time! The Lunar Reconnaissance Orbiter (LRO) science team today released the oblique image above and in close-up to the right, showing what they call a “silicic volcano.” From the release:

The Mairan T dome is a large silicic volcanic structure with a pronounced summit depression. Remote sensing indicates that the composition of the volcanic material (lava) making up the dome is enriched in silica (SiO2). This rock type would be classified as either rhyolite or dacite on Earth, and the composition starkly contrasts with the dark, iron-rich mare basalts that embay the Mairan T dome. Most of the volcanism on the Moon is basaltic or iron-rich. Still, silicic volcanism also occurred on the Moon. Indeed, bits and pieces of similar materials were found in the Apollo samples; however, all are small fragments delivered to the Apollo sites as material ejected from distant impact events.

One of the great questions for lunar science is how the silicic materials formed. On Earth, specific tectonic settings and higher water contents in the rocks favor the formation of such lavas; however, the Moon lacks plate tectonics and water-rich sediments. NASA is planning a Commercial Lunar Payload Services (CLPS) lander mission to another, larger silicic volcano, one of the Gruithuisen domes, to address this question.

The scientists also note that this volcano formed first, and then was partly covered by the dark flood lava that surrounds it.

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Engineers test fly prototype balloon for Venus

9:31 am

JPL engineers have successfully completed two test flights of a smaller-scale prototype balloon intended to fly in the atmosphere of Venus.

The shimmering silver balloon ascended more than 4,000 feet (1 kilometer) over Nevada’s Black Rock Desert to a region of Earth’s atmosphere that approximates the temperature and density the aerobot would experience about 180,000 feet (55 kilometers) above Venus. Coordinated by Near Space, these tests represent a milestone in proving the concept’s suitability for accessing a region of Venus’ atmosphere too low for orbiters to reach, but where a balloon mission could operate for weeks or even months.

“We’re extremely happy with the performance of the prototype. It was launched, demonstrated controlled-altitude maneuvers, and was recovered in good condition after both flights,” said robotics technologist Jacob Izraelevitz, who leads the balloon development as the JPL principal investigator of the flight tests. “We’ve recorded a mountain of data from these flights and are looking forward to using it to improve our simulation models before exploring our sister planet.”

The idea is an upgrade of two French-built balloons that flew on two Soviet-era missions to Venus in the 1980s and operated in the Venusian atmosphere for almost two days, flying 33 miles in altitude and traversing almost 100 degrees in longitude in that short time due to Venus’s high winds.

This project wants its balloon to survive more than 100 days. As it is presently in very early development, no launch date is even proposed.

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New rocket startup focusing on new concepts to make upper stage reusable

9:22 am

Capitalism in space: Another new rocket startup, Stoke Space, is working to develop a new innovative reusable design for its upper stages.

Most commonly, a traditional rocket has an upper stage with a single engine. This second-stage rocket engine has a larger nozzle—often bell-shaped—to optimize the flow of engine exhaust in a vacuum. Because all parts of a rocket are designed to be as light as possible, such extended nozzles are often fairly fragile because they’re only exposed above Earth’s atmosphere. So one problem with getting an upper stage back from Earth, especially if you want to use the engine to control and slow its descent, is protecting this large nozzle.

One way to do that is to bury the engine nozzle in a large heat shield, but that would require more structure and mass, and it may not be dynamically stable. Stoke’s answer was using a ring of 30 smaller thrusters. (The tests last month only employed 15 of the 30 thrusters). In a vacuum, the plumes from these nozzles are designed to merge and act as one. And during reentry, with a smaller number of smaller thrusters firing, it’s easier to protect the nozzles.

Will this company succeed? Who knows? It is presently very early in development. However, that its founders are former engineers from SpaceX and Blue Origin is encouraging, especially based on this comment about why the Blue Origin guy, Andy Lapsa, left that company:

“I love Jeff [Bezos]’s vision for space,” Lapsa said in an interview with Ars. “I worked closely with him for a while on different projects, and I’m basically 100 percent on board with the vision. Beyond that, I think I would just say that I will let their history of execution speak for itself, and I thought we could move faster.”

Lapsa apparently was part of the exodus of high level managers and engineers that occurred at Blue Origin after Bezos hired Bob Smith as CEO. All complained of the company’s far-too-cautious management style under Smith.

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