Tag: spaceflight

A confused spiral galaxy

10:34 am

An irregular spiral galaxy

Cool image time! The picture to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope and released today. From the caption:

The irregular spiral galaxy NGC 5486 hangs against a background of dim, distant galaxies in this image from the NASA/ESA Hubble Space Telescope. The tenuous disc of the galaxy is threaded through with pink wisps of star formation, which stand out from the diffuse glow of the galaxy’s bright core. While this particular galaxy has indistinct, meandering spiral arms it lies close to the much larger Pinwheel Galaxy, one of the best known examples of ‘grand design’ spiral galaxies with prominent and well-defined spiral arms. In 2006 Hubble captured an image of the Pinwheel Galaxy which was — at the time — the largest and most detailed photo of a spiral galaxy ever taken with Hubble.

This galaxy is defined I think as an irregular spiral because if you look close, you can see a very faint hint of a central bar and two large arms spiraling away at its ends. It is faint however, and might simply be caused by the human mind’s natural desire to see patterns. To my eye this galaxy could just as well be a patchy elliptical galaxy, with no arms at all.

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Juno captures close-up images of Jupiter’s moon Io

10:25 am

Io as seen by Juno

On March 1, 2023 the Jupiter orbiter Juno passed within 33,000 miles of the gas giant’s moon Io, getting its first close-up images.

Several citizen scientists have processed those images. The photo to the right, cropped and reduced to post here, was created by Andrew R Brown. This particular picture was one of five taken by Juno during the fly-by. Jason Perry processed all five here, with this caption:

Most of the dark spots seen across Io’s surface are the result of volcanic eruptions. These include East Girru, a dark spot that was not seen the last time Io was seen at this resolution during the New Horizons encounter with Jupiter in February 2007. East Girru was undergoing a major eruption at the time but hadn’t had time to produce a new lava flow before the end of the week-long encounter. This small flow field, measuring 3,200 square kilometers (1,390 square miles) in size, may have also been reactivated during an eruption in October 2021, as seen by Juno JIRAM.

Another apparent surface change is at Chors Patera, which has undergone a significant reddening since Galileo last observed it in October 2001. Reddish materials on Io are indicative of the presence of short-chain sulfur and are often associated with high-temperature, silicate volcanism. Additional dark spots near the terminator, the boundary between Io’s day and night sides, are the shadows of tall mountains. The dark spot at middle right in the upper right image may be due a mountain 5500 meters (18,000 feet) tall.

The smallest object resolved in this image is about 22 miles across.

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ISRO attempting controlled reentry of old satellite originally lacking in such plans

9:54 am

India’s space agency ISRO has been attempting the controlled reentry of an old India-French climate satellite that had originally been placed in a high enough orbit that de-orbit was not expected.

An uninhabited area in the Pacific Ocean between 5°S to 14°S latitude and 119°W to 100°W longitude has been identified as the targeted re-entry zone for the [Megha-Tropiques-1 (MT1)]. Since Aug 2022, 18 orbit manoeuvres have been performed to progressively lower the orbit and on March 7 the ground impact is expected to take place between 4.30 p.m. and 7.30 p.m. IST.

The satellite, once no longer able to do its primary function, still had a lot of fuel left that left it a threat. ISRO managers decided to use that fuel to lower the high orbit — where MT1 was expected to remain for at least 100 years — so that the satellite could be brought down safely now.

The real story here is ISRO’s decision to commit funds to pay for this work. Until recently, most satellites are launched without any funding to remove them once launched. SpaceX changed this with its Starlink constellation, with deorbit always included as part of each satellite’s operational plan.

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Sightseeing in the region near the Starship Mars landing zone

4:21 pm

Sightseeing in the region near Starship's landing zone
Click for original image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken on November 30, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a bulbous hill in the icy northern lowland plains of Mars. That it is icy here is indicated by the glacier features that appear to fill the small crater near the bottom of the picture.

You can get a better sense of stark alien nature of this terrain by looking at an MRO context camera image of the same area, taken on April 1, 2008. The subject hill is the first hill on the image’s west side, going from the top. This is a flat plain interspersed with crater splats, mounds of a variety of sizes, and a puzzling meandering dark line that suggests a crack from which material is oozing.

The geology to be studied here might be endless but for tourists the views will be astounding in their alienness.
» Read more

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SpaceX launches another 51 Starlink satellites into orbit

11:48 am

SpaceX today successfully placed another 51 Starlink satellites into orbit, using its Falcon 9 rocket and launching from Vandenberg Space Force Base.

The first stage completed its 12th flight, landing safely on a drone ship in the Pacific. The fairing halves completed their fifth and second flights, respectively.

The 2023 launch race:

15 SpaceX
7 China
3 Russia
1 Rocket Lab
1 Japan
1 India

American private enterprise now leads China 16 to 7, and the entire world combined 16 to 12. SpaceX by itself leads the entire world, including other American companies, 15 to 13.

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Sunspot update: After going through the roof last month, sunspots drop into the attic this month

11:05 am

With the start of another month NOAA this week updated its graph that tracks the number of sunspots on the Sun’s Earth-facing hemisphere. As I do every month, I have posted that updated graph below, adding some additional details to provide some context.

Last month the number of sunspots rocketed upward to the highest seen since 2014, and only the second time since November 2002 that the Sun was that active. In February those high numbers dropped, though the sunspot activity during the month remained well above the 2020 prediction by NOAA’s panel of solar scientists.

» Read more

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ESA attributes Vega-C launch failure to faulty nozzle from the Ukraine

8:49 am

The European Space Agency (ESA) has concluded that the launch failure of the second stage of Arianespace’s Vega-C rocket on December 20, 2022 was caused by a faulty nozzle produced by a company in the Ukraine.

[T]he Commission confirmed that the cause was an unexpected thermo-mechanical over-erosion of the carbon-carbon (C-C) throat insert of the nozzle, procured by Avio in Ukraine. Additional investigations led to the conclusion that this was likely due to a flaw in the homogeneity of the material.

The anomaly also revealed that the criteria used to accept the C-C throat insert were not sufficient to demonstrate its flightworthiness. The Commission has therefore concluded that this specific C-C material can no longer be used for flight. No weakness in the design of Zefiro 40 has been revealed. Avio is implementing an immediate alternative solution for the Zefiro 40’s nozzle with another C-C material, manufactured by ArianeGroup, already in use for Vega’s Zefiro 23 and Zefiro 9 nozzles.

The press release goes to great length to reassure everyone that these Ukrainian nozzles are still flightworthy, that the fix is merely changing the material used in the nozzle’s throat insert.

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JAXA reschedules first H3 rocket launch following investigation

8:39 am

Japan’s space agency JAXA has rescheduled its second attempt to launch its new H3 rocket for March 6, 2023, following the completion of its investigation into the launch abort at T-0 on February 16, 2023.

As a result of the investigation, it is estimated that the first-stage flight controller malfunctioned due to transient fluctuations in the communication and power lines that occurred during electrical separation between the rocket and the ground facilities.

As a result, the solid rocket strap-on boosters did not ignite as planned, and the rocket’s computer, sensing this anomaly, shut down its main engines. The press release says they are installing “countermeasures” but provides no other information.

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Endeavour docks with ISS

11:58 pm

Endeavour tonight has successfully docked with ISS.

When the spacecraft got within about 70 feet of the station, there was a delay of a little more than an hour while ground controllers installed a software overide to a sensor for monitoring the position of one of the 12 hooks on Endeavour, used to lock it to ISS’s docking port. Though visual and other data showed the hook was working, the sensor could not, and without that software override Endeavour would automatically abort the docking.

This same sensor had caused a delay in the opening of the capsule’s nosecone yesterday shortly after launch.

As of posting the hatch had not yet been opened, something that should occur in about an hour or so. Though Endeavour is docked, more checks needed to be done beforehand.

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A Martian glacier waterfall?

12:48 pm

A Martian glacier waterfall?
Click for original image.

Cool image time! The photo to the right, cropped, reduced, and sharpened to post here, was taken on October 25, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small meandering canyon that appears to drain into a larger side canyon, all part of a region of chaos terrain dubbed Galaxias Chaos in the Martian northern mid-latitudes.

Though the latitude is 35 degrees north, where we should see lots of evidence of glacial features, especially because this is chaos terrain — terrain unique to Mars — that generally appears formed by such processes, I find few outright obvious glacial features in this cropped portion or in the full image.
» Read more

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Scientists publish their results from the impact of Dimorphos by DART

10:53 am

Seconds after impact
Seconds after impact. Click for movie, taken by amateur
astronomer Bruno Payet from the Réunion Island.

Scientists today published five papers outlining their results from the impact of Dimorphos by DART, summed up as follows:

  • Dimorphos’s density is about half that of Earth’s, illustrating its rubble pile nature.
  • The orbital period around the larger asteroid Didymos was changed by 33 minutes.
  • The ejection of material from Dimorphos during the impact had a greater effect on the asteroid’s momentum than the impact itself
  • The mass ejected was only 0.3 to 0.5% of Dimorphos’s mass, showing that the asteroid was not destroyed by the impact.
  • The impact turned Dimorphos into an active asteroid, with a tail like a comet.

The data not only tells us a great deal about this asteroid binary itself, it suggests that this impact method might be of use in defending the Earth from an asteroid impact. There are caveats however. First, the orbital change was not to the system’s solar orbit, the path that would matter should an asteroid threaten the Earth, but to Dimorphos’s orbit around its companion asteroid. We don’t yet know the effect on the solar orbit. Second, the impact did not destroy this small rubble pile asteroid, which means such an asteroid might still be a threat to the Earth even after impact. Third, in order for an impact to be the right choice for planetary defense, detailed information about the target asteroid has to be obtained. Without it such an impact mission might be a complete waste of time.

The irony to all this is that we knew all this before the mission. DART in the context of planetary defense taught us nothing, so NASA’s claim that this mission was to learn more about planetary defense was always utter bunkum. The mission’s real purpose was the study of asteroids, but selling it that way was hard. The sizzle of planetary defense however was a better lobbying technique, and it worked, even if it was dishonest.

That the press was also fooled by it, and continues to be fooled by it, is a subject for a different essay.

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Rocket Lab might forgo use of a helicopter in recovering its Electron 1st stages

10:20 am

According to Rocket Lab’s CEO, Peter Beck, the company might abandon the use of a helicopter and the in air capture of the first stages of its Electron rocket 1st stages and instead simply fish them out of the water, refurbish them, and then reuse them.

In the second attempt last November, Rocket Lab called off the helicopter catch because of a momentary loss of telemetry from the booster. The company instead allow the stage to splash down in the ocean, where a boat recovered it and returned it to Rocket Lab’s facilities. “This turned out to be quite a happy turn of events,” he said on the call. “Electron survived an ocean recovery in remarkably good condition, and in a lot of cases its components actually pass requalification for flight.”

He said the company is planning an ocean recovery on an upcoming flight after incorporating additional waterproofing into the vehicle “Pending this outcome of testing and analysis of the stage, the mission may move us towards sticking with marine recovery altogether and introduce significant savings to the whole operation.”

As Elon Musk has said, “The best part is no part.” It appears that by having the stage come down softly and controlled by parachutes it is possible to get it out of the water fast, without much damage. If the first stage can then be reflown then it makes sense not to bother with the helicopter recovery.

Beck also indicated during his phone presentation that the company is still targeting fifteen launches in 2023, and that the demand for launches has allowed the company to maintain its launch prices, with the prospect of raising them soon.

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