Tag: engineering

China launches new crew to its space station

3:55 pm

China today successfully launched a new three-person crew to its Tiangong-3 space station, its Long March 2F rocket lifting off from its Jiuquan spaceport in northwest China.

No word on where the rocket’s side boosters or lower stages, using toxic hypergolic fuel, crashed inside China. The crew will dock with the station mid-day tomorrow.

The leaders in the 2024 launch race:

105 SpaceX
49 China
11 Russia
11 Rocket Lab

American private enterprise still leads the rest of the world combined in successful launches 122 to 72, while SpaceX by itself still leads the entire world, including American companies, 105 to 89.

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A return to Phantom and the reminiscences of an Apollo astronaut

3:04 pm

Charles Duke, Apollo 16 astronaut
Charles Duke, Apollo 16 astronaut

Yesterday I had to pleasure of getting my second tour of the Phantom Space facilities, located here in Tucson. Jim Cantrell, the founder of the Tucson-based rocket/satellite company Phantom Space, had last week graciously invited me to attend the event he was holding there, where astronaut Charles Duke, from the April 1972 Apollo 16 lunar landing, would be giving a talk to the company’s employees, investors, and customers. Duke had become an advisor for the company, and this would be his first visit to its operations.

First, the talk by Charles Duke, describing his life and Apollo 16 walk on the Moon, was as usual awe-inspiring, mostly because Duke spoke like every astronaut I’ve ever met so matter-of-factly about what he had done. During the second of three excusions on the surface with his commander John Young, they drove their rover up the slope of nearby Stone Mountain, climbing to an elevation of 500 feet, the highest any human has so far been on the lunar surface. From there he could look back and see for miles, including the entire valley where the lunar module was nestled as well as the mountains and craters that surrounded it.

When I asked him if he had had any sense of his remoteness from humanity, his response was a good-natured laugh. “We felt at home there!” They had done so much study of the terrain beforehand, including simulations, that from the moment they approached to land it all looked very familiar. This is where they were supposed to be!

Following Duke’s presentation we all were given a tour of the facility. My first visit there had been in 2022. At the time Cantrell’s effort was to aggressively succeed from his earlier failure at the rocket startup Vector, focusing this new company on building its Daytona rocket. After the tour I concluded as follows:
» Read more

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Arecibo telescope collapsed because of a surprising engineering failure that inspections still should have spotted

1:41 pm

Illustration of cable failure at Arecibo

According to a new very detailed engineering analysis into the causes of the collapse of the Arecibo radio telescope in Puerto Rico in 2020, the failure was caused first by a surprising interaction between the radio electronics of Arecibo and the traditional methods used to anchor the cables, and second by a failure of inspections to spot the problem as it became obvious.

The surprising engineering discovery is illustrated to the right, taken from figure 2-6 of the report. The main antenna of Arecibo was suspended above the bowl below by three main cables. The figure shows the basic design of the system used to anchor the cable ends to their sockets. The end of the cable bunches would be inserted into the socket, spread apart, and then zinc would be poured in to fill the gap and then act as a plug and glue to hold the cables in place. According to the report, this system has been used for decades in many applications very successfully.

What the report found however was at Arecibo over time the cable bunch and zinc plug slowly began to pull out of the socket, what the report labels as “zinc creep.” This was noted by inspectors, but dismissed as a concern because they still believed the engineering margins were still high enough to prevent failure at this point. In fact, this is exactly where the structure failed in 2020, with the first cable separating as shown in August 2020. The second cable did so in a similar manner in November 2020.

The report concluded that the “only hypothesis the committee could develop that provides a plausible but unprovable answer to all these questions and the observed socket failure pattern is that the socket zinc creep was unexpectedly accelerated in the Arecibo Telescope’s uniquely powerful electromagnetic radiation environment. The Arecibo Telescope cables were suspended across the beam of ‘the most powerful radio transmitter on Earth.'”

The report however also notes that the regular engineering inspections of the telescope had spotted this creep, which was clearly unusual and steadily becoming significant, and did not take action to address the issue when it should have. It also noted the slow response of the bureaucracy, not only to the damage caused earlier to the facility by Hurriane Maria in 2017, but to obtaining the funding for any repairs.

Ray Lugo [the principal investigator for Arecibo] described to the committee how months of his time during 2018 were spent writing, resubmitting, and justifying repair funding proposals. Repairs had to go through the traditional “bid and proposal” process, described in more detail below, which added years of delay.

We can forgive the inspectors somewhat for not noting the creep when they should, as its cause appears to be very unusual, still uncertain and rare, but the red tape that prevented proper and quick repair effort after the hurricane is shameful. Had the telescope gotten the proper support on time, the creep itself might have even been addressed, because the resources would have been there to deal with it.

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Successful deployment of large array antennas on all five AST’s satellites

12:48 pm

AST SpaceMobile has now successfully unfolded the large array antennas on all five the satellites it launched in September, and did so six weeks ahead of schedule.

“The unfolding of the first five commercial satellites is a significant milestone for the company. These five satellites are the largest commercial communications arrays ever launched in low Earth orbit,” commented Abel Avellan, founder, Chairman and CEO of AST SpaceMobile, in a statement. “It is a significant achievement to commission these satellites, and we are now accelerating our path to commercial activity.”

The satellites are designed to act like cell towers in space, providing direct satellite-to-cellphone coverage and fill gaps in ground-based cell service. ATT has already signed a contract with AST to use these satellites.

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Lab tests suggest water brines could also exist on large asteroids

12:28 pm

Gullies in crater on Vesta
Click for original image.

In attempting to explain the existence of flow features that have been found on the interior walls of craters on the asteroids Ceres and Vesta — as shown in the image above — scientists recently performed a laboratory experiment which determined that a mixture of water and salt could produce those gullies.

The team modified a test chamber at the Jet Propulsion Laboratory to rapidly decrease pressure over a liquid sample to simulate the dramatic drop in pressure as the temporary atmosphere created after an impact on an airless body like Vesta dissipates. According to Poston, the pressure drop was so fast that test liquids immediately and dramatically expanded, ejecting material from the sample containers.

“Through our simulated impacts, we found that the pure water froze too quickly in a vacuum to effect meaningful change, but salt and water mixtures, or brines, stayed liquid and flowing for a minimum of one hour,” said Poston. “This is sufficient for the brine to destabilize slopes on crater walls on rocky bodies, cause erosion and landslides, and potentially form other unique geological features found on icy moons.”

The press release makes it sound as if this result makes the existence of subsurface water ice more likely on such asteroids as Ceres and Vesta, but previous research from the Dawn asteroid probe made that fact very clear, especially for Ceres, years ago. All this does is provide some evidence of what might be one process by which these erosion gullies form.

Hat tip to reader Milt.

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Perseverance looks across Jezero Crater from on high

11:11 am

Panorama of Jezero Crater
Click for full resolution annotated image. Click here for unannotated full resolution image.

Cool image time! The panorama above, cropped, reduced, and sharpened to post here, was assembled from 44 pictures taken by the rover Perseverance on September 27, 2024 as it began its climb up the rim of Jezero Crater. If you click on it you can see the full resolution image that is also annotated to identify features within the crater as well as places where Perseverance has traveled.

The overview map below, with the blue dot showing the rover’s location when this panorama was taken. The yellow lines indicate the area covered by the panorama, with the arrow indicating the direction.

Overview map
Click for interactive map.

According to the information at the link, the rover has been experiencing some slippery sandy ground as it has been climbing.
» Read more

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Two cubesats on Hera signal home

10:07 am

Engineers on the ground have now established good communications with the two cubesats that are being carried by the European probe Hera on its way to the binary asteroids Didymos and Dimorphos.

“Each CubeSat was activated for about an hour in turn, in live sessions with the ground to perform commissioning – what we call ‘are you alive?’ and ‘stowed checkout’ tests,” explains ESA’s Hera CubeSats Engineer Franco Perez Lissi.

…Travelling with Hera are two shoebox-sized ‘CubeSats’ built up from standardised 10-cm boxes. These miniature spacecraft will fly closer to the asteroid than their mothership, taking additional risks to acquire valuable bonus data.

Juventas, produced for ESA by GOMspace in Luxembourg will make the first radar probe within an asteroid, while Milani, produced for ESA by Tyvak International in Italy, will perform multispectral mineral prospecting.

This use of small cubesats in conjunction with a larger interplanetary probe is becoming increasingly routine, and provides a cheap and efficient way to increase the data and information obtained. Note too that both cubesats were apparently built entirely by private companies, thus establishing their creditionals as providers of interplanetary probes.

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ExoAnalytic now identifies more than 500 pieces from Intelsat satellite breakup

9:57 am

The private commercial space tracking company ExoAnalytic has now identified more than 500 pieces from Intelsat 33e satellite breakup.

Some of the smaller debris might actually quickly disappear as these pieces are possibly bits of solid fuel that will evaporate.

Much of the press has suddenly decided this failure is all Boeing’s fault, because the satellite was built by that company a decade ago. This seems a bit unfair, since Boeing’s problems now seem far removed from its design and construction of satellites then. At the same time one must wonder. Boeing built four of these type satellites for Intelsat, and the first was lost in 2019 when either it was hit by a meteor or had “a wiring flaw, which led to an electrostatic discharge following heightened solar weather activity.”

That means two of the four satellites have been lost, though the second, 33e, didn’t break-up until twelve years of operation, almost its expected lifespan. Furthermore, the other two satellites are still working fine.

All in all, that suggests to me that though there may be a technical cause that can be traced back to the company, it is more likely we are simply seeing a random expression of the dangers of space to engineering, by anyone.

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NASA picks nine lunar south pole candidate sites for Artemis-3 manned landing

10:37 am

The Moon's south pole, with candidate landing sites
Click for NASA’s original image.

NASA today revealed the nine candidate sites in the Moon’s south polar region for its Artemis-3 manned mission, presently targeting a 2026 launch date.

The map to the right shows the location of those nine sites, numbered in order of priority, as follows:

  • 1. Peak near Cabeus B
  • 2 . Haworth
  • 3. Malapert Massif
  • 4. Mons Mouton Plateau
  • 5. Mons Mouton
  • 6. Nobile Rim 1
  • 7. Nobile Rim 2
  • 8. de Gerlache Rim 2
  • 9. Slater Plain

The map also shows the planned landing sites for Intuitive Machine’s Athena lander in January 2025, and China’s Chang’e-7 lander in 2026, as well as where India’s Virkam lander touched down in 2023.

Cabeus B is likely the prime candidate site because its high elevation will make communciations easier, while placing it closer to the crater Cabeaus, which was impacted by the LCROSS mission in 2009 and found a significant signature of water in the ejecta plume of that impact.

To make a final decision NASA will be consulting all players, from the science community as well as the engineers. All of this however depends on other factors outside of science and engineering, mostly related to politics and practicality. The entire mission relies on the full version of the SLS rocket, the manned lunar version of SpaceX’s Starship, launched by Superheavy, and a working version of Lockheed Martin’s Orion capsule, none of which are presently flightworthy.

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Old rockets clash with new rockets in Europe

9:35 am

Two stories today from Andrew Parsonson at his website Europeanspaceflight.com today illustrate the battle going on in Europe’s vast space bureaucracy over its future rocket development, and clearly tell us who is winning.

First Parsonson described a presentation put forth by Arianespace officials at an “Ariane-6 User’s Club” meeting two weeks ago, outlining the planned and proposed upgrades Arianespace intends for the Ariane-6 rocket over the next decade. All the upgrades are focused on increasing the rocket’s payloac capacity. None will make any of the rocket reusable in order to lower its high cost which makes it uncompetitive in the modern launch market.

What was significant about Parsonson’s report is that he also noted that many of these upgrades need to be approved by the European Space Agency (ESA), and its officials won’t make that decision until 2025 during a planned conference. Thus, this presentation by Arianespace was essentially a lobbying effort to convince ESA to approve these upgrades.

Parsonson’s second story then told us what ESA is approving, right now.

The European Space Agency has selected Rocket Factory Augsburg, The Exploration Company, ArianeGroup, and Isar Aerospace to develop reusable rocket technology.

On 9 October, ESA held its Future Space Transportation Award Ceremony in Paris. During the event, the agency announced the four awardees under two initiatives focused on the development of reusable rocket technology: the Technologies for High-thrust Reusable Space Transportation (THRUST!) project and the Boosters for European Space Transportation (BEST!) project.

Except for ArianeGroup, these are new startups. The German companies Rocket Factory and Isar are developing their own rockets, while the French company Exploration has so far focused on making cargo capsules to supply future space stations.

ArianeGroup meanwhile is the joint partnership between Airbus and Safran that built and owns the Ariane-6, and actually has more say on its future than Arianespace, which is merely a government agency that in the past (but no more) managed and controlled all of Europe’s rockets. ArianeGroup hasn’t abandoned Ariane-6 by no means, but clearly is shifting its interests in new directions.

Interestingly, the final decisions on some of these reusable projects will be made at that same 2025 conference.

Want to bet that ESA at that conference shifts its focus from upgrading the non-reusable Ariane-6 and instead goes whole hog for reusability? I expect that, especially because all recent political signs at ESA has indicated no interest in maintaining Arianespace any longer. For example, ESA has taken the Vega family of rockets away from Arianespace and given it back to Avio, the Italian company that manufactures it. ESA has also returned management of French Guiana from Arianespace to France’s space agency, which owns the site.

Designed as the commercial arm of ESA, it no longer has a function, now that Europe is shifting from the Soviet-model of its rocket operation run by the government (Arianespace) to a capitalism model where competing independent companies provide products and services to that government.

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ISRO head unveils new timeline for major missions

10:06 am

The head of India’s space agency ISRO, S. Somanath, yesterday unveiled a new timeline for several of that nation’s major missions, both manned and unmanned.

The new timeline is as follows:

  • 2025: NISAR: a joint Indian-American radar orbiter, long delayed
  • 2026: Gaganyaan-1, India’s first manned orbital mission
  • 2028: Chandrayaan-4, an unmanned sample return mission to the Moon
  • 2028: Chandrayaan-5, a joint lander-rover to the Moon

The last project will be done in partnership with Japan, with India building the lander and Japan the rover.

2028 will be a very busy year for India in space. The Indian government had previously announced that ISRO would launch in 2028 the first module of its space station as well as a Venus orbiter.

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Unidentified astronaut from recent ISS mission released from hospital

9:54 am

Though NASA’s press release provided little informationto protect the astronaut’s privacy, including his or her name, the unidentified astronaut who was held overnight for observation after returning from a seventh-month stay on ISS mission has now been released from the hospital.

After an overnight stay at Ascension Sacred Heart Pensacola in Florida, the NASA astronaut was released and returned to NASA’s Johnson Space Center in Houston Saturday. The crew member is in good health and will resume normal post-flight reconditioning with other crew members.

This has happened before. Readapting to a 1G environment after months in weightlessness can be difficult, even if one does all the exercises required while in orbit.

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