Tag: engineering

Puzzling telemetry from Voyager-1 suggests problem

9:49 am

Engineers are puzzling over strange operational data coming from Voyager-1, launched in 1977 and now in interstellar space more than 14 billion miles away, that suggests a technical problem but also makes no sense.

The engineering team with NASA’s Voyager 1 spacecraft is trying to solve a mystery: The interstellar explorer is operating normally, receiving and executing commands from Earth, along with gathering and returning science data. But readouts from the probe’s attitude articulation and control system (AACS) don’t reflect what’s actually happening onboard.

The AACS controls the 45-year-old spacecraft’s orientation. Among other tasks, it keeps Voyager 1’s high-gain antenna pointed precisely at Earth, enabling it to send data home. All signs suggest the AACS is still working, but the telemetry data it’s returning is invalid. For instance, the data may appear to be randomly generated, or does not reflect any possible state the AACS could be in.

The issue hasn’t triggered any onboard fault protection systems, which are designed to put the spacecraft into “safe mode” – a state where only essential operations are carried out, giving engineers time to diagnose an issue. Voyager 1’s signal hasn’t weakened, either, which suggests the high-gain antenna remains in its prescribed orientation with Earth.

Figuring out what has happened is made more difficult by distance. It takes about 20 hours for signals to get from Voyager-1 to Earth, even at the speed of light. Thus, any attempted fix will arrive almost two days after it first occurred, at the soonest.

Both Voyager-1 and Voyager-2 are still operating, though at significantly reduced power. It is expected that sometime in the next few years their nuclear power sources will finally be unable to produce enough power to keep them functioning. If so, both spacecraft will have survived the maximum time predicted when launched.

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A giant elliptical galaxy

3:14 pm

A giant elliptical galaxy
Click for full image.

Cool image time! The image to the right, reduced to post here, was taken by the Hubble Space Telescope of the giant elliptical galaxy NGC 474.

Located some 100 million light-years from Earth, NGC 474 spans about 250,000 light-years across – that’s 2.5 times larger than our own Milky Way galaxy! Along with its enormous size, NGC 474 has a series of complex layered shells that surround its spherical-shaped core. The cause of these shells is unknown, but astronomers theorize that they may be the aftereffects of the giant galaxy absorbing one or more smaller galaxies. In the same way a pebble creates ripples on a pond when dropped into the water, the absorbed galaxy creates waves that form the shells.

About 10% of elliptical galaxies have shell structures, but unlike the majority of elliptical galaxies, which are associated with galaxy clusters, shelled ellipticals usually lie in relatively empty space. It may be that they’ve cannibalized their neighbors.

NGC 474 is no exception, also located in a relatively empty region of space.

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The tuffy ground in the foothills of Mount Sharp

11:50 am

Shelfstone on Mars?
Click for original image.

Cool image time! The photo to the right, reduced and enhanced to post here, was taken on May 13, 2022 by the high resolution camera on the rover Curiosity, looking down at some of the unusual features on the ground near the rover.

The lighter circular feature in the center is not natural, but created by Curiosity’s Dust Removal Tool (DRT). As explained on May 16th on the science team’s blog:

When that dust settles on rocks, it can partially mask the chemistry and surface texture of these rocks from APXS and MAHLI in particular [two other Curiosity instruments]. Brushing rock surfaces with the DRT is not always possible, but it does improve scientific assessments of these surfaces.

What attracted me to this photo was the tuff-like look of that uplifted flat rock. It looks just like many surfaces one sees in a cave, where the surface gets covered with calcite flowstone or popcorn, due to either water flow or condensation and then evaporation of calcite-saturated water on the surface. In this case the cave formation this flat rock most resembles visually is shelfstone, though the formation process and chemistry was certainly different. It does suggest strongly however that some form of water process occurred here.

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NASA announces new possible launch dates for first SLS launch

10:13 am

NASA on May 16th announced the new possible launch dates for first SLS launch, outlining potential launch windows through the first half of 2023, with the first at the end of July 2022.

The calendar of launch windows through June of ’23 can be viewed here [pdf].

The July 26th to August 10th window is the one the agency is clearly targeting for that first launch, but it will not confirm this until after SLS successfully completes the next dress rehearsal countdown attempt in June. That the agency is now showing us potential launch dates in ’23 also suggests it is anticipating the possibility the launch could be delayed that much, especially if it determines it must replace the SLS’s two solid rocket boosters because they have been stacked unused for too long.

SLS was initially planned for a launch in 2015. It is now seven-plus years behind schedule, which is how long it took SpaceX to go from a blank sheet of paper to launching its Falcon Heavy for the first time.

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NASA bans American spacewalks on ISS because of chronic spacesuit issues

10:04 am

NASA's failed spacesuit
NASA’s failed Moon spacesuits

Because of repeated water leaks in the helmets of NASA’s complex spacesuits and the agency’s inability to fix the problem, agency managers have to decided to cease all American spacewalks on ISS until engineers can definitively solve the problem.

The problem first occurred during a 2013 spacewalk, causing a major investigation. Though engineers managed to gain some control over the problem, it was never truly solved. In the most recent spacewalk on March 23rd, astronauts found water inside one helmet after the walk was over. That suit will now be returned to Earth for inspection and engineering work.

This suspension of spacewalks likely delays four spacewalks planned this year to complete the upgrade to the station’s power system.

Meanwhile, NASA’s own program to build new spacesuits for its lunar missions has been an utter failure — costing more than a billion dollars over fourteen years and producing nothing — thus forcing the agency to turn to the private sector to get new suits.

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ABL completes and ships new upper stage only 4 months after test explosion

9:46 am

Capitalism in space: The smallsat rocket startup ABL has successfully completed construction and testing of a new upper stage for the first launch of its RS1 rocket, shipping it to the launch site in Alaska only four months after an explosion during testing destroyed an earlier stage.

Before the January accident, the company had planned a first launch of the RS1 rocket, capable of placing up to 1,350 kilograms into low Earth orbit for a list price of $12 million, early in the year. Shortly after the accident, the company estimated a three-month delay in its plans. Piemont said after the recent acceptance tests that the company was now targeting “early summer” for its first launch, pending completion of acceptance tests of the first stage.

Though the company’s goal had been to lose only three months and the actual delay was four months, the overall speed in which it recovered is impressive. Right now ABL is one of four smallsat rocket companies (ABL, Firefly, Aevum, and Relativity) attempting to complete its first launch this year. This success suggests ABL has a good chance of succeeding.

Below is a video of a successful static fire test of this new stage, released by the company. It is a pleasant change from most such PR videos, in that the company simply shows us the test, with some minor editing, but includes no dramatic but fake background music. Life isn’t a movie.
» Read more

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InSight likely to shut down by the end of summer

9:33 am

Martian quake map as seen by InSight
Martian quake map as seen by InSight, adapted from this 2021
presentation [pdf]

According to the InSight science team, the Mars lander and its seismometer will likely shut down operations by the end of the summer due to lack of power.

“Towards the end of summer of ’22, we anticipate our seismometer will be turned off, not because we want to turn it off but unfortunately, we don’t have the energy to run it,” Garcia said. She said the team will use it intermittently after that as long as power is available, but by the end of the year the spacecraft is expected to fall silent.

The intermittent readings of the seismometer will be of extremely limited use, as it will then be pure luck whether it detects a quake, and any detection will not provide the true rate of quakes on Mars.

The loss of power is due to dust on the solar panels. The team had hoped a dust devil would come by periodically to blow the panels clean, as happened routinely with the Spirit and Opportunity rovers, but InSight has not been so lucky.

It appears the safe mode that occurred shortly after InSight detected its largest Mars quake yet on May 10th was very temporary, though right now the seismometer is essentially the only instrument they have power to run.

Overall, this mission has a very spotty history. Its launch was delayed two years when the French attempt to build the seismometer failed. The delay cost NASA’s planetary program $150 million, at a minimum.

Then lander’s second of two main instruments, a German experiment to dig down 16 feet to insert a heat sensor into the ground, failed when its digging tool, dubbed the mole, was unable to penetrate the alien Martian soil.

Fortunately, InSight’s prime instrument, the seismometer (finally completed by JPL) worked, giving us a first look into the structure of Mars’ interior as well as where earthquakes are found on its surface.

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SpaceX successfully launches 53 Starlink satellites

8:54 am

Capitalism in space: SpaceX this morning successfully used its Falcon 9 rocket to send another 53 Starlink satellites into orbit.

The first stage completed its fifth mission, landing on the drone ship.

The leaders in the 2022 launch race:

21 SpaceX
15 China
6 Russia
3 Rocket Lab
2 ULA

The U.S. now leads China 29 to 15 in the national rankings, and the entire world combined 29 to 24.

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Pointy rocks on Mars

11:45 am

Pointy rocks as seen by Curiosity
Click for full image.

Pointy rocks as seen by Perseverance
Click for full image.

We have two cool images today from both of America’s rovers on Mars, each of which illustrates the alien nature of the red planet.

First on the right, cropped, reduced, and sharpened to post here, is a close-up taken by Curiosity’s high resolution camera on May 14, 2022 of the rightmost jagged boulder in yesterday’s navigation panorama. The number of layers is astonishing, though hardly a unique phenomenon as seen by Curiosity in its travels. Each likely marks one of many climate and geological cycles, each laying down another unique stratum for a relatively short period of geological time. Some might be volcanic ash or lava layers. Some might be layers caused by climatic changes.

The ability of these thin layers to extend outward so much, almost like they were floating, illustrates the weak Martian gravity, as well as the thinness of its atmosphere. On Earth, if the wind and weather didn’t cause these flakes to break, the gravity would.

Second on the right, cropped and sharpened to post here, is a high resolution photo taken by Perseverance on May 15, 2022 of one of the cliff faces seen by the rover looking up into the delta in Jezero Crater. Here again we see many layers and jagged, pointy rocks, illustrating again the many cycles in the past that formed the delta as it flowed into the crater.

The smoothness on the surface of the leftmost pointy rock suggests that it has stood in this position for a long very time, allowing the wind of Mars’ very thin atmosphere to erode its rough surface.

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More Chinese space junk crashes in India

9:52 am

It appears that debris from an upper stage of a Chinese Long March 3B rocket, launched in September ’21, fell in India on May 12, 2022.

Local media reported that the objects crashed with “loud thuds that shook the ground” in Gujarat. There were no casualties or property damage, according to The Indian Express. The crashed objects were all discovered within a 15-kilometer radius, and among them was a black metal ball weighing around five kilograms, the newspaper said.

Though the sources objects have not been identified with certainty, they look like inner tanks from a rocket, and the only object that reentered the atmosphere on this date and also had an orbit that crossed this part of India was the Long March 3B.

This is second time in less than a month that debris from an abandoned Chinese upper stage has crashed in India. Both are thought to have come from Long March 3Bs. More important, both now prove that China has no protocols when it launches these rockets to de-orbit the upper stages in a controlled manner.

Stay tuned for more Chinese space junk heading your way. In the next seven months it will launch two Long March 5B rockets, the large core stage of which reaches orbit. In all of the previous 5B launches, that stage — big enough to hit the Earth — then quickly fell back in an uncontrolled and unpredictable manner. Fortunately, each time it crashed in the ocean, though the May 2020 deorbit ended up with some debris landing near villages in Africa.

Recent tests of the 5B’s core stage’s engine have suggested that China might have redesigned it to allow it to be restarted, which would allow them to control its deorbit. This fact however has not been confirmed.

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Launcher fills customer list for first flight of its space tug

9:33 am

Capitalism in space: The startup space tug company Launcher announced yesterday that it has signed deals with ten customers, filling its manifest, for the first test flight of its Orbiter tug.

The tug and its payloads will be launched in October on a Falcon 9. Six of those customers, all cubesats, will be deployed into their preferred orbit by the tug, while four others are payloads that will simply ride on the tug.

The company is now selling planned future missions scheduled in ’23 on other Falcon 9 launches. It is also developing its own smallsat rocket, Launcher Light, with a planned first launch in ’24.

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Curiosity climbs on!

11:47 am

Curiosity's view to the southeast, May 15, 2022 (Sol 3474)
Click for full resolution. Original images can be found here, here, and here.

Overview map
Click for interactive map.

Cool image time! The panorama above, created from three photos taken on May 15, 2022 by the right navigation camera on Curiosity, shows the rocky and hilly terrain directly ahead of the rover’s present course. In the far distance in the center left can faintly be seen the lower flanks of Mount Sharp itself. The dust in the winter air acts to partly obscure those distant slopes.

The overview map to the right shows us what we are looking at. The yellow lines are my rough guess at the terrain covered by the panorama. The blue dot marks Curiosity’s present position. The red dotted line the rover’s original planned route. The white arrows indicate one of the more interesting upcoming geological features, dubbed by scientists the “marker horizon,” a distinct layer found in many places on the flanks of Mount Sharp.

The green dot marks the approximate location of a recurring slope lineae, a place where the cliff is seasonally darkened by a streak that appears each spring and then fades.

The navigation panorama taken on May 15th also included four more shots covering terrain to the southwest, so what we see above is not necessarily where the rover is heading. The eventual goal is to get back to that red dotted line, but how the rover does so is apparently still being discussed by the science team. It appears they are trying to decide whether to head west again to reach Gediz Vallis Ridge, or instead cut south heading directly for Gediz Vallis.

Either way, that teethlike row of boulders in the near foreground is certainly impressive.

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