Tag: engineering

The battlelines and alliances shift over big satellite constellations in space

9:41 am

Two stories today show that the competition for frequency use and orbital territory in space are shifting, partly because of international politics and partly due to changes in technology.

First the harsh conflict between OneWeb and Starlink over the positioning and frequency use of their constellations in orbit now appears to have vanished.

The companies have written a joint letter to the U.S. Federal Communications Commission (FCC), declaring harmony in low Earth orbit (LEO) for spectrum coordination between their respective current and next generation broadband constellations.

In the letter, which is dated June 13, SpaceX and OneWeb request that the FCC disregard previously filed dissenting comments regarding spectrum coordination in LEO. SpaceX and OneWeb both submitted proposals for their first-generation internet constellations to the FCC in 2016, followed by a second round of proposals in 2020 for each company’s next-generation broadband satellites. Simultaneously, both SpaceX and OneWeb submitted complaints with the FCC in an attempt to get a leg up on each other. Now, it seems the companies are operating on friendlier terms.

The article I think correctly speculates that this new-found cooperation probably resulted from OneWeb’s need to use SpaceX Falcon 9 rockets to get its satellites in orbit, caused by Russia’s confiscation of 36 OneWeb satellites in response to Europen sanctions over the Ukraine War. During the launch negotiations I am sure SpaceX demanded both iron out their differences relating to the satellite constellations. While SpaceX might have been able to gain some advantages in that negotiation due to its strong position, I also suspect that OneWeb has not been hurt in any major way.

In the second story, SpaceX ramped up its opposition to a Dish 5G system in a wavelength used by its Starlink satellties.
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Psyche software issue could prevent launch this year

9:08 am

In a remarkably brief announcement on the Psyche website, the engineering team suggested that the flight software issue that forced a seven week delay in its launch might now prevent a launch this year.

This is the entire announcement:

NASA’s Psyche mission team continues to assess ongoing issues with the spacecraft’s flight software. The team is evaluating its ability to meet a schedule to launch in 2022 – the current launch period is Sept. 20 to Oct. 11. If it is determined that launch in 2022 is not possible, a full range of actions for how to proceed will be considered.

This year’s launch window would have gotten the spacecraft to the asteroid Psyche in 2026. Since this flight path required a fly-by of Mars, it is very unclear when another launch window will be available.

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China’s Kuaizhou-1A smallsat rocket launches technology test satellite

8:47 am

China today used its smallsat solid rocket Kuaizhou-1A to put a technology test satellite into orbit.

The Kuaizhou-1A rocket is not the same as the Kuaizhou-11 rocket, which some have speculated exploded during a static fire test in the fall of ’21. Both are part of a family of rockets designed for fast launch.

The leaders in the 2022 launch race:

26 SpaceX
19 China
8 Russia
3 Rocket Lab
3 ULA

The U.S. still leads China 35 to 19 in the national rankings, and the entire world combined 35 to 31.

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Has work begun on a dedicated helicopter mission to Mars?

12:42 pm

Overview map

The easternmost point in the Mars Helicopter traverse
Click for full image.

In my routine searches through the image archive for the high resolution camera on Mars Reconnaissance Orbiter, I recently came upon several images labeled “Candidate Mars Science Helicopter Traverse” that I at first thought referred to Ingenuity’s extended mission in Jezero Crater.

A closer look however revealed these photos have nothing to do with Ingenuity or Jezero Crater. Taken in November ’21, January ’22, and March ’22, the images instead cover parts of the south rim of Valles Marineris, the solar system’s largest canyon, and appear to be research for a future dedicated Mars helicopter mission. The overview map above shows the location of these photos by the black dots. Three locations have each been imaged twice to produce a stereoscopic view that can precisely measure the topography.

The photo to the right, cropped and reduced to post here, shows the easternmost image, taken November 3, 2021. Not only does it show ample flat areas, the picture captures an impressive avalanche flow coming down from that southern interior canyon slope.

All the images were requested by planetary scientist Edwin Kite of the University of Chicago. Though I tried several times to contact Dr. Kite to get more information, he unfortunately did not respond. It could be this work is still too preliminary and thus he does not wish to comment.

Nonetheless, the extent of the three sets of images give us a fair idea of the kind of missions Kite and others might be considering. From east to west the distance between the images is about four hundred miles, and covers a traverse of the southern interior slopes of Valles Marineris along that entire length. The photos look mostly at the base of the canyon’s slope, each showing clearly that a helicopter flying there would have plenty of landing spots.

Obviously this first dedicated Mars helicopter mission might not cover this entire distance. Right now these images could simply be the first tentative research on choosing potential landing areas. Regardless, it appears that at least one scientist has already concluded that Ingenuity has proven such helicopter missions make sense, and is beginning to target one of Mars’s most spectacular locations, Valles Marineris, for that mission.

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South Korea successfully launches its Nuri rocket

9:04 am

The new colonial movement: South Korea today successfully launched its home-built Nuri rocket, placing a test satellite, a dummy satellite, and four university cubesats into orbit.

The government program to build this rocket began in 2010 and cost $616 million, though not all of that money was devoted to the rocket. South Korea’s space agency has four more launches planned through 2027.

This was obviously South Korea’s first launch this year. The leaders in the 2022 launch race thus remain the same:

26 SpaceX
18 China
8 Russia
3 Rocket Lab
3 ULA

American private enterprise now leads China 35 to 18 in the national rankings, and leads the entire world combined 35 to 30.

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SLS dress rehearsal countdown ends at T-29 seconds

7:47 pm

NASA’s fourth attempt to complete a full dress rehearsal countdown of its giant SLS rocket today ended at T-29 seconds, just short of the complete countdown.

It appears the countdown had one issue — a hydrogen fuel leak at the point where the umbilical fuel line attaches to the rocket — that mission control decided to ignore (or “mask” to use their word) so that they could proceed into the count as far as possible. It was this decision however that caused the two-hour delay in the countdown. They then resumed the countdown at T-10 minutes, the beginning of terminal count.

During the terminal count, the teams performed several critical operations that must be accomplished for launch including switching control from the ground launch sequencer to the automated launch sequencer controlled by the rocket’s flight software, and important step that the team wanted to accomplish.

NASA will hold a press conference tomorrow at 11 am (Eastern) to discuss the results of this dress rehearsal. While the leak is concerning, I expect NASA to decide that this dress rehearsal was a success, that they will roll the rocket back to the vehicle assembly building where they will fix this problem, after which the agency will declare the rocket ready to launch by the end of August.

While risky, doing otherwise likely raises other risks. If they decide to do another dress rehearsal the launch faces more delays. And waiting much longer continues to increase the danger that the solid rocket side boosters will not function as intended because they have been stacked almost a year longer than their accepted use-by date.

If this turns out to be the plan, expect the actual launch countdown to be as plagued with issues and delays and scrubs. NASA has yet to demonstrate it can do this smoothly with no problems. Worse, this level of mediocre performance has been par for the course for this entire SLS program.

If that launch should go smoothly it will be a welcome and unprecedented event.

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Water and dry ice at the Martian north polar ice cap

12:41 pm

water and dry ice at the Martian north pole
Click for original image. Click here for full image.

In our third Martian cool image of the day, we go to the north pole of Mars, as seen from orbit by the high resolution camera of Mars Reconnaissance Orbiter (MRO). Taken on March 30, 2022 and cropped and reduced to post here, this picture shows some of the distinct and unique geological features found only on the polar caps of Mars. From the caption by Candy Hansen of the Planetary Science Institute in Tucson, Arizona:

Both water and dry ice have a major role in sculpting Mars’ surface at high latitudes. Water ice frozen in the soil splits the ground into polygons. Erosion of the channels forming the boundaries of the polygons by dry ice sublimating in the spring adds plenty of twists and turns to them.

Spring activity is visible as the layer of translucent dry ice coating the surface develops vents that allow gas to escape. The gas carries along fine particles of material from the surface further eroding the channels. The particles drop to the surface in dark fan-shaped deposits. Sometimes the dark particles sink into the dry ice, leaving bright marks where the fans were originally deposited. Often the vent closes, then opens again, so we see two or more fans originating from the same spot but oriented in different directions as the wind changes.

The top layer of translucent dry ice falls as dry ice snow during the winter, than sublimates away with the arrival of spring. Since this photo was taken in autumn, we are looking at features left over from the activity from the spring and summer.

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Perseverance peers towards the rim of Jezero Crater

12:17 pm

Perseverance peers through winter haze
Click for full image.

Overview map
Click for interactive map.

In our second cool image from Mars today, the Mars rover Perseverance gives us its own long distance view of the dusty winter air inside Jezero Crater. The photo above, cropped and reduced to post here, was taken on June 16, 2022 by the rover’s left high resolution camera, and looks to the southwest towards the crater’s western rim.

As with today’s previous cool image from Curiosity, we can see several ranges, each with distance faded more by the dust that hangs in the air during the winter on Mars. In the foreground right is the nearest cliff of the delta that flowed into Jezero over time in the past. Next is a knob and ridge line, also part of that delta flow but farther away. Third are some farther ridges that might have been part of that flow but maybe not.

Faintest of all are the highest mountains that form the western ridge of Jezero Crater, barely visible in the haze.

The blue dot in the overview map to the right marks Perseverance’s approximate position when the photo was taken. The yellow lines my guess as to the area covered by the photo. The green dot marks Ingenuity’s present position after its last flight, much closer to the delta that I had predicted.

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Martian mountains, near and far

11:44 am

Navigation image
Click for full image.

Martian mountains, near and far
Click for full image.

Cool image time! The photo to the right, taken on June 18, 2022 by high resolution camera on the Mars rover Curiosity, provides a close-up of the area indicated by the arrow in the navigation camera image above taken three days earlier.

Because the rover had moved uphill slightly during those three days, the close-up can peek over what was the most distant ridge to see farther up Mount Sharp. (For context take a look at the overview map here.) All told, this close-up to the right shows four mountain ridges/ranges. First we have the ridgeline to the right, partly in shadow, which forms the right wall of the saddle that Curiosity appears heading for. Next we can see to the left the top section of the large 1,500 foot high mesa on the other side of the canyon Gediz Vallis. Note its many layers, all of which are going to become a major item of study as Curiosity gets closer.

Third we have a very rough and tumbled ridgeline, formed in a layer the geologists have dubbed the sulfate bearing unit. This layer tends to be very light in color, and more easily eroded. Curiosity is presently beginning to move into this layer as it climbs.

Finally there is the most distant ridge, which is simply the higher reaches of Mount Sharp though not its peak by a long shot.

The dusty winter air is quite evident by the chariscuro effect, causing the more distant ridges to appear more faded.

Note: This will be the first of three cool Martian images today. Stay tuned.

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SLS dress rehearsal countdown continues, though T-0 delayed two hours

9:33 am

The SLS dress rehearsal countdown is proceeding today as planned, though the countdown’s end at T-0 is now 4:38 pm (eastern), two hours later than previously announced.

Apparently they have delayed T-0 from the beginning of the two-hour simulated launch window to its end. This decision so early in the count suggests the launch team wants to give itself extra time either to deal with some issue that has come up that they haven’t told us about yet, or to give themselves more time in case some issue should come up.

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ISS forced to dodge space junk from Russia’s November ’21 anti-sat test

9:26 am

Last week the Russians were forced to use the engines of the Progress cargo capsule docked to ISS to shift the station’s orbit slightly to avoid a collision with some debris left over from Russia’s anti-satellite test in November 2021.

“I confirm that at 22.03 Moscow time, the engines of the Russian Progress MS-20 transport cargo ship carried out an unscheduled maneuver to avoid a dangerous approach of the International Space Station with a fragment of the Kosmos-1408 spacecraft,” Roscosmos chief Dmitry Rogozin wrote on Telegram (opens in new tab), according to a Google translation, using Roscosmos’ designation for Progress 81.

While the Russians have consistently denied the anti-sat test and the 1,500 satellite pieces it created would cause a collision threat, yesterday’s action was not a surprise, and was predicted by many right after the test.

The concern however is not the debris that has been identified and is being tracked, since collisions from that stuff can be predicted and avoided. The concern is from the smaller pieces that were not identified.

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SLS dress rehearsal countdown begins

10:07 am

NASA engineers began their fourth attempt to complete a full dress rehearsal countdown of the SLS rocket yesterday, with everything proceeding so far as planned.

Overnight, engineers powered up the Orion spacecraft and the Space Launch System’s core stage. Teams also configured several systems on the ground, rocket, and spacecraft and performed activities to prepare umbilicals that connect the rocket and spacecraft to the mobile launcher and are used to provide power, communications, coolant, and propellant.

Actual fueling begins tomorrow, when the countdown is supposed to conclude at T-0 at 2:40 pm (Eastern).

NASA live stream is available here.

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