Wednesday, August 10, 2022

SpaceX Static Fires Both Booster 7 and Ship 24

On Tuesday, SpaceX static fired one engine on Booster 7, and about three hours later static fired two engines on Ship 24.  

On Monday evening at 5:20 pm local time in South Texas, engineers ignited a single Raptor engine on the Super Heavy booster that serves as the rocket's first stage. This is the first time the company has conducted a static fire test of the booster, which will ultimately be powered by 33 Raptor rocket engines.

About three hours later, on a separate mount at its "Starbase" facility in Texas, SpaceX ignited two engines on the Starship upper stage of the rocket. The company later shared a short video on Twitter of the evidently successful test.

That's a 10 second video.  NASA Spaceflight.com's video is a bit easier viewing because of camera angles than Lab Padre's videos - one for B7 and one for S24.  I'm sure there must be more out there.  NASA Spaceflight's video also is 10 minutes long with the second half of it being content they usually put in their daily update videos. I typically fast forward or skip over most of that.

These two static firings, which are intended to test the plumbing of the rocket's liquid oxygen and methane propellant systems, are significant. They are the first static fire tests of 2022 at the South Texas launch site. Moreover, these vehicles—dubbed Booster 7 and Ship 24 to reflect their prototype numbers—could be the ones that SpaceX uses for an orbital launch attempt. Finally, this is the first time SpaceX has test-fired its new version of the Raptor engine, Raptor 2, on a rocket.

I was a bit shocked at these being the first static firings of 2022; it felt like a long time, but not that long.  An important thing not mentioned there is the explosion that B7 endured back on July 11th.  The booster was quickly rolled back to the High Bay and spent three weeks being repaired while the Orbital Launch Pad's damage also was being repaired.  Amazingly, B7 rolled back to the launch area four days ago, and has already undergone enough testing to be confident it was ready for this test three days later.  

B7 with one Raptor 2 firing - SpaceX photo.

The explosion back in July was blamed on the spin start test they were performing on B7 and Elon Musk pretty much said, "we're not gonna try a spin start test on 33 engines again!" But they have to.  Superheavy boosters carry 33 engines - or will for real orbital flights.  There's talk about stray gas igniters to clear out any fumes or other possible measures.  For now, I expect they'll start working up to larger numbers of engines being static fired.  Perhaps two days ago, Elon tweeted that the goal was to test the outer group of 20 engines.  Those are the only engines installed on B7.  

I think we can expect to see quite a bit more testing before they're done with B7 and S24.  

These vehicles are experimental and may fail. SpaceX uses an iterative design process to reach a flight-ready version of Starship. To that end, the company has already nearly completed "Ship 25" in a high bay facility about 2 km from its launch site in South Texas and is working on elements of Ships 26 and 27. Meanwhile, Booster 8 is coming along in another large bay as work progresses on Booster 9 and 10.



Tuesday, August 9, 2022

Strange Bedfellows in Space

Today we learned that Northrup Grumman has partnered with both rocket startup Firefly and SpaceX to keep the Cygnus cargo capsule to the ISS flying as the Antares rocket is becoming non-procurable and the successor version of Antares won't be available in time.  Firefly will build the new rocket, and SpaceX will fill the gap with cargo launches to the ISS until Firefly's new rocket is ready .

The new and improved Antares 330 rocket could debut as early as late 2024. The existing Antares 230 rocket has just two launches left before a lack of new hardware from crucial Ukrainian suppliers will permanently ground it – a time Northrop Grumman estimates will come as early as spring (Q2) 2023. To fill Antares’ 18-month availability gap, Northrop Grumman says it has purchased three SpaceX Falcon 9 launches to continue Cygnus space station cargo deliveries largely unabated.

While it's surprising to see Northrup Grumman signing with SpaceX, nominally their competitor, to help continue the mission, the last time something happened to the Antares - a loss of vehicle incident in 2014 - they contracted with United Launch Alliance for some Atlas V launches.  Now that Atlas V has had new contracts shut down, and its successor (Vulcan) isn't flying there it was clear that SpaceX was the only viable option.  With SpaceX's launch cadence at least 10 to 20x any other American launch provider, it's clear they were pretty much the only way to bridge the gap between Antares and Firefly.

Northrup Grumman has contracted for three SpaceX Falcon 9 flights:

The wording of that tweet makes it sound like SpaceX will launch Cygnus cargo containers.  While I'm not 100% sure they can't, I think just putting a different payload on a Falcon 9 might not be simply stacking the two together.  At a minimum, some sort of adapter seems necessary, but they might mean that SpaceX will simply launch Cargo Dragon missions instead of the Cygnus.  

Another interesting little part of this story is that considering the Antares rocket is always referred to as Northrup Grumman's, it's a bit surprising how little they have to do with actually manufacturing the vehicle. 

The only major components of Antares-Cygnus Northrop Grumman (through its 2018 acquisition of Orbital ATK) is responsible for building are the rocket’s Castor 30XL second stage and Cygnus’ service module. Cygnus’ silver pressure vessel is built by Thales Alenia Space, the payload fairing is built by RUAG, the Antares booster engines are supplied by Russia’s NPO Energomash, and the Antares booster structures are built by Ukraine’s Yuzhnoye SDO and Yuzhmash.

That last sentence about the Ukrainian suppliers is the problem.  The Yuzhmash factory was reportedly struck by cruise missiles in July, killing several people.  The photos at that BBC link make it seem that the Yuzhmash factory was badly damaged as well so it may well be out of commission for the foreseeable future.  Not to mention that Antares used Russian engines, which we know were banned for import some time ago. 

The Antares 330 booster Firefly intends to build for Northrop Grumman will be substantially larger and “significantly increase” the rocket’s performance to low Earth orbit (LEO), which currently sits at 8 tons (~17,500 lb). Intriguingly, the booster Firefly will supply appears to be the latest iteration of the first stage of the medium-lift Beta rocket the startup has been working on for some time. According to Firefly’s recently updated Beta webpage, the next-generation rocket is expected to measure 4.32 meters (14.1 ft) wide and 55.7 meters (182.5 ft) tall; produce about 720 tons (1.6M lbf) of thrust in vacuum, and launch up to 13 tons (28,700 lb) to LEO.


Northrup Grumman rendering of the new Antares 330 booster from Firefly with a Cygnus vehicle mounted to the top.  

 

 

Monday, August 8, 2022

Rocket Lab CEO on Their Launch Cadence

Too depressing a day in the news.  I need something optimistic.  

Rocket Lab CEO Peter Beck talked about their launch cadence in a recent interview, and while they could launch faster, they spend more time waiting on customer's payloads to go much beyond their current 10-15 launches per year for the foreseeable future.  Their Electron booster just tied its record for successful launches in one year with August 4th's launch for the National Reconnaissance Office, NROL-199, at six launches.  

It has been a positive year for Electron.  In addition to tying the record, on June 28th, Rocket Lab successfully launched NASA's CAPSTONE project (middle part of this article).  This mission  demonstrated that a small rocket could launch a deep space mission and proved out the capability of the company's Photon satellite bus for complex in-space operations.  

Rocket Lab has been successful, and like 99.99% of all big successes, it has been delivered by tons of hard work.  Beck said these successes and the higher cadence, were possible because of "mature" processes now in place at Rocket Lab and the experience gained over the previous five years.  Developing repeatable ways of manufacturing high quality products is what manufacturing engineering is all about.

Building the first couple of rockets for any launch business is an all-hands-on-deck effort, with engineers and managers closely following the rocket down the production line. Now, Beck said, Electrons are built by technicians with a set of work instructions. "We invested a tremendous amount in all of the systems and processes to be able to do that," Beck said. "All of our production systems are really mature."

Rocket Lab is now ready whenever its customers are, Beck said. With its existing workforce, the company can build an Electron launch vehicle every 18 days. It has two launch pads and three clean rooms for pre-launch processing, and it holds two rockets at its New Zealand launch site at all times. Because of its vertical integration efforts, more than 80 percent of an Electron is built in-house, leaving its production less vulnerable to supply chain issues. "Because you are a dedicated service, you're offering a premium service such that you go when the customer is ready," Beck said.

Beck continued on to say that they expect to fly 10 to 15 launches this year.  In terms of numbers of launches that will make them second in the Western world behind SpaceX. Being a small satellite launcher, though, their total tonnage to space will be behind bigger companies like United Launch Alliance and Arianespace. 

Their facility in New Zealand can launch an Electron once a week.  15 launches/year is one every 3-1/2 weeks.  10 launches/year is one every 5-1/4 weeks.

"The reality is that we built everything to be able to launch once a week," Beck said. "Everything in the factory is designed to be able to process and push through one rocket a week. So from an infrastructure perspective, we can do that. And from a system's perspective, we can do that. It would just require a larger workforce. But the reality is that it's the market that's the driver. For us, our cadence today is 100 percent driven by market demand."

August 4th launch of the NRO payload - Rocket Lab photo.

The problem that Beck describes is that the small satellite launcher business just isn't there.  There aren't enough payloads to support the capacity that the newborn industry expected.  Beck is saying they have the hardware infrastructure to do a launch a week instead of their current, slower cadence.  To increase it, "all they'd really need to do" is add more workers.  It's just that the demand for launches isn't there.  We just read that Astra is aiming for the same market, or put another way, aiming to take at least some of Rocket Lab's business.  

Some commentators have been saying for a couple of years that the small launch business is headed for some sort of thinning of the herd.  This is more evidence.  

That's one reason Beck is pushing for the development of their Neutron rocket.  Neutron is the successor to Electron that's capable of delivering 8 metric tons to low Earth orbit with a fully reusable first stage. That's the direction the market, driven by megaconstellations, is moving toward.

Rocket Lab calls Neutrons fairings and their upper stage deployment system the "Hungry Hippo" fairing and once you've seen that, you can't unsee the little kids' game.

In addition, Rocket Lab continues to work on recovering the Electron boosters, as you might recall from May.  The helicopter pilot briefly captured the first stage but then released, saying the recovered booster didn't feel like any of the practice missions.  Rocket Lab still fished the booster out of the water and Beck said they found it to be in the best condition of any previously recovered first stage. 

 

 

Sunday, August 7, 2022

How The World's Governments Helped Advance the 19th Century's Internet

They thought there was nothing to the idea and didn't try to help it along.  They pretty much left it alone.

“It,” the 19th century's version of the internet, was the telegraph.  Not telegraph by radio, but by long wires stretched across countries and then farther.  Arguably, the telegraph was one of the most important innovations of the 1800s.  Unarguably, the telegraph revolutionized communications.  In an interesting historical article from the Foundation for Economic Education, Lawrence W. Reed provides several interesting notes about the period.

As Tom Standage explained in his splendid book, The Victorian Internet, messages before the telegraph traveled at the speed of horses. From London to New York, a message required weeks of travel by ship. But after the transatlantic cable debuted mid-century, a telegraphed message from London showed up in New York in a matter of minutes. The world over, this was greeted as nothing short of miraculous. 

Given the very obvious advantages of the telegraph it's remarkable how short-sighted the entrenched interests were.  

The first electric telegraph was demonstrated in 1816 by Sir Francis Ronalds of the UK, who then brought his invention to the attention of the British Admiralty.  Francis Ronalds (not knighted until much later in his life) was 28 years old at the time.  The year before, 1815, Ronalds had developed the first electric clock.

[H]e had good reason to expect a positive reception. Quite possibly the world’s first electrical engineer, he had already accomplished the impossible by transmitting a signal across eight miles of wire. It was the world’s first working electric telegraph.

On August 5, 1816, Sir John Barrow delivered the British Admiralty’s stunning verdict. Ronalds’ invention was “wholly unnecessary,” he said. His Majesty’s military would continue to communicate via semaphore (signal flags and the like), as it had for centuries.

In spite of the Admiralty’s judgment, Francis Ronalds saw the value in his invention and worked at developing it.  He became a wealthy man and one of the world’s most respected scientists.  Known even in his lifetime as the “father of electric telegraphy,” he made immense contributions to civil and mechanical engineering, meteorology, and early camera technology.

Of course, I can't just pick on the British Admiralty for being short-sighted and making a stupid decision.  The US government doesn't play second to anyone on Earth at making stupid decisions. 

In America, the first telegraph line was run by the federal government, from 1844 to 1846. As historian Burton Folsom explained,

Cave Johnson, the Postmaster General, argued that the use of the telegraph “so powerful for good or evil, cannot with safety be left in the hands of private individuals uncontrolled.” Only the government, Johnson concluded, could be trusted to operate the telegraph in “the public interest.”

Johnson’s assessment proved dead wrong. After two years, Congress tired of the losses and privatized the line. Entrepreneurs figured out how to make it profitable and quickly turned the telegraph into a national, then international enterprise.

Of course, governments making stupid decisions because they think they know better didn't stop in the 1800s.  It should go without saying that just because someone trying to predict the future is from the private sector doesn't guarantee they won't do something stupid.  They'll just throw away their own money.  Reed lists several examples of more recent government stupidities, just to reinforce his point that the best thing they did for the telegraph was leave it alone; to leave it to the private sector. 

An 1800s-style telegraph key, a style called a straight key today (although no one uses one by tapping it with one finger like that).  Image by iStock, from the FEE article.  



Saturday, August 6, 2022

Astra Announces Pivot from Their Business Model

Astra seemingly burst onto the launch scene a few years ago with a bold vision and different sort of approach to the launch business.  It would build cheap launch vehicles and cycle through them quickly.  Instead of sparing no expense to ensure highly reliable vehicles, they assumed their small satellite customers would accept a bit more risk, so they could cut down on their testing, analysis, and redundancy in design.  In return, Astra would pass those launch savings along to customers.  Astra co-founder Adam London had said, "it's a no-brainer from an economics perspective that for these kinds of payloads, you should not be targeting 100 percent reliability," back in February of '20.

It hasn't quite worked out that way

At the time London said that, the company was working on their Rocket 3 vehicle, a micro launcher said to be capable of putting small payloads of about 50 kg into low Earth orbit. That rocket exploded within one month during a wet dress rehearsal test on the launch pad.  

Since then, Astra has attempted seven launches of its Rocket 3 vehicle. Only two of these seven flights were successful. Particularly embarrassing was the company's most recent launch of Rocket 3 two months ago, when the upper stage shut down early, failing to put two tropical activity monitoring satellites into orbit for NASA.

While customers might well settle for a bit less reliability in exchange for a more affordable launch, they probably envision something like dropping from 99% reliability to 90%, not 29% like this.  

Given all of this, Astra on Thursday announced a reset of its plans moving forward with regard to launch activity. The most recent failure appears to have catalyzed Astra to move in a new direction. In short, Astra will shift away from its previous mantra of being lean in terms of staffing, moving at breakneck speed, and being willing to tolerate failure in launch vehicles. It will also be going bigger in terms of its rocket size.
...
"We've made a few key decisions," [CEO Brian] Kemp said. "First, we've increased the payload capacity target for launch system 2.0 from 300 kg to 600 kg. Second, we're working with all of our launch service customers to re-manifest on launch system 2.0. As such, we will not have any additional flights in 2022. And third, we're increasing investments in testing and qualification which will add additional time and test flights to our schedule prior to resuming commercial launch operations."

This is more confusing if you're not familiar with Astra, but they're abandoning the Rocket 3 program and moving to what they've previously called (are you ready?) Rocket 4 - but which will also be called Launch System 2.0.  They're going to the 600 kg payload largely in effort to appeal to the companies trying to put up mega-constellations.  Elsewhere, Eric Berger at Ars Technica was able to determine the projected cost is $5 million for a Rocket 4 mission.  That puts Rocket 4 at about double the payload capacity of Rocket Lab's Electron vehicle at two-thirds the price.  

Rocket Lab isn't standing still, of course; they're developing the Neutron launch vehicle to compete with the Falcon 9.  SpaceX isn't standing still either, of course.  Competition is good, of course.  

The question, of course, is whether they can pull this off.  Not just the talent pool but the funding (which is easier to get information on). We know they say they've tripled the size of their workforce; we don't know if the people hired can accomplish what Astra needs.

It is not clear whether a larger Astra has the finances to survive one to two years of development work. Astra reported a net loss of $168 million during the first half of 2022, with revenues of just $6.5 million. Meanwhile, the company has cash and marketable securities of about $200 million on hand.

To reach the point where it can start launching Rocket 4, Astra will probably need to raise additional money, trim expenses, and increase sales of its other main product, the "Astra Spacecraft Engine," an in-space electric propulsion engine. The company says it has started delivering these engines to customers, but it offered few details on potential revenue from these sales.

Rocket 3.3 before the TROPICS mission in June. 



Friday, August 5, 2022

Even Though SLS Has Never Flown

As the Space Launch System (SLS) prepares for its roll out to pad 39B on August 18 and first launch August 29,  NASA is preparing to award a contract to a Boeing-Northrop Grumman joint venture for SLS missions that could run through the middle of the 2030s.

On July 26, NASA issued a pre-solicitation notice for its Exploration Production and Operations Contract (EPOC), which would shift procurement of SLS launches to a services contract. The contract won't start until the late 2020s.

NASA envisions EPOC as a means of saving money as well as opening the door to other uses of the heavy-lift rocket. The baseline contract would cover missions Artemis 5 through 9, with an option for missions Artemis 10 through 14 and another option for up to 10 non-Artemis launches. If the options are exercised, the contract would run through the Artemis 14 mission that NASA projects flying in 2036.

The source article at Space News doesn't mention the October '21 request from NASA to everyone in the industry that said "Cut SLS Costs by 50% and We'll Use it 'Till 2050."  My own wild-ass guess is that awarding this contract exclusively to one supplier is another way of saying that SLS "is what it is" and either no other company responded to that Request for Information, or none of them could bid building a replacement for SLS without massive costs and delays.  

NASA expects to award the contract to a new joint venture called Deep Space Transport LLC. That joint venture consists of Boeing, the prime contractor for the SLS core stage and the Exploration Upper Stage that will be used on SLS missions starting with Artemis 4, and Northrop Grumman, the prime contractor for the SLS solid rocket boosters.
...
“To have another company manufacture the Core Stage and Exploration Upper Stage may take as long as 10 years,” NASA states in the documents, with “a duplicative cost to the Government not expected to be recovered through competition.” Producing the five-segment boosters would take another company up to nine years, NASA estimates, and seven years for an alternative manufacturer of the RS-25 engines for the core stage produced by Aerojet Rocketdyne.

Artemis/SLS on the way to pad 39B on March 17th for the first attempts at the WDR. 

In communications prior to the pre-solicitation notice NASA stated that it expects to make the EPOC award to Deep Space Transport by the end of 2023.


 

Thursday, August 4, 2022

Not Many People Noticed Today Was a Loaded Day of Launches

I only knew half of it, but today was a loaded launch day for American launch companies, as reported in Ars Technica's weekly Rocket Report newsletter (which I can't link to because they won't post it online until tomorrow).  

It began at 05:00 UTC or 1:00 AM EDT, when Rocket Lab's Electron vehicle launched the NROL-199 mission into low Earth orbit for the US National Reconnaissance Office (NRO).  This launch was from Rocket Lab's New Zealand launch site.  While they were founded in New Zealand, they've since incorporated in the US and have launched from Wallops Island.  The mission for the NRO was the second of a pair of launches intended to demonstrate how fast Rocket Lab could launch successive missions - the first, NROL-162, was July 13.  That demonstration slowed down a bit when the NRO had to change the software in the satellite and delayed the mission themselves. 

Five and a half hours later, at 10:29 UTC, 6:29 AM EDT,  United Launch Alliance's Atlas V rocket sent a Space Based Infrared System satellite into orbit for the US Space Force from Cape Canaveral Space Force Station.  More details here.  That launch was about 20 minutes before sunrise, an optimum time for launch and it did produce somewhat of a "space jellyfish" display.  Someone whom I won't name neglected to set his alarm and slept right through it. (Liftoff is around 37 minutes into that video, so skip ahead to that if you want to skip chat about everything).

But while two launches in a day is pretty active, this day was far from done.  At 1337 UTC (9:37 AM EDT), Blue Origin's New Shepard rocket launched the NS-22 suborbital space tourism mission. This launch was from Blue's launch facility in Texas. While it's suborbital, it's still considered a launch into space.

The final launch of the day was tonight as SpaceX launched the Korea Aerospace Research Institute's Korean Pathfinder Lunar Orbiter (KPLO) spacecraft to the Moon at 23:08 UTC (7:08 PM EDT) also from Cape Canaveral SFS, SLC40.  This one was good viewing from our location, mostly since the evening sun was well-placed to not interfere with our views.  We could see the Falcon 9 clearly until after the first stage separated and follow the second stage for a while. The KPLO launch is interesting in that it takes a different approach to the moon than the direct approaches of the Apollo era. The reasoning is that it takes longer to get there, but costs less and uses less fuel, both big considerations. It's reminiscent of the approach CAPSTONE is using but a very different orbit.

Rocket Lab kicked the day off with this smallsat launch for the US NRO. 

The editor of the Rocket Report, Eric Berger, noted,“I cannot recall a time when four different US rockets launched during the same calendar day, but this probably won't be the last time, given all the development of new US boosters, large and small. We truly are entering an era of launch abundance.”  A day like today really does give the impression that the best is yet to come.  

 

 

Wednesday, August 3, 2022

NASA's Lucy Mission to Jupiter's Trojan Asteroids is Back on Track

Last October 16, NASA's Lucy spacecraft started its multiyear mission to Jupiter's Trojan asteroids.  Within two days, it was reported that one of the solar power arrays had not unfolded and latched properly.  In an update today, August 3rd, NASA Goddard Space Flight Center announced that the efforts to repair the satellite have succeeded and the mission will proceed as planned

NASA Goddard released this rendering of the satellite before work was done and it's easy to see the solar array on the right isn't fully opened.  They explained that even in this position, it was producing about 90% of its rated power, so the mission didn't seem to be in lots of trouble.  

Although not in lots of trouble, it was imperative to understand what had really happened so they could be sure it wouldn't degrade even farther on its own.

In situations like this, the standard response is to call together a "Tiger Team" or (less flashy named) anomaly response team of scientists and engineers from all the contractors involved: spacecraft builder Lockheed Martin, solar array designer Northrop Grumman, science mission leader Southwest Research Institute (SwRI); and mission operations leader NASA’s Goddard Space Flight Center.  From the description at NASA's Goddard SFC:

To evaluate Lucy’s solar array configuration in real time, the team fired thrusters on the spacecraft and gathered data on how those forces made the solar array vibrate. Next, they fed the data into a detailed model of the array’s motor assembly to infer how rigid Lucy’s array was – which helped uncover the source of the issue.

At last, they closed in on the root cause: a lanyard designed to pull Lucy’s massive solar array open was likely snarled on its bobbin-like spool. 

After months of further brainstorming and testing, Lucy’s team settled on two potential paths forward.

In one, they would pull harder on the lanyard by running the array’s back-up deployment motor at the same time as its primary motor. The power from two motors should allow the jammed lanyard to wind in further and engage array’s latching mechanism. While both motors were never originally intended to operate at the same time, the team used models to ensure the concept would work.

The second option was simply to use it as it was.  Since they were getting 90% of the expected power out of that panel and designing a critical system like that without lots of design margin Just Isn't Done, there was no reason to think they absolutely needed to open the array completely.  But they went ahead and tried.  

After months of simulations and testing, NASA decided to move forward with the first option – a multi-step attempt to fully redeploy the solar array. On seven occasions in May and June, the team commanded the spacecraft to simultaneously run the primary and backup solar array deployment motors. The effort succeeded, pulling in the lanyard, and further opening and tensioning the array.

The mission now estimates that Lucy’s solar array is between 353 degrees and 357 degrees open (out of 360 total degrees for a fully deployed array). While the array is not fully latched, it is under substantially more tension, making it stable enough for the spacecraft to operate as needed for mission operations.

The next mission milestone for Lucy is a gravity assist flyby of Earth this October.  Lucy is not scheduled to reach the first asteroid on its mission until April of  '25.  Here, I'm going to fill in some background from the piece I wrote on this mission in October '21.

Lucy is an interesting mission that seems totally academic.  The mission is to the Trojan asteroids, orbiting at the LaGrange points of Jupiter, ahead of and behind Jupiter itself in its orbit around the sun.  

The $981 million mission will fly an extremely complex trajectory over the span of a dozen years. The spacecraft will swing by Earth a total of three times for gravitational assists as it visits a main-belt asteroid, 52246 Donaldjohanson, and subsequently flies by eight Trojan asteroids that share Jupiter's orbit around the Sun.
...
Lucy will fly by its first asteroid target in April 2025, a main-belt asteroid named after Donald Johanson, the American anthropologist who co-discovered the famed "Lucy" fossil in 1974. The fossil, of a female hominin species that lived about 3.2 million years ago, supported the evolutionary idea that bipedalism preceded an increase in brain size.

The mission itself is named after that fossil Lucy as well.  It's a fanciful name, but these asteroids themselves are considered to be old fossils from the formation of the solar system. 

This is Lucy's trajectory over the next 12 years.  It looks complex but it's even more complex than this shows.  This perspective is created by fixing Jupiter's position, so during the 12 years of the mission that this is showing, Jupiter and both groups of Trojan asteroids will complete a little more than one full orbit around the sun, making this a more complex plot.  Plot from the Southwest Research Institute, the scientists behind the mission.  

I'll leave you with this mind-blower.

Somewhat ironically, although Lucy is visiting the "Jupiter trojans," it will never be closer to Jupiter than when it is on Earth. This is because the Trojans trail Jupiter at a greater distance than the distance that lies between Earth and the Solar System's largest planet.

 

 

Tuesday, August 2, 2022

A Couple of Good Days to Watch Starbase

We seem to be coming up on a couple of good days to keep an eye on the goings on at SpaceX's Starbase Boca Chica.  

The week started out with talk about possible road closures from 10AM to 10PM Monday through Thursday.  So far, Monday and Tuesday have gone by with no road closures and continued work on the infrastructure.  We know that a warning to mariners about possible over pressure events, or other things to be avoided was issued for the four days, and there have been rampant rumors that Ship 24 will be static fired this week.  I think they won't issue notices like that without knowing some probability exists they'll get to the test, but I don't know what the chance is.  

Still, if it's going to be this week, it's either Wednesday or Thursday.  

There still have been tests and things going on at Starbase, even though it hasn't been involving long pillars of fire.  While last week was quiet, they did rather substantial testing on the tank built to test all their changes to the way tanks are built, with a test tank called B7.1, because it's built identically to Booster 7, B7.  It appears every test was passed with no issues.  

The company began testing B7 months before B7.1, subjecting the full-size booster to multiple cryogenic proof tests and Raptor thrust simulation testing to qualify its new thrust ‘puck’ and several other structural changes. SpaceX began testing B7.1 in late June, shortly before Super Heavy Booster 7 was damaged by an unplanned explosion that halted its first Raptor engine test campaign. B7.1 testing then restarted in mid-July and was completed by the end of the month.

For unknown reasons, SpaceX’s decision to build and test Booster 7 before B7.1 meant that any significant issues discovered during subsequent B7.1 testing could disqualify the booster for flight testing, potentially wasting the months of work and tens of millions of dollars already invested in the prototype. Ultimately, though, B7.1 appeared to sail through multiple cryogenic proofs and crush tests without any catastrophic issues. Only on the last crush test did any part of the test tank finally give way, and the resulting damage was minor.

Photo by Mary, Boca Chica Gal from NASASpaceflight.com.  

Test tank B7.1 is seen in the center here, with vertical straps from the test system called the "Can Crusher" arrayed around its circumference.  During the test, when the tank contains the desired amount of liquid nitrogen those black straps are pulled downwards putting tremendous crushing forces on the tank. 

It's believed that the test is aimed at replicating as much of the thermal and mechanical stresses of the real cryogenic fuel/oxygen tanks and the weight of the vehicle above this point in the tank as it can simulate.  While the straps are being pulled down, additional rams installed under B7.1 push up to simulate the thrust of 13 central Raptor engines, so that the test item is subjected to crushing loads from both directions.  The real load a booster will face the from the weight of a fully-fueled Starship sitting on top of it is ~1350 tons or ~3 Million lb.s pushing down.  The thrust of 13 Raptor engines pushing up is ~6.5 Million lb.s.

While it appears it's a good idea to keep an eye on your favorite way to watch things (I tend to watch Lab Padre's Rover 2.0 camera to start), of course I have no way of knowing if they actually plan to run a static fire test.  For what it's worth, I'll have a browser tab open on it all day tomorrow. 

UPDATE 080322 3:23PM.  All road closures have been cancelled for this week.  So much for a static firing. 


 

Monday, August 1, 2022

It's August in Central Florida

I'm not saying that because of changing the page on the calendar.  From the feel of being outside, it has been August for a few weeks.  Heck, I know a guy who has a lawn service business and he was saying it has been full tilt summer since about day 1: the solstice back on June 21.  

A sure indicator is when the UV Index says 11 on a scale of 1-10 and uses the description, "Potentially Fatal."  We know that's aimed at visitors to the area who aren't used to it and don't pay much attention.  

There are many places where folks look forward to summer; it's time to go outside - maybe for the first time in months, enjoy warm, glorious days; garden, bike, picnic; maybe enjoy a book while lounging on the beach.  Songs like Nat King Cole's classic "Lazy, Hazy, Crazy Days of Summer" come to mind.

That's not here.  Here, summer is something to be a bit more reserved about.  If you live here, you can keep up with your regular life.  If you were from a moderate place, not used to our heat and humidity, running or other outdoors activity could conceivably kill you.  August marks the Dog Days of Summer; everything outdoors slows.  Fishing slows - sure the fish have to eat, but they become more active after dark.  Animals are more sluggish.  Ordinarily, it can be nasty here from about mid-July to almost the middle of September.  The worst of it is August.  

The Minnesotans for Global Warming cherish the summer and endure the winter.  Here it's the opposite. 

When we first got an HDTV around 20 years ago, Mrs. Graybeard and I naturally spent much of our TV time searching out HD programming.  One of the first movies we watched was "The Chronicles of Riddick".  You have to understand this is not even particularly good scifi.  It's a fun movie to watch, it's a visual treat, it's a fantastic display of special effects perfect for HD, but don't pay too much attention to the story.  To quote a review (long gone from the net), "Furyans, Necromongers, Elementals, The Underverse, the Threshold...it so clearly wants to be epic that it forgets to tie all of these disparate worlds, universes and civilizations into a coherent story. (Director) Twohy clearly makes the mistake of not realizing that there is a huge difference between being grand and being simply confusing and the more ideas that are introduced, the more lumbering it becomes…"   

We still watch it on occasion when we run into it.

A large portion of the movie, and one of the longest action sequences, takes place on the planet Crematoria (many of the names in the movie are that cheesy).  Crematoria is a planet that has a tremendous temperature variation (probably an impossible amount) with daytime temperatures of 700F and night time temperatures 300 below zero.  When the sunrise terminator sweeps through, the force of the heat gales that come with it is literally enough to blow you apart, disintegrating flesh and blowing pieces off until you die.  There's a scene where a character (Purifier), a Furyan like Riddick, sacrifices himself by walking into the sunrise terminator and self-immolating.  That's him trying to stand up to the gales while being set afire and having pieces of burning flesh blown off him.

The first time I saw that scene, it reminded me of the time we decided to do a long bike ride on July 4th (I think it was a hundred mile ride, but for sure it was a virtually all day ride).  I mentioned it to Mrs. Graybeard who said, "sure, we've been out on days like that."   

The National Weather Service publishes charts for heat index that show the amount of danger from the combination of heat and humidity.  This is one of their charts.  I've drawn a box around the typical morning conditions here.  When I finished my ride this morning, Weather Underground was reporting 86 with a "feels like" temperature of 96.  On the top right side of that box I added.  "Extreme caution" conditions are common.  In the afternoon, it pushes farther into the orange, maybe red.  

And that's what life here is like for August plus or minus a week or two.  Stay out of the sun.  Do your outdoor activities near sunrise or sunset.  Don't expose bare skin to the sun any longer than necessary - and even then, use sunscreen if you need to be out when the sun is intense, say from 10 AM to 4 PM.  SPF 3 million is adequate.  Without air conditioning and mosquito control, a technological civilization could not exist here.

Oh, and for those greenies and others pushing the idea that Americans are lazy for having air conditioning because they don't do that in Europe.  Our latitude is well south of Europe, like toward the south end of the Sinai Peninsula.  Sharm el-Sheikh airport is just a few miles south of our latitude.  All of Europe is well north of us.   


 

Sunday, July 31, 2022

NRC Announces It Will Certify The First SMR

Whut?  The US Nuclear Regulatory Commission announced Friday (.pdf warning) that they will certify the Small Modular Reactor design from a company called NuScale.  The reactor is a first in an important class of designs; the SMR isn't built on the site of a power plant like the big reactors most of us have read about.  The small reactor is built on a production line that one would hope could allow some of the continuous improvements in quality and safety - not to mention the cost reductions - that we see in virtually every mass-produced item.  After manufacturing, it is shipped (presumably by truck) to the site where it will be installed.

The reactor design approval process began in 2016 (which is a different problem) and approval has reportedly been expected since 2020, when the SMR received its safety approval from the NRC.  

The NuScale SMR is a 76-foot-tall, 15-foot-diameter steel cylinder capable of producing 50 megawatts of electricity.  The reactor is not one of the newer designs we keep reading about, like molten salts, thorium or something based on another radioactive isotope; rather, it's a pretty conventional steam generating design based on heat from uranium with control rods to absorb neutrons and reduce the heat.  The steam produced is maintained internal to the reactor, and their design features passive safety and fault tolerant design elements.  

The design features a passive cooling system, which means no pumps or moving parts are required to keep the reactor operating safely.  The pressurized internal hot loop is arranged so that it allows hot water to rise through the heat exchanger coils and sink back down toward the fuel rods after it cools.  

In the case of a problem, the reactor is similarly designed to manage its heat automatically. The control rods—which can encase the fuel rods, blocking neutrons and halting the fission chain reaction—are actively held in place above the fuel rods by a motor. In the event of a power outage or kill switch, it will drop down on the fuel rods due to gravity. Valves inside also allow the pressurized water loop to vent into the vacuum within the reactor's thermos-like double-wall design, dumping heat through the steel exterior, which is submerged in the cooling pool. One advantage of the small modular design is that each unit holds a smaller amount of radioactive fuel, and so it has a smaller amount of heat to get rid of in a situation like this.

 

NuScale image of their SMR.

While it's a 50 megawatt reactor, they envision a plant employing up to 12 of these reactors in a large pool like those used in current nuclear plants, to generate 600 megawatts.  

It's important to note that they're not done with the hurdles before these can be installed around the country.  The NRC has to approve the specific sites where any of these reactors are deployed.  Currently, one such site is in the works: a project called the Carbon Free Power Project, which will be situated at Idaho National Lab.  That has been scheduled to be operational in 2030 but has been facing some financial uncertainty.  As I'm sure you're noticed, the people who claim to be in favor of minimizing CO2 emissions are largely devoutly opposed to nuclear power.  



Saturday, July 30, 2022

So... Maybe Russia Isn't Really Gonna Leave the Space Station

Earlier this week, the story broke that the Yuri Borisov, the new head of Russia's space agency Roscosmos, said they would be abandoning the International Space Station when their current contract expires in 2024.  

That story was on Tuesday, July 26.  The next day, the story started to break that the situation wasn't that straightforward.  The bigger picture is they're saying they're not leaving the ISS until their replacement space station is operational.  I stumbled across this while trying to track down why my weekly Rocket Report from Eric Berger at Ars Technica hadn't arrived.  I went looking for his Twitter account and found this:

The Tweet he references is from Katya Pavlushchenko, whom it turns out I've quoted before on a similar subject (the original "Russia is abandoning the ISS" stories last March).  I understand she can read the original sources in Russian and references them in posts.  Her Twitter account includes much more discussion about this and the format being spread over several screens a few lines at a time makes it hard to summarize.  

The shortened version seems to be that Russia is aware that without continued work in their module on the ISS they're going to lose the valuable experience of having crews get time on orbit.  The first module of what's called #ROSS on Twitter is talked about as launching in 2028.  

At the first phase, #ROSS will be placed on a solar-synchronous orbit with an altitude of 334 km and inclination of 96.8°. Later it will be changed to 372 km and 96.9°. This will allow to observe most of the territory of Russia (and not only Russia, as Soloviev noticed).

This orbit will also allow to conduct the study of both Earth poles with optical, infrared, ultraviolet, radio and other detectors, and will allow to track the movement of various objects in the areas of the poles, which is an important scientific experiment.
...
#ROSS will work mostly in automatic mode, without human presence on board, but may be visited if needed. As a result, the station will be used more efficiently not only from scientific, but also from the economic point of view.

There's much more to wade through but among the key points is that it hasn't actually been designed.  Everything spoken about is more design goals than known characteristics.  On May 27, Roscosmos and the Council on Space of the Russian Academy of Sciences produced this concept of the station. It appears smaller than the ISS, and if it's not going to be continuously manned, that's probably something that can be put up with.  I don't recall where I heard this, but the saying was that, "the only people comfortable with the ISS are submariners."

I'm inclined to agree with Eric Berger.  If Russia is really saying they're not leaving the ISS until their own station is completed, 2030 or later is likely, especially with their first launch being talked about for 2028.  Recall that the ISS is expected to either be retired or require more regular maintenance by 2025. 



Friday, July 29, 2022

Mars Ingenuity Is Changing Future Missions

I mentioned in passing yesterday that the success of the Ingenuity helicopter on Mars is impacting future missions.  One of those in particular is a mission related to the Ingenuity mission, and the main emphasis of that mission, the Perseverance rover.  Since the earliest days of the Perseverance/Ingenuity mission, the plan has been for the rover collecting interesting rock samples from Jezero Crater (where it's currently exploring) so that a later mission, called the Mars Sample Return Program, could find Perseverance, retrieve the samples and return them to Earth.  

The coverage for details, this time goes to Ars Technica, where the explanations and descriptions are better than at Machine Design. 

At one time, the plans included a second rover from the European Space Agency.  It seems to be getting simplified. 

The Mars sample return plan involves a large collection of challenges, but a central one is that the samples are currently in Perseverance but eventually have to end up in a rocket that takes off from the surface of Mars. That means that Perseverance will have to get close enough to the rocket's landing site—which we can't choose precisely—to exchange the samples, possibly diverting it from scientific objectives. It also can't be too close when the rocket lands since the rocket's landing and its associated hardware could pose a risk to the rover and its samples.

The original plan included a contingency. Perseverance would approach after the rocket had landed, and the samples would be transferred directly. If that didn't work out for whatever reason, a second rover sent to Mars by the ESA would act as an intermediary, visiting a site where the samples had been cached, retrieving them, and then delivering them to the rocket.

In the current plan, the second rover has been eliminated and replaced by two helicopters.  The two will be delivered as part of the same payload as the rocket carrying the samples back up to Mars orbit.  As a result, there's only a single lander that will carry both the return rocket and the helicopters, significantly lowering the risk of the overall plan.  The helicopters have the additional advantage that samples could be cached away in a "safe place" away from Perseverance, then carried back to the lander where the Mars Ascent Vehicle will be loaded.  There's no mention of the detail of how many grams of rocks can be moved by the helicopters and how many grams or ounces the system can return to Earth.

A conceptual sketch from NASA/JPL-CalTech, showing a helicopter, Perseverance, and the ESA Mars lander on the bottom row, and the ESA's Earth Return orbiter, left, and NASA's Mars Ascent Vehicle top right.  The upper left corner picture appears to be a gibbous Earth, but Earth couldn't possibly appear that big from Mars.  I'll write that off to someone at JPL-CalTech being overly artistic.

The current plan is for the two space agencies to get together for a design review meeting and decide on the final details.  Launch looks to be in the 2028/2029 Mars launch window, leading to the ESA Mars lander arriving six to eight months later, and the rocks to arrive back on Earth by 2033. 

EDIT 1101AM 7/29/22:  Corrected the link to Ars Technica.  Thanks to commenter Sam for pointing it out.



Thursday, July 28, 2022

Ingenuity Mars Helicopter Wins Aviation Collier Trophy

The story got past me when it was first announced because it was in Machine Design and not one of the space news sites I regularly cruise, but in mid June, the team that developed the Ingenuity helicopter that flew to Mars with the Perseverance rover was awarded the prestigious Collier Trophy from the National Aeronautic Association.  The award, of course, is for being the first vehicle to fly on another planet.  For more than a century, the Collier Trophy has been awarded annually to mark the major achievements in aviation. 

The helicopter was developed by a team of engineers from NASA’s Jet Propulsion Laboratory (JPL), AeroVironment, and maxon.

The helicopter was built by AeroVironment, a company that specializes in unmanned air vehicles, under contract from JPL. Maxon provided six precision DC motors, each with a diameter of only 10 mm; they move the swashplates on the rotors. Swashplates, which are found on all helicopters, adjust the angle of the rotor blades and control the helicopter’s flightpath. The Perseverance rover, the spacecraft that carried the helicopter to the surface of Mars, also relies on maxon motors to collect and store soil samples that will be retrieved from Mars on a future NASA mission.


As we've been talking about since the first mention of the helicopter, flying on Mars isn't like flying on Earth. While Ingenuity never flew more than 40 feet above the surface, that's equivalent to nearly 100,000 feet altitude on Earth and one doesn't see helicopters up there.  This means the helicopter had to be extremely light, and it weighs in at just under 4 lb.  The weight limitations meant the solar-charged batteries and maxon DC motors also had to be light and highly energy efficient.   A measure of the success of the mission is that it started out as an experiment to answer if can we make something that can fly on Mars and do something useful.  The initial goal was five test flights.  They've flown 27.  It has been so successful, the idea of using a helicopter is moving into problem solving on other missions.  

The motors strike me as the "stars of the show" since they're driving the propellers, and a more recent article says those motors are 10mm in diameter and 20mm long.  That's a bit bigger than 3/8" diameter by 3/4" long - bigger in both directions.  Machine Design has a separate article on the motor development, in an interview between one of their editors, Rehana Begg, and Florbela Costa, the project manager for the development of the motors.   The video interview is 16 minutes long, and the discussion is worth listening to, although not very detailed about the engineering.  I'm pretty sure maxon would consider much of that proprietary.  It drifts into more of an interview with Ms. Costa about her background and the job position after the 10 minute mark.

Florbela Costa holding up an equivalent motor to the ones powering Ingenuity.  Screen capture from the video on Machine Design that I can't embed here.  Ms. Costa has a bit of a Portuguese accent, but I had no trouble understanding her. 



Wednesday, July 27, 2022

About That Kamala Harris Quote

Every news site has posted about that quote from Kamala Harris yesterday.   You know, 

'My Pronouns Are She And Her, And I Am A Woman Sitting At The Table Wearing A Blue Suit.'

When I saw it, my first reaction was, "the table's wearing a blue suit??"  

As a sort-of writer-dude, that's what we call a dangling modifier.  The modifier after the word table is more associated with the closest noun, table, not woman.  Sitting is OK where it is, it could be before or after Woman, although saying 'A Sitting Woman At The Table Wearing A Blue Suit' is arguably worse.  

That's all.  Just wanted to spread this idea virus.
 


Tuesday, July 26, 2022

Dmitry? Is That You?

It seems like just a few weeks ago that the former head of the Russian space agency Roscosmos, Dmitry Rogozin suggested that Russia was going to no longer support the International Space Station.  To be fair, it was last April.   So pardon me if it seemed like same old, same old when I read on Ars Technica today that Russia says it's abandoning its ISS partnership when the current contract expires in 2024.  Except it's not Rogozin who said this, it's his new replacement Yuri Borisov.  

Russia has supplied a number of modules to the ISS, and its segments host solar panels that contribute to the station's power budget. More critically, it has provided the thrust that allows the ISS to maintain its orbit, which would otherwise gradually decay. At present, it's unclear what will happen to Russia's hardware when the country exits the partnership.

Still, the availability of Dragon crewed vehicles has made Russia's participation less essential than it was just a few years ago. And by fulfilling its commitments to the end of 2024, Russia will provide NASA with a significant amount of time to develop alternate plans that could allow the ISS to remain occupied through 2030.

As we've covered here, even before the April discussion, the US doesn't need Russia to raise the station's orbit as it decays over time.  We have three options that are capable of maintaining the ISS in its desired orbit: Northrup-Grumman's Cygnus cargo drone as well as SpaceX's, Cargo and Crew Dragons.  If I understand correctly, we can add in Boeing's Starliner as well.  In March, when Rogozin first Tweeted the threat "... who will save the ISS from an unguided de-orbit...?" we saw this exchange. 

This led to Rogozin deriding the Falcon 9 as a flying broomstick, which lives on as a perpetual joke as comments to F 9 launches and Tweets about them. 

According to The New York Times, Borisov told Russian President Vladimir Putin that the 2024 date gives his country time as well. “I think that by this time, we will begin to form the Russian orbital station,” he said.

I don't think so.  Roscosmos is currently shutdown with no income and some workers sent home/laid off.  All launches from the western countries have been held, with some companies going to the European Space Agency and at least OneWeb going to SpaceX.  Amazon announced a contract for their Kuiper internet service that's basically, "we'll buy a ride from anyone except SpaceX:" 38 Vulcans, 18 Arianespace 64s and 12 Blue Origin New Glenns.  It's an interesting side note that not one of those three listed boosters actually exists yet.  To be fair, they also have nine ULA Atlas V and two RS1 launches from startup ABL booked as well.  At least the Atlas V exists, although they are at end of life and when ULA's supply of the engines on hand for the remaining Atlas V missions are used up, that's the end of the line for the Atlas, in service in one form or other since 1957.  

I suppose I should emphasize that this doesn't take effect until some date in 2024, and in the intervening years, the astronaut swaps we talked about recently are still going forward as outlined.  Expect NASA astronaut, Frank Rubio, to fly the Soyuz MS-22 mission and cosmonaut Anna Kikina to fly on the SpaceX Crew-5 mission. 



Monday, July 25, 2022

Solar Cycle Progression Update

It has been since February that I've posted plots like these, an update to solar cycle 25.  For those of us watching solar activity and experimenting (that is, playing) with it regularly, it has been rather interesting.  

Both plots are pretty similar, but emphasize different aspects.  First off is the Cycle 24/25 plot from the National Oceanographic and Atmospheric Administration, NOAA, and their Space Weather Prediction Center.  This plot shows the sunspot numbers and you can read numbers directly by hovering your mouse over one of the points on the chart - on the website linked there, not this graphic.

There is a very obvious separation between the actual values (smoothed values as the purple line and monthly values as the black dots on that line.  Note this is sunspot number and not the 10.7 cm solar flux.  For the second to last dot, this past May, the predicted value was 39.7 while the observed sunspot number was 96.5; almost 2-1/2 times the predicted value.  The last dot, June's, was substantially lower in measured at 70.5 while the predicted number was a bit larger than May's at 42.8.  There's always up and down variation in these plots, but the trend has been above the predicted values since cycle 25 started. 

The next plot is an update to the second plot in the February post, the one I jokingly refer to as my "ham radio autobiography" because these are smoothed sunspot plots of every solar cycle since 1976, the year I got my first ham license. 

You'll note that almost without exception every data point of every cycle is lower than its predecessor since 1976, the top curve (blue).  Except that short gray trace that shows cycle 25 advancing in from the bottom left corner.  Every single point in cycle 25 is greater than or equal to the previous cycle, shown here in pink.  This plot is from Space Weather News, which says it's from a site called Solen.info, but I don't see it at that link.

Looking at the bottom left corner where Cycle 25 is coming in shows the bigger picture that 25 is doing better than cycle 24, and the previous plot showed it's doing well above predictions.  The thing to bear in mind is that Cycle 24 was the weakest in a hundred years, so doing better than that isn't necessarily saying it's going like gangbusters.  While I think the big picture is a bit more optimistic than it was almost six months ago, that discussion concluded with a plot from Dr. Ron Turner of ANSER Research Institute in Virginia, via Spaceweather.com, showing how the beginnings of 24 and 25 overlap well.  Dr. Turner's conclusion wasn't that 25 was going to match 24, just that it's too early to predict something much better based on the early numbers. 

I think we're in a better place now, but not at a point where we can confidently say 25 will be much stronger or not.  In another year?  Probably.  That plot shows us being at month 24 and by month 36, cycle 24 was close to its peak. 

I've noted that there have been higher solar flux numbers in the last month or so than I've seen in quite a while.  At some point late last week I saw a solar flux over 170, and the solar flux data archived at WM7D.net shows it has happened a few times on a cyclic basis.  The VHF band I hang out on the most, 6m, has had its moments of really great propagation, but I haven't really heard any of those since June.  



Sunday, July 24, 2022

Picture of the Weekend

Hat tip to Teslarati with an author I haven't seen before for a link to a SpaceX Tweet that featured a fortuitous alignment of Friday's Starlink launch from Vandenberg.  You can go to that Tweet link and watch loops of six seconds of video with this part near the middle as many times as you'd like.  Yeah, it's just a coincidence of the line of sight, but I've got to tell you lots of photographers strive for alignments like this.


This morning's launch from the KSC didn't offer such views and especially not from here.  I was able to glimpse the F9 within the first minute after launch, through the branches of my neighbor's tree, but except for one bright spot climbing into the bright morning sky, which would have been easy to miss,  you wouldn't have guessed a launch had taken place.  

Friday's and this morning's launches from opposite coasts marked SpaceX’s fifth and sixth Starlink missions for July, which were their 32nd and 33rd launches for 2022.  Those two wrap up July, with the next launch set for nine days from today, August 2nd, from launch complex 40 (SLC-40) on Cape Canaveral.  



Saturday, July 23, 2022

James Webb Telescope Uses a Comically Small Solid State Drive

Do you have a 64 gig USB storage device hanging around; that is, a 64 GB thumbdrive?  You have just a little bit smaller solid state drive than the $10 Billion James Webb Space Telescope, which uses a 68 GB SSD.  That drive holds roughly one day's worth of images and is cycled through daily.

IEEE Spectrum reports Webb generates about 57GB of data each day. In comparison, Hubble generates about 1 to 2GB of daily data. Webb reserves 3 percent of its 68GB SSD for engineering and telemetry data. Scientific data that Webb collects during its mission will also need to be stored on board, as the telescope doesn't maintain constant communication with Earth. However, before the drive fills, which takes about 24 hours, Webb will beam data back to Earth during a pair of four-hour contact windows each day.

Data transmission is a critical component of the Webb mission and has been carefully studied and planned for decades. The telescope is about 1.5 million km (932,000 mi) from Earth at Lagrange point L2. That's a long way to send data. Webb is the first mission to use Ka-band frequencies to send its relatively high amount of data. Specifically, IEEE Spectrum notes that the JWST is transmitting data on a 25.9GHz channel at up to 28Mb/second (0.0035GB/sec). That works out to about 12.6GB per hour.

I've got to say that I was annoyed initially by the statement that the downlink issues had been studied and planned "for decades" but then realized it was correct.  The program planning began in 1997, more than two decades ago, so it's correct.  The originally planned launch date was 2007.  More details on how the schedule slipped over the years is here

My home turf is radio design, so moving over to that I read that the images are sent over a 25.9 GHz Ka-band channel, (pronounced as the letters K and A separately not as "Kah" or "Kay") chosen for its higher available data rates, which translates to higher bandwidths.  There was a design trade of using a more established band, like X-band (7-11.2 GHz) instead of Ka.  For the required antenna gain to get the needed transmitter data rates (bandwidths) required an antenna that was physically larger, and they concluded it was too big for the optical designers to be comfortable around it.  That 12.6 GB/hour rate that IEEE spectrum reports means that the day's 57 GB of image data takes around 4-1/2 hours to transmit.

There are other channels used for technical data exchanges.  Those are in S-band, where many spacecraft operate.  An uplink (ground to Webb) at 2.09GHz transmits observation schedules at about 16Kb/s.  Webb "talks back" (downlinks) at 2.27GHz at 40kb/s.  This is where Webb transmits engineering data, including operational status and system health.

The JWST image released on the 12th of Stephan's Quintet, a famous grouping of five galaxies about 290 million light-years away in the Pegasus constellation. The compact galaxy group was discovered way back in 1787.   Yes, it's five not four - the one in middle, slightly lower right element of an obvious trio, is really two galaxies, NGC7318 A and B.  If you think you've seen it before (and you're not an amateur astronomer) you might remember it from the Christmas classic movie, It's A Wonderful Life.

You might be asking why 68 GB?  That would require access to program records to answer, but my guess is it's really something like a 128 GB drive or bigger that's radiation-hardened and not the consumer-level drives we're used to.  They're expecting Webb to last for 20 years instead of the originally-intended 10, so that drive needs to be more robust and withstand cycling better than the typical ones.  The "brute strength and awkwardness" approach to withstanding cycling better is simply to have tons more memory locations than its rating.