Sunday, March 26, 2023

Resurrection Weekend

No, not that resurrection.  That resurrection weekend is still two weeks away.  This was about as far from that as one can get. 

Back in '18, I needed a little computer that could run my Computerized Battery Analyzer (CBA-IV) and since the native software is Windows, ended up buying a small computer probably more intended for running an audio-visual setup of some kind, called a NUC, made by Intel.  It was fine for that, but it's a Windows 10 box (pretty sure it was my first introduction to Win 10) and like all Windows versions, it slows down over time as the OS gets more bloated.  As I wrote about in July '21, when I told the story of getting 3D Printer control program called Pronterface running:

To make the long story short it took a couple of days to get that to work.  Hours upon hours of those days were waiting for Windows to stop doing shit so I could do what I wanted to.  With machines that aren't on regularly, Windoze 10 is a giant Pain In The Ass - calling home and tying up the machine literally for hours over my WiFi network.

This is a computer I run maybe every few months for a day or two or maybe less than that.  Like all Windows10 computers I've seen, there's no place to tell it that I don't want it to play music files, or show me videos.  I want it to run my battery analyzer or talk to my printer interactively.  Still, every time I turn it on, it has to go look for security updates, and if I have a battery to test that I think is going to run for hours, I need to turn the NUC on two hours before I can start.  And every few cycles of that, I have to sit around and tell it, no I don't want to pay for your cloud storage, I don't want to sync my Android phone because I don't even have one, I don't want your browser because this little machine doesn't need to have a browser on it, and a bunch more crap.

Plus it does other things I personally find annoying, like changing my desktop picture to something I have on one of my other computers.  Doesn't anybody at Microsoft who designs this software think that a user might have more than one picture they want on their computers?  And they might not want them all to look the same?  How about interacting with software like, "when I want it to do something, I'll ask?"

As a result, I got pretty tired of putting up with the NUC and realized I still have the computer that used to be my desktop here, that was replaced in November of '19.  The NUC is on top of the older Dell desktop.

Resurrecting that computer and getting it to run the way it should has been the big job this weekend.  I can't say I'm done, yet.  The biggest problem was that the little CR2032 battery used to backup the clock (and whatever else) had died and getting it to even boot up took most of yesterday.  Since it's a Win 7 machine, long out of support, I don't want it going out on the network.  There are no updates for it to go find and install, so no need for WiFi to be on.  That might be part of what's slowing it down, but I really don't want it calling home all day long to check on something. 

It still takes it far too long to do simple tasks like uninstalling a file, and I'm troubleshooting that.   The root problem, though, is that I haven't had to do anything like this in years, and it has been longer since I had to work on a Win 7 machine.  The other Win 7 computer I have (runs the CNC mills and lathe) has been off the network since Win 7 went away.  It does what I need, when I need it to, every time I turn it on.

Saturday, March 25, 2023

A Mild Rant: Not Everything is a Carrington Event

Larry Lambert over Virtual Mirage, one of the more eclectic minds you'll come across in the blogosphere, led us to a post on American Thinker called, "Dodging the Apocalypse" about the recent geomagnetic storms and the apparently truly Epic Coronal Mass Ejection that led to the storm.  Credit where due, the first person I saw writing about this event was the Come and Make It blog.  

The article is by a regular writer there, J.R. Dunn, and while I'm going to do my best to cut him slack, he really triggered me.  The biggest thing is tying this CME to the Carrington Event in 1859, which I've written about a half dozen times before.  For the uninitiated, the Carrington Event was a massive solar geomagnetic storm that happened around the start of the widespread use of electricity.  Widespread electric power was still a half-century away, but the telegraph had led to long wires being used to communicate by what we now call On Off Keying or OOK.  The disruptions to the geomagnetic field around Earth caused open telegraph keys to spark, insulators on poles to arc over, started fires and more. 

The event was witnessed in real time by British astronomer Richard Christopher Carrington.

"Two patches of intensely bright and white light broke out," he later wrote. Carrington puzzled over the flashes. "My first impression was that by some chance a ray of light had penetrated a hole in the screen attached to the object-glass," he explained, given that "the brilliancy was fully equal to that of direct sun-light."

Note that these flashes were so much brighter than the projected image of the sun in his dark room that he thought daylight was somehow getting into the room.  The story itself is amazing.  That evening, when the Coronal Mass Ejection hit, telegraph operators were able to run without batteries; the flare-induced voltages on their wires working better than batteries.  The aurora display was global, even in the deep tropics. 

The American Thinker article quotes "experts" saying the March 13th CME was "was ten to a hundred times more powerful than the one of 1859."  My immediate problem with that is how do we know that number?  The 1859 event happened only one time in human history and it happened in a time when instruments today's experts would use didn't exist.  There are other things that have been attributed to massive Carrington-like storm but the problem of no measurement is compounded by no observers, and the most remote-sounding observations imaginable.  To quote from this blog in 2012 about an increase in Carbon 14 levels being attributed to a Carrington-like storm in the year 774 AD, 

There are a couple of known mechanisms for creating C14 in the atmosphere, one is a massive solar flare.  774 AD was 600 years or so before the first telescopes were used, so there was no Carrington to be watching.

So when a college student from UC-SD found a record of a “red crucifix” in the skies over Britain in that year, Nature published his note.

I've never heard of anyone saying there was a crucifix of any color in the skies back in 1859.  

We've seen this kind of hype more recently.  Back in November of  2003, toward the end of cycle 23, there was a super flare that was genuinely scary and the kind of flare to worry about.  The biggest flare seen since the satellite age started, it was classed as X28 in retrospect - only because it saturated the X-ray detectors on the satellites and they couldn't measure it properly.  Why didn't it harm us? Because it was on the limb of the sun and the CME went 90 degrees to our direction.  So not only does this extremely rare event need to happen, but it has to be pointed at Earth - basically perfectly centered on the sun from where we view.  It's important to remember that during the peak days of cycle 23 we were getting X-class flares a few times every month, and the grid was fine, wasn't it?

I haven't seen anyone say that last week's CME came with an X-class flare or put a number like that X28 on it, but that would be interesting to find out. 

Probably the most obviously wrong thing he said was “We do know that we have two more years before the current solar cycle tops out, and so far, this has been one of the most intense on record.” The best answer to show just how wrong that is to show this plot of just the five most current solar cycles from

The current cycle, 25, is at the bottom left in kind of a brown or olive drab color and ending at 32 "Months after cycle start."  It can be seen that it's higher than the previous cycle (in pink) at pretty much every point and it's currently stronger than cycle 24 was at this point.  It's just that being better than cycle 24 isn't really saying anything impressive.  Cycle 24 was the weakest cycle in the last hundred years.  Cycle 25 is predicted to be stronger than 24 but might not even equal the next stronger cycle, 23.  It obviously isn't cycle 23 level yet (23 is red).  Where he says, “ far, this has been one of the most intense on record,” it has actually been one of the weakest on record.

This chart, by the way, doesn't include the strongest cycle since the 1780s, cycle 19 from the late 1950s.

It's almost guaranteed that someday there will be something like a Carrington Event again, we just don't and can't know when.  When something has happened once in recorded history, it's hard to assign a periodicity to it.  If that observation about the 774 AD CME is correct, does the 1085 years between them mean anything to predictions?  I don't think we can just say it's a thousand year cycle.  To say a massive CME has something to do with solar cycles isn't much of a reach, given what we know from observing hundreds or thousands of solar flares and CMEs and knowing those track with solar cycles.  

I know alarmism sells but I find it exhausting.  I try to bound problems to give me some feel for how likely some problem is.  In the case of the CME it's not just that probability there's also the probability of it being optimally placed on the sun to do the most damage.  Is that two degrees of solar longitude?  Five degrees?  The probability of independent things like this get multiplied.  If the chance of a big enough CME to cause a disaster is 1 in 100 years and the probability of it being in the right place on the sun is 1 in 180 (two degrees longitude), the probability of both is 1/100 * 1/180, or .0000555 (55.5*10-6). 

Friday, March 24, 2023

Weekly Small Space News Story Roundup 4

Sort of Weekly?  #3 was two weeks ago.

Virgin Orbit May Have a Financial Future

On Wednesday, Reuters reported that the company may have arranged a $200 million deal with Texas-based venture capital investor Matthew Brown.  

The space startup did not comment on the likely deal, but said on Wednesday it would resume operations on March 23 and prepare for its next mission by recalling some of its employees, sending its shares up 60% in premarket trading.

The two parties (Virgin Orbit and Matthew Brown) aimed to complete the deal by Friday (today) with Virgin saying more employees will be back to work on March 27, Monday.  As of this afternoon's updates, I see that Virgin stock is up 50% on the day but nothing saying the deal has been finalized.

April will be a Heavy Lift Month's extended schedule today is showing that April will feature a launch of Falcon Heavy on the 8th and a Delta IV Heavy 12 days later.  Both dates should be considered No Earlier Than and preliminary/subject to change.  There are launches between these two but a little semi-skilled photo editing makes it look like they're this close.

ULA has only two remaining Delta IV Heavy rockets; the one for this mission and one set to fly in 2024.

Since SLS has successfully flown, although still not out of its qualification missions, it's now the most powerful rocket in the US inventory.  Falcon Heavy is number two and Delta IV Heavy is number three.  

Looks Like Another Month Before Starship Flies

I've long since lost count of the number of tentative launch dates for SpaceX's Starship's first orbital attempt that have been cancelled. reports. "SpaceX will be ready to launch Starship in a few weeks, then launch timing depends on FAA license approval. Assuming that takes a few weeks, first launch attempt will be near end of third week of April, aka …" SpaceX founder and CEO Elon Musk said via Twitter.

The "aka..." bit, by the way, is presumably a nod to the possibility that Starship could launch on April 20, which is a sort of holiday for cannabis culture. Musk is fond of making 4/20 references and jokes.

Considering the number of times this test flight has been talked about and then postponed, it's best to consider this Extremely Preliminary. 

Speaking of Launch Delays is reporting the Boeing's Crew Flight Test of their Starliner Capsule has been bumped out from the planned April launch date, NET May but probably into the summer. 

"We're adjusting the @Space_Station schedule including the launch date for our Boeing Crew Flight Test as teams assess readiness and complete verification work. CFT now will launch following Axiom Mission 2 for optimized station operations," NASA human spaceflight chief Kathy Lueders said via Twitter on Thursday (March 23).

Axiom Mission 2, or Ax-2 for short, will be the second crewed mission to the ISS operated by Houston-based company Axiom Space. It will employ a SpaceX Falcon 9 rocket and Dragon capsule, as Ax-1 did in April 2022, and is tentatively scheduled to launch in early May.

I find it a little curious that Boeing's CFT is being assigned lower priority as a mission than Axiom Space's Ax-2.  I think Boeing's CFT is under their contract with NASA to deliver "taxi rides" to the ISS, so while it's arguable Ax-2 is a private mission, CFT is a NASA-Boeing mission.  Perhaps Ax-2 is a paying customer while CFT isn't?  Or is that too cynical?

Thursday, March 23, 2023

Relativity Terran-1 First Flight "a Successful Failure"

Relativity Space's video coverage last night, which they were calling part 3, began the same way as the first two attempts I watched.  When I turned on the coverage, it was T-25 minutes and counting. Then, just like every other one I watched, they went into a hold.  At that point, knowing that both it was going to push the liftoff until well after 10:30 PM and that it was the one night/week when we just can't stay up to any time we might want, we shut down the computers and went to bed.  

Which meant Murphy's Law demands it would launch last night, and it did, lifting off at 11:25PM EDT.

"Successful Failure" is an odd turn of phrase that I'm borrowing from Eric Berger at Ars Technica.  By the things that count the most, the mission was a failure.  Terran-1 failed to reach orbit, after the second stage failed to ignite properly and stay lit.  Furthermore, their chance of being the first rocket burning methane/oxygen to achieve orbit is pretty much over, barring some strange events happening to all the other engines and platforms.  

Berger argues that the mission was successful, proving out the most important aspects of the mission.  The first stage did a complete burn, going through Max Q (highest aerodynamic pressures on the vehicle) at about 80 seconds into the ascent and burning for over two minutes.  The 3D-printed booster stage seemed to perform completely nominally as did its nine 3D-printed engines.  That has to be a great relief to all involved.  

After all that and stage separation, something went wrong. It appeared the second-stage engine attempted to ignite but could not sustain this ignition. So far the company has not stated precisely what went wrong and we can only hope they got crap loads of data, enough to diagnose what happened.  Scott Manley has some video of the failure, and some of his analysis, but no major revelations.

Eric Berger writes:

It is proper to characterize Wednesday's launch as a success. Of the new era of commercially developed small launch vehicles, the Terran 1 rocket made it further on its debut flight than Astra, Virgin Orbit, Firefly, and ABL Space Systems. Only Rocket Lab, with the debut of its smaller Electron rocket in 2017, had a more successful initial flight. In producing a rocket with about 85 percent additively manufactured material, Relativity has flown with a substantially new manufacturing process.

The extent to which Wednesday's launch validated the additively manufactured structure of the Terran 1 rocket will need to be assessed with data from the flight—was it a close call, or was the structure genuinely robust? This information will likely help determine how much of Terran R is produced through 3D-printed technology.

Back in October '22, I had posted that CEO Tim Ellis was very aware that no privately funded company has achieved orbit on their first attempt but thought the mission might be graded on a curve.  That is, if they don't make orbit, customers pretty much get to decide if it was "close enough."  As he put it:

"While the rocket-loving engineer in me wants to say it's really orbit or nothing for the first flight, I think the business leader part of me knows that customers are going to tell us what enough looks like for the first flight."

Without hard data on what happened to the second stage anything here is guessing.  I mean, Virgin Orbit's mission had the same basic failure - second stage didn't work right - and that was a bad fuel filter in a system that has made orbit a few times.  The ESA's Vega C launch in December failed because of its upper stage on its second orbital mission.  It's not unprecedented for a rocket that has flown before to have that sort of failure.  

The big questions are whether or not the customers give the rocket a passing grade and if Relativity Space does another Terran-1 mission or goes directly to the bigger Terran-R.  We'll have to wait to find that out.

Terran-1 lights up the sky last night from Cape Canaveral, its methalox engines creating an unusual blue color in the flames. Relativity Space photo.

Wednesday, March 22, 2023

About That Latest Roscosmos Problem

Over the course of the last few days (it seems) I noticed some blurbs saying that the Russian space assets had been taken over by Kazakhstan, the country they're located in.  None of my usual sources had anything concrete on it until today.  It's a real standoff between Russia and Kazakhstan, there are real problems stemming from this and it doesn't look to blow over or otherwise go away on its own in a few days.   

Let's start here because people who don't study this area (like me!) might be hazy on some of these details.  Kazakhstan was part of the USSR when they (the USSR) decided to build their launch facilities, the Baikonur Cosmodrome, on the vast open plains of Kazakhstan beginning in 1955.  A few years later, it became the world's first spaceport with the launches of the Sputnik 1 and Vostok 1 missions.

After the breakup of the Soviet Union, Russia leased the spaceport from the government of Kazakhstan and currently has an agreement to use the facilities through the year 2050. Russia pays an annual lease fee of about $100 million. Neither country is particularly happy with the relationship; the Kazakh government feels like it is under-compensated, and the Russian government would like it to be in its own country, which is why it has moved in recent years to build a new launch site for most of its rockets in the Far East of Russia, at Vostochny. 

Screen capture of a Duck Duck Go map, with the red bubble pointing out the Baikonur Cosmodrome.  Note at the far left of the screen is Ukraine and north of that "all roads lead to Moscow."

Russia's rocket industry has fallen behind the west and desperately needs that facility to be available.  They're in the early stages of developing a new launch vehicle, the Soyuz-5, a three-stage rocket powered by RD-171 engines that will burn kerosene fuel. It's a medium lift vehicle but they hope to be able to compete cost-wise with SpaceX.  Their most recently publicized plans say they intend to launch the Soyuz-5 from the "Baiterek" launch pad at Baikonur and intended to start preliminary construction on that launch pad last year.  It doesn't appear that they've started. 

Earlier this month, a Kazakh news site, KZ24, reported that the Republic of Kazakhstan had seized the property of TsENKI, the Center for Utilization of Ground-based Space Infrastructure, in Kazakhstan. This firm, which is a subsidiary of Roscosmos, is responsible for launch pads and ground support equipment for the Russian space corporation. According to the report, [be aware - in the Kazakh language (?)] which was translated for Ars by Rob Mitchell, TsENKI is barred from removing any assets or materials from Kazakhstan.

"A ban on utilizing resources and conducting financial operations, as well as instability in negotiating positions as a whole are slowing down the priority direction of work at Baikonur, namely the construction of a new launch pad for the Soyuz-5 Booster," the report states.

Look at that map again.  Note the size of Kazakhstan compared to Ukraine, Georgia, and "the 'stans" (Uzbekistan, Turkmenistan, and so on).  With the exception of Russia itself, Kazakhstan is the biggest country you can see on that map.  Perhaps that's why there's a lot of politics at play here.  Kazakhstan has nominally been a sovereign nation since 1991, but in the last three decades, it has maintained close ties to Russia and lies well within the Russo-political sphere.  

...Russia's invasion of Ukraine appears to have changed the calculus of this relationship. Namely, Kazakhstan's president, Kassym-Jomart Tokayev, apparently sees Russia's preoccupation with Ukraine as a window of opportunity to assert greater autonomy for Kazakhstan.

Russia, for its part, has pushed back on further autonomy for Kazakhstan. Weakening ties with the large country to its south could lead to a further crumbling of the Russian Federation. At times, the rhetoric has grown heated. For example, former Russian President Dmitriy Medvedev has called Kazakhstan an "artificial state" and, on the Russian social media site VKontakte, accused the neighboring country of planning genocide against ethnic Russians in Kazakhstan.

It wouldn't be a story involving Russia without that sort of blustery rhetoric. The former head of Roscosmos, Dmitry Grogozin, was pretty well-known for that.  The current head, Yuri Borisov, is quite a bit more restrained.  

Borisov, who prefers to keep a low profile, and at least in his public dealings with NASA has struck an apolitical posture, has so far not commented on the dispute. Nor has Roscosmos said anything on its Telegram channel [apparently in Russian], which now effectively acts as its primary public outreach tool.

It strikes me that this is some sort of political standoff, and until it's resolved the development of  the Soyuz-5 is on hold.  An interesting side note is that Russia has been working toward moving their launches into their own country, which is why it has moved in recent years to build that new launch site at Vostochny in the Far East of Russia.  A quick search for that name doesn't show me anything that I can pin down to a location.  There is a mountain (or mountain range) by that name on the Kamchatka peninsula which is pretty much on the Pacific, but I don't know if that's what they're referring to.

"May you live in interesting times," right? 

Tuesday, March 21, 2023

Japanese Hakuto-R Enters Lunar Orbit

One of the interesting missions of the last several months that I've been keeping an eye open for is the Japanese Hakuto-R lunar Mission.  The first post that included the probe was two months before its launch, although there's more background on the mission almost exactly a month later.  The mission launched December 11 on a Falcon 9 launch from CCSFS, SLC-40. The same launch carried another important lunar probe, this one for NASA's JPL, called the Lunar Flashlight.  Flashlight was a cubesat that was originally supposed to fly on Artemis I, and was lucky not to have, as the way Artemis I unfolded appears to have destroyed half the cubesats on board.

Today we get word that as of last night, March 20, the HAKUTO-R Mission 1 (M1) lander entered orbit at 9:24 p.m. Eastern.

The spacecraft will attempt a landing in Atlas Crater, located on the edge of Mare Frigoris in the northeastern quadrant of the near side of the moon, around the end of April. The company said March 21 it would announce a specific landing date in the near future. Mission 1 is carrying a set of customer payloads from companies and organizations, such as a small rover called Rashid developed by the United Arab Emirates.

The company is working on a second lander, Mission 2, that is similar in design to the spacecraft now in lunar orbit. It is scheduled to launch in 2024 carrying another set of customer payloads as well as a “micro rover” ispace has developed. Mission 3 will use a larger lander developed by ispace’s U.S. subsidiary in partnership with Draper, which won a NASA Commercial Lunar Payload Services award last July to fly payloads to the lunar farside.

Hakuto-R M1 is a privately developed mission by the Japanese company ispace.  A successful landing on the moon will make ispace the first private mission to land there, and only the fourth entity overall.  Only the governments of the former USSR, the USA and the People's Republic of China have landed on the moon.  

Back in November, ispace posted a mission summary that captures some of the ambitious story of the mission.

M1 is considered a technology demonstration with an overall objective to validate the lander’s design and technology, as well as ispace’s business model to provide reliable lunar transportation and data services. For M1, ispace has set 10 milestones between launch and landing, and aims to achieve the success criteria established for each of these milestones. Recognizing the possibility of an anomaly during the mission, the results will be weighed and evaluated against the criteria and incorporated into future missions, supporting the company’s evolution of sustainable technology and its business models.

The accumulated data and experience from M1 will be incorporated into future designs and operations to enhance missions, beginning immediately with Mission 2, which is already in the development stage and is scheduled for 2024. As a private corporation, ispace’s business model calls for continuous, short cycles of technology development to increase capability and reliability in order to usher in an era of full-scale commercialization of the space industry. This model will incorporate knowledge from both missions into Mission 3 (M3) planned for 2025. M3 will contribute to NASA’s Artemis Program under its Commercial Lunar Payload Services program with a mature lander design and operations based on data and experience acquired during the first two missions.

 The 10 M1 Milestones. ispace graphic.  Today marks Success 7 being achieved. 

Monday, March 20, 2023

Has SpaceX Made Launches Boring?

It's an interesting question I hadn't thought over before, but for years the launch providers have talked about aiming for the model of the pace, reliability and efficiency of airline operations.  No, they're not there, although they may be closer than any group in history.  Increasingly, though, I have to concede the answer is probably “yes.”  I also need to rush to add that it's a good thing.  In spaceflight: Boring Is Good.  Especially when it's never interrupted by pure terror, horror, or just plain disappointment.

Last Friday, for example, I had their launch channel on in the background, set to start when their coverage for the Friday afternoon launch from Vandenberg went live.  With no chance of going outdoors to watch it, I just watched the live stream until they landed the booster on their drone ship Of Course I Still Love You and ended the live coverage.  But I forgot to reset the streaming channel for Friday night's launch from Cape Canaveral.  Although I've known for days, at least, that there was going to be an evening launch, the thought of changing my routine to watch a launch went away.  About 2 minutes after launch, so about 7:40 PM, the rumble of the Falcon 9 reached us.  We instantly knew what that sound was - and that it was too late to see anything outside.  So we watched them land the booster on the drone ship over here (JRTI).

Total time between those launches (a continent apart) was four hours and twelve minutes, which broke SpaceX's corporate record for the shortest duration between two launches.

However, the overall record for the lowest time between two launches of the same rocket still belongs to the Russian-built Soyuz vehicle. In June 2013, Roscosmos launched a Soyuz booster from Kazakhstan, and Arianespace launched a Soyuz from French Guiana within two hours. Those launches were conducted by two separate space agencies on separate continents, however.

Those St. Patrick's Day launches were SpaceX's 18th and 19th launches of the year, on the 76th day of the year.  Just dividing 76 days by 19 launches gives 4 days per launch.  At this pace, they're somewhat behind the stated goal of 100 launches this year; with 289 days left in the year, they'll launch 91 at the current pace.  Getting the pace up to 3-1/2 days per launch will get them to their goal.  

To put this into perspective, a decade ago, the United States launched an average of 15 to 20 orbital rockets a year. In 2022, the United States recorded its most launches in any calendar year, ever, with 78 orbital flights. This year, barring a catastrophic accident with the Falcon 9 booster, that number will easily get into triple digits. The all-time record for orbital launches in a single year is held by the Soviet Union, with 101, in 1982.

OBTW; that number of 78 US launches last year includes SpaceX's 61 launches, or 78.2% of all US launches were SpaceX.  When SpaceX first started launching Falcon missions, they completed three in one year, which was doing pretty well.  Their competitors were largely the Russians, the European Space Agency and United Launch Alliance.  Through 2023 'til today, Russia has launched three rockets, two Soyuz and one Proton.  Neither the ESA or ULA have launched one. 

Looked at from a slightly different perspective, their three largest competitors have launched three rockets in three months.  If you include the CRS-27 resupply mission on the night of the 14th, SpaceX has launched three rockets in three days. 

Followers of the Starship program know they talk of eventually launching the same Starship multiple times in one day.  It still takes a couple of weeks to refurbish a Falcon 9 booster, and if that was cut in half, there's still time to refurbish the launch pads that doesn't look to get much shorter than about a week.  

In the meantime, while the interest in watching launches varies with the time of year (visibility is best in the winter), time of day, and familiarity with the vehicle, trajectory and so on, I still find watching them land the booster worth watching.  No other company, or country, on Earth has landed an orbital class booster yet, and there's no indication of a test mission coming that will recover one.

I was looking through my posted pictures for a pretty launch, but in a different sort of way, this sums it up better.  From last October, a Falcon 9 heads for orbit in the background, while an "experienced" booster is being processed in Port Canaveral to be transported up to the north end of KSC to be refurbished to fly again. That booster looks dirtier than Hans Solo's Millennium Falcon.  Jenny Hautmann photo

Sunday, March 19, 2023

Rolls-Royce to Develop Nuclear Power for a Moon Base

In what must be an unusual Sunday, press release, the U.K. Space Agency and Rolls-Royce announced the agency has decided to continue funding Rolls-Royce's project to create a small nuclear-powered reactor that could serve as a long-term energy source for lunar bases. 

The new boost to Rolls-Royce’s research pot follows a previous $303,495 (£249,000) study funded by the U.K. Space Agency in 2022. With the new funds, the company hopes to have a demonstration model for a modular micro-reactor ready to deliver to the moon by 2029.

The article grabbed my attention simply because it mentioned Rolls-Royce and I had no idea that the luxury car company had anything to do with small nuclear reactor design or production. The press release goes on to say:

Relatively small and lightweight compared to other power systems, a nuclear micro-reactor could enable continuous power regardless of location, available sunlight, and other environmental conditions.

Rolls-Royce will be working alongside a variety of collaborators including the University of Oxford, University of Bangor, University of Brighton, University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) and Nuclear AMRC. The funding means Rolls-Royce can further strengthen its knowledge of these complex systems, with a focus on three key features of the Micro-Reactor; the fuel used to generate heat, the method of heat transfer and technology to convert that heat into electricity.

Artist's illustration of a Rolls-Royce microreactor on the moon. (Image credit: Rolls-Royce Holdings)

The quote above said the work will focus on the "three key features of the Micro-Reactor; the fuel used to generate heat, the method of heat transfer and technology to convert that heat into electricity," and that implies they have barely scratched the surface of what they need to know to successfully run a small reactor in that environment.  As you undoubtedly already know, the majority of near-Earth and inner solar system missions depend on solar power for their energy; photovoltaic cells like you can put on your roof.  Probes to the outer planets, such as the Voyager, Cassini and other probes, tended to run instead on small Radioisotope Thermoelectric Generators or RTGs.  

RTGs aren't conventional nuclear reactors by any means, but aren't dependent on the diminishing sunlight as the probes went ever farther from the sun.  The RTG uses the difference in heat from the nuclear-isotope (the isotope used varied with the mission) and the cold of deep space to drive a thermoelectric generator; something not likely to work baking in the daytime temperatures on the surface of the moon.  A small thermoelectric generator can be a hobbyist toy, and they're cheap and easy to play with. 

It sounds to me like what Rolls-Royce is looking to develop is something like the KRUSTY system we talked about nearly five years ago.  KRUSTY was the acronym for Kilopower Reactor Using Stirling TechnologY that used nuclear fuel to produce heat, Stirling engines (another hobbyist favorite) to turn that heat into mechanical energy and then convert that mechanical energy into electrical energy.  

Conceptual illustration of a complete lunar base, powered by the reactors visible in the foreground and middle distance.  (Image credit: Rolls-Royce Holdings) 

Closing words to the UK Department of Science, Innovation and Technology:

"Partnerships like this, between British industry, the U.K. Space Agency and government, are helping to create jobs across our £16 billion space tech sector and help ensure the U.K. continues to be a major force in frontier science," George Freeman, Minister of State at the Department of Science, Innovation and Technology, said in the March 17 press release.

Saturday, March 18, 2023

The Ham Radio Series 38 - Meet Mr. Smith Chart Part 2

Before we start, let me do a crash review.  The Smith chart is a way of plotting impedances of the form R +/- X or their reciprocals, called admittances, and provides graphical ways of solving for impedance matching problems.  Look at the top chart in part 1; the central axis (pure resistance) goes from zero to infinity, which means the right end is pretty packed and it’s impossible to distinguish, say 10,000 from 1 million or 1 billion ohms.  Left to right, it’s low impedances to high impedances.  The center, marked 1.0, on that chart is usually normalized to the impedance level you’re working with, and 50 ohms (pure resistance) is far more common than much higher or lower.  The top semicircle is inductive impedances, while the bottom semicircle is capacitive impedances.

At the end of the first part of this series, I remarked that next we’d talk about electrical length on the Smith chart.  The “secret” part of that is that the complete circumference of the chart is never more than 1/2 wavelength, 180 degrees.  At 0 and every multiple of 1/2 wavelength, we’re at the left end of the central axis where the chart presents the same impedance and (zero).  The same principle applies for 1/4 wave – the opposite side of the chart is an open circuit and the impedance repeats every half wavelength, or every odd multiple of 1/4 wavelength (1, 3, 5, 7... waves). 

I put the word secret in scare quotes because it’s hard to be less secret. It’s printed right there on the left. Above the real axis, along the top of the chart it says, “wavelengths toward generator” while along the bottom radial scale it reads, “wavelengths toward load.” Some charts will say the same thing on the right side of the chart around the infinite impedance point. 

This is where one of famous behaviors of a transmission line comes from.  Let’s say you want to keep some interfering signal out of a receiver (TV, FM radio, whatever), you isolate the offending frequency and cut a piece of transmission line that’s 1/4 wavelength long, leaving the end open.  It behaves like a dead short to the signal you cut the line for and any signal reflecting to the high impedance end sees an open circuit.  

The line used for the shunt 1/4 wave stub should match the impedance of the circuit, say 75 ohms for cable TV or 300 ohms for an FM receiver, and that 1/4 wavelength means it’s shorter than a quarter wave in free space by the velocity factor of the transmission line.  That means you calculate the length for your frequency, and look up the velocity factor for the transmission line you’re using.  Typical coax would be around 0.6 to 0.7, so once you find that number, you cut the line to 60, 66 or 70% - or whatever the percentage of the computed length.

You can also impedance match on the Smith chart by modeling pieces of transmission line.  A well known example is a quad antenna, which is one full wavelength loop.  The impedance of a 1 wave loop is usually said to be 100 ohms, and it’s recommended to include 1/4 wavelength of 75 ohms for each loop in a multiband quad array.  Unfortunately, that’s not exactly true.  To really match 100 to 50 ohms  requires 1/4 wave of SQRT(50*100) or 70.7 ohms (where SQRT is short for “square root of”), leaving a plot like this:

You can see that if you had 70.7 ohm line, it would work perfectly.  In the case of using 75 ohm line, you get a slightly higher VSWR, 1.15:1.  No big deal.  This works for a 25 ohm antenna as well.  It starts on the opposite end of the axis and SQRT(25*50) is 35.4 ohms.  The problem is that 35.4 ohm coax is harder to find than 70.7 ohm line - except I can find no evidence either impedance line exists.

Also note this is for 10 MHz, and a quarter wave is much less coax than if you wanted to try this on 80 or 160m.  Note how for the simplified model of the coax it says 19.18 feet long.  For comparison, I took a real world plot of an electrically short vertical (my MA8040V, which you might read to be an 80/40 Vertical – as it is) on 160 m and put in 90 degrees of coax to make it a high impedance.  That line was 113 feet long. 

The antenna itself, measured at the radio end of my antenna coax and switches, is the pink arc at lower left – so very low impedance and entirely capacitive.  The green arc is after the additional 113 feet of RG-8U coax.  As you can see, it’s transformed to much higher impedances, but an uncomfortable thing happens.  The curve goes from inductive to capacitive.  The frequency where it goes from inductive to capacitive is just above the top of the 160m band at 2.000 MHz.  I think a shorter transmission line would make the matching a bit less sensitive, but this is purely academic, not a ready to build project.  I can’t see leaving (at least!) a hundred feet of coax in the radio room to get a not very efficient station on 160m.  

Housekeeping: Something I didn’t say in part 1 is the Smith chart is named for Dr. Phillip Smith who published on it in 1939, and not Snuffy, just a cartoon I remember the name of from my little kid days.  I mean like over 60 years ago.   

Friday, March 17, 2023

Virgin Orbit pauses all operations

In the wake of their failure to achieve orbit in the mission launched from the UK in January, BBC News reported yesterday that Virgin Orbit has announced a pause in all operations and that it will furlough almost all of their staff.  

In a statement, the company merely said, "Virgin Orbit is initiating a company-wide operational pause, effective March 16, 2023, and anticipates providing an update on go-forward operations in the coming weeks." Shares dropped 18.8 percent to 82 cents (72p) in extended trading in response to the news.

It's no secret that they've been in a financial squeeze for a while; that was reported on before the January mission.  From the January 2nd post, about three weeks before the second stage malfunction that cost the launch vehicle from the UK and its mission.

This has led to concern about Virgin Orbit's financial viability, which was then reinforced by the company itself.  Virgin Orbit announced on the evening before Thanksgiving the "cessation" of a securities offering, saying, "Due to current market conditions, the company has elected not to proceed with an offering. Any future capital-raising transactions will depend upon future market conditions." In the short term, they have enough capital to keep going, but they need to dramatically increase their launch cadence to reach profitability.

Everyone knows that Virgin Orbit is Sir Richard Branson's child; it couldn't have existed without him starting it and providing funding to keep it operational.  

Independent estimates suggest that Virgin Orbit spent as much as $1 billion to develop and test its LauncherOne rocket and air-launch system. The company made its first successful launch in January 2021 and has averaged one mission every six months since then. Virgin Orbit went public in 2021, but it raised just $68 million and had to turn to private investments for an additional $160 million to keep operating.

Most recently, Branson has been propping up the company's finances. He invested $25 million in November 2022 and another $20 million in December 2022. Importantly, this was a secured note, giving Branson priority as a creditor for the company's assets, including "all aircrafts, aircraft engines (including spare aircraft parts), and related assets."

It appears that Virgin Orbit is also being affected by the worldwide, slow motion, economic slowdown, particularly the cost of money (interest rates).  In February, the company announced it had borrowed an additional $10 million from Virgin Investments Limited, owned by Branson.  In the launch business, $10 million isn't a lot of money, and especially not for a business with the payroll and expenses of Virgin.  That's a couple of weeks of funding, and here we are around four weeks later. 

Moreover, the note has an interest rate of 12 percent, which is double the rate of the November and December notes, which had interest rates of 6 percent. And finally, the new filing contains a separate security agreement that explicitly turns the unsecured November Branson note into a secured obligation.

Sir Richard Branson in mission control for January's launch.  Virgin Orbit photo.

What's the long term outlook?  Is there a long term outlook?  I'm not optimistic about that, but all we can do is wait and see.

Thursday, March 16, 2023

Interesting Launch Week

On Tuesday, March 14 at 8:30 PM EST, we had the opportunity to watch SpaceX launch the Cargo Dragon on an ISS-resupply mission, CRS-27 from the yard.  The Falcon 9 booster B1073 took its 7th flight and the Cargo Dragon itself, C209, was on its third mission to the ISS.  B1073 landed successfully on A Shortfall Of Gravitas (ASOG), at T+7:45.  Liftoff is a bit after 29:10 in this video, but (as usual) YouTube and blogger don't allow me preset that for you - the booster touchdown is at 37:15. 

Sometime later this spring, B1073 will be converted into a Falcon Heavy side booster for the EchoStar-24 mission currently "penciled in" for NET May '23.

This evening, the launch moved too far from our backyard to see, way up to Wallops Island, Virginia, where Rocket Lab launched the Stronger Together mission carrying two satellites for Capella Space, who calls themselves "the Leaders in Synthetic Aperture Radar (SAR)" for Earth observing satellites. 

Since the booster isn't recovered, I embed a shorter video; the full launch video is an hour long, around 50 minutes of which is between achieving orbit and deploying the payload.  The longer video is here, if you want it.  

That's only half of it.  Literally.  There are two more SpaceX launches tomorrow, the first from Vandenberg Space Force Base, SLC-4E, at 3:21 EDT and the later launch from Cape Canavaral Space Force Station SLC-40 at 7:38 PM EDT.  

Relativity Space has slipped the next attempt to launch their Terran-1 mission "Good Luck, Have Fun" until next Wednesday, March 22.  There have been other slips since their last attempt to launch, so consider that more tentative than usual.  It's a first launch ever for the company and the vehicle so schedule slips are not unusual.  (Do I need to link to the joke about Tom Jones syndrome?)

Wednesday, March 15, 2023

Axiom Space Reveals Their Advanced Spacesuit for Artemis

Last June, NASA awarded contracts for the next generation moon exploration spacesuits to Axiom Space and Collins Aerospace.  Today, nine and a half months later, Axiom Space publicly showed their advanced spacesuit for the first time.  The suit is based on NASA's xEMU suit that was developed by the engineers at NASA's Johnson Space Center in Houston

Houston – When astronauts return to the Moon for the first time in over 50 years as part of NASA’s Artemis III mission, they will be wearing Axiom Space’s next-generation spacesuit to walk on the lunar surface.

“We’re carrying on NASA’s legacy by designing an advanced spacesuit that will allow astronauts to operate safely and effectively on the Moon,” said Michael T. Suffredini, Axiom Space president and CEO. “Axiom Space’s Artemis III spacesuit will be ready to meet the complex challenges of the lunar south pole and help grow our understanding of the Moon in order to enable a long-term presence there.” has more photos and a short video showing the suit with someone inside demonstrating some of how it works.  

Now it's time to say the quiet part out loud.  This isn't actually the suit they'll be wearing.

Since a spacesuit worn on the Moon must be white to reflect heat and protect astronauts from extreme high temperatures, a cover layer is currently being used for display purposes only to conceal the suit’s proprietary design. Axiom Space collaborated with costume designer Esther Marquis from the Apple TV+ series, “For All Mankind” to create this custom cover layer using the Axiom Space logo and brand colors. 

My interpretation of that first sentence is that they're concerned Collins Aerospace might use knowledge of what Axiom has done to improve their competing suits.  Or perhaps another competitor, real or imagined.

Axiom Space partnered with a team of industry experts to create the AxEMU, including KBR, Air-Lock, Arrow Science and Technology, David Clark Company, Paragon Space Development Corporation, Sophic Synergistics and A-P-T Research. Though Axiom has trained privately-funded crews (AX-1 mission) to launch to and live on the International Space Station and is developing its own commercial space station, this is the first time that the company has built a pressurized garment for use in space, let alone the moon. adds the note that, “Unlike the iconic garments worn by the Apollo astronauts more than 50 years, this new suit is a "rental" — designed, built and soon to be leased to the space agency by Axiom Space, a space services company.”


Tuesday, March 14, 2023

Pi Day

As usual, I pretty much missed it.  Most people will see this on 3.15 and not 3.14.  It's a slow news day in Space, and while the news made me want to do a piece on central bank insanity, the problem is that there's nothing new there.  I have lots of old articles I could repost, with the built in problem that they all have things in them younger readers won't understand.  Simple example: if they don't know who Ben Bernanke was, how will they understand references to Helicopter Ben or The Bernank?  What about Alan Greenspan?  What about when Janet Yellen was the "head of the Fed?"

Of the few pi day posts I've done, this one appeals to my warped sense of humor the most. 

From Saturday Morning Breakfast Cereal. 

Being an engineer, which one never really retires from, I'm required to be pedantic enough to point out there can only be a pi day in countries that use month/day format rather than day/month.  According to the Wikipedia, it's not strictly an American thing.  It's the US, Philippines, Federated States of Micronesia and Marshall Islands.  The last two were US territories until the 1980s while the Philippines became independent from the US in 1946 after WWII. The rest of the world will never know Pi day.

In addition to being pi day, it's also Albert Einstein's birthday and the day that Steven Hawking shuffled off this mortal coil. I think nobody in the current generation of scientists has been compared to Einstein as much as Hawking was.  It's interesting they have the same day as major bookmarks in their lives.  One checking in, one checking out.

Monday, March 13, 2023

The Cost/Benefit Of Orbital Debris Removal

Space News is reporting today that last Friday (March 10), NASA released a cost/benefit analysis study (pdf warning) of various methods for clearing near-Earth space of debris from rocket and satellite operations.  The study, released by NASA’s Office of Technology, Policy and Strategy, examined the costs of several approaches to removing both large and small debris and the benefits they offered to satellite operators by reducing the number of avoidance maneuvers and losses of satellites damaged or destroyed by debris collisions.  They billed it as "the most rigorous cost-benefit analysis to date of orbital debris remediation," noting that previous debris removal analyses had largely focused on emphasizing sustainability and the “moral responsibility” of doing so.

The topic of space junk comes up and I know I've done some coverage of it.  The most recent article I posted, last December, concluded with an expert (from a startup company, so someone with financial interest in making it sound dire) ended with predictions that in the next 10 years, "we are going to lose the ability to use certain orbits because the carrying capacity is going to get saturated by objects and junk;" and "we will see a loss of human life by (1) school-bus sized objects reentering and surviving reentry and hitting a populated area, or (2) people riding on this wave of civil and commercial astronauts basically having their vehicle getting scwhacked by an unpredicted piece of junk." 

Given that, the study from NASA is a bit surprising in saying, "some methods of removing orbital debris could pay for themselves within a decade by reducing the costs and risks borne by satellite operators."  It will take 10 years for it to pay for itself?  That long?  The astrodynamicist who made those last predictions made it sound like we don't have 10 years. 

The analysis, which looked at both the cost of establishing various approaches to removing debris as well as the costs incurred by satellite operators from debris, found the most effective approaches involved ground- and space-based lasers to remove large amounts of small debris between 1 and 10 centimeters across. Both laser systems would create benefits that exceed their costs within a decade.

The other effective approaches involved “just-in-time collision avoidance” involving the largest debris objects, using rockets or lasers to nudge such debris to avoid collisions with satellites or other debris. Such approaches could have net benefits almost immediately, or no more than a few decades in a worst-case assessment.

The authors acknowledged that the general perception is that such lasers are weapons or that they could be used as weapons.  They state the power of debris-removal lasers would be too low, by a factor of 1,000, to be effective as a weapon against active satellites, “though perceptions may be harder to navigate.”  

They then go on to say that forcing reentry of larger debris objects (think upper stages of boosters) could break even in as little as 20 to 25 years, but in worst-case scenarios might take close to a century to yield benefits. The study found similar time frames for “sweeper” spacecraft that would physically remove small debris. It also examined recycling debris by turning it into propellant, but found breakeven times of a few decades, in part because of large upfront research and development costs for the technology.

There's a lot of interesting things in this paper, including moments of "is that all?" or "huh."  Granted this is limited to US interests only but they found the estimated annual costs to US launch operators of only $58 million a year.  That's less than the cost of one launch on just about any orbital rocket and includes all military as well as civil operational satellites, like Landsat and weather satellites.  I believe that includes the burgeoning field of internet via space, like Starlink, OneWeb and coming systems like Kuiper. 

“We found that most satellite operators do not incur much cost from conjunction assessments or collision avoidance maneuvers,” said Bhavya Lal, NASA associate administrator for technology, policy and strategy, in a speech at the American Astronautical Society’s Goddard Memorial Symposium March 10 that coincided with the release of the report. “The key takeaway here is that the risk to satellite operators need not increase at the same rate as orbital debris increases.”

Still, the fastest payoff (cost to benefit) was a decade.  When does that decade start?  While the observation that to be a weapon a laser would have to be about 1000x the power they're talking about for clearing out small debris, what about aiming it?  Naturally, being "fully trained in the four rules" of gun handling, I think of the aiming accuracy to affect a "few cubic inches" of junk up 300 or so miles, more specifically, Rule 4: "be sure of your target and know what's behind it."  Now think that there are estimates that put the number of pieces of orbital debris about the size of a blueberry (which can't be tracked by radar from the ground) in the hundreds of thousands of pieces.  

Sounds like a space-based laser is called for.  Maybe that decade could start in a decade - at best?

An illustration of objects and space debris in Earth orbit.  Credit: ESA/ID&Sense/ONiRiXEL, CC BY-SA 3.0 IGO

NASA said they plan to organize a roundtable among various launch industry and satellite operators to get feedback on the study before starting a second phase that will improve the model and incorporate even smaller debris.



Sunday, March 12, 2023

The Ham Radio Series 37 - Smith Charts - An Addendum

A few words about complex numbers seem to be appropriate.  

If you reread (or read) my intro to Smith charts, you’ll notice that I didn’t mention at all that impedance is a complex number; that is, instead of the (R, X) that I used, most text books will talk of impedance as R + j*X, where j is an imaginary number, the square root of -1.   

Decades ago, I ran into a math article somewhere that argued the concept of imaginary numbers kept a number of people from being comfortable with complex numbers and all of the useful applied math they bring to the world.  Admittedly, there just isn’t a good word for a number that multiplied by itself comes out negative, since every other negative number times itself (or times any other negative number) gives a positive result. The problem is that we need two component numbers with resistance and reactance to be useful.  The author of the article I read said we could just as well refer to these instead of as the “real and imaginary” parts of the number as the “humpty and dumpty” parts.  The terms real and imaginary are just as useful as calling them humpty and dumpty.

(In the last year or so, when the conversation started up that math is independent of who’s doing it, so it couldn't possibly be racist, some teacher made a big deal about arguing 2+2 doesn’t always equal 4.  His argument was that 2 apples and 2 bananas didn’t add to 4 anything, which simply proved he can do elementary school math at a 2nd grade level.  I honestly don’t recall if I learned that in 2nd grade, but the point is that when you deal with units, any numbers must be in the same units before you can add them.  If you say you’re 6’ tall and 180 pounds, those two units can’t be added in any way whatsoever to come up with a single number.)

Impedances require attention because resistance and reactance both use ohms as their units.  Practically, impedances are an ordered pair; that is, an impedance where R=40 ohms and X=10 ohms can be written (40,10) and the plus sign is implicit for both parts without specifically writing it.  If Z was capacitive instead of inductive, that would be written (40,-10) and those are not the same coordinates on a Cartesian XY plane or the Smith chart.  The only reason I can think of to keep and use the “j” in (R + j*X) is as a reminder that inductive reactances are positive and capacitive reactances are negative.  If you have two components with (R, X) values you can add parts in series by adding (R1 + R2) and (X1 + X2) to find the total impedance.  To add them in parallel, you need to turn them into the reciprocals of their impedances, called their admittances.  The concept is the same as combining resistors in parallel. 

This is where I need to point out that doing Smith chart work with drafting tools and a paper blank is pretty much dead.  The company I was working for 25 years ago threw out their paper Smith Chart blanks (the red/green kind in the original post - I know because I fished them out of the dumpster) and everything was done in software.  Software is the way to go.  I’ve used a Smith chart display output of all the professional level CAD programs, and a few different dedicated Smith chart programs.  Lately, I’ve been using the very good freeware package I mentioned called SimSmith, by Ward Harriman, AE6TY.  His latest release of the program is now called SimNEC, which merges his Smith chart program with a NEC2 engine.  NEC is the Numerical Electromagnetics Code that’s used for antenna analysis.  It’s a natural combination.  

You don’t need to solve for series or parallel complex impedances; you just choose the circuit model you want to use, enter the component values and let SimSmith (or SimNec) tell you what it’s going to do.  Like most things in life, the more you use it, the better you’ll get with it.

Oh, yeah.  You can do things like sweep a filter design in SimSmith to see how it should work. 

This is 4 pole 2 meter, narrowband filter I designed for a 2m transverter back in the days when I was fending off roaming velociraptors while not working in the lab.  Red is insertion loss, S21, and blue is input return loss, S11.

Saturday, March 11, 2023

The Ham Radio Series 37 - Meet Mr. Smith Chart Part 1

The Smith chart is really complex looking chart that is so common to radio frequency (RF) design that it's practically the symbol for RF design.  There are so many books with a Smith chart on the cover, I have a few within arm's reach right now, that you'd think RF designers couldn't live without them.  That may actually be true.  

So what's up with these things?  They are simply a very concise way of displaying a ton of information that has to do with the impedances in something you're working on and solving matching problems.  What gets most people is there is only one straight line on a Smith chart, horizontal and straight left to right down the middle of the chart.  The basic construction of a Smith chart showing the straight line and a couple of characteristics is shown here:

The only purely resistive impedances on the chart are located on that line.  The top half of the chart is impedances that are inductive (R+X) while the bottom half is capacitive impedances (R-X).  The impedance at the left end of the chart is zero ohms.  The impedance at the right side is infinite impedance; an open circuit.  That means trying to plot high impedances gets pretty cramped in that area.  If you look closely at the middle you'll see that number (just to the left of my red line) is 1.0.  Ordinarily, the chart you use is normalized to put the impedance you're working with at that center dot, so you divide every value by 50 ohms (usually, in radio design), which makes the right end a bit less cramped.

It's important to say that impedance could just as well be plotted on a regular Cartesian graph like you're used to for an XY plot.  The plot like this, with arcs and circles everywhere has advantages that are hard or impossible to achieve in the Cartesian "Y is perpendicular to X" plot and the Cartesian plot has the serious disadvantage of only giving you half the chart to work with. On a Cartesian plot  none of the resistances would be negative, so you'd only get the positive values of R with +/- values for X.  You'd get half a plane.  The first step in transitioning from a Cartesian graph to the Smith chart is to transform everything into polar coordinates: magnitude and angle. 

Since every point on the above chart represents R+X, those are series impedances.  It's also possible to get a version of this chart that shows the reciprocal of impedance, called admittance.  These show parallel R and X.  The red circles represent constant reactance, the green circles are constant susceptance, the reciprocal of reactance. 

Perhaps an example of use would help without overloading you. 

I've mentioned before that I had made a simple little circuit to ensure that my 80 and 40m trapped vertical would be usable on 30m.  My previous radios had never blinked at matching to that antenna, but the new radio would measure the SWR, decide it was over the 3:1 it's rated to match to and just stop.  My trick was to put an LC  in series with the antenna coax inside the shack that dropped the SWR from just about 6:1 down to comfortably under 3:1.  I made it fairly close to just under 3:1 so I wouldn't mess up the bands the antenna was designed for.  The first thing I did was sweep the antenna with my old VNA, an AIM4170, and plot its impedance on the Smith chart. I put two markers on the plot and those impedances, the bottom and top of the 30m band, are at the bottom of this chart (I also circled them in blue for you).  You can see they're high impedance because they're toward the right edge of the chart and they're capacitive because they're below the middle straight line.  

The next step was to match those to be inside of 3:1.  Smith charts allow you to plot a circle of constant SWR so you simply add a part or two to push the points you're interested in inside that circle.  The SWR circle can be done on paper by drawing a circle with a compass that is centered on 1.0 (50 ohms), put the pencil tip down on the 3.0 marker and draw the circle with that radius.  That's the 3:1 SWR circle, in black in this graph from the excellent freeware program SimSmith. The light blue trace shows the impedance of the antenna before and the dark blue trace is after adding a shunt capacitor series inductor combination (seen at the top left of this screen capture - the left most block is the antenna impedance).

The dotted pink trace uses the same color as C1 in the circuit diagram, and green trace shows the transformation from L1 in its color.  I checked both ends of the 30m band and verified that SWR was transformed to under 3:1, and that adding my little circuit didn't affect the 80 and 40m bands.  I've been using that for around 2-1/2 years now and it has been zero problems. 

Now look a little closer at this plot.  The dotted pink trace is very close to an admittance circuit.  That tells you adding a shunt capacitor always moves clockwise on (or "parallel to") an admittance circle.  A shunt inductor will always move counterclockwise.  Similarly, the green dotted trace is along a circle on the impedance chart.  A series inductor always moves counter clockwise (toward the inductive reactance side of the chart) while a series capacitor always moves counter clockwise or toward the capacitive side of the chart.

Next time, I'll talk about how the chart can cover from zero on the left to infinite on the right and how those are only 1/4 wave apart.

Friday, March 10, 2023

Weekly Small Space News Story Roundup 3

Arianespace chief plans on rapid Ariane 6 ramp-up

Arianespace had a rough time in 2022. Among the issues they dealt with were the sudden loss of cooperation with Russia for launches via the Soyuz vehicle, the December Vega C launch failure when the second stage failed, dooming the mission, and further delays in readying the Ariane 6 rocket for launch. In a paywalled op-ed published in the French publication Les Echos, Arianespace President Stéphane Israël defended the European launch company saying it would be wrong to criticize them

That's a lot to ask ... Rather, he argues that better times are coming for the European launch industry, noting in particular that the Ariane 6 vehicle had won a "historic" contract for 18 of Amazon's Project Kuiper satellite launches. To meet this demand, he says, Arianespace plans to be launching a dozen Ariane 6 rockets a year by 2025. This ramp-up is "essential" Israël said. It may indeed be essential, but launching an Ariane 6 rocket a month in 2025, with the booster unlikely to make its debut before early 2024, seems almost like magical thinking.

What's all this NSSL Phase 3 stuff, anyway?

A gold rush.  

The US military recently released a rather mundane-sounding document titled "National Security Space Launch Phase 3 DRAFT Request for Proposals #1." That may be a mouthful of jargon, but it's still a rather consequential document. Effectively, its release is the starting gun for the next round of launch contracts for US spy satellites, secure communications satellites, and more.

The US military issues these requests for proposals from time to time.  Proposals for launch contracts worth billions of dollars—substantially more than $10 billion—as the military seeks to secure launch deals for the late 2020s and early 2030s.  

The bottom line could be that they're finally getting serious about commercial space.  

In 2012, after SpaceX had already successfully flown the Falcon 9 four times, the military nonetheless awarded a block-buy contract exclusively to United Launch Alliance. Commercial launch startup be damned, the Department of Defense stuck with its monopoly.

As the Falcon 9 continued to fly, with prices substantially undercutting United Launch Alliance, this decision came to look pretty silly. So a few years later, the program was modified to allow SpaceX to win a few of these military contracts.

 Blue Origin and Northrup Grumman were told "thanks for playing; try again later." 

The Phase 3 contract is subdivided into subcategories such as Lanes 1, 2 and more.  Lane 1 is for smaller, less critical payloads.

... about 30 "Lane 1" missions will be awarded during a five-year period from fiscal year 2025 to 2029. These satellites will mostly fly into low-Earth orbit, and the missions are more "risk tolerant," meaning that if the rocket blows up and the satellite is lost, it will not have a hugely adverse effect on the military's operations.

The goal is to provide an opportunity for companies developing new medium-lift rockets to enter the competition. This includes Rocket Lab (with its Neutron rocket), Relativity Space (with its Terran R vehicle), and ABL Space (which has not named or announced a vehicle), Pentecost said. Companies with larger launch vehicles, like United Launch Alliance, SpaceX, and Blue Origin, are also eligible to compete in Lane 1. There likely will be many potential providers. Pentecost said 27 companies signed up for an "industry day" on February 28 to discuss this opportunity.

Lane 2 is the more traditional procurement strategy. About 40 missions will be awarded during a five-year period beginning in 2025. These are payloads that require the greatest capabilities from launch providers: the ability to deal with difficult orbits, secure rooms for pre-launch processing, and heavier lift capabilities.  Space Systems Command will select only two companies for this lane, which will split the mission awards in a 60-40 ratio; the way the current split between ULA (60) and SpaceX is currently built.  

There are lots of interesting side aspects to this and anyone interested should read the whole thing.  For one, the launch systems don't have to actually have been certified to any required "reference orbits" or not even actually flying.  They simply need to have agreed to complete the certification processes before they're eligible to fly those national security payloads.  That leaves room for companies like Blue Origin.  Space Systems Command expects to issue a "final" request for proposals in the third quarter of 2023 and then announce its two "Lane 2" awardees during the summer of 2024. It's entirely possible, even likely, that New Glenn will not have flown yet when this decision is made.

Perhaps the most interesting little bit is a report that Boeing will propose to use the Space Launch System - SLS.  

No, wait, they're serious ... "We believe the proven SLS capabilities can be an asset for the ... [NSSL] Phase 3 contract," the company told Klotz. While I applaud Boeing's ambition, it is difficult to see the SLS rocket being seriously considered in an open competition. Its price (probably above $2 billion) will easily be five times, or even 10 times that of the rockets it is competing against, and, with a low flight rate, it is unlikely to answer the military's priorities for schedule and reliability.

A Falcon Heavy rocket launches the USSF-67 mission for the US Space Force this past January (2023).  SpaceX photo.