Tuesday, November 5, 2024

So Where Are We? What Now?

As I sit to write, it's before 8:00 PM ET and polls all along the time zone are either shut down or getting ready to shut down.  Florida has a section in the panhandle that's on central time, pretty much the 10 westernmost counties in the state but with one exception along the gulf coast, and as a general rule the state doesn't like to give the results out until after the central time results are done.  The state got a well-deserved reaming after the Bush-Gore recounts in 2000, but it has almost gone completely unmentioned in TV coverage that the state dramatically improved after that and the votes will be completely counted soon.  Around 7:30 I saw a news report that the state had around 66% of all ballots counted.  Due to the time, I'd assume that excluded the Central Timezone counties.

I used to write much more about politics than I do now, so forgive me this rant down this old road. 

Early voting started in early October, but Mrs. Graybeard and I voted on Wednesday, October 30th. I won't get so boring as to list entirely who I voted for, but I voted for Trump/Vance, Voldemort -um, I mean Rick Scott, and pretty much what I consider a "conservatarian with Christian backing" approach.  For example, the ballots we get for every statewide election have votes on whether judges in the various courts should be retained. This year I adopted a new algorithm for deciding who to keep: I looked up how long those judges have been on the benches and if they were there three terms (12 years) I instituted my own term limits.  To my surprise, most of them were there less than 8 years and I said OK; ISTRC one judge had been there 15 years and I said "go home." 

Our long time US representative, Bill Posey, decided not to run for reelection this year and in the primaries a former state senator ran to replace him and won. Posey was good, but I was getting uncomfortable with how long he was working up in DC with no term limits.  Due to a roundabout story that I won't get into, the guy running for Posey's old job is in a "friend of a friend" of ours circle and got our votes. Note that's FOAF and not FAFO. 

In general while I don't think term limits are ideal, I tend to like them. In Florida law, we have term limits. The problem is that too many people seemingly tend to vote on name recognition so office holders just kind of rotate between jobs without ever getting off the government payroll and becoming useful citizens again. It's not like after some number of years as a representative they get a promotion to the senate, they go back forth.

As usual, there were a handful of state constitutional amendments to vote on as well as county and city charter issues.  The two state constitution amendments that got talked about the most were the "Big Weed" amendment 3 and "Big Abortion" amendment 4; I voted against both - and primarily because they both favored the big powers and didn't seem to make either situation better. 

I've read various estimates of what the marijuana industry pumped into #3 that would widen the uses of their products, but Open Secrets shows that by the middle of October, they had spent over $81 million.  I'd guess they probably got close to $100 million in the last couple of weeks.  Those opposed didn't quite get to the $20 million spent line, but perhaps by now. The bill looks to cause more problems while not solving anything I know of. 

The other one, #4, looked like it allowed everything and used vague terminology where precise wording is called for. A glaring example is it didn't define who a "medical provider" is and yet they can approve anything.  It doesn't say medical doctor, or any other state recognized term so I can envision a Haitian Voodoo practitioner, or worse, saying they're the provider. It totally removes parental rights to even know if their daughter is being sent for an abortion. I could easily see it harming women instead of helping them.  In this case, Open Secrets shows the abortion industry spent $60.7 million while those opposed to it didn't even get to 1/6 of that; spending $9 million. 

Interestingly, those two amendments had a total, in mid-October, of $171.9 million spent on them (for and against).  Of the remaining amendments, Open Secrets shows nothing spent either way.

The county passed out these stickers instead of the American flag ones they've been using for as long as I can remember.



Monday, November 4, 2024

China Shows Plans to Develop Starship Copy

The only thing surprising about that is that they announced it publicly.  Eric Berger at Ars Technica (that link) has been following them for years and reports on the changes to what has been called the Long March 9 since the initial concept was released about 10 years ago. The initial design concept drawings were a pretty conventional-looking rocket. It was fully expendable, with three stages and solid motors strapped onto its sides. That sounds like the US Space Launch System (or SLS).  

All that changed. Two years ago, China had re-imagined the design with a reusable first stage.

Now, based on information released at a major airshow in Zhuhai, China, the design has morphed again. And this time, the plan for the Long March 9 rocket looks almost exactly like a clone of SpaceX's Starship rocket.

Let me be clear that the Long March 9 is not a direct copy of Starship and Superheavy.  It's smaller and less powerful. 

Based on its latest specifications, the Long March 9 rocket will have a fully reusable first stage powered by 30 YF-215 engines, which are full-flow staged combustion engines fueled by methane and liquid oxygen, each with a thrust of approximately 200 tons. By way of comparison, Starship's first stage is powered by 33 Raptor engines, also fueled with methane and liquid oxygen, each with a thrust of about 280 tons.

The quick multiplication is that the Long March 9 will have 6000 tons of thrust while Starship Superheavy has 9240 tons of thrust, over 1.5 times the thrust of the Long March 9.

The new specifications also include a fully reusable configuration of the rocket, with an upper stage that looks eerily similar to Starship's second stage, complete with flaps in a similar location. According to a presentation at the airshow, China intends to fly this vehicle for the first time in 2033, nearly a decade from now.

A translated slide from a presentation on China's latest plans for the Long March 9. Credit: Weibo 

Note the Total Length of 114 meters; the Starship web site shows 121 m. On the other hand, this slide shows the diameter of the LM9 body to be 10.6m, while Starship is 9m. A direct comparison is difficult. Eric Berger adds:

In related news, last week, a quasi-private Chinese space startup, Cosmoleap, announced plans to develop a fully reusable "Leap" rocket within the next few years. An animated video that accompanied the funding announcement indicated that the company seeks to emulate the tower catch-with-chopsticks methodology that SpaceX successfully employed during Starship's fifth flight test last month.

Let's be real for a minute. These are not the first times Chinese rocket programs have emulated SpaceX, such as when Space Pioneer planned to develop a Falcon 9 clone. Both the state-run rocket agency and the company's private industries are copying the best practices of SpaceX as they seek to catch up. At this point, China's launch industry is basically hanging out in the SpaceX waiting room to see which ideas it should swipe next.

The idea that the Chinese are embedding people in American companies to return design information is practically as widespread as one could get. The big thing I notice here is that the Chinese (party) Space Agency recognizes that reusability is the key, while the NASA and the US congress still seem to want cost-plus jobs like the SLS. This excess cost, which some have noted seems to simply flow around between the space industry and the regulators, could be directed toward the kind of technological advances that might keep the US civil space program ahead of China.

A miniature model of the Long March 9.  Image credit Weibo. 



Sunday, November 3, 2024

I'm Tired... So Tired of it over and over again

Today, it's not just the Flying Fertilizer (a creative way of saying bullshit) as we approach the election. It's also switching the clocks back to standard time, despite the passage of state and national laws to stay on one time all year long. 

Florida's law was passed in 2018 and it's probably not necessary for me to point out: that was six freaking years ago!!! The kicker is that Florida did it wrong (I know: quelle surprise). 

By overwhelming, bipartisan majorities, the normally fractious Senate and House agreed this week to make Florida the first in the nation to adopt year-round daylight saving time statewide. It would mean later sunrises and sunsets from November to March, peak tourist season for many beach cities.

That's right, for some reason, they want us to stay on DST all year long - in essence, putting us in the next time zone east of us. According to Federal law, a state can refuse to go on DST and they're free to do so, but to stay on DST requires congressional approval. That's even illogical for something coming out of Washington. 

As I've said before, if I wrote such ninny legislation, I would have made Standard Time the standard time.  Solar noon is when the sun is on the meridian, that line that goes from north to south passing directly overhead.  With DST, solar noon occurs closer to 1PM, not 12 noon.  Maybe I'm anal-retentive, but having solar noon at 1PM forever is just wrong. 

It's not just Florida, though, three of the New England states, Massachusetts, New Hampshire and Maine, want to stay on DST all year, too (or move one time zone east, however you like to think of it). I don't see where the authority to regulate clocks comes out of the constitution, but to mimic Dr. McCoy from the original Star Trek series, "dammit Jim, I'm radio designer not a lawyer." 

Which makes me ask why doesn't congress scrap their legal control over staying on DST making staying on DST like a state deciding to never go on DST?  Cancel all those laws. Instead, the Senate passed a bill in March of 2022 to end DST. I assume the bill must have been killed in the house when it had to go there for approval. 

Since 2015, 30 states have introduced legislation to end the twice-yearly changing of clocks, with some states proposing to do it only if neighboring states do the same. A 2019 poll found 71% of Americans prefer to no longer switch their clocks twice a year. The only controversy seems to be if states prefer to stay on standard time year round or stay on DST all year.

Yeah, you'll have groups in each state that want the opposite times.  That's inevitable.  In Florida it appears the main tourist industry reps wanted to stay on DST. The tourist industry backing is how they got the law passed while some other groups wanted to stay on standard time.  The inevitable physics of the situation is that states get different variations of their amount of sunlight because that varies with latitude and it changes far more the farther north you get. That change in sunlight hours with the seasons is caused by the 23.5 degree inclination of Earth's axis.  

Here in the southernmost reaches of the US, (I'm not in the tropics - none of Florida is) we have less variation.  On the summer solstice, our day is just short of 14 hours long - 13:55.  On the winter solstice it's 3 hours 34 minutes shorter, 10:21. (source)  In Minneapolis, MN, their longest day is 15:37 - just over an hour and half longer than ours - and the shortest day shortens down to 8:46, virtually seven hours shorter than their longest day.  Compare that to our 3-1/2 hour difference between the longest and shortest days.  Nothing can be done to change those times.  All DST does is change what we call them. 


It may be a bit melodramatic to say the clocks are killing people, but there are some well-documented side effects of the "jet lag" people get from the time changes: more car accidents, more accidents at work, higher rates of heart attacks and strokes, and more. This image is from entrepreneur Scott Yates, who runs a website called #LockTheClock, dedicated to keeping pushing on this issue. That website is quite different from 2020 when I first used the image.  He's trying to push that boulder uphill and it's tough. 



Saturday, November 2, 2024

Once in a Lifetime

You know the old song

Once in a lifetime
A man has a moment
One wonderful moment
When fate takes his hand

I thought this looked like it could be my weekend for a once in a lifetime moment, but reality said not me, not now. 

Relax, I'm not talking about normal, human stuff, like this love song. I'm talking ham radio here. I'm talking one of those goals that virtually all hams strive for at some point, Worked All States or WAS. In this case, on the VHF band where I tend to spend more hours than on any other band, 6m (50.0 to 54.0 MHz). 

In my first couple of years as a ham, I targeted getting my WAS using only CW.  It took me three years and I recall trying for a long time to get my last state, which was Idaho.  This time, my last state is Alaska. In my lifetime on 6m, I started playing on the band in 2002, I have met and read of many people who have WAS, but it's hard from Florida. Here in Central Florida, we're about as far from Alaska as we can be and still be in the continental United States. 

The key this time is we're in the peak of solar cycle 25 and we're getting solar flux numbers we haven't seen since cycle 23, 22 years ago.  This week, the F2 (longest range ionospheric) propagation has shown up as the Solar Flux Index spent days at 270. The rule of thumb for F2 propagation is that it's not just a daytime phenomenon, if you have a directional antenna, you should point it under where the sun is beating down. That is, in the morning point toward the East, as the sun goes through the meridian, propagation will start to favor north/south paths and in the afternoon, point toward the West.  

On Thursday morning, propagation reports showed dozens of contacts from Europe into the Eastern US, spreading farther west as the day went on. Eventually, around 1800 UTC to 1930 (2:00 to 3:30 PM EDT), Alaskan stations started being heard across the country, starting in northern tier of states and spreading south. I saw the reports but never heard one of the Alaskan stations. 

On Friday morning, I prepared for a repeat and essentially got one.  The big picture, if anything, was a little better than the day before, evidenced by the Alaskan stations being heard by some stations around Florida much later into the evening, even showing up in reported spots as late as 2330 UTC (7:30 PM EDT). In keeping with being a repeat I never heard one of the half dozen different Alaskans, only other stations calling them with very, very few of those others stations completing a contact. At one point, I noticed my station had copied a station in the Midwest working Alaska and looked up where they were about 800 miles NW of me in Missouri. 

Today, the solar flux had dropped into the 250s and the propagation suffered.  Yes, there were some Alaskan stations on the air, but they never made it even as close as that 800 miles NW of me. 

Here's a plot I’ve shown regularly which shows the SSN for the last five cycles back to 1975. I like this plot because it’s my ham radio biography in one plot. That is, every cycle I’ve been through is on this plot (and I was a shortwave listener for the cycle before the first one here). The plot is posted to Space Weather News, but is created by a separate site, Solen.info. The last time I posted this was back in May, which is about midway between 40 and 50 months on the X-axis. The smoothed sunspot number has taken a dramatic rise since then, and looks like it may exceed cycle 23 in the next few months.  I may get more chances at Alaska as the cycle peak unfolds.



Friday, November 1, 2024

Voyager 1 Switches to Backup Transmitter to Phone Home

The punch line to this story is that backup transmitter hasn't been used since 1981.  

About two weeks ago, October 16, Voyager 1 put itself into a safe mode after receiving a transmission from its mission control via the Deep Space Network commanding the satellite to turn on one of its heaters.  Because it takes just about a full day for radio transmission to get to the satellite and another full day before the response is known, they found out on October 18 that Voyager failed to respond.  

According to a post from NASA, it took a little while to discover that Voyager had switched off its primary X-band transmitter and switched over to its secondary S-band radio transmitter, which uses less power.

Then, on Oct. 19, communication appeared to stop entirely. The flight team suspected that Voyager 1’s fault protection system was triggered twice more and that it turned off the X-band transmitter and switched to a second radio transmitter called the S-band. While the S-band uses less power, Voyager 1 had not used it to communicate with Earth since 1981. It uses a different frequency than the X-band transmitters signal [and] is significantly fainter. The flight team was not certain the S-band could be detected at Earth due to the spacecraft’s distance, but engineers with the Deep Space Network were able to find it.

While the first thought might be to turn the X-band transmitter on, the Voyager team is more cautious than that, wanting to understand what caused the fault protection system to trigger and switch the transmitters. 

[T]he team sent a command on Oct. 22 to confirm the S-band transmitter is working. The team is now working to gather information that will help them figure out what happened and return Voyager 1 to normal operations.

Two days later on the 24th, the team was finally able to connect with the elderly spacecraft, now in the 47th year of its four year mission. Voyagers 1 and 2 (a few weeks older than 1) are the only man-made objects to reach and operate in interstellar space.  Their advanced age has meant an increase in the frequency and complexity of technical issues and new challenges for the mission engineering team. Which has met those challenges so far.

How do you hear a signal from a low power transmitter that's 23 light hours, that is, 16 billion miles away? A high gain antenna. This the Deep Space Network antenna in Canberra,Australia.  With a diameter of 70 meters, or 230 feet, the DSN stations are the three most sensitive radio receiving stations on Earth. Image credi: NASA/JPL-Caltech



Thursday, October 31, 2024

Small Space News Story Roundup 45

Is the "reusability changes everything" idea catching on? 

European Space Agency Commits to Two Reusability Programs

The ESA has selected four European companies to work on two new programs aimed at reusability.  

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

Gee...THRUST! and BEST! sure sound like serious names. I have a personal bias against the excessive use of exclamation points, but that's just me.

The THRUST! initiative aims to push forward the development of European liquid propulsion systems, and Rocket Factory Augsburg and The Exploration Company were selected to develop projects under this initiative. The Exploration Company is already working on a high thrust engine in the 200 tons of thrust class, called the Typhoon, while Rocket Factory Augsburg has been working on considerably smaller engines (more like 10 tons) so it's a bigger leap for them.

The BEST! project was launched to stimulate the development of future reusable rocket first stages or boosters; ArianeGroup and Isar Aerospace were chosen for this. Europe has a number of initiatives now aimed at developing a reusable rocket, but it seems doubtful that a European rocket will launch to orbit in the 2020s and successfully return to Earth.

UK Startup Aiming at Fully Reusable Rocket

SpaceNews is reporting that Astron Systems is developing a fully reusable two-stage rocket that will be able to transport about 360 kilograms to low-Earth orbit. That payload, around 790 pounds, puts it in the small payload class, but still bigger payloads to LEO than Rocket Lab's Electron, which advertises 300 kg or 660 lb. Rocketlab is progressing in the reusability direction, but hasn't achieved the kind of "fully reusable" level Astron appears to be aiming for. 

“The main driver of cost and time for putting stuff into space is production and assembly,” Eddie Brown, Astron Systems founder and CEO, told SpaceNews. “If you can spread out that cost over many flights, the per-flight cost can be a lot lower. And you can ramp up to a higher cadence and be much more responsive to customer schedules.”

Astron Systems, founded in 2021 and located at the Harwell Science Campus in England, is one of 12 startups in the Fall 2024 class of the TechStars Space Accelerator. Prior to TechStars, the European Space Agency Business Incubator Centre United Kingdom supported Astron Systems’ early hardware development.

Founder Eddie Brown noted, “If you want a small rocket engine to use for 50, 100 flights today, that’s not something you could buy off the shelf.”  He said Astron is driving towards a methalox engine: methane and oxygen, like SpaceX's Raptors and Blue Origin's BE-3 and BE-4 engines, to name a few.  Their twist is the desire to use biomethane "to reduce its environmental impact." 

Artist's concept of a reusable booster after landing, from the French space agency CNES. 



Wednesday, October 30, 2024

Blue Origin Moves One Step Closer to First Flight

Blue Origin took another step closer to the first flight of their New Glenn vehicle by finishing assembly of the first stage that will fly and rolling it to their launch pad on Tuesday evening October 29.  The long-awaited first flight is being talked about as "before the end of the year," contingent on passing some major test milestones between now and the first launch. 

Moving the rocket to the launch site is a key sign that the first stage is almost ready for its much-anticipated debut. Development of the New Glenn rocket would bring a third commercial heavy-lift rocket into the US market, after SpaceX's Falcon Heavy and Starship vehicles. It would send another clear signal that the future of rocketry in the United States is commercially driven rather than government-led. Critically, New Glenn is also designed to have a fully reusable first stage, which will attempt a droneship landing on its first flight.

The rocket will undergo two significant tests; first a WDR or Wet Dress Rehearsal in which it gets fully fueled and every aspect gets tested as if it was going to launch, stopping just short of starting the engines, and the second being like that but the engines will ignite and run a static fire test of some (currently unstated) duration.  

You may recall that Blue went through this sequence with the second stage in the last week of September (last story in a Small News Roundup). That was preparation for this in some sense; I mean, it had to be done before the entire vehicle can be stacked for launch and it probably was a good use of their launch pad facilities. 

These are the pivotal final steps before launch, but this is also a period when problems can be found. For example, this will be the first time the flight versions of the first and second stage will be mated and integrated, and then connected to the ground systems at Cape Canaveral. As the size of the transporter suggests, these are large and complex machines. Inevitably, there will be challenges in the coming weeks.

Blue's founder, Jeff Bezos, has been pushing to get New Glenn launched before the end of the year and time is getting tight.  You'll remember that the first launch for a New Glenn was originally supposed to be the ESCAPADE mission to Mars, which required launching during a narrow window between October 13 and 21; the end of the window wasn't even two weeks ago. NASA scrubbed that mission on September 6th, expecting that Blue couldn't get the vehicle ready to launch that soon. I think that was a good call.

According to the Date Calculator, this is day 305 of the year, meaning we have 61 days left (because being a leap year, the year is 366 days long). Is that enough time?  At best, it will be close. Eric Berger at Ars Technica (source article) uses a couple of paragraphs in a comparison with the first flight of the Falcon Heavy.  That first launch had the vehicle delivered to the launch pad on December 28, 2017, static-fired on January 24, 2018 and the liftoff of the first flight was on February 6. All of this work comprised 40 days. 

In my book, it's not a comparison that means anything. SpaceX had far more operational experience than Blue does; they had launched 50 Falcon 9s by then while Blue Origin has launched nothing.  SpaceX has demonstrated a "hardware rich" design philosophy, which tolerates more problems with smaller assemblies to learn more by testing more.  Blue is the opposite. Finally, SpaceX demonstrates remarkable speed in getting things done all the time. I don't believe that has ever been said about Blue Origin. 

That said, I wish them luck.

Blue Origin's New Glenn rocket rolls out of its hangar on Tuesday night. Credit: Blue Origin



Tuesday, October 29, 2024

The Orion Heat Shield - This Might Be My Shortest Post Ever

NASA says they have found the root cause of the Orion heat shield issues.  But they're not telling us what it was.  Maybe by the end of the year.

The pitting experienced by Artemis 1 during reentry.  According to the OIG report, NASA found more than 100 locations on the heat shield where material “chipped away unexpectedly”.

The End.

Seriously



Monday, October 28, 2024

Psst. Hey buddy... Wanna Buy Starliner?

Not a Starliner capsule. The entire program.  

Reports are starting to circulate that Boeing is looking into selling its space business, including Starliner program.  The reason is the large financial losses that the Starliner team incurred, currently $1.85 billion as covered last Thursday. Boeing's defense, space and security business, reported $3.1 billion in losses (against $18.5 billion in revenues) in the first nine months of 2024, so Starliner is responsible for more than half their losses (according to Boeing's 3rd quarter results).

The discussions are said to be "at an early stage," according to an exclusive in the Wall Street Journal.

Boeing is known for decades of work with NASA, including being the prime contractor for the International Space Station. (The company continues engineering support services for ISS to this day.) But Boeing is facing mounting financial issues this year, including a protracted strike by its largest labor union and significant deficits in the Starliner program.

It's worth noting that the WSJ also emphasizes the discussions about selling are "at an early stage." 

Interestingly, Boeing may hold onto its Space Launch System (SLS), presumably because as a cost plus contract, they didn't incur losses on SLS; they passed those extra expenses on to American taxpayers. Don't forget that Boeing has a 50% ownership along with with Lockheed Martin in United Launch Alliance. ULA has a large backlog of work over the next few years and I haven't seen anyone comparing Vulcan to SLS so that seems like a good business to hold on to.

Given that overview, they might sell only Starliner and I can't imagine they could find a buyer. First off, it'll be 2025 before you blink another few times and that means the ISS has around five years left in operation before it's scheduled to be de-orbited.  With Crewed missions typically staying in space six months, that means roughly 10 missions to bring a crew to orbit, and SpaceX will get at least half of those. Which leads to the rough trade off of how much would the new owner pay to get Starliner approved by NASA (not a guarantee) and how much will they get paid to fly five missions. Is there a profit to be made?

It seems Boeing has a good business (1/2 of ULA), a profitable business that might be standing on shaky legs because it's unreasonably expensive (SLS), and one Stinker.  Back in my early days as an electronics tech 50 years ago, we used to joke about work being a game we called Gems and Turds.  You picked up something to work on and it was like reaching blindfolded into a bag of Gems and Turds. Which one you got was pure luck of the draw. Buying something like the Starliner business should be nothing like that. The buyers should know what they're getting.

Boeing CEO Kelly Ortberg wants to sell the turds and just keep the gems.  Good luck with that. 

Boeing's Starliner spacecraft launches atop a United Launch Alliance Atlas V rocket on June 5, 2024 from Cape Canaveral Space Force Station in Florida. Image credit: Joe Raedle/Getty Images



Sunday, October 27, 2024

The Ham Radio Series 44 - More Intro to Moonbounce

A week ago, I did a post on communicating by bouncing ham radio signals off the moon (and gave the post a title so that after a few months I'll never find it again). Looking back at that, I found a few things that I didn't include that are very important, and another few things that make a good addition to it, so more on the subject tonight. 

The thing I forgot to mention is vitally important to getting started and describes my situation perfectly.  That article talked about sending a signal to the moon and hearing your own echoes, but it's possible to complete contacts via moonbounce without being able to hear your own echoes.  The important thing is there are two stations involved and it all comes down to whether the other operator can hear you, and his station is powerful enough for you to hear his signal bouncing off the moon. 

Let me just lift a little from that prior piece so that you don't have to keep another tab open.

The next big concern is the same as every communications link everywhere else: the amount the signal attenuates - weakens - over that 500,000 miles. The term for this is path loss, and back in the Voyager article, I used a handy form that gets you within less than half a dB of the more theoretically-backed equation.  

Path loss in dB = 37 dB + 20log(f) + 20log(d)  where,f is the frequency in MHz and d is the distance in miles.

So PL = 37 + 20log(50) and 20log(500,000) or 185 dB.  

Let's say we put 1000 W out of our antenna (it could be less power in the transmitter and more antenna gain, or a simpler antenna and more out of the transmitter).  That's +60 dBm (power compared to 1 milliwatt in 50 ohms) or one million milliwatts. 

That means the signal coming back is  +60dBm output -185dB path loss or -125 dBm at our receiver input. In a 50 ohm receiver, that's 0.13 microvolt (130 nV). Is that usable?  I almost hate to say this, but it depends.  It's weak for a 0.13 microvolt SSB (phone or voice) signal, but experienced CW operators won't have much trouble if it's a Morse code (CW) signal.

The thing you're looking for here is the sensitivity of the system - the heart of how we used to buy receivers as hams - and in a room temperature receiver the noise floor can be given by 

 Noise Floor in dBm = -174 dBm + 10log (receiver BW in Hz) + Noise Figure (or NF)

Let's say our 6m receiver has 4 dB NF, the CW noise floor could work out to  -170 + 10Log(500) or -143 dBm.  That means the -125 dBm signal from the moon has an 18 dB SNR - piece o' cake.  In SSB mode, I'll make that -170 + 10Log(2000) or -137 dBm and the resultant SNR is 12 dB, or 6 dB worse.  A 12 dB SNR for phone is not as easy to understand as an 18 dB SNR for CW, but it's not bad. Some speech compression to raise the volume of the quieter parts of speech would help.

Here I have to add there's a lot more potential places for this to break down in reality.  I alluded to how much signal is lost on the reflection from the moon:

Wait.  There's a nasty assumption hidden in there, that the reflection from the moon is perfect. No signal loss, it just changes direction. That implies the signal reflected back has an angular diameter less than the moon - or some would be lost  around the edges.  The diameter of the moon is just over 0.5 degree, which is very tight for an antenna beam.

Let's say the transmitting antenna's beam is twice the diameter of the moon - 1.0 degree.  That figures to be saying half the signal doesn't reflect back - the return is 3 dB less than the calculated 185 dB.  It also implies that the reflection off the moon's surface is the radio equivalent of  a perfect mirror. There are no losses. While I don't know that the losses are I'd be pretty sure there are some.  The transmit and receive numbers aren't including the actual power at the antenna, and there are always losses in the cables connecting the power amp to the antenna.  There shouldn't be much, tenths of a dB rather than whole numbers, but don't forget it's something to keep track of. 

The place where the most improvement seems to have come is in the Weak Signal digital modes that are available now, especially the WSJT-X software that has taken the amateur radio world by storm.  JT is Joe Taylor, a Princeton University physicist and ham who has developed algorithms that make these digital signal processing tools easy to get into your station. There's more than one mode that is specifically intended for moonbounce.  

JT4, JT9, and JT65 use nearly identical message structure and source encoding (the efficient compression of standard messages used for minimal QSOs). They use timed 60-second T/R sequences synchronized with UTC.  JT4 and JT65 were designed for EME ("moonbounce") on the VHF/UHF/microwave bands.  JT9 is optimized for the MF and HF bands.  It  is about 2 dB more sensitive than JT65 while using less than 10% of the bandwidth.  Q65 offers submodes with a wide range of T/R sequence lengths and tone spacings; it is highly recommended for EME, ionospheric scatter, and other weak signal work on VHF, UHF, and microwave bands.

Unfortunately, I've never seen numbers for things like the SNR or input signal required for given small error rates in the received signal. 

While every example I've worked and included was aimed at 6m, it might be that the easiest band to get started with moonbounce is 2m.  The same gain antenna is much smaller because everything scales by wavelength, so while those names (6m and 2m) aren't really the electrical lengths, 1/2 wave (approx. a yagi element) is 9'4" on 6m, it's 3'3" on 2. On 6m, I have a 5 element yagi that's 12' long.  That scales to 4' 2.5" long on 2m. Or more antenna gain in the same length.  Gain and low noise figure are relatively cheap on 2m compared to microwaves and there are many all mode radios for 2m. 

A screen capture from this video.

There are several videos where guys build a station that they only put in place for EME, like this.



Saturday, October 26, 2024

Crew 8 Astronaut Released from Hospital

Last night, the story started showing up that one of the four Crew-8 astronauts who returned to Earth Friday before dawn was hospitalized. The news didn't say which of the four crew members it was or why that person was hospitalized while the other three returned to Houston. Everything mentioned was rather generic.

In an Oct. 25 statement, NASA said the unidentified astronaut “experienced a medical issue” after the Crew Dragon splashdown in the early morning hours off the coast of Pensacola, Florida. The astronaut “is in stable condition under observation as a precautionary measure” at Ascension Sacred Heart Pensacola hospital.

All four Crew-8 crewmembers were transported to the hospital for additional medical checks after undergoing routine post-flight medical examinations on the SpaceX recovery ship. “During routine medical assessments on the recovery ship, the additional evaluation of the crew members was requested out of an abundance of caution,” NASA stated.

Crew-8 consisted of NASA astronauts Matthew Dominick, Michael Barratt and Jeanette Epps along with Roscosmos cosmonaut Alexander Grebenkin. SpaceNews reported all four seemed to be in good condition when exiting the Crew Dragon spacecraft on the SpaceX recovery ship. A little more than half an hour after splashing down, the four could be seen smiling and waving at the camera. 

Apparently soon after that, one crew member started showing signs of some sort of medical problem and the four were taken to that hospital near Pensacola in the westernmost Florida panhandle. The landing zone itself is offshore the Pensacola area.

This afternoon we got the news that the crew member has been released from the hospital. 

In a statement, NASA said the astronaut, whose identify has not been disclosed, was released from Ascension Sacred Heart Pensacola hospital after an overnight stay. “The crew member is in good health and will resume normal post-flight reconditioning with other crew members,” the agency said. 

It's generally being reported that some transient medical conditions aren't unusual after spending a long time in space.  That's part of the reason for the "normal post-flight reconditioning" NASA talks about.  Crew-8 was the longest of the numbered Crew missions at 235 days due to the delays induced by Starliner which had them wait for the Crew-9 mission to arrive at the station.  Return to Earth was further delayed by weather systems in Gulf. 

The Crew-8 Dragon capsule early Friday morning after splashdown off Pensacola.  Credit: SpaceX



Friday, October 25, 2024

India Preparing Next Lunar Landers

You'll remember India's successful lunar lander Chandrayaan-3 from last summer through the fall. With that mission, India became the fourth nation in world history to soft land a probe on the moon and the first to land as close to the south pole as they did, essentially 70 degrees south latitude. At last week's International Astronautical Congress (IAC) convention in Milan, the ISRO (Indian Space Research Organization) announced India’s plans for the Chandrayaan-4 lunar sample return mission. This mission will target a landing between 85 and 90 degrees south latitude. They also talked about a follow-up joint lander and rover mission with Japan. 

The Chandrayaan-4 mission will consist of two stacks launched on two separate rockets and will target the vicinity of the lunar south pole, according to P. Veeramuthuvel of the Indian Space Research Organization (ISRO), speaking at the International Astronautical Congress (IAC) in Milan, Oct. 17. 

The mission will aim to collect around three kilograms of samples from near the south pole, around which water-ice is thought to be available. ISRO will require several new technologies, including the ability to scoop from the surface and drill to a depth of around two meters to sample the subsurface.

They haven't completely finalized the landing location, but it's an ambitious mission that will include lunar landing, sampling, docking in lunar orbit and returning to Earth safely with the samples. All of these are technologies and techniques that will be useful for India in their plans to put astronauts on the moon by 2040.  

The separate Chandrayaan-4 stacks will each have a mass of around 4.6 tons, making a total mass of 9.2 tons, each launching on an LVM-3 launch vehicle. The modules will dock in geosynchronous transfer orbit—using a circuitous route to the moon, as with Chandrayaan-3—and travel to the moon as one. An earlier mission design envisioned using one LVM-3 and PSLV launcher for the two launches.  

As the infomercials on TV used to say, "but wait! There's more!"

JAXA also released some information on  the Chandrayaan-5 mission, also called LUPEX, which is a joint mission between ISRO and The Japan Aerospace Exploration Agency (JAXA). 

The landing mission will also target the lunar south pole, with coordinates of 89.45°S, 222.85°E, on an elevated ridge near Shackleton crater. There are permanently shadowed regions within the vicinity, potentially for the mission rover to explore. The rover will drive between 500 and 1,000 meters, taking in-situ measurements, including determining potential water-ice deposits.

India will provide the lander, mission planning and payloads, while Japan will contribute the launch vehicle, various payloads and the rover. Payloads will include ground penetrating radar, a range of spectrometers and water analysis instruments contributed by both sides.

Spacecraft renders for the Chandrayaan-4 and Chandrayaan-5/LUPEX moon missions. Credit: P. Veeramuthuvel/ISRO

It's interesting to see the determined efforts from ISRO. In addition to the Chandrayaan-4 mission, a Venus orbiter, their first crewed space station module, and a reusable launch vehicle also received approval last month.



Thursday, October 24, 2024

It's a Boeing Kind of Day

A couple of unrelated small stories about the giant corporation.

Boeing is Still Bleeding Cash on Starliner

Boeing's new CEO, Kelly Ortberg, led the company's first quarterly finance report since becoming CEO on Monday, Oct. 21. The world was expecting a report of loss of value with the labor troubles, the resulting strike, and troubles with various products including Starliner. The company reported a loss of $6.2 billion. Starliner was a small part of that, $250 million or 4%.  Both of those numbers ($6.2b and $250m) are just from the last quarter: July through September. 

Back around the less-than-glorious conclusion of the Starliner Crewed Flight Test, I had found (and posted) that as of July, Boeing has reported nearly $1.6 billion in losses to pay for delays and fix technical problems on Starliner.  I think that means the $250 million is on top of the $1.6 billion. The problem flowing out of this one is that Boeing has to resolve the thruster problems and helium leaks that led NASA to tell them to leave astronauts Butch and Suni on the space station to bring Starliner home empty. Industry watchers say that could take many months, a year or more, and will cost additional hundreds of millions of dollars, and this was shown in the SEC filing Boeing submitted Wednesday.

After that September end of the mission, NASA said it didn't know when it would buy more Starliner missions and Boeing said they didn't know when they'd be ready - with an implication they may not be willing to spend the money.

A week after Starliner landed, Boeing's chief financial officer, Brian West, echoed that line. "There is important work to determine any next steps for the Starliner program, and we'll evaluate that," he said at a conference sponsored by Morgan Stanley. 

 One aspect of Ortberg's presentation stood out like a sore thumb to me.  

In response to questions Wednesday from Wall Street investment firms, Ortberg, who took the CEO job in August, suggested it's time for Boeing to look at cutting some of its losses and recalibrate how it pursues new business opportunities. Boeing's previous CEO, Dave Calhoun, said last year the company would no longer enter into fixed-price development contracts.

"I think that that we're better off being doing less and doing it better than doing more and not doing it well," Ortberg said. "So we're in the process of taking an evaluation of the portfolio. It's something a new CEO always does when you come into a business."
...
Ortberg didn't specify any programs that Boeing might consider trimming or canceling, but said the company's "core" business of commercial airplanes and military systems will stay.

In even fewer words, "we're an airplane company." There were some words that might convince me that they're willing to stay with programs like the Artemis/SLS program, which has been financially much worse for the American people and our space programs than for Boeing. I can't say I'm convinced they'll stay with Starliner.

NASA still wants to certify Boeing's Starliner spacecraft to provide the agency with a second commercial option for getting astronauts into orbit. A fundamental goal set out for NASA's commercial crew program more than a decade ago was to develop two dissimilar human-rated transportation systems for access to low-Earth orbit. The idea here is competition will drive down costs, and NASA will have a backup option if one of the commercial crew providers runs into difficulties.

NASA hasn't said they're going to require a crewed mission to the ISS before they'd grant certification to Starliner and there's talk they're looking at flying Starliner as a cargo ship to the ISS, which could allow them to verify that fixes done to the helium leaks and thruster issues have been successful. 

NASA is making moves while assuming Boeing will stay in the game. Astronauts are still assigned to train for the first operational Starliner mission, although it's not likely to happen until the end of next year or in 2026. Earlier this month, NASA announced SpaceX will launch a four-person crew to the International Space Station no earlier than July of next year, taking a slot that the agency once hoped Boeing would use.


It's hard to assess blame on this addendum

Kelly Ortberg's stances that they're an aircraft company and they should work at "doing less and doing it better," seem like they could be a pretty solid introduction to this story.  

An Intelsat satellite in geosynchronous orbit that Boeing was the prime contractor on exploded on orbit, according to Intelsat declaring it "a total loss" on Monday Oct. 21

The Intelsat-33e communications satellite is no longer operational after an outage Oct. 19; affected customers are being moved to other platforms, the company added in a statement. Meanwhile, U.S. Space Force was tracking around 20 pieces shortly after the incident, the military branch noted on X, formerly Twitter.

The satellite had been in service for seven years while other satellites like it are rated for between 15 to 20 years.  Even then, failure by explosion is rare, which opens the possibility that a piece of space junk or space rock struck it.  In addition the report that the USSF was tracking "around 20 pieces" might have been a bit premature.  Swiss tracking company s2a Systems noted 40 fragments as of Monday (Oct. 21). Another tracking company in the U.S., ExoAnalytic Solutions, saw 57 pieces that same day. 

The geosynchronous orbit is a relatively small area of the sky, 22,236 miles above Earth and there are satellites spaced 2 degrees apart. I imagine tracking the exact positions of all the fragments is a bit more difficult than tracking larger objects but I have to assume (and the article says) that there is concern that the fragments could damage another satellite. 

An artist's impression of the Intelsat 33e communications satellite. (Image credit: Boeing)



Wednesday, October 23, 2024

ULA Prepares Vulcan For 1st Mission

While the Vulcan has not yet been approved for US National Security launches, and the investigation into the solid rocket booster failure isn't complete, United Launch Alliance has continued preparations for the first such launch "before the end of the year."  A bit optimistic but, the first rocket assembly milestone, "Launch Vehicle On Stand," took place Monday at Cape Canaveral Space Force Station in Florida.  

The first stage of ULA's third Vulcan rocket sports a different paint scheme than the first two missions, with solid red replacing a red flame pattern. Image credit: United Launch Alliance

Space Force officials say they expect to issue the approval without requiring another test mission.  The Vulcan has flown two certification missions, with the first in January and second at the start of October. The Cert-1 (first) mission was essentially flawless, while the second had an anomaly on one of the two strap-on Solid Rocket Boosters, with what appeared to be large sections of the engine's bell breaking off.

The rocket's twin BE-4 main engines, made by Blue Origin, corrected for the asymmetric thrust from the two strap-on boosters. Vulcan's Centaur V upper stage also fired its engines longer than planned to make up for the shortfall in performance from the damaged strap-on solid motor. Ultimately, the rocket reached its planned trajectory and delivered a dummy payload into interplanetary space.

Col. James Horne, who oversees launch execution for Space Systems Command, called the test flight a "successful launch" in an interview with Ars. The nozzle failure caused a "significant loss of thrust" from the damaged booster, he said.

The Vulcan rocket's ability to overcome the dramatic nozzle failure, which was easily visible in video of the launch, "really demonstrated the robustness of the total Vulcan system," Horne said.

Horne went on to note that he thought it might have been, "...probably one of the most accurate orbital insertions that I've seen them fly yet." Since the certification depends on them placing the payload in the claimed orbit, "one of the most accurate orbital insertions" is optimum. Horne considers the mission successful. 

As a side note, any control system designer will tell you there is a range of errors that can be adjusted out and systems typically have a point at which they lose control ("lose lock"). I think that it could be argued that this mission might have had a lot of spare ability in the corrections it could apply that won't always be there.  On a bigger payload with a bigger error injected by the SRB, it might lead to mission failure. The fact that Vulcan's systems corrected the SRB issue shouldn't mean they let the whole thing be forgotten about.

Investigation into the SRB problem is paramount.  

“I think, when folks zoom in on the video, they see thrust, hot gas burn-through, potentially, in the bottom of the rocket section," Horne said.

Tory Bruno, ULA's chief executive, posted on X shortly after the October 4 launch that initial findings suggested the rocket casing itself did not suffer a burn-through, which would allow super-hot gas to escape the booster. However, there were visual indications of a plume of hot exhaust appearing just above the bell-shaped nozzle, possibly near where it was bolted onto the booster's main body.
...
Horne said the Space Force is "assessing schedule impacts" to the next couple of Vulcan launches as engineers probe the booster malfunction. Military officials hoped to launch the first two national security missions on the Vulcan rocket by the end of this year. That's still the hope, Horne said, but he expects there will be "some impact" on the schedule for the next two Space Force missions, named USSF-106 and USSF-87.

The Vulcans that will be used for those next two launches will have four of those strap-on SRBs instead of the two the Cert-2 flight had. Does that double the chance of the kind of SRB nozzle failure seen on Cert-2?

Don't forget that ULA has a backlog of these National Security Missions.  Under existing contract, they're to launch a little more than half of the military's national security space missions over the next few years, (SpaceX is booked for the rest of the missions).  In the contract talked about two days ago, SpaceX won all the missions.

Tory Bruno has said they're targeting 25 launches a year but it may take a couple of years to get there. Next year, they're speculating "up to 20 launches," including the Vulcan and using up the last of the Atlas V missions. 



Tuesday, October 22, 2024

Starship Test Flight 5 "Worries" The IAC

The IAC; the International Astronautical Congress, the organization that held their annual meeting in Milan last week, that big professional organization expressed worries after Test Flight 5?  The mission that has gotten tons of pundits talking about what an incredible accomplishment it was - including a big group of pundits that aren't space reporters and don't follow everything going on - has gotten the IAC worried?  That's the headline at SpaceNews: "Latest Starship flight prompts praise and worries at IAC" and it caught my eye. 

SpaceX themselves kept a low key at the IAC. They didn't have a booth at the show, and didn't put on any big presentations. They let the test flight speak for itself. Along with some other big names that also spoke for it.

“Just yesterday, SpaceX has a very successful fifth launch as they develop this very large rocket,” NASA Administrator Bill Nelson said during an Oct. 14 plenary session that features the heads of several space agencies. “This was another one of the steps in the iteration of developing that.”

He added at a press conference the next day that work on the HLS version of Starship was on schedule. “I think you saw as a result of Sunday’s test of SpaceX and its big rocket that they are moving along very well, and that will determine ultimately the timing for the landing of Artemis 3 on the moon,” he said. “As of Sunday’s test, it was right on the mark.”

“They are right on making the benchmarks as they are planning to land in late ’26,” he said of SpaceX later in the briefing.

The worries end up being nothing negative about the test flight itself. The worries are that SpaceX is so far ahead of the rest of the industry that they can't catch up. Things like last night's post about them getting 100% of new contracts might become more common. 

“Congratulations to SpaceX, what an incredible feat of engineering! Mars, here we come,” Rocket Factory Augsburg stated in a social media post Oct 14. “At the same time, the coin has a second side: it shows and confirms that Europe has completely lost touch. Can it still catch up? No chance. At least not the way things are going at the moment.”

Rocket Factory Augsburg?  They're the company that had a static fire test of their rocket end in a RUD in August (first story in a Roundup post). They're a privately owned space company but the European Space Agency isn't that far ahead of them. They used to be one of the world's major space agencies, but seem to have lost their recipes. 

In an Oct. 15 interview, Josef Aschbacher, director general of the European Space Agency, said he was “fascinated” by the launch from an engineering perspective. “I then have to think, what does it mean for Europe, and to see what would be the change in the landscape and the ecosystem, and what do we need to do.”

Europe, he acknowledged, cannot compete head-to-head with Starship but could instead take advantage of broader changes in the space economy enabled by Starship. “How do we position ourselves in this ecosystem that is developing now?” he said. “You can imagine that if Starship brings 100 tons into space frequently, this will change everything out there in space, how things are constructed and how space is being utilized.”

Screen grab from a video seconds before the grab. Image credit: SpaceX 

While the American "old space" industry still hasn't really come to the realization that reusability changes everything, the Chinese are getting close to reusability and the Indian Space Research Organization (ISRO) has announced a development program for a Next Generation Launch Vehicle that will provide increased payload performance over existing rockets and be based on a reusable booster. S. Somanath, chairman of the Indian space agency, estimated NGLV will take six years to develop.

“I think all of you realize that reusability is mandatory for launchers,” he said. 

Meanwhile, we have an American old space company (whose name I will omit out of too much courtesy) is figuratively saying, "we'll spit the engines out of the booster and let them fall into the ocean. Then we'll just clean 'em up and reuse 'em. They're more expensive than the rest of the booster."  This is reusability as an afterthought.



Monday, October 21, 2024

SpaceX Dominates ULA in latest Space Force Bidding

The US Space Force's Space Systems Command announced Friday that in their latest contract competition, it has ordered all nine launches from SpaceX.  This was in the bidding competition for the first batch of dozens of missions the military will buy in the next phase of national security launch contracts.

The nine launches are divided into two fixed-price "task orders" that Space Systems Command opened up for bids earlier this year.  One task order is for seven launches of missile tracking and data relay satellites for the Space Development Agency's constellation. The other is for two launches for the National Reconnaissance Office, the US government's spy satellite organization. SpaceX won both task orders for a combined value of $733.5 million. 

The only two companies invited to bid on the contract were SpaceX and the United Launch Alliance. 

The contracts they're reporting on appear to be the ones mentioned this June in that they use the same terminology of Phase and Lane. 

This is the Space Force's first firm order for rocket launches in the so-called Phase 3 round of launch procurements. The Space Force has divided 79 missions for competition in the Phase 3 procurement into two classifications: Lane 1 and Lane 2.

The task orders announced Friday are the first awarded in Phase 3 Lane 1, which is for less demanding launch profiles into low-Earth orbit.

"We are excited to kick off our innovative NSSL Phase 3 Lane 1 effort with two task orders that support critical NRO and SDA missions," said Lt. Col. Douglas Downs, Space Systems Command's material leader for space launch procurement. "Industry stepped up to the plate and delivered on this competition."

While the USSF has mentioned several more possible competitors for these Lane 1 launches, including Blue Origin's New Glenn, military officials require a rocket to complete at least one successful orbital launch to become qualified for a Lane 1 task order and New Glenn hasn't flown. While Vulcan has carried out two successful orbital test flights - they don't have the full certification for all USSF launches yet. That certification will be a requirement for the coming Lane 2 missions, which are going to be more challenging military missions, typically larger, more expensive payloads destined for higher orbits. 

The Space Force is expected to soon select launch providers for Lane 2 missions. These launches will require the Space Force to certify the rockets, whereas the military is comfortable accepting a little more risk for the Lane 1 missions.

SpaceX's Falcon 9 and Falcon Heavy are currently certified for national security launches. 

File photo of a Falcon 9 launch from Vandenberg Space Force Base, SLC-4E. Image credit: SpaceX



Sunday, October 20, 2024

The other 90% of my weekend

I did a deep dive into an area of ham radio that I've known about for as long as I can remember, but never tried to get into because the price of entry has been just too high (in time, money, and effort). The common name for this is moonbounce, but the more technical guys tend to call it EME - for Earth Moon Earth.  

There were two reasons for trying more this weekend.  First, this weekend was a major EME contest, put on the American Radio Relay League, and these contests tend to bring out a lot of activity.  More activity means more people to listen for. The second reason was some online chatting with a guy who does quite a lot of it. He doesn't know about this blog, and I didn't ask for permission to talk about him so I won't. But he asked me if I was going to try to listen in this weekend and after some chatting about my station by email he gave me some hints on setting things up to try to listen and contact some of the guys who have invested a lot in EME activity.

Let me just put the "Bottom Line Up Front" (BLUF): I didn't hear a single station in the couple of hours I thought my station might be able to turn the trick.  Neither Friday or Saturday around moonrise. 

So let's start at the beginning. For newbies, I did a post about trying to communicate with the two Voyager satellites. The concerns are identical but the numbers are vastly different.

This was all done at 50.2 MHz. The idea is simple: you point an antenna at the moon, 250,000 miles away (not exactly) and listen for signals coming from the moon. If you've got a really good station, you can hear your own signal after you wait for the echo from the moon.  The speed of light (which is radio) is 186,000 miles/second.  Remember, your signal has to go from your station to the moon and back or 500,000 miles. That means you'll hear the echo 2.69 seconds later.  

The next big concern is the same as every communications link everywhere else: the amount the signal attenuates - weakens - over that 500,000 miles. The term for this is path loss, and back in the Voyager article, I used a handy form that gets you within less than half a dB of the more theoretically-backed equation.  

Path loss in dB = 37 dB + 20log(f) + 20log(d)  where,f is the frequency in MHz and d is the distance in miles.

So PL = 37 + 20log(50) and 20log(500,000) or 185 dB. 

Wait.  There's a nasty assumption hidden in there, that the reflection from the moon is perfect. No signal loss, it just changes direction. That implies the signal reflected back has an angular diameter less than the moon - or some would be lost  around the edges.  The diameter of the moon is just over 0.5 degree, which is very tight for an antenna beam. OK, let's just keep a note on that. Maybe there's a useful approximation people have made. Maybe someone said just add (some number) of dBs to your path loss.

Where does this leave us?  Let's say we put 1000 W out of our antenna (it could be less power in the transmitter and more antenna gain, or a simpler antenna and more out of the transmitter).  That's +60 dBm (power compared to 1 milliwatt in 50 ohms) or one million milliwatts.

Signal coming back is  +60dBm -185dB path loss or -125 dBm at our receiver input. 

So what? It's a good time to say, "what does that mean?  Is that a useful signal?  Do I need more power, or more gain, to get more signal at the receiver? 

At this point, we have to dive into the improvements that have made EME more accessible to more hams than when we operated voice or CW (Morse code).  That's a topic for another day.

A graphic from a guy who's among the biggest names in EME, especially 6m EME. Lance Collister, from Montana. From there, he links to his main web page on EME.



Saturday, October 19, 2024

Just a Little Thing to Share - Ham Radio Event

We are in the midst of a Special Event that caught my eye.  For people who think hams are too serious or have no sense of humor, I give you National Sasquatch Awareness Day. 


As you can see this is a week-long special event, and working various combinations and numbers of special stations listed in that first paragraph gets you a BIGFOOT Certificate! (Suitable for framing, I'm sure).  This is a screen grab from station W7B's page on QRZ.com.

While that Special Event Station screen capture follows the "click-it to embig-it" rules of thumb, this version gets Even Bigger when you click it:

The desire to collect certificates for special events or other contacts that are out-of-the ordinary in some way is almost universal in ham radio.  Pretty much every day, and especially on weekends, two of the most popular things to do are go to a nearby park or the top of a nearby hill and operate Parks On The Air (POTA) or Summits On The Air (SOTA).  The person going to ("activating") the park or hilltop gets their own points, and the people contacting ("working") those stations get a different credit.  Each and every one of those pieces of what's generally referred to as wallpaper is valuable only to the people who collect them. 



Friday, October 18, 2024

No - Just No, Space.com

Space.com posts a story I saw references to last night, that Sierra Space has a contract to produce a trash compactor for the International Space Station.  

An International Space Station (ISS) resupply mission in 2026 will send up the Sierra Space trash compactor for testing, company officials stated in a press release on Wednesday (Oct. 16). Like many other space station testbeds, this trash compactor will assess how to deal with the problem of garbage on eventual crewed moon or Mars missions, where disposal will be even more of an issue.

All well and good - but then they added:

and some media outlets say the machine looks like Wall-E.

No. I never saw the movie but I know what Wall-E looked like and I see no resemblance whatsoever.  Here's the two, side by side:

Unsurprisingly, a bunch of artists in a movie company that specializes (or did back then) in animation could produce a much more anthropogenic robot with much a more expressive "face" than a hardware company that's, well, producing what used to be called a trash masher.

Not that there's anything wrong with a trash masher (compactor), or what Sierra Space is doing here. It just doesn't look like the movie star robot.



Thursday, October 17, 2024

Don't Count on Next Year's Artemis II Flight

Eric Berger at Ars Technica has gone through some Fed.gov General Accountability Office reports on preparations for next September's Artemis II launch, the first mission back to the moon since the end of the Apollo programs, and says they have pretty much used every bit of schedule slack they had reserved. His conclusion was, "It’s increasingly unlikely that humans will fly around the Moon next year."  

A new report from the US Government Accountability Office found that NASA's Exploration Ground Systems program—this is, essentially, the office at Kennedy Space Center in Florida responsible for building ground infrastructure to support the Space Launch System rocket and Orion—is in danger of missing its schedule for Artemis II.
...
The new report, published Thursday, finds that the Exploration Ground Systems program had several months of schedule margin in its work toward a September 2025 launch date at the beginning of the year. But now, the program has allocated all of that margin to technical issues experienced during work on the rocket's mobile launcher and pad testing.

NASA has been reasonably cautious in following the step-by-step approach Apollo used in going with the unmanned Artemis I and then the lunar fly-by of this mission next September ('25) followed by the Artemis III lunar landing mission in September '26.  The Apollo program had more hardware and concepts to test, and did so after the Apollo I disaster before landing with Apollo XI. There were many more test missions than in the Artemis program. Still, Artemis I was almost two years ago (November of '22) and NASA still hasn't reached a decision on what seems to be the most critical thing: the Orion capsule's heat shield issues

The report continues:

"Earlier in 2024, the program was reserving that time for technical issues that may arise during testing of the integrated SLS and Orion vehicle or if weather interferes with planned activities, among other things," the report states. "Officials said it is likely that issues will arise because this is the first time testing many of these systems. Given the lack of margin, if further issues arise during testing or integration, there will likely be delays to the September 2025 Artemis II launch date."

Weather?  Like the Hurricane of the Month Club?    

This kind of boggles the mind. Yes, the ground systems program has had to complete some important work since the Artemis I mission in late 2022, including building an emergency egress system for astronauts in the event of a problem during the launch countdown. But by September of next year, the agency will have had the better part of three years to work on those and other accommodations. At this point, there is no longer any margin in the schedule.

Artemis I mission during one of its trips to the pad that didn't result in flying, August 2022.   NASA Photo.

Eric Berger's conclusion:

To prepare for the Artemis II launch next September, Artemis officials had previously said they planned to begin stacking operations of the rocket in September of this year. But so far, this activity remains on hold pending a decision on the heat shield issue. Asked when NASA now plans to start stacking operations, the space agency official said, "We are still tracking toward stacking beginning this fall."

The bottom line is that NASA is facing schedule challenges on multiple fronts for the Artemis II mission. Although a launch delay is unlikely to be announced soon, we can be fairly confident that it is eventually coming.

I saw a story today that Michael Bloomberg, the founder of Bloomberg News and a former US Presidential candidate, called for cancelling the SLS program. The only thing I'm sure cancelling the SLS would do is guarantee that the next boots on the moon will have launched from China, and that may happen regardless of what we do about the outrageously bad SLS program. China says they plan to land a crew on the moon in 2030, but I wouldn't be surprised if they did it sooner.