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#76 2022-12-19 20:13:28

SpaceNut
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Very nice

Seems that all of the payloads for the ride share got to a state that due to delays has been causing many to fail.

Dead Artemis Spacecraft Careens Out of Lunar Orbit

these were the cube sat that were sent

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#77 2022-12-31 18:05:22

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Happy New Year,  all!

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#78 2022-12-31 18:22:17

SpaceNut
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Yes happy new years to all

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#79 2023-01-04 16:03:23

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Last few days have been unusual.  There's been an 8-point whitetail buck deer hanging around here.  He's been sleeping in my front porch flowerbed,  and hangs around the house and shop a lot.  This kind of behavior is so odd in a whitetail deer that I believe he is either injured or sick,  although I see no signs of injury or disease externally. 

Have talked to the sheriff,  there is little that can be done for a wild animal like that.  Between the hooves and the antlers,  he is big enough to present a threat to my cat.  The cat smells him,  but has bad vision,  and so has not seen him.  I have to be sure to go outside with the cat to protect him.

In other news,  I have put up a posting on "exrocketman" about towed aircraft decoys.  I did that for a living back in the mid-1980's.  The title is "Towed Hardbody Decoys",  dated 1 January 2023.  Watch for another that I will post soon,  about the difference between "naked-eye astronomy" and "naked eye-astronomy".  It's all in the punctuation!!

Hope everybody had a good Christmas (or whatever applies) and a Happy New Year!!  We did,  here. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#80 2023-01-04 16:16:46

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

For GW Johnson re #79

Thanks for your family update with good news and enjoyable holidays.

***
Your report of the deer losing fear of humans rang a bell... I'd like to encourage you to seek more knowledgeable help than the Sheriff.

I've  been seeing scattered reports of a disease in white-tailed deer, but they have been generally North and East of you.

I expect the State of Texas wildlife agency would be quite interested if you were to call them.

Here are some snippets:

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Hemorrhagic disease is an infectious disease of white-tailed deer, with outbreaks occurring sporadically in Missouri. Hemorrhagic disease (HD) includes both epizootic hemorrhagic disease (EHD) and bluetongue (BTV) viruses. These diseases are very closely related and produce similar symptoms in deer.

Potential Diseases and Parasites of White-tailed Deer in ...https://extension.missouri.edu › publications
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Common signs that may indicate a deer is sick include poor body condition (e.g., rib, hip and/or back bones showing) and lack of alertness (e.g., do not react to sounds around them). Deer with CWD may also have lost their fear of humans.Nov 9, 2022

Hunters: Look for signs of illness in deer - Chronic Wasting ...https://www.canr.msu.edu › news › hunters-look-for-si...
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Hemorrhagic Disease & the White-tailed Deer - MDWFPhttps://www.mdwfp.com › diseases-and-abnormalities
Hemorrhagic disease is the most important endemic infectious disease in white-tailed deer in the Southeast. Outbreaks occur every year and are highly variable ...

Recognizing Whitetail Deer Diseases - TRACKER Off Roadhttps://www.trackeroffroad.com › articles › whitetail-de...
Chronic Wasting Disease (CWD) is the most widely recognized disease among hunters. CWD is a nationwide problem, but it's not the only disease impacting deer ...
Chronic Wasting Disease... · Epizootic Hemorrhagic... · Brucellosis

What is chronic wasting disease? | U.S. Geological Surveyhttps://www.usgs.gov › faqs › what-chronic-wasting-dis...
Chronic wasting disease (CWD) is a fatal, neurological illness occurring in North American cervids (members of the deer family), including white-tailed deer ...

Chronic Wasting Disease (CWD) | Prion Diseases - CDChttps://www.cdc.gov › prions › cwd
Chronic wasting disease (CWD) is a prion disease that affects deer, elk, reindeer, sika deer and moose. It has been found in some areas of North America, ...

White-Tailed Deer | FWChttps://myfwc.com › research › wildlife › health › white...
White-Tailed Deer · Chronic Wasting Disease (CWD) CWD damages the brains of infected animals, causing extreme weight loss, abnormal behaviors, and death. · CWD ...

Deer Diseases - NC Wildlifehttps://www.ncwildlife.org › ... › Deer Diseases
Hemorrhagic Disease is the most important infectious disease of white-tailed deer, and outbreaks occur almost every year in the Southeast. It is caused by ...

Epizootic Hemorrhagic Disease - White-tailed Deer Illinoishttps://deer.wildlifeillinois.org › deer-ecology › diseases
The two most prevalent wildlife diseases impacting Illinois deer are chronic wasting disease (CWD) and epizootic hemorrhagic disease (EHD).

10 Common Whitetail Deer Diseases That Are Plaguing Herds ...https://www.wideopenspaces.com › whitetail-deer-disea...
Feb 23, 2021 — Have you shot a whitetail only to find it had one of these common diseases or parasites? · Hemorrhagic Disease · Blue Tongue (BTV) · Deer Warts.
Hemorrhagic Disease · Deer Warts · Chronic Wasting Disease...

Hunters: Look for signs of illness in deer - Chronic Wasting ...https://www.canr.msu.edu › news › hunters-look-for-si...
Nov 9, 2022 — Chronic wasting disease (CWD) is a disorder of the neurological system that affects cervids, or animals that are members of the deer family, ...

(th)

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#81 2023-01-04 20:18:48

SpaceNut
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

I have had deer and even bear cubs within 50 feet of the home and scared a few when going out startling them back into the trees.
But you are right it is odd and yes, they can catch viruses such as covid so take care.

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#82 2023-01-05 10:02:11

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

No sign of him this morning.  He was rather thin-looking,  and had little fear of me,  so CWD (chronic wasting disease) is a good candidate.  I have been careful not to get too close,  nor to let my cat get too close.  He had spent the previous 3 nights in my front flowerbed.  I will re-contact the game warden and try to communicate that suspicion to him. 

Bear cubs,  Spacenut?  The mother should be close by,  so be VERY careful!  Mother bears protecting cubs are VERY dangerous. 

Astronomy/punctuation posting mentioned above is now up on "exrocketman".  Titled "It's All In the Punctuation!",  dated 1-5-2023.  Labeled specifically as "fun stuff".

The towed aircraft decoy article did not draw the readership interest that I expected.  Surprising to me. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#83 2023-01-06 16:34:19

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Talked to game warden and state biologist extensively,  and shot photos and video for them,  of the deer.  They are of the opinion he was somehow injured and bleeding internally,  although they are worried about chronic wasting disease,  too. 

I was to call them and put him down this morning (12 gauge buckshot),  except that he disappeared yesterday afternoon,  and did not return last night,  or today (Friday).  I told them that I think being pursued for photography disturbed him enough that he moved on.  I have a good hunch he went in search of water,  and I told them where I thought he might well be,  about 2 miles away from me here. 

Unless he returns,  it's out of my hands now.  Despite the reluctance to kill,  It would be a mercy to him,  if he's in that much pain or misery.  Whatever is wrong,  it will be fatal,  and not very many days away. I could see a distinct degradation yesterday,  while doing the photography.

--  GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#84 2023-01-06 19:09:29

SpaceNut
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

It is one of the reasons for selective hunting seasons for all animals across the US.
Good to know and as for the bear cubs the mother was alone the roadside as it had been hit and was dead.

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#85 2023-01-08 15:26:53

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Observation #1:  A couple of years ago,  Elon Musk was actively involved with his Boca Chica "Starbase",  and he pissed off the FAA and some other feds (and state officials) with his tweets,  and with his aggressive approach to what was actually covered in the permits that he did have.  Pissing off the regulators is quite stupid,  as we all know.  Which is really why "Starships" alone haven't flown in 2 years,  and neither has the "Starship/Superheavy".  But,  Musk about 2 years ago went mostly off-site and paid much more attention to Tesla,  and SpaceX without him has since mostly repaired its relations with the feds,  to the point that they might actually get to fly again this year.  Repairing that relationship does take multiple years,  as we all know.

Observation #2:  Musk went to Tesla and starting playing fast and loose with the rules for publicly traded company stocks,  tweeting about taking Tesla private with money from the Saudis,  when that deal had actually not been finalized at all.  Tesla is now the subject of a federal court lawsuit over that behavior,  and its stock has been tanking.  Meanwhile,  Musk has moved on to Twitter.  My prediction is that it will take a year or three for Tesla to recover from the damage Musk and his big mouth did them with the feds.  They make a good car,  as evidenced by the family in California surviving a 250+ foot plunge off a cliff.  Although,  new AI shortcomings seem to show up every year for the self-driving mode.  (I think AI is still an oxymoron,  but then,  what do I really know about modern computers?)

Observation #3:  Musk seriously mishandled trying to buy Twitter,  although he finally did,  as we have all seen.  He has since pretty much run it into the ground,  mismanaging things to a political agenda,  as we have all seen.  This has cost him a LOT of money!  In point of fact,  he doesn't think he can get a fair trial over the Tesla stock thing in California,  because of the damage he did to so many people in California when he fired half of Twitter's staff.  All this has been in the news for all of us to see.  Rather gross mismanagement. 

My conclusions: 

At 0 for 3,  Musk is quite clearly NOT the genius at running businesses that he was cracked up to be.  And he certainly has some very serious character flaws (not at all surprising in the filthy rich,  actually)!  I would NOT EVER want to work for him,  he treats employees terribly,  as we have all just seen at Twitter. 

He still has not learned that his best role is to set up the goal or dream for a new company,  supply the wherewithal to get it going,  then find somebody who actually knows what they are doing to run the company for him,  and then get the hell out of the way.  Things go better by far when he is not there micromanaging things and shooting off his big mouth.  We have all seen it,  3 times now. 

SpaceX is actually run far better by Shotwell,  when Musk is not there.  I'm not sure Tesla has a Shotwell yet.  And there is certainly no Shotwell at Twitter to run things right.  QED.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#86 2023-01-10 11:27:39

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

SearchTerm:aerospike rocket design

In response to posts and discussion by Void, GW Johnson provided a deep dive into the pro's and con's of aerospike concepts for rocket (or jet) engines.

http://newmars.com/forums/viewtopic.php … 09#p204909
http://newmars.com/forums/viewtopic.php … 28#p204928

(th)

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#87 2023-01-11 10:47:24

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

I'm working on an "exrocketman" posting that specifically covers the nozzle issues I have been addressing,  to include specifically an aerospike.  The earlier "how nozzles work" article looked at a twin spike free-expansion design,  but not the annular or linear aerospike.

It's not ready yet.  But,  I'll let everybody know when it is.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#88 2023-01-11 19:53:19

SpaceNut
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Even the J2 engine was experimented with this and was cast aside when it came down to being used.

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#89 2023-01-14 14:17:55

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

I have the bugs worked out of my spreadsheet now,  that does (and compares) bell nozzles with aerospikes.  I have the article drafted up,  and mostly edited,  plus a user's manual in work for the spreadsheet.  These need to stew a few days,  which makes editing for clarity far more effective.  Then I can post the article on "exrocketman",  and make the spreadsheet file and user's manual available,  if anybody wants it.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#90 2023-01-14 15:39:47

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

SearchTerm:shield heat shield alternatives limits features needs for development

GW Johnson wrote:

There's been a weirdly-overlapping boundary between low orbit capabilities,  and capabilities to go elsewhere,  for many decades now.  All of the nonreusable launch vehicles,  and even some semi-reusable things today,  can send significant payloads to low orbit.  Unrefueled,  and flown with much smaller payloads,  they could also go elsewhere.  It costs a whole lot more to go to highly-elliptical high orbit about the Earth than it does low eastward circular. 

But it costs very little more than that to go to the moon one-way,  or even further one-way,  like Venus or Mars.  The problem always was very much smaller payload to the higher energy missions.  It still is. 

To break that impasse,  one either had to use much more gigantic launch vehicles,  or refuel them in low eastward circular orbit,  or both!  And when you talk about return trips,  the payloads get really,  really big.  Or else you have to make refueling propellant there.  Or both.

That's just the nature of the problem.  Complicated.

Multiple outfits are now addressing the reusable first stage problem.  SpaceX has been the first to attempt addressing the reusable upper stage problem to low Earth orbit with its Starship,  but NOT with its Falcons.  That reusable upper stage problem is a very much tougher problem to solve,  than the lower stage problem.  That's why they never developed a reusable Falcon upper stage. 

Once again,  the biggest first step is getting back from low circular eastward Earth orbit,  versus getting back from any of those other higher-energy missions.  As it turns out,  the physics of entry at only 8 km/s allows either ablative heat protection,  or re-radiating refractories that do not ablate.  It may yet prove possible to do metals cooled by transpiration cooling,  we don't know yet. 

But for the higher-energy missions,  entry is nearer 11 km/s or higher,  and only ablatives are known to work as solutions.  None of those will be usable more than once or maybe twice,  certainly only a single handful of times,  even if carbon-carbon composite.  That does not offer much prospect of reusability in the sense of only occasional refurbishment. 

I've seen some of the new super-ceramics with the extremely-high melt-points touted as the solution to that problem,  but that's quite mistaken!  Those are all high-density,  high-thermal-conductivity items,  and will soak out during exposures to a near-isothermal condition at a really high temperature.  So there will be no way to hang onto it!  And if you cannot hang onto it,  what good does it do you as a heat shield?  I've seen no answers to that question.  None.

The technology does not yet exist to make these super-ceramics in a low-density form with internal void spaces.  But if it did exist,  these would be low thermal conductivity,  and they would behave very far from isothermal during heating exposures.  Those you could hang onto as a heat shield.  But the internal voids and low density also inherently make the material strength low!  Such will always be fragile,  just like shuttle tile was.  But that low density thing was exactly what made shuttle tile functional as a heat shield that one could hang onto! 

The problem with alumino-silicate shuttle tile wasn't so much the 3250 F melt-point,  it was the 2250 F solid phase change point that caused shrinkage by about 3% and extensive shrinkage-cracking!  That is where the only-2000 F temperature limitation for shuttle tile came from,  and which in turn restricted it to low eastward circular Earth orbit missions.  And it had to be black on the windward side,  where heating was higher,  in order to re-radiate efficiently.  And it was still inadequate for stagnation heating on the nosetip and leading edges (those were carbon-carbon,  replaced every few flights).

Find a way to make low-density forms of the super-ceramics with internal void structure,  but with a far-higher temperature restriction,  and you have found a way to make non-ablating refractories that might do higher-energy entries.  The next problem to solve is at what speed the plasma goes opaque to infrared radiation,  cutting off the ability to cool by re-radiation.  At that point,  you will have to actively-cool the material in some way,  with a sacrificial liquid.  I'm not sure,  but I think that is about 10 km/s,  where plasma radiation heating starts to dominate over convective heating.

There's a lot of complicated physics involved with such an endeavor.  I hope I have provided a guide to what might be,  and what might not be,  possible.

GW

Originally posted in Stoke Space topic.

()th)

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#91 2023-01-14 15:46:13

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

For GW Johnson ....

Your proposal to offer Space Tug services for large shipments going to and returning from Mars has the potential to provide gentle admission to Earth's atmosphere.

Can you (would you) be willing to consider the potential of using the orbit plan you described for Space Tug, to reduce the velocity of a returning payload to a level comparable to the Eastward Circular return you described in your post about heat shields?

The Space Tug flight plan needs to include refueling in any case, so dropping the velocity of the payload to the Refueling Station orbit would facilitate an easier descent for the customer vehicle.

(th)

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#92 2023-01-14 15:51:36

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

This is a follow up for GW Johnson ....

India is the only Nation currently planning a flight to Mars in the next Launch Window.

I would guess their leadership is unaware of the work you have done.  They probably don't follow the Mars Society closely.

Would you be willing to prepare an updated set of proposals for them?

There is time for them to add a water search system, and they are not limited to the number of ships they can launch, other than by budget.

Competition with the US, Russia, Europe, Japan and most of all, China, might provide incentive for them to consider your proposals.

In particular, the throw-weight increase you offer with Space Tug might well be worth their time.

If they can put landing fuel and oxidizer in orbit around Mars they would be well ahead of the competition for a landing of significant mass.

(th)

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#93 2023-01-16 22:23:21

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

For GW Johnson .... just FYI .... the folks at Space-Plane.org inquired about your Space Tug papers.  i provided links to the papers as we saved them in Dropbox for the Space Conference.

If you would like to see additional views of their lifting body design please let me know.

The procedure is to take "snapshots" of the view and post the images in imgur.com.  I don't mind doing that.  The folks at Space-Plane.org are apparently thinking about how to make a Youtube video just for you.

I am pitching the idea that they would find some of your suggestions for heat shield / return from orbit interesting.

Their planned vehicle is 60 meters long ....

(th)

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#94 2023-01-20 16:34:53

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

GW Johnson completed a revision of the Space Tugs work done earlier.

This version is confidential and will not be published for the time being.

The next Mars Launch window is 2024.

A successful implementation of Dr. Johnson's work would dramatically increase the throw weight of a Mars bound package.

(th)

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#95 2023-01-22 11:23:28

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Bad news.  I tripped and fell last night,  and broke my left arm,  right up at the shoulder.  ER trip.  Supposed to see orthopedic surgeon Monday. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#96 2023-01-22 11:28:23

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

For GW Johnson re #95

Thanks for letting us know (with one finger typing and (I'm sure) a ** lot ** of pain to contend with!

Best wishes for the very best care that Texas has to offer! 

What a bummer!

***
For all.... I have completed word-by-word review of GW Johnson's latest proposal (for a Space Tug concept downsized from Large Ship).

There were two minor nits, which I am hoping GW can fix despite this serious setback!

(th)

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#97 2023-01-22 12:19:05

tahanson43206
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

For Space-Plane.org, and any NewMars members who may be interested.

In light of Dr. Johnson's fall, the plans for a Zoom meeting are on hold.

In the mean time, here is a small pdf Dr Johnson prepared for Space-Plane.org.

https://www.dropbox.com/s/bt6v8dro6tjul … f.pdf?dl=0

While the document points to a Wordpress blog, much of Dr. Johnson's work is available for study by looking earlier in this topic.

The files are stored in Dropbox, and available by clicking a link.

(th)

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#98 2023-01-22 15:35:13

SpaceNut
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Ouch, get better soon.

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#99 2023-01-22 18:09:42

Steve Stewart
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From: Kansas (USA)
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

GW Johnson,
Sorry to hear about your fall. Hope you get better soon.

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#100 2023-01-25 15:38:53

GW Johnson
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Re: GW Johnson Postings and @Exrocketman1 YouTube videos

Got in 2 days early to see orthopedics guy today,  on a cancellation.  Surgery not needed,  alignment is good enough as it is.  They did give me a factory-made sling to replace the home-made sling I have been using.  Weeks to knit,  months until fully functional.  Will likely need therapy to regain range of motion,  and even then,  not all of it. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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