GW Johnson Postings and @Exrocketman1 YouTube videos

GW Johnson · 2023-12-16 13:05:12

I've made 3 presentation videos. There are two about 5 minutes long: the Mars rocket hopper, and the Mars truck train. There is one other about 8 minutes long, for the Mars Orbit taxi that is also a rocket hopper. I know I uploaded the two shorter ones. I don’t think I ever uploaded the longer orbit taxi hopper.

I have no videos yet regarding the lunar propellant for LEO studies, although I have a couple of slide sets and scripts. One looks at various basing options about or on the moon for coordinated pairs of delivery vehicles, and for the single direct vehicle. The other looks at the rocket equation "how to" for that single direct transport vehicle from the lunar surface to LEO, which looks to be the least energy-intensive option, but also the most demanding in terms of propellant combination.

These last two are nowhere near 5 minutes long, they are longer, as measured by simply timing how long it takes to read the scripts out loud.

As for check valves, yes, I am very familiar with them. Every fire sprinkler system I ever engineered had them. They usually go in pipes or tubing. But, I don’t understand how having one in the feed line to the turbopumps might stop the sloshing of propellants in the tank.

That tank absolutely cannot be 100% full of liquid, there has to be a “vapor head space” that’s in the vicinity of 10% of the total tank volume. The liquid is incompressible. Without that compressible head space vapor, the slightest liquid temperature increase will rapidly over-pressurize (and burst) the tank, due to thermal expansion of the warming liquid.

Even the pressure-expulsion bladdered tanks must have a vapor head space for safety’s sake. It’s just not inside the bladder. When filling such tanks, you never quite fully fill the bladder, thus not quite pushing it out everywhere into full contact with the tank wall. The noncontact space between bladder exterior and inner tank wall surface is your “vapor head space” to allow for thermal expansions.

GW

Last edited by GW Johnson (2023-12-16 13:08:38)

tahanson43206 · 2023-12-16 13:49:59

For Dr. Johnson!

Thanks for the good news of your work on the videos!

For all ... if there is any interest in seeing these videos before they are released to the public, please let us know.

***
For GW! Thanks for making the connection between a check valve (which you have actually used on a small scale) and what is needed for the Booster tanks ... What is needed for the booster tanks is a redesigned baffle ... the baffle that is needed will allow fluid to flow one way but not the other. This design will allow you to keep 10% expansion room at the top of the tanks. The problem to be solved is keeping the liquid at the bottom of the tank when negative G force occurs.

I expect that when you "see" the new baffles in your mind's eye, you'll be able to "see" how to design them.

No one on Earth has ever done this before, and I am confident most human engineers will not be able to imagine this design, let alone actually build or implement one.

Fortunately, you've allowed yourself to interact with the Mars Society, where creative thinking occurs occasionally.

(th)

GW Johnson · 2023-12-17 10:20:08

Not so sure about "small scale" with those check valves. Most underground fire mains are 6 or 8 inch pipe size, some 10 inch. Every tap off a city water main has a check valve to prevent backflow into the city water system, should something go wrong with the local system. Similarly, there is always a check valve in the feed riser for the sprinkler and hose systems inside the building. I've never seen anything less than a 6 inch riser. The ball-and seat types are for itty bitty plumbing (meaning under 1 inch). The big ones are usually some kind of flapper valve. They're built really stout, because of the water hammer forces, which are brief but extreme.

GW

tahanson43206 · 2023-12-18 18:58:09

This post is reserved for a link to a pdf document about balloons on Mars.

GW has already posted about balloons on Mars, so there are no surprises.

Instead, he has added images of charts to support his conclusions.

I'll add the link here as soon as I get it set up on Dropbox.

https://www.dropbox.com/scl/fi/wx5m8yr1 … q66x6&dl=0

(th)

tahanson43206 · 2023-12-19 07:43:00

This is a follow up to Post #204

Calliban suggested a practical application for a 150 meter diameter balloon on Mars, and NASA has already flown a balloon that is almost exactly that size:

https://newmars.com/forums/viewtopic.ph … 26#p217326

The article at the link below shows ferris wheels up to and over 150 meters diameter:

https://www.yahoo.com/lifestyle/15-bigg … each%20car.

(th)

GW Johnson · 2023-12-19 10:16:13

Link to balloon document works fine. -- GW

Mars_B4_Moon · 2023-12-23 08:55:20

If you are flying in a low land region basin like from the giant region of Hellas, those numbers are wrong and not much use
Hellas is as high as 0.012 atm or 12 mbar maybe higher, not 0.006 atm pressure not 6 mbar

GW Johnson · 2023-12-24 10:32:13

Sorry. Twice near-nothing is still near-nothing. Use my equations and run it for yourself.

GW

Last edited by GW Johnson (2023-12-24 10:33:04)

Mars_B4_Moon · 2023-12-24 10:48:52

GW I appreciate the time you put into writing up that stuff, pictures, graphs but the base number is still in error for Hellas. Some people can be great and embrace criticism and revise figures but we are humans and can can get emotional after putting in time and work on something. I never insulted your personally or asked you to calcuate a Balloon at Hellas so there is little reason to have an emotional response.

GW Johnson wrote:

Sorry. Twice near-nothing is still near-nothing.
GW
GW

GW it can be difficult to step outside ourself and take critical comment without a reaction

That's fine, if you want to ignore what I pointed out and have 'ego' about it all and not admit an error that's on you GW
its not a margin of error of 0.5% nor is it you are ten percent off in regard to the Hellas Basin

If we do stuff with bias it can end up being a bogus showing of data. Your base figure for a place like Hellas is bogus by 'Twice' its number as you yourself now admit

It is not a personal attack on you do not take it as such, when talking about Airplane and Balloons I often refereed to Hellas Planitia which seems like the most logical place to start, to its completely up to you Texas GW if that's what you wish to push as 'correct' data

Robert Zubrin Article mentions Balloons in 2023

Rethink the Mars Program
https://spacenews.com/rethink-the-mars-program/
It’s time to consider alternatives to sample return

For the same $10 billion now projected to be spent on the MSR mission over the next 15 years, we could send 20 missions averaging $500 million each in cost. These could include landers, rovers, orbiters, drillers, highly capable helicopters, and possibly balloons or other more novel exploration vehicles as well.

Mars_B4_Moon · 2023-12-24 10:54:07

I see you edited your post GW, thanks I might run your equations when I have the time.

However for now I am almost satisfied with the 'opinions' of John Vistica Aerospace Consultant, Robert Zubrin and Mark Adler an American software engineer that worked on Mars Rovers who already stated that 'Balloons' can 'possibly' work on Mars.

GW Johnson · 2023-12-29 09:49:45

Mars_B4_Moon:

I didn't say they could not work. I said they cannot work very well. Enormous balloons to carry tiny payloads is just not a very favorable outcome.

GW

tahanson43206 · 2023-12-30 08:55:44

For GW Johnson ....

Please take a look at the Argentina Chapter YouTube channel, as posted by Mars_B4_Moon...

https://newmars.com/forums/viewtopic.ph … 91#p217891

That is a good example of what your collection of course materials might look like.

(th)

tahanson43206 · 2023-12-31 11:42:41

Re your question about Louis ...

Registered: 2008-03-24 (0.0.0.0)
Last post: 2022-04-09 17:23:13
Last visit: 2022-04-09 17:23:14
Posts: 7,208 - Show all topics - Show all posts - Show all subscriptions

(th)

SpaceNut · 2023-12-31 11:47:37

No one thought a helicopter on mars would be able to fly but it has and does quite well with scouting the surface.
True it may take a while to be able to do cargo of any size but that can happen on mars once we are there.
It may be a mixed technology of thrusters and prop to make it do so.

tahanson43206 · 2024-01-04 12:04:07

Dr. Johnson has prepared a file/pdf with analysis of SpaceX rocket design/testing

https://www.dropbox.com/scl/fi/j18gxm3r … 9wt0x&dl=0

I finally got to watch the video recording of SpaceX's own video broadcast for Starship/Superheavy flight test 2. I found it and their public assessment of the results on their website. The attached pdf file is what I think I learned from this information, which is worthy of putting in the drop box thing with a link on the forums.
I'm beginning to think Bob Clark may be at least partly right about there still being a serious problem with the Raptor-2. I saw the same laterally directed plumes of gas from Starship as I saw from Superheavy, that preceded its explosion. Those absolutely should not be there.

(th)

GW Johnson · 2024-01-07 21:16:42

The MP4 videos of the slide presentations for (1) the Mars rocket hopper, (2) the Mars rocket hopper/orbit taxi, and (3) the surface truck train are all on Youtube now. The site is my Exrocketman1 channel on Youtube. Those 3 and 1 other from 2 years ago are up there. The old one is something my son posted for me: my 1952-vintage electric train set. The 3 Mars presentation things went up there tonight (1-7-24).

GW

tahanson43206 · 2024-01-07 22:30:20

For GW Johnson re #216

Congratulations on your success in restoring access to Exrocketman1 channel, and adding three more videos!

I would like to take this opportunity to thank kbd512 for his expertise and patience, as we worked our way through numerous issues.

The re-opening of the Exrocketman1 channel is a break through that has been pending for a number of weeks!

I am ** really ** happy to see it coming back to life!

(th)

tahanson43206 · 2024-01-08 08:43:22

For all ... here is a text capture of the YouTube.com/@Exrocketman1 page as of 2024/01/08 at 9:40 New Hampshire time:

https://YouTube.com/@Exrocketman1

ExRocketMan1
@ExRocketMan1
‧
4 subscribers
‧
4 videos
More about this channel
4:05 minutes
Mars truck train short
6:00 minutes
hopper taxi short
4:02 minutes
NSS Hopper etc
3:20 minutes
Antique Train Set Still Runs!
1.3K views
12 years ago
Subscriptions

NewMars members can subscribe to this channel.

I am hoping Dr Johnson will continue adding content in support of the course on Basic Orbital mechanics and other subjects.

Update: GW Johnson provided this list of the videos:

What is on Youtube at Exrocketman1:
Date link what it is, how long
1-8-24 https://youtu.be/NjZwouch5L0 Truck Train for Mars slide presentation 4:05
1-7-24 https://youtu.be/EXCip2dR2q4 Mars rocket hopper/orbit taxi slides 6:00
1-7-24 https://youtu.be/uCxjF2xLKB0 Mars rocket hopper slide presentation 4:02
12-30-11 https://youtu.be/wd5upqaernQ Lionel train set from 1952 video 3:20

(th)

tahanson43206 · 2024-01-09 07:32:51

As of Tuesday Morning, we are up to five subscribers...

ExRocketMan1
@ExRocketMan1
‧
5 subscribers
‧
4 videos
More about this channel

NewMars members can help by subscribing to this channel. I'll be attempting to find ways to publicize the channel, with a budget of zero to work with.

https://youtube.com/@Exrocketman1

(th)

tahanson43206 · 2024-01-09 09:01:26

I asked ChatGPT4 for assistance designing a press release to support publicity for Exrocketman1 ...

We Need Your Input for a Press Release!
Hello everyone!
We're excited to announce that a member of our forum has launched a new YouTube channel, and we need your help to craft an engaging press release. To make this as impactful as possible, we need some specific information about the channel.
Channel Name and Theme: What is the name of the YouTube channel, and what is its primary focus or theme?
Channel name: Exrocketman1
Theme: ? suggestions ?
Unique Selling Points: What makes this channel unique or different from others in the same genre?
Suggestions?
Background Information: Is there any interesting background information about the forum member or the channel?
GW Johnson has quite a bit to fill in this section
Launch Date and Content: When was or will the channel be launched? Are there any specific videos or series that should be highlighted?
The channel itself was launched 12 years ago ... it is being re-activated in January of 2024
An overview video might be appropriate here
Future Plans: Are there any upcoming projects or plans for the channel that can be mentioned?
The entire Basic Orbital Mechanics course might be offered here
Additional courses on rocket design and related subjects might be offered
Contact Information: Should the press release include contact information for further inquiries?
GW provides contact information in all his presentations
Any Additional Details: Any other specific details or points that you want to be included in the press release?
Suggestions?
Your input is invaluable, and we're looking forward to your responses to create a fantastic press release. Thanks in advance!
Best,
[Your Name or Forum Handle]
eg, tahanson43206 but any member may send out the press release when it is ready

(th)

SpaceNut · 2024-01-09 18:10:34

I d i d e n j o y v i e w i n g t h e 4 s i t e v i d e o s.

Y e s, I w o u l d l i k e t o s e e t h i s g e t o u t.

Encountering the Apache failure for this small post. Something in the second line with no spaces is causing it.

kbd512 · 2024-01-09 18:23:41

Let's see if this works:

Mars truck train short - Dr GW Johnson - ExRocketman1

NSS Hopper etc - Dr GW Johnson - ExRocketman1

hopper taxi short - Dr GW Johnson - ExRocketman1

kbd512 · 2024-01-09 18:30:08

I'm subscribed to GW's YouTube channel, so I will get notifications when he posts new videos.

Calliban · 2024-01-10 04:40:40

I like the solar road train presentation. It is an elegantly simple idea and is definitely something that will be used in real life. We have an existing thread on this topic in the planetary transport section that should be kept going. This concept is simple enough that it should be possible to build it on Mars as soon as ISRU is advanced enough to create steel components. Each car needs its own DC motor and solar panel. These parts could be imported. The cars can use fixed gearing, as speeds are going to be about human walking speed and will be a direct function of solar intensity. Each car needs independant steering, allowing the train to follow the contours of the road. This could be done by embedding a wire in the road, which each car will track, allowing a computer to adjust the wheels on each car. So the whole train will be capable of snaking round bendy roads.

If the train moves at an average speed of 1m/s, it would take 124 days (4 months) to get from one side of the planet to the other in a straight line. The vehicle has no fuel cosrs, so operating cost is essentially ware and tear.

Last edited by Calliban (2024-01-10 04:53:11)

GW Johnson · 2024-01-10 13:24:29

Well, the idea must be to minimize the infrastructure to be emplaced. That costs plenty here. For the foreseeable future, emplacing infrastructure will be astronomically expensive. If you will forgive my choice of words.

GW

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#201 2023-12-16 13:05:12

Re: GW Johnson Postings and @Exrocketman1 YouTube videos

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