Zoom Collaboration

kbd512 · 2022-05-30 07:00:55

tahanson43206,

The danger of "the bends" occurs DURING the EVA (when it's very difficult for anyone else to help you if you're totally disabled)!

We don't need a research station in Peru. We can simulate any artificial atmosphere environment we choose in a NASA or US Navy hyperbaric chamber. NASA did that prior to their Skylab missions, because until their biomedical research was conducted nobody actually knew what the results would be. Now we know. We already know that humans can adapt to lower levels of O2 over significant periods of time. We also know that humans can survive much greater ppO2 at greatly reduced total atmospheric pressure (74% ppO2 at 5psi, the Skylab station's atmosphere). We also know that such atmospheric compositions are NOT ideal from a human physiology standpoint, so we're accepting an engineering and biomedical trade-off in return for something else that we want (zero pre-breathe EVA). If you suffer a serious bout of "the bends" during an EVA, then there's a better than average probability that you will die before we can get you into a hyperbaric chamber.

I would like to plainly state that I AGREE with RobertDyck about what the atmospheric composition should be, if we need a bunch of people to perform a bunch of EVAs to construct the Mars base. However... Long term, as in "the rest of your natural life", the human body is best adapted for 14.7psi, period. Millions of years of evolution have "made that so", and it should come as no surprise to anyone that "it is so".

GW Johnson · 2022-05-30 11:40:01

There is a switchover in the body when breathing Earthly air below and above 2500 m = 8200 ft. It switches from holding blood CO2 concentration constant at variable O2 concentration below that point, to maximizing blood O2 concentration with a rapidly-reducing blood CO2 concentration, as you go higher and higher. That 2500 m = 8200 ft altitude is the critical point for developing chronic mountain sickness in a significant portion of the population if you live at altitude.

Presumably the "collapsed lung" risks would go along with all the other risks of chronic mountain sickness. It's all ultimately driven by biochemistry, which is not my specialty, so don't ask. I've told you all I know.

I posted an article on "exrocketman" that uses data published in AAAS's "Science" journal about this chronic mountain sickness/long-term hypoxia problem. It was more of a news article than a research report, but it cited data derived from studying populations living at high altitudes in the Andes and elsewhere. I used the data associated with that critical elevation, as a long-term hypoxia criterion to recommend some habitat and suit atmospheres, such that EVA's with no pre-breathe were possible, while also avoiding risk of long-term hypoxia/chronic mountain sickness in the habitat. I also looked at fire danger.

Childbirth problems do seem to correlate as part of the multiple health risks associated with chronic mountain sickness. The “Science” article mentioned that, in the context of the Spanish colonial experiences 4 and 5 centuries ago, and continuing ever since. That's really why I chose to use the "Science" elevation data for developing my long term hypoxia criterion. It's not a sharp thing, the risk of chronic mountain sickness seems to be zero below 2500 m, and increases rapidly with altitude above it, to something like at least 25% at 5100 m. That was a mining town in Peru.

According to the standard atmosphere table, the pressure at 2500 m = 8200 ft is 0.7373 that of sea level. In other words, you can safely breathe 20.94% O2 diluted with N2 (or N2 plus a dash of Ar) down to a total habit pressure of 10.835 psia. Below that pressure, you must increase the oxygen percentage to avoid the risks of long-term hypoxia/chronic mountain sickness (and presumably elevated childbirth risks).

In a two-gas mix of O2 and N2 at 10.835 psia and 20.94% O2, the N2 partial pressure is 8.5662 psia. The no pre-breathe ratio of 1.2 then says the pure O2 suit pressure must be at least 7.138 psia to avoid the bends risk. Which neatly explains the trend toward higher suit pressures proposed by the traditional vendors, both here and in Russia.

But this ignores the long history we have of using 40% O2 in hospitals at elevations as low as sea level. That is an O2 partial pressure of 0.40 atm at sea level, lower at elevation. The risk is oxygen toxicity, for which the rule of thumb from diving has been 1 atm pure O2 kills half the people breathing it, and 2 atm pure O2 kills all the people breathing it. The hospital oxygen mask at 0.4 atm seems to provide much benefit without killing anybody. So, even without considering vented oxygen masks at high altitudes for air crews, with which we also have over half a century of experience, I think a rough limit for avoiding oxygen toxicity might be the hospital max 0.4 atm partial pressure.

I think the proposed hab atmospheres that Rob and I bandied back-and-forth all meet the long-term hypoxia/chronic mountain sickness criterion, the oxygen toxicity criterion, my wet-in-lung hypoxia criteria (both long and short-term), and the factor 1.2 for no pre-breathe, for suit pressures near 3 psia. And these atmospheres present no more fire danger than warm sea level Earthly air (based on oxygen mass concentrations in kg/cu.m), as would be used in a 1-step, 2-component Arrhenius reaction rate equation model. They are all near 40-45% O2 in 0.40-0.45 atm total pressure.

For the record, the article in which I addressed a long term hypoxia criterion based on risks of chronic mountain sickness (related to childbirth difficulties) was "Habitat Atmospheres And Long-Term Health", posted 1-11-2022 on "exrocketman". The update for 2-2-2022 addresses CO2 displacement effects for the alveolar gas equation. I don't use it because nobody knows or agrees on what the correct blood CO2 concentration is, above 2500 m.

So, they don't know what the "right" value is, to use in the alveolar gas equation, when total pressures are under 10.835 psia. Using the below-2500 m values leads to too much displacement, too low an alveoloar O2 concentration estimate, and thus too high a recommended suit pressure (surprise, surprise!). It is already known to produce incorrect estimates for mountain climbers above 2500 m.

I just use the "wet" oxygen concentration in the freshly-inhaled air for my criteria and analysis. Those data for water vapor displacement are very well known.

GW

PS -- I had meant to sign in and participate yesterday evening, but had received some very disturbing news that afternoon, and was in no condition or fit state to do so. Maybe next time.

Last edited by GW Johnson (2022-05-30 11:47:52)

tahanson43206 · 2022-05-30 12:05:01

For GW Johnson re #327

Thank you for once again posting on this important subject, in the NewMars forum.

Clearly it is helpful to keep repeating these posts, because (obviously) not everyone has read them, or is aware of them.

I hope that whatever came up on Sunday is something that can be dealt with in time. Not everything can.

***
Had you ** BEEN ** able to attend, and assuming the conversation was similar (which is unlikely with a third party present), you would have heard the question posed: Why does the space station proposal at the Gateway web site show default Earth sea level atmosphere?

The snap reaction was that humans evolved with that atmosphere, so there is no reason not to go with it.

In fairness, there ** was ** acknowledgement of the value of the Atmosphere proposal from RobertDyck, which comes pretty close to yours ...

By choosing partial pressures carefully, a Mars resident or space craft traveler can go EVA with no (or greatly reduced) risk of the bends.

I would like to think that the designers of the Gateway space station are simply unaware of the work done by Mars Society members and others, to arrive at the Atmosphere Prescription published here multiple times, and in multiple topics.

If the designers ** were ** aware of the Mars Habitat atmosphere prescription, as published here, they might well embrace the recommendation for many reasons.

***
All that being said, it ** is ** possible to test the Mars Prescription on Earth, by building a Mars Habitat Simulation facility at that mining site in Peru, if the government of Peru is willing to support such a venture.

The participants in such a venture would be using ** real ** EVA suits when they step out of the habitat, instead of pretend ones such as (I understand) are in use at the Utah facility.

Ideally, the experiments would be set up, supervised and reported upon by ** real ** scientists, supported by eager volunteers I am sure.

(th)

kbd512 · 2022-05-30 12:53:09

GW,

Nobody in a hospital is breathing 40% ppO2, except after a serious injury or during the terminal phase of their life. We don't have many people breathing 40% O2 for months to years on end, and virtually all of those people would otherwise be dead much sooner without increased O2 concentration. I never stated that it wasn't feasible to use higher ppO2 at reduced total pressure, either, merely that it wasn't ideal from a human physiology standpoint.

We're making concessions here to eliminate EVA pre-breathes, and we should be honest with everyone about why we're really doing this, rather than coming up with false justifications for why this shouldn't affect people, especially when we know that it will affect people over time.

NASA's own fire research aboard ISS shows that O2 concentration as a total percentage of the atmosphere is what increases the flammability of various materials:

Oxygen Partial Pressure and Oxygen Concentration Flammability: Can They Be Correlated?

GW Johnson · 2022-05-30 17:42:23

What the cited report calls "oxygen concentration" is really the volume percent oxygen.

What I used is the oxygen concentration expressed as mass of oxygen per unit volume of total gas. That has the units of density, being kg/cu.m, not volume per unit volume. That sort of thing worked very, very well for me decades ago, when I tried to model fuel-air reactions in the flameholding zones of ramjet engines. My models actually did successfully predict combustor blowout and ignition limits as functions of air delivery conditions, mixture ratio, and physical size.

I was using an Arrhenius reaction rate expression r = C Cfuel^r Coxy^(n-r) exponential T factor, to model 1-step 2-component overall reactions that were of order 2 (n = 2) with a near-unity exponent on the fuel concentration (r = 1). It worked just fine. So why would it not work for a flammable immersed in some sort of habitat air? I don't think anyone could say "no, it won't work".

As for 40% oxygen masks in hospitals, there are those who are supplied this way for weeks at a time. For any of a variety of reasons. Ignoring the breathe-back breath displacement in the vented mask, that is oxygen at 0.4 atm partial pressure at sea level, lower at elevation. Deaths are not attributed to oxygen toxicity, near as I can tell.

As for pilot oxygen masks, the Navy says go on 100% oxygen at 5000 feet, the Air Force at 10,000 feet. These are vented, so the pressure inside the mask is the same as the ambient atmospheric pressure. The Navy criterion corresponds 0.83 atm partial pressure of oxygen, ignoring any displacement by exhalation or water vapor. The Air Force criterion corresponds to 0.68 atm partial pressure of oxygen. Both have been used, with ZERO oxygen toxicity reported, for over half a century now.

What I was taught decades ago in scuba diving class was that 1 atm partial pressure of oxygen was lethal to about 50% of the people breathing it (exclusive of any exhalation or water vapor displacement effects), and that 2 atm partial pressure was lethal to 100% of those breathing it. Which is why pure oxygen breathing rigs are restricted to a maximum depth of 33 feet, and then only for military use.

0.4, 0.68, 0.83 atm, makes little difference. It's a fraction of an atmosphere. Choose the lowest: 0.4 atm is the most restrictive oxygen toxicity limit that has any roots in real human experience. And NONE of the proposed atmospheres by either Rob or me come anywhere close to that limit.

Volume fraction x total pressure = partial pressure. That's straight from the gas laws.

In my last posting on exrocketman about this topic, I didn't try to force a low oxygen suit pressure and from it derive a hab atmosphere. I worked the other way around from my wet in-lung inhalation oxygen partial pressure allowing for water vapor displacement, but ignoring the carbon dioxide displacement effect.

Both my analysis and my criteria are based on this inhaled wet oxygen pressure, so they are consistent. All I did was add a long-term hypoxia/chronic mountain sickness criterion based on the data I found in the "Science" journal.

Using that long-term hypoxia criterion to set hab atmosphere, I fell in the very same ranges that I fell into before, around 0.4 to 0.45 atm at around 40 to 45% oxygen by volume. The corresponding zero-pre-breathe suit pressures still fell nearer 3 psi, than anything I see out of NASA (or the Russians).

That being the case, why would I continue to worry? Especially since the fire danger concentrations all fell below (or well below) the 0.275 kg/cu.m oxygen concentration of 70 F sea level air?

Go look at my article on "exrocketman". I think you will find most enlightening. And far more sophisticated than the usual papers I see coming out of NASA.

GW

kbd512 · 2022-05-30 22:33:36

GW,

NASA has already done testing on this for the Skylab missions. After 90 days of elevated O2 at 5psi, the test subjects lost about 10% of their pulmonary capacity. I will readily concede that their sample size was very small and there could've been any number of factors that affected the results, but your argument is with their data, not me.

As far as elevated ppO2 at lower total pressure increasing the flammability of materials, did we learn nothing from Apollo I? Do we need to kill more people for that to be accepted as being true, or was three dead astronauts enough?

tahanson43206 · 2022-06-05 10:42:43

Today is Zoom day on NewMars....

We have no reservations for either the European Zoom at 19:00 UTC or the Early session at Midnight UTC.

I'll be joining host kbd512 as usual at 1 AM UTC.

Topics often range widely, but I am hoping for progress in one or two of these:

1) Solar Trough >> long chain hydrocarbon fuel as a viable long term business

2) Solar Trough to power a flow of sea water from the Pacific to the Great Salt Lake

3) Water processing suitable for New Hampshire ground water (or any non-acceptable water)

PS ... one of the many links Mars_B4_Moon found recently was a Ukrainian who'd built working solar trough systems

This gent used fixed position reflectors made of reflective foil glued to inexpensive back plane.

? other ?

(th)

tahanson43206 · 2022-06-12 09:52:25

Today is Zoom day on NewMars forum...

The "Early" (European) session is scheduled for 19:00 UTC. If anyone would like to attend next week, please post a message in this topic.

The Midnight UTC session is available next week if anyone is interested. Please post a message in this topic if you would like to attend that session.

The "NightOwl" session is on schedule, at 1 AM UTC. I'll be filling in for host kbd512.

This will be a one hour session, because the Seattle Mars Society Chapter will be holding a meeting at 2 AM UTC.

We have two guests/members lined up, and would be happy to include others.

(th)

tahanson43206 · 2022-06-12 19:54:15

Today's NightOwl Zoom was well attended and quite productive.

FriendOfQuark1 has decided to take us (NewMars) up on a standing offer for a membership, so I will take care of that tomorrow.

James Burk logged on to say hello, and to remind us of the Seattle Chapter meeting a 2 AM UTC.

FriendOfQuark1 informed me that London time and UTC are NOT the same. I had blithely assumed they were the same, so appreciate the correction.

GW Johnson is working on an update of his lander proposal, and I expect to have that available for NewMars members to see tomorrow.

kbd512 was online as host, and I sure am glad he was there because of the time mixup with FriendOfQuark1

FriendOfQuark1 is interested in the problem of financing Large Ship.

We need some ballpark figures to work with, so kbd512 suggested 3 $billion (USD) to build the ship, and we (group) floated $10 $billion (USD) for the flight to and from Mars, including fuel and specialty equipment such as Space Tugs (see presentation by GW Johnson at North Houston for details).

(th)

SpaceNut · 2022-06-12 20:05:32

Those are great details to see that even with our small core of contributors that we are still progressing.

kbd512 · 2022-06-12 22:15:28

tahanson43206,

$3B for the development program, based upon a similar tonnage military warship, the LCS program. I will, of course, look for ways to pare down the development budget by incorporating as many off-the-shelf components as we can repurpose. We need distributed propulsion technology development here. We don't need much development of any other technology. Every other technology is perfectly adequate to the task demanded of it. We're not going to reinvent any wheels here.

Examples:

1. Power - scale-up of thin-film ROSA technology currently being deployed aboard ISS
2. Propulsion - scale-up of laser ablation of solid propellants
3. Life Support - scale-up of NASA's CAMRAS and IWP
4. Navigation - repurpose Lockheed-Martin's Orion Program navigation computers and software
5. Communications - repurpose of the NASA / Harris Software-Defined Radio (SDR)

Software Defined Radios (SDR) for NASA Spaceflight Applications

Space Software Defined Radio Characterization to Enable Reuse

SDR/STRS Flight Experiment and the Role of SDR-Based Communication and Navigation Systems

6. Radiation Protection - repurpose of NASA's hand-portable "water bricks" (flexible plastic bags containing potable water)
7. Food - use of commercial shelf-stable freeze-dried food sold to the general public

$250M to $350M to build each ship, presuming SpaceX is accurate in their estimate about $2M Starship Super Heavy launch costs.

The 2019 list prices for Boeing 787s range between $248.3M and $338.4M.

The Lockheed-Martin Freedom-class Littoral Combat Ship costs $362M and weighs 3,500t at full load.

The ship I want to create would weigh about 1,000t. ISS weighs 420t for comparison purposes. We require at least 1,000N of thrust to achieve acceptable acceleration rates the produce escape velocity in about a month. I think we need around 23MWe to generate 1,000N of thrust using laser ablation / thermal acceleration of H2 propellant. NASA's X3 ion engines would only require about 9.5MWe, which looks pretty good until you realize that the propellant used (Xenon) is almost unobtanium and the engine generates a maximum specific impulse of 2,650s. At that point, it doesn't look so great compared to the 86,308kg / 1,233m^3 of LH2 (something is wrong with my math there, I think it should be about 200t of propellant for 8.9km/s of dV, which is about 0.9km/s more than you actually need) that the laser ablation propulsion would required, at 4,077s. It's hard to say exactly how much laser power is required because lasers can generate thrusts between 100N/MW and 10,000N/MW, but the higher thrust levels also sacrifice specific impulse and require metallic propellants such as Aluminum.

Either way, we need to de-couple the power generation facility from the ship itself. A laser power / propulsion station that sits in high orbit can direct the laser onto mirrors used by ships to achieve escape velocity. The power station's mass and weight does not need to be endlessly moved about the solar system. These stations can be deployed using conventional electric propulsion at very low acceleration rates.

Even at the expense of specific impulse, Aluminum is a much more desirable propellant than Hydrogen because it's so dense and indefinitely storable. If spin-launch can cheaply hurl cannon balls into orbit, then Hydrogen is probably a technological dead-end, except for chemical propulsion to get off the surface of a planet.

kbd512 · 2022-06-13 00:55:36

I keep going back-and-forth on this idea of distributed power and propulsion, but I don't think we can get away from it using technology we actually know how to make and use. The alternatives are unaffordable propellant costs, thus unaffordable ticket costs, and "habitat modules" that closely resemble the upper stages of rockets. To be fair, this ship is still a giant tin can, but at least it's not almost entirely propellant.

Using the Alibaba price of $610/t for rather cheap 1026 carbon steel, which is still sufficiently strong, even if it's nowhere near the strength of the 2X more expensive C250 maraging steel, or the 3X more expensive 304L stainless steel- which is still weaker than 1026, our total steel bill to enclose 29,608m^3 of interior volume in 2mm thick steel, providing an opulent 59.216m^3 per person, is less than the price of most houses. NASA's long duration habitability studies says 25m^3 of space per person is the "Gold Standard".

The surface area for the pair of 25m inner radius / 5m torus diameter / 5,922m^2 surface area per torus, totals to 11,844m^2 of surface area. At 15.68kg/m^2 for 2mm thick 1026 plate, that works out to 185,713.92kg or 186t. 186t * $610/t for 1026 sheet/plate = $113,460 for enough steel to provide more than double the habitable volume that NASA says is required for crew comfort and privacy. The price of steel could double or triple or quadruple, but that's still "noise" when compared to the total cost of rocket transport for fabrication / construction, consumables, and propellant.

If we were sensible about our total habitation ring volume allocated to crew use, then we only need 93t of steel for that purpose, with the other 93t reserved for the connected spokes and center barrel sections. Some additional steel will also be required for internal reinforcement / compartmentalization. I'm budgeting around 250t for structures. The interior will be rather plain in appearance, because there's not enough mass that can be devoted to outfitting the vessel like a luxury cruise liner.

The crew will sleep in hemp "sail cloth" hammocks, similar to the crews of sailing vessels. Each man / woman / child will have a small pillow, a wool blanket, personal clothing items, a towel, a washcloth, toiletries (soap / shampoo / toothbrush / toothpaste / comb / razor / nail clippers and file), a single pair of sneakers, a wristwatch / personal communicator, and a tablet for learning or entertainment. There needs to be a cap at 20kg for all personal effects, which will include silverware / plate / cup.

After more thought on how much food the ship is carrying, I don't think it's realistic to carry more than 9 months of food. There's no practical way to send it back to Earth without first stopping in orbit at Mars. At 1.25kg of food per person per day, that's still almost 169t of food. If we carry 200L of water per person, then we're add 100t of water.

By the time we include the hull structures, food, water, atmosphere, crew, and personal effects, we're rapidly closing in on 600t. We still haven't included the mass of a 500kW solar array, communications equipment, avionics, life support equipment, etc. All that stuff adds up really fast.

I think we need at least 4 Starship flights to load all consumables, so we're already at $16,000 per person simply to get to Mars. If the ticket prices get much more expensive, then there simply won't be a sufficiently large pool of applicants who can afford to pay their own way, which means it won't succeed as a business proposition. Can we find at least a million people who can pay that kind of money? Probably, but they also have to be mentally suitable, pass physical health screenings, pass a rigorous training program, and then be gainfully employed on Mars. In short, we're asking for a lot. We have to prove that we can make a large ship concept work well enough to dissuade people like Elon Musk from attempting to use much smaller ships where vastly more money has been paid for propellant vs people and useful cargo. It's a tough sell, but I think there's an economics-based case to be made.

tahanson43206 · 2022-06-13 07:27:31

For kbd512 re Zoom meeting and posts 336 and 337.

First, thanks ** very ** much for connecting by phone from Chicago. That was helpful because FriendOfQuark1 had logged in early due to my error.

I had ** thought ** that London time is the same as UTC, and it is NOT. I will avoid making THAT mistake again.

For all future Zoom meetings, everyone is invited to use time.is/UTC as the common point of reference.

Second, thanks for the two detailed posts, covering much of the discussion Sunday, but more importantly, providing a reference point for FriendOfQuark1.

One point of possible confusion that I want to clear up now is the specific Large Ship for which funds are to be raised.

In the absence of RobertDyck, I will hold the fort for Large Ship as the 5000 ton vessel with a Unitary Rotation design, 1060 passengers and crew, and all propulsion managed by Dr. Johnson in such manner as he sees fit. The mission of Large Ship is to carry passengers and crew to Mars, or other Solar System destinations, safely and in reasonable comfort. The expenses must be dealt with, and they **will** be dealt with, if Large Ship comes to pass.

In the presence of kbd512, we have an alternative proposal that uses counter-rotating habitats, electric propulsion and has capacity for 500 passengers and crew. Of the two proposals, yours seems (to me at least) to have the greater chance of materializing, but we shall see.

For SpaceNut ... please continue thinking about how you want to organize work on financing of these two alternative Large Ship designs.

I will personally try to maintain an even hand as RobertDyck's vision and the vision of kbd512 compete for market share.

As a suggestion to kbd512.... Please consider working up a formal proposal to be delivered at the North Houston chapter in the present year.

The proposal of RobertDyck is the one that has primary focus, because RobertDyck gave his talk to the Chapter, and because Dr. Johnson came along afterward to push the concept over the conceptual finish line.

You can achieve similar status for your vision, with a bit of work.

Reminder to all:

Executive Director James Burk is looking for presentations for the upcoming Mars Society conference.

I have already inquired about the presentation by GW Johnson.

At this point, I haven't heard if a Zoom presentation by RobertDyck would be accepted, but that would be highly desirable from my point of view.

If there is anyone else in the membership who would be interested in giving a presentation to the Mars Society, please let us know.

You can post in this topic so we have a common point of reference for planning.

Because this is a major conference, it will be helpful if there is an example of previous work saved on the Internet for review.

It is even possible that NewMars could secure an entire track for Large Ship proposals, but that may happen in future years.

In any case, Large Ship is a multi-year undertaking, and participants need to be prepared for a marathon and not for sprints.

(th)

tahanson43206 · 2022-06-16 10:27:06

Heads up for NewMars Zoom uses...

Executive Director James Burk has rewarded the NewMars Zoom faithful with our very own Zoom account.

The borrowed account we've been using is going away (or has gone away most likely)

I have 72 hours (more or less) to learn how to set up the new official NewMars account.

Mr. Burk has kindly offered to provide assistance if it is necessary.

I'm hoping the Zoom tutorials will be sufficient.

We'll see.

Special for kbd512 ... by any chance do you want to work on this?

If you do, I'll forward the confidential message from Mr. Burk.

The opportunity (request) is to set up a recurring Zoom. I ** think ** but do not ** know ** that admission of guests to the Zoom may be possible, so folks can just click on a link as we do for the North Houston Zoom meetings.

***
As part of this change, I am (tentatively) planning to drop the European (Early) Zoom .... Since November of 2012, none of our European members have taken advantage of the standing offer, so there would appear to be no reason to set up a session at that hour. If someone from Europe ever ** does ** want to join a Zoom, I am hoping the new account will be capable of accepting requests for admission to be monitored by the host, so folks can just click on a link if they are up late and want to participate.

Again, we'll see ..

(th)

SpaceNut · 2022-06-16 18:53:03

It would seem that we have been noticed via this form of communications and how much it was used.

kbd512 · 2022-06-17 14:31:11

I'm back from Chicago today and will start working on my proposal this weekend. As usual, all the significant development required is on the propulsion side, which I cannot provide good cost estimates for. I know roughly what we need and how much, but not enough to provide detailed development cost estimates. Distributed power / propulsion and associated development costs, plus launch costs, are the driving cost centers for this proposal. I think I can provide reasonably good cost estimates for all the other systems because they've already been developed to the degree required. The hull development is an engineering exercise, avionics / life support / electrical power / food / water are all commercial products available through NASA's contractors.

tahanson43206 · 2022-06-17 18:54:48

For all ... I ** think ** our new Zoom account is set up.

The settings appear to be adjustable, so if it needs to be fine tuned, we should be able to make any needed changes.

I set up a recurring meeting at 1 AM UTC.

Here I'll paste part of the set up:

Meetings
Webinars
Personal Contacts
Whiteboards
Recordings
Settings
Account Profile
Reports
Zoom Learning Center
Attend Live Training
Video Tutorials
Knowledge Base
Personal Menu ListAdmin Menu ListCurrent page
Meeting Info Page
My Meetings Manage "NewMars Nightowl "
TopicNewMars Nightowl
Time
Jun 19, 2022 01:00 AM Universal Time UTC
Every week on Sun, until Jul 31, 2022, 7 occurrence(s) Show all occurrences
Add to
Meeting ID
### #### ####
SecurityPasscode ******** Show Waiting Room
Require authentication to join
Invite Link

To start this off, I'll send the invitation link and passcode to the Zoom participants we've seen so far.

If we decide it is safe to do so, we can publish the invitation link, and use the Waiting Room to admit attendees.

(th)

tahanson43206 · 2022-06-18 07:52:40

Report on first test of new Zoom account ....

I clicked on the link to the new Zoom account, after copying the code to another computer.

There is good news, and there is bad news!

Good news: The account opened with the title: NewMars Nightowl

Bad news: Please wait for the host to start this meeting

I have NO idea what to do now.

By clicking the link, I am taking the place of a prospective attendee.

Obviously the host has to be present, but equally obviously, the "regular attendee" link does NOT allow admission as host.

We still have 48 hours to find out how to do this.

As a backup plan, if I can't figure this out, I can remove the Waiting Room feature.

(th)

tahanson43206 · 2022-06-19 09:57:18

Today is Zoom day for NewMars forum.

We have a new (professional) Zoom account.

In attempting to configure the new account, I have activated the Waiting Room feature.

However, I have no experience with that feature, so there may be a hiccup at 1 AM UTC when the NightOwl session opens automatically.

I ** think ** I have to log in with the credentials sent by Executive Director James Burk.

Hopefully (???) some sort of alert will appear when members request access to the Zoom.

If anything out of the ordinary occurs, please use this topic for communication.

My first suggestion for a backup plan is to turn OFF the Waiting Room feature.

However, if we can get Waiting Room to work, then we can publish the link to the session so that attendees do not need to be pre-approved.

I'd like it to be easier for folks to join the Zooms than it is now.

Please use time.is/UTC as the common time for these sessions.

(th)

kbd512 · 2022-06-19 18:04:12

I've started the meeting using the old account that was provided to us (same bat time, same bat channel), but if nobody shows up after about 15 minutes, then I'm going to sign off and then use the new account during the new "Night Owl" meeting.

tahanson43206 · 2022-06-19 18:11:42

Hi kbd512...

Keep the existing channel running for a couple of minutes
I'll switch over the the Zoom computer and check in.

(th)

kbd512 · 2022-06-19 18:28:35

I'm in the new meeting and waiting for you to request to join.

kbd512 · 2022-06-19 18:31:13

I tried simply starting a new meeting and joining from the link, but I don't see you requesting access.

kbd512 · 2022-06-19 18:34:06

Alright, I ended the meeting. I'm going to try joining the "Night Owl" session at 8:00PM and then maybe we can figure out what went wrong.

tahanson43206 · 2022-06-19 18:34:12

Hi kbd512,
Sorry for the delay!
I did not have a copy of the admissions link on the Windows 7 system I use for Zoom
I'm going back to the Linux system to retrieve it.
***
For all who might be planning to attend / join the Zoom this evening...

kbd512 is connected as host, so he will be able to admit anyone who knocks on the door.

If there is a NewMars member who would like to join the Zoom please post a message here.

(th)

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