Deal Breakers

louis · 2018-10-03 04:42:46

There are a number of deal breakers that could yet stop Space X Mars Mission:

1. Lack of funds.

2. Opposition of US government.

3. Failure to develop BFR.

4. A Challenger-type disaster.

5. Failure to develop the required life support and propellant plant.

6. Failure of the initial cargo mission.

7. Failure of test landings or other tests.

8. Opposition from US government, NASA or UN.

But also:

9. Inability to guard the health of the crew against cosmic radiation.

NASA recently issued a report on experimentation with mice that showed there was damage to the gut and possibly other internal organs from exposure to that sort of heavy radiation. Unfortunately I don't have a link to that.

I am linking to this article which discusses the issue:

https://www.popularmechanics.com/space/ … -16887969/

We've discussed this before, but it's probably a good time to go over this again. How do people here assess the risks? Are they life-threatening, life-shortening or mission-threatening? What can be done to attenuate the risk?

This is an interesting discussion of the scope for creating a magnetic field around the spacecraft to protect the crew.

https://space.stackexchange.com/questio … ld-require

It seems that anything from 100 Watts to 5 Kws of power could be require. I think that would not be an issue for the BFS with its large solar array. But even if not probably 10 tonnes of methane and oxygen would be enough to power it on a 6 month flight.

I wouldn't be surprised if Space X were looking into this with some urgency.

It seems a lot can also be done with plenty of plastic lining or water shielding.

JoshNH4H · 2018-10-03 14:13:21

I think radiation is a serious threat but not a mission-ending one. I don't doubt that astronauts will tend to take a lot of radiation over the trip and that they will have a higher chance of negative health effects later in life, but I do expect that they will go into the mission fully aware of this and accepting it as the price of being First.

Solar flares are a different problem and adequate shielding there is vital, but much less demanding than cosmic ray shielding.

Short term damage from chronic exposure to radiation would be a bigger problem. It seems possible, although hopefully not severe. If damage to the gut comes from poor health for intestinal bacteria, the astronauts might be on a course of probiotics during the mission. If it comes from damage to tissue that's a more severe problem and we'd need a lot more research (which incidentally is very hard to conduct on Earth) to find out. Part of any deep space mission is going to be finding out what we need to deal with up there. We'll design around what we know, but astronauts are going to be uncomfortable some of the time.

Frankly, if astronauts are held to the same safety standards as researchers or industrial employees it will be literally impossible to send people to Mars. There's nothing wrong with trying to make things safe (it has very real benefits measured in human lives after all) but we need to be smart about what it gets us or we will choke off our ability to do new things.

louis · 2018-10-03 15:26:39

I agree that a Mars Mission has to take risks. But we are in uncharted waters with cosmic radiation in deep space. NASA send out v. mixed messages on the subject.

What I would say is we need to have some deep space testing before we embark on a Mars Mission...Judging from this -

https://history.nasa.gov/EP-177/ch3-4.html

that would involve some v. extended lunar orbits over say at least 3 months.

JoshNH4H wrote:

I think radiation is a serious threat but not a mission-ending one. I don't doubt that astronauts will tend to take a lot of radiation over the trip and that they will have a higher chance of negative health effects later in life, but I do expect that they will go into the mission fully aware of this and accepting it as the price of being First.
Solar flares are a different problem and adequate shielding there is vital, but much less demanding than cosmic ray shielding.
Short term damage from chronic exposure to radiation would be a bigger problem. It seems possible, although hopefully not severe. If damage to the gut comes from poor health for intestinal bacteria, the astronauts might be on a course of probiotics during the mission. If it comes from damage to tissue that's a more severe problem and we'd need a lot more research (which incidentally is very hard to conduct on Earth) to find out. Part of any deep space mission is going to be finding out what we need to deal with up there. We'll design around what we know, but astronauts are going to be uncomfortable some of the time.
Frankly, if astronauts are held to the same safety standards as researchers or industrial employees it will be literally impossible to send people to Mars. There's nothing wrong with trying to make things safe (it has very real benefits measured in human lives after all) but we need to be smart about what it gets us or we will choke off our ability to do new things.

Belter · 2018-10-03 16:50:34

I wish we were putting our energy into advanced robotics and and manufacturing in space than manned missions outside of Earth orbit. We should constructing habitats on the moon with robots, mining minerals and water. Then sending astronauts. Sight seeing tours are kind of dumb if we can't do anything while we're there.

JoshNH4H · 2018-10-03 18:07:32

louis wrote:

I agree that a Mars Mission has to take risks. But we are in uncharted waters with cosmic radiation in deep space. NASA send out v. mixed messages on the subject.
What I would say is we need to have some deep space testing before we embark on a Mars Mission...Judging from this -
https://history.nasa.gov/EP-177/ch3-4.html
that would involve some v. extended lunar orbits over say at least 3 months.

I don't know if the Moon is far enough or if you still get some protection there from the Earth's magnetic field. It's outside the radiation belts, sure, but I would think there would be some shadowing still. Or maybe not, really I don't know.

The core of Zubrin's message on this I think is that "if you want to go to Mars, go to Mars". We have some research on chronic radiation exposure that suggests it shouldn't affect astronauts too much, so while there might be negative effects it wouldn't kill the mission.

If I were in charge of a space program, I would spend probably 90% of my human exploration budget on missions to Mars and the other 10% on earthbound design/testing of key technologies required for settlement to build them into actual usable products.

Not to say there's no value in detours, I just don't think it's the best use of money. If SpaceX wants to muck around in lunar orbit I'm sure they'll learn a lot.

louis · 2018-10-03 18:21:57

I completely disagree with that. Musk has got it totally right. Mars should be the prize. Everything else should be ancillary. That is how we will progress at the fastest rate in our exploration of the solar system. Having humans in an quasiearth environment like Mars will amplify our space exploration technology hugely. Mars First.

Belter wrote:

I wish we were putting our energy into advanced robotics and and manufacturing in space than manned missions outside of Earth orbit. We should constructing habitats on the moon with robots, mining minerals and water. Then sending astronauts. Sight seeing tours are kind of dumb if we can't do anything while we're there.

louis · 2018-10-03 18:26:24

Moon is about 250,000 miles away I think...the above link says the magnetosphere extends something like 370,000 miles away from the sun (shorter as you go close to the sun). So I am thinking a v. elongated orbit around the Moon might allow you to test how your crew protection works in deep space.

I don't really see lunar orbit testing of Mars craft as a "detour"...just a necessary proving ground. You might even land a BFS on the Moon and trying living there for a few months to test your overall mission design.

JoshNH4H wrote:

louis wrote:
I agree that a Mars Mission has to take risks. But we are in uncharted waters with cosmic radiation in deep space. NASA send out v. mixed messages on the subject.
What I would say is we need to have some deep space testing before we embark on a Mars Mission...Judging from this -
https://history.nasa.gov/EP-177/ch3-4.html
that would involve some v. extended lunar orbits over say at least 3 months.
I don't know if the Moon is far enough or if you still get some protection there from the Earth's magnetic field. It's outside the radiation belts, sure, but I would think there would be some shadowing still. Or maybe not, really I don't know.
The core of Zubrin's message on this I think is that "if you want to go to Mars, go to Mars". We have some research on chronic radiation exposure that suggests it shouldn't affect astronauts too much, so while there might be negative effects it wouldn't kill the mission.
If I were in charge of a space program, I would spend probably 90% of my human exploration budget on missions to Mars and the other 10% on earthbound design/testing of key technologies required for settlement to build them into actual usable products.
Not to say there's no value in detours, I just don't think it's the best use of money. If SpaceX wants to muck around in lunar orbit I'm sure they'll learn a lot.

Belter · 2018-10-03 19:33:58

I think going to Mars without landing the craft on the moon and coming back is sort of a deal breaker. That should be a minimum standard test. Though I think the overall Mars plan is fairly sound and sensible over all. And at least Musk is doing amazing work with landing a first stage on small targets with few accidents. At least set down on the moon, hang out for a few weeks or more, come back. Really, it should be more of a long term platform for debugging the systems. Then bring them back, see if you can land them on Earth.

SpaceNut · 2018-10-03 19:46:27

Apollo did give some data for the crews which were only out there for 2 weeks time and that is a variety of cancers, cateracts ect.. its a small sample and the time would need to be longer but its still data points along the way.
Giving measure layers of protection for the same duration of exposures would surely give more data but how long to when we will know...

Void · 2018-10-03 19:54:32

I am afraid I think the Moon is huge! Potential revenues. Also for providing resources.

I do understand that BFS will start as LEO-Fueled > Mars Surface.
However in very short order I believe that at least Oxygen to provide to the BFR could largely come from the Moon, reducing the necessity of using BFR/BFS from Earth surface to LEO for repropellanting.

I expect almost all of the labor force on the Moon to live on the Earth as a biological unit, with cyborg enhancements, but to live on the Moon as an extra cyborg brain in an avatar. The persons on Earth would get paychecks and high adventure for doing this.

If you watch Elon, you can see a pattern:
Link humans to a extra layer of brain as a cyborg.
https://www.recode.net/2017/3/27/150792 … eural-lace
Create a communication projector.
https://www.cnet.com/news/how-spacex-br … rth-orbit/

So, the only humans and animals I think should be necessary to live on the Moon would be to check biological reactions to low g. That will be important to Mars. But there may be tourism to live on the Moon. Revenue there as well perhaps. More easy to do, also if cyborgs living on Earth are providing consumables on the Moon.

But I think the Moon will be fabulous as an increasing source of resources to project humans to Mars and beyond. And jobs for people on Earth, with paychecks.

Of course he is into tunneling (Boring Company). How useful would tunneling be on Mars?

Done.

Last edited by Void (2018-10-03 20:03:16)

Terraformer · 2018-10-04 07:31:53

Mars is not *the* prize. Mars is one prize among many, and it's not even the lowest hanging of fruit. Luna is a lot quicker to get to, and the Lunar poles have what we need to sustain settlement. More importantly, it's easier to make a business case for a Lunar base than it is for a Mars base - the frequent launch windows and low transit time make tourism, science research, and mining a lot more viable.

Once Luna has paid for the fuel depots and mature life support system, then we can send humans to Mars to set up a base for the cost of a space probe.

louis · 2018-10-04 15:27:32

Yes, but of course the Moon can only be a test of sorts given the difference in gravity and the day/night cycle. Probably a fairly short stay on the Moon would suffice as you suggest, given those differences.

Belter wrote:

I think going to Mars without landing the craft on the moon and coming back is sort of a deal breaker. That should be a minimum standard test. Though I think the overall Mars plan is fairly sound and sensible over all. And at least Musk is doing amazing work with landing a first stage on small targets with few accidents. At least set down on the moon, hang out for a few weeks or more, come back. Really, it should be more of a long term platform for debugging the systems. Then bring them back, see if you can land them on Earth.

louis · 2018-10-04 15:36:06

I agree and disagree. Of course Mars is not the only prize but it is the top prize I think, because ultimately it is our best candidate for making a true second (and safe) home for humanity. A major comet impact on Earth could easily wipe out a lunar colony as well. I don't see any real conflict between Mars colony development and lunar colony development. The two will go hand in hand and now we have the BFR, we can see how the two projects can mesh very nicely. But the idea of delaying Mars colonisation to allow concentration on the development of the lunar colony I find incomprehensible.

Terraformer wrote:

Mars is not *the* prize. Mars is one prize among many, and it's not even the lowest hanging of fruit. Luna is a lot quicker to get to, and the Lunar poles have what we need to sustain settlement. More importantly, it's easier to make a business case for a Lunar base than it is for a Mars base - the frequent launch windows and low transit time make tourism, science research, and mining a lot more viable.
Once Luna has paid for the fuel depots and mature life support system, then we can send humans to Mars to set up a base for the cost of a space probe.

Belter · 2018-10-04 16:25:26

But surely you can see how many people think that trying to populate Mars without testing those things on a perfect and nearby test bed is incomprehensible, right? Not even in any sci-fi I've seen or read does Mars come before a moon base.

Void · 2018-10-04 18:32:17

This is interesting and sort of on the topic:
https://www.usatoday.com/story/money/na … 518713002/
Quote:

Could the next astronaut on the moon travel in this space lander from Lockheed Martin?
Aerospace company Lockheed Martin unveiled a spacecraft concept it says can land humans on the moon once again, responding to NASA's call for more missions to the moon and Mars.
Lockheed Martin's lunar lander is able to launch four astronauts and 2,000 pounds of cargo to the moon, and can remain on the moon's surface for up to two weeks before needing to refuel, the company said Wednesday in Germany.
"This lander could be used to establish a surface base, deliver scientific or commercial cargo, and conduct extraordinary exploration of the Moon," Lisa Callahan, vice president and general manager of Commercial Civil Space at Lockheed Martin Space, said in a statement.
The lander uses NASA-proven technologies and systems from the Orion spacecraft, which has already flown two orbits around Earth.
After direction from the Trump administration, NASA is working to return humans to the moon for the first time since the historic 1972 landing. The space agency has also asked aerospace experts to create plans for a space station, the "Lunar Gateway," that will orbit the moon and serve as a hub for moon missions.
More: First moon outside our solar system discovered, astronomers think
More: Scientists discover ice on the moon using NASA tool, say it could help future space missions
"The Gateway is key to full, frequent and fast reusability of this lander," said Tim Cichan, space exploration architect at Lockheed Martin Space, who presented the lander concept at the International Astronautical Congress. "Because this lander doesn't have to endure the punishment of re-entering Earth's atmosphere, it can be re-flown many times over without needing significant and costly refurbishment."
Lockheed Martin says the new lander could help pave the way for future human missions to Mars.
Follow Ashley May on Twitter: @AshleyMayTweets

So then the Lunar Gateway explained a bit more at least. Another similar article indicated that at first the lander being fueled at the gateway would have enough fuel to return from the surface of the Moon, but later propellants would be manufactured on the Moon.

Last edited by Void (2018-10-04 18:34:05)

Void · 2018-10-04 18:40:27

I see belter already discussed the last post in the gateway topic.

If you don't mind, I will interrupt and give "My" view of the four earliest worlds (Other than NEO's) that should be worked with.

First no harm in trying to do telepresence on the Moon. Actually it has already been done, but not to the level that it could be done.
Get resources from the Moon to a orbital depot (Lunar Gateway!!!! ). Use those to help get to Mars, and to develop other things.
Venus? What to do with that? Well, I suggest a scientific outpost, refuge in orbit. Some trips to Mars could pass Venus, and I can imagine events where it might be useful to be able to abort a mission to Mars by dropping into Venus orbit, (Aerocapture and/or thrusters).

A small group of scientific researchers, also capable of doing doctoring. They would need protection and resources. Those at least at first would come from the Moon/Earth. If a ship had to abort to Venus, then supplies and medical help. For the most part the bulk of the stored supplies would serve as radiation protection. Probably magnetic radiation protection needed as well.

So, both the Moon and Venus "Seeds" being to promote the transfer of human activities to Mars. Not necessarily before the first Mars missions, but helpful somewhere along the line.

Done.

Last edited by Void (2018-10-04 18:45:08)

JoshNH4H · 2018-10-04 19:27:41

Terraformer wrote:

Mars is not *the* prize. Mars is one prize among many, and it's not even the lowest hanging of fruit. Luna is a lot quicker to get to, and the Lunar poles have what we need to sustain settlement. More importantly, it's easier to make a business case for a Lunar base than it is for a Mars base - the frequent launch windows and low transit time make tourism, science research, and mining a lot more viable.
Once Luna has paid for the fuel depots and mature life support system, then we can send humans to Mars to set up a base for the cost of a space probe.

I would say Mars is the biggest prize and the Moon is low-hanging fruit (Literally, if you're a geocentrist!). Both are valid targets for exploration and settlement, and I would support a program targeted at either.

What I can't endorse is an unfocused program that includes spurious missions to secondary targets. The moon is not on the way to Mars in any consequential way. The relevant technologies and procedures can be tested on Earth, in LEO, or perhaps in a free-return mission if necessary.

I have basically no power over the direction of any space program, so my "endorsement" really doesn't matter. I don't have a ton of hope right now for anyone's space program. Here's what would give me hope that settlement was really happening:

A reason for going that makes sense. Examples include:
- Profit
- Opening a new frontier
- Establishing an off-Earth tax haven for billionaires and corporations
- Research
- Military Supremacy or Geopolitical Preeminence
A single, clear destination (vs. "Moon and Mars", "All of the Above", "Moon on the way to Mars", "Let's just build this rocket and use it for everything", "Hey what if we try to capture a NEO and put it in Lunar Orbit that's cool isn't it", etc.)
A mission design that makes sense as a way of fulfilling the program's purpose
- A program designed to turn a profit for a company is probably going to go to the Moon for the shorter timescales and should have a reasonable expectation that their efforts will eventually make them money
- A military program will probably be composed overwhelmingly of robots with a few human minders, possibly stationed temporarily
- A program whose aim is research will probably be lightly and temporarily staffed and focus on regions that are of scientific (rather than economic) interest. For example, a lunar farside radio telescope; An IR observatory in a permanently shadowed crater; [Something about geology and planetology--hard for me to say exactly which sites are of the most interest]
- No side missions to secondary destinations
The organization should have the financial, technical, logistical, etc. resources to accomplish the task they are undertaking or the ability to acquire them; the organization's broader purpose should align with the purpose of the mission (Universities won't fund a program aimed at military supremacy or profit; Private companies won't fund pure research, etc.)

SpaceNut · 2018-10-05 07:50:39

The geni is out of the bottle in that unmanned probes have sent back the hopes and dream of man exploring all of them. Anyone that wants to do this as a crew member is not looking at profit its the others that do not even travel that are trying to create a meal ticket. Those providers are the limiter to destination but then again its the ones that are paying that get to pick where they are going an why. So companies like Space x, Boeing, Lockheed, Serria Nevada, ULA, plus others and even Nasa thou its more directed as to what it will do are all just the launcher to make the destination happen for the customer.

Mars_B4_Moon · 2021-12-10 08:04:36

For some putting modified people and engineered animals into space was a deal-breaker, it was morally wrong or unethical. I guess one reason why some of us might follow space is because its where a lot of the fringe far out sciences meet and old discussions can become new, an idea from the future like 3-D printing can suddenly become reality. I think there is a debate still out there about modification of animals, the engineer of an insect or mammal that could be part robotic, have cyber qualities and its genes and DNA altered. It is a ethical and moral debate but some say the Bush Admin made America fall behind when they cut funding to 'Stem Cell' research. There were other discussions and debates on this in old newmars thread one called on 'More weird fringe technology - honestly, the weird **** we invent'.... it was about Mice having hardware implanted into their brains so they could fly planes, another debate talked of the 'Long-term irrelevance of human space colonization' there was a debate on newmars saying that if we alter people to go itno space they will be post-human or homo-superior or robotic enhanced or not fully human some thing like that.

Here are some news items on futurist biological and physical sciences.

Powered exoskeletons could be the ultimate fitness machines
https://www.freethink.com/technology/po … xoskeleton

Repair your cyborg legs?
The US Copyright Office just struck a blow supporting right to repair
https://www.theverge.com/2021/10/27/227 … ing-report

Bionic Eye Ready For Human Trials
https://evolvera.tech/2021/12/05/phoeni … an-trials/

Jason Barnes, The “Bionic Drummer”
https://www.techeblog.com/james-barnes-bionic-drummer/

Nanobots Will Be Flowing Through Your Body by 2030
https://interestingengineering.com/nano … dy-by-2030

Patient receives the world's first fully 3D-printed prosthetic eye ...so far cosmetic and not really functional
https://www.engadget.com/patient-receiv … 28877.html

As SpaceNut once said in another thread there will be problems of producing food, air and water on the ISS or the Moon or Mars or on another body, a problem of Science, Technology, and Astronomy.
It doesn't have to be about Mars! and its all part of ... life support.... cloning a Beast of Burden, or modifcation of an animal for space.
Here is a discussion on insects and bees for Mars maybe to help crops inside a biodome, 'transportation of bee larvae to Mars plus design of food supply to encourage desired development'
http://newmars.com/forums/viewtopic.php?id=9715

louis wrote:

Of course Mars is not the only prize but it is the top prize I think, because ultimately it is our best candidate for making a true second (and safe) home for humanity.

I think Mars is one of the top prizes perhaps the top prize but by the time there are people on Mars, there will probably be colonization of the Moon, Titan, Europa etc perhaps even robots on their way to Alpha Centauri

SpaceNut wrote:

Giving measure layers of protection for the same duration of exposures would surely give more data but how long to when we will know...

More Biosphere experiments could be launched, China already had its Moon Rover with a small biosphere inside

Last edited by Mars_B4_Moon (2021-12-11 11:43:11)

Oldfart1939 · 2021-12-10 10:40:23

It seems to me that many (most) of the posters to this thread haven't read Zubrin's works on the significance of radiation? In all of his books, he details cosmic radiation dosages in a quantitative manner, and this age-old "Radiation Will Kill Us All!" story keeps coming back to haunt us. A single trip to Mars will not kill anyone but slightly increase the risk of cancer later in life. We would be wise to send older astronauts who are no longer reproducing in order to prevent damage to the yet-unborn and yet-to-be conceived.

"Entering Space" by Zubrin is a great place to refresh one's optimism.

Last edited by Oldfart1939 (2021-12-10 10:41:19)

kbd512 · 2021-12-10 12:24:44

Floating around in the clouds, high above the surface of Venus, you're in the closest approximation to an Earth-like environment that exists anywhere outside of Earth, in our solar system. You have 94% Earth gravity, radiation protection equivalent to Earth sea level with enhanced UV protection, Earth sea level temperatures and atmospheric pressure. While the atmosphere does contain sulfuric acid clouds, those clouds would be the colony's source of water and plastics that are impervious to sulfuric acid. You also have far more solar and aero-thermal (heat power from hot atmospheric CO2 at lower altitudes) power available than Earth can provide, because you're 50% closer to the Sun, and there are no dust storms that drastically reduce solar panel output, so nuclear power is not required. We have already built airships that stayed aloft for 10 years, hovering over battlefields in the Middle East while supplying electronic signals intelligence, so we clearly have the technology to keep an airship in the air for at least that long. From what I've read, the cold and thermal cycling is what ultimately kills those airships, but on Venus at the correct altitude the "local weather" is about like a Texas summer day.

So, no, it's not at all apparent to me that Mars is actually "top prize" amongst the other planets. If it turns out that humans don't function well with only 38% of Earth gravity, then Venus or orbital bases supplying Earth-like artificial gravity are likely the only other practical candidates for permanent human settlement. Mars is definitely a "fixer-upper" planet, but we humans like a good challenge. It has a surface to roam around on, which is important to a lot of people, but that's about the extent of what it has going for it over Venus if habitability is the prime concern.

GCR won't outright kill anyone and a number of astronauts have had perfectly normal babies after receiving significant radiation doses. Women are more vulnerable than men, but it can hurt both sexes and children in different ways. The benefit of being on a planet is that 50% of GCR is immediately blocked out by virtue of being on the surface of the planet, and some of the lower mass GCR (relativistic Hydrogen ions) is still absorbed or deflected by the thin Martian atmosphere. The Venusian atmosphere intercepts nearly all of it. SPE / CME are the only immediately life-threatening forms of radiation. Those solar particle events can be lethal to humans in hours to days, but are also far easier to shield against. As such, the greatest threat to humans living in space, apart from low gravity / loss of power / atmospheric leaks, is and always has been the Sun itself. All stars are engines of breathtaking power, and intrinsically dangerous as a result. Earth is simply a very unique place, quite unlike all the other planets in the solar system. Venus at the correct altitude (50km or so, IIRC) above the surface is the closest analog to Earth. The atmosphere is not breathable, but in all other respects it's far more benign than any other place in the solar system.

GW Johnson · 2021-12-10 12:37:35

It's not cosmic radiation that threatens crews' lives, it is solar eruptions. GCR varies from 24 to 60 REM/year with the sunspot cycle. The allowable career maximum is max 400 REM accumulated over a career, with no more than 25 REM in any one month. The number is reduced a tad for younger ages and differently by gender. A 3 year trip at 60 REM/year is only 180 REM accumulated for the trip. If that were the only exposure, that astronaut could make 2 such trips.

Solar eruptions on the other hand, while a lower-energy type of radiation that is easier to shield, comes in brief but extremely intense floods. The least of these are on the order of 100 REM over a few hours. The worst (the 1972 event) exceed 10,000 REM over several hours. LD50 is thought to be 300 REM in a "short time". LD100 is pretty well accepted to be 500 REM in a "short time". "Short time" means minutes, hours, even days.

When the naysayers claim it is GCR that is the lethal threat, you ALREADY KNOW they are lying! Because it ain't GCR that is the threat,
it is solar flares of large sizes. Whether they are lying out of ignorance or malice makes no difference. THEY ARE STILL LYING. Simple as that. Pointing at GCR as a reason not to go is UTTER BULLSHIT!!! and there is no other more-accurate way to say that!

GW

Last edited by GW Johnson (2021-12-10 12:42:18)

SpaceNut · 2021-12-10 19:43:23

The real "deal breaker" is not having enough paying customers in order to get the Starship to orbit with a volume of people on board that is paying even if its just to the ISS for a short stay with limited numbers onboard the station while doing science onboard the Starship. Under pricing a launch is just as bad as not having enough high paying launches at this point.

kbd512 · 2021-12-11 11:39:24

SpaceNut,

That's probably a more pointed observation than anything else we've discussed here, but it was also #1 on Louis' list of deal breakers. Maintaining a customer base that is willing and able to pay for all the required hardware will make or break this entire enterprise in an absolute sense. The government has other peoples' money to play with, whereas nearly all commercial enterprises are playing with their own money. The defense contractors are the only notable exception to that rule.

GCR is somewhat akin to Gamma Rays, meaning extremely high energy and very penetrating as a result. GCR is an actual threat to fetal and early childhood development, but for anyone past the age of puberty, the most it could do would be to shorten their lifespan towards the end of life- people who are of retirement age who have been exposed to GCR for all or most of their adult life, and have had DNA damage as a result, which typically manifests itself as cancer. I can see GCR ultimately killing some people by the time they're 60 to 70, but by then the next generation of grown adults has already entered the workforce. Any time you get after age 50 is borrowed time, with or without GCR exposure. The human body wasn't meant to last forever. In all probability, accidents and suicides will ultimately kill a lot more young people than radiation, as is already the case both with and without radiation threats here on Earth. On Mars, these people will be so heavily shielded from all forms of radiation that it simply won't be a particularly notable issue.

The radiation doses that the people living near Chernobyl received were extreme events brought about through direct exposure to what is normally on the inside of an operating nuclear reactor, due to the complete lack of a containment vessel. No human can survive the environment inside a nuclear reactor core, period. In contrast, there were no significant increases in cancer deaths amongst those living near Three Mile Island or Fukushima since those reactors featured substantial containment vessels around their cores so that neither a partial (Three Mile Island) or full (Fukushima) meltdown resulted in significant radioactive particle releases.

For Mars-based Aqueous Homogeneous Rectors (AHR) reactors, the fissile inventory in the core is so low (mere tens of kilos of Uranium or Plutonium for 10s of MWs of thermal output power), that widespread contamination is not feasible, even if you could melt down the core, which they initially tried to do numerous times, and failed every single time, because the operating temperatures are insufficient to melt stainless steel or Aluminum. Beyond that, the neutron poisons are continuously removed, so the short lived fission products (short half lives are associated with extreme radiation intensity and long half lives are associated with low radiation intensity, contrary to popular media hysteria about long-lived radioactive materials, which are used to stoke fear amongst the ignorant), which are extremely radioactive, are easily separated and appropriately stored for the brief period of time where they pose a significant biological threat.

SpaceNut · 2021-12-11 13:08:11

Lack of funds can also come from under pricing the service being provide to under cut the old guard companies and that is what was done.
It is a short term gains but will loss in the long run as the volume is under estimated for the service. Musk has started to rob all of his assets to keep things running and the gamble is about to fail.

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#1 2018-10-03 04:42:46

Deal Breakers

#2 2018-10-03 14:13:21

Re: Deal Breakers

#3 2018-10-03 15:26:39

Re: Deal Breakers

#4 2018-10-03 16:50:34

Re: Deal Breakers

#5 2018-10-03 18:07:32

Re: Deal Breakers

#6 2018-10-03 18:21:57

Re: Deal Breakers

#7 2018-10-03 18:26:24

Re: Deal Breakers

#8 2018-10-03 19:33:58

Re: Deal Breakers

#9 2018-10-03 19:46:27

Re: Deal Breakers

#10 2018-10-03 19:54:32

Re: Deal Breakers

#11 2018-10-04 07:31:53

Re: Deal Breakers

#12 2018-10-04 15:27:32

Re: Deal Breakers

#13 2018-10-04 15:36:06

Re: Deal Breakers

#14 2018-10-04 16:25:26

Re: Deal Breakers

#15 2018-10-04 18:32:17

Re: Deal Breakers

#16 2018-10-04 18:40:27

Re: Deal Breakers

#17 2018-10-04 19:27:41

Re: Deal Breakers

#18 2018-10-05 07:50:39

Re: Deal Breakers

#19 2021-12-10 08:04:36

Re: Deal Breakers

#20 2021-12-10 10:40:23

Re: Deal Breakers

#21 2021-12-10 12:24:44

Re: Deal Breakers

#22 2021-12-10 12:37:35

Re: Deal Breakers

#23 2021-12-10 19:43:23

Re: Deal Breakers

#24 2021-12-11 11:39:24

Re: Deal Breakers

#25 2021-12-11 13:08:11

Re: Deal Breakers

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