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Posts: 3488
Joined: Jan. 20 2004
From: Austin, Texas USA
Space-X Falcon Heavy Launch
A friend e-mailed asking what I thought of the successful launch and the return of the two boosters to Cape Kennedy. Here's what I wrote in reply:
My father was born the year the Wright brothers first flew. He learned to fly in a Curtiss Jenny and a DeHavilland DH-4. He retired from the Air Force with Command Pilot wings, checked out in the F-105 supersonic fighter-bomber. My earliest memories are of airplanes.
My brother headed the Flight Medicine Branch of NASA throughout the Apollo moon landing program. I spent 43 years working on space related military projects. I was Radar Test Director on Space-X's first flights, and on the first successful one, conducted at Kwajalein in the Central Pacific. I loved working with the Space-X people. They were young, smart and highly motivated.
When that big rocket lifted off, I choked up and got tears in my eyes. It was like watching my grandchildren setting out for Mars.
On another explorative note, Japan is sending a very large mirror telescope to the Atacama desert later this year. It's infrared, so it will see the Galaxy in new ways. It doesn't replace Hitomi the lost telescopic satellite, but it softens the loss. Soon we'll see great things from Space-X and the high desert of Chile.y
That is indeed lovely. It looks like the private sector is going to be our best hope at pushing space exploration. Musk has been very upfront about his double entendre with his cars IE model S, 3, X, I wonder if his "falcon heavy rocket" is not also sly joke. Say it quickly.
2024 is the projected date to send people to mars, along with supplies to build up the base and look for water and materials. I argued with a skeptical family member about it, as he didn’t think Elon is taking serious enough, nor had solved the issue of deep space radiation exposure. He was operating on the assumption that it would take 6 months to land on mars from its closest to earth distance, as it takes our robot probes that are currently there. I looked up the Raptor engine technology he developed and it seems he can make it there in 80 days, and plans to increase that engine performance to 30 days over time! He will be launching a fleet (up to 1000!) of these things every two years (with crew and supply ships etc) and build up the planet pretty quickly. Exposure to radiation will be minimal time wise, and once on mars, the crew can generate some sort of artificial magnetic field similar to what Earth has. Also the 100+ crew compartment has special locations to sit out Solar storms (protected by shielding and water tanks)...in addition to the movie theatre and casino and such to keep those 30 days feeling quite short!
Posts: 3497
Joined: Jul. 12 2009
From: Washington, DC
RE: Space-X Falcon Heavy Launch (in reply to Ricardo)
quote:
Exposure to radiation will be minimal time wise, and once on mars, the crew can generate some sort of artificial magnetic field similar to what Earth has.
Earth's magnetic field (which protects us from radiation) surrounds circulating electic currents in the Earth's molten, metalic core that are the field's source. It is the Earth acting like a dynamo, and the field extends far out into space. I have not seen anything to indicate how explorers/scientists on Mars could possibly generate an "artificial magnetic field similar to what Earth has."
I would be interested if you could cite a source for this observation. To create a magnetic field on Mars similar to that found on Earth would require Mars to act as a dynamo, with internal electric currents generated by a molten, metalic core like that found on Earth. If Mars lacks this attribute, how would it be artificially accomplished by visitors to Mars? Even if we are talking about a magnetic field restricted to the area surrounding the crew's quarters, it would have to extend far into space to achieve the same protective effect as Earth's magnetic field.
Bill
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And the end of the fight is a tombstone white, With the name of the late deceased, And the epitaph drear, "A fool lies here, Who tried to hustle the East."
Posts: 3488
Joined: Jan. 20 2004
From: Austin, Texas USA
RE: Space-X Falcon Heavy Launch (in reply to BarkellWH)
On the way to Spain from Kwajalein in 2007, we stopped off in San Francisco, Santa Barbara and Los Angeles (actually Manhattan Beach). In those days Space-X had only about 300 employees, mostly at El Segundo (also in L.A. area).
We were invited to a party. Space-X employees were not only young, smart and highly motivated, they could also throw one hell of a toga party.
RE: Space-X Falcon Heavy Launch (in reply to Ricardo)
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"Anything you do can be fixed. What you cannot fix is the perfection of a blank page. What you cannot fix is that pristine, unsullied whiteness of a screen or a page with nothing on it—because there’s nothing there to fix."
reaching mars in 80 days sounds possible to me, but an artificial magnetic field like that of earth not so. just like bill said, the van allen belt is an extremely powerful magnetic field that luckily shields us from a good portion of harmful solar winds and ionized particles. it's because mars's magnetic field not being powerful enough to shield the planet from solar radiation that mars' atmosphere succumbed to it in the end. can't imagine anything manmade as compact as the earth's core could generate such magnetic power. and if so, an external magnetic field of this magnitude might interfere with other stuff people would want to do. I'd be interested in sources as well ricardo
But there are significant logistical problems (significant amount of infrastructure required, so too much mass to carry that infrastructure in one single launch, energy requirements, etc.). It doesn't sound like a solution for the first guys out there, but maybe for the longer term. The other options (physical shields or medical advancements) might protect astronauts out there, but a magnetic shield does much more than that, possibly (if NASA's ambitions come to fruition) recreating a viable atmosphere on Mars. It's theoretically possible, but we may have to wait a bit longer than 2024
I do agree with Ricardo's friend that Elon Musk has been rather cavalier about it. At least in his public speeches. Perhaps behind the scenes he's hard at work to find a solution but publicly he's just been saying that it's "no big deal", whereas researchers in the field say otherwise. I'll bet money the first launch isn't in 2024. It's not being pessimistic, I'm really excited at the prospect and really think they'll get there. But it's like large construction projects. There's always something that comes up and adds delays. Hell, even this falcon heavy launch was supposed to happen 5 or 6 years ago so I figure it's safe to assume there will also be delays for the first Mars mission. Unless China announces it's sending people up there, then you know everything will speed up!
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"Anything you do can be fixed. What you cannot fix is the perfection of a blank page. What you cannot fix is that pristine, unsullied whiteness of a screen or a page with nothing on it—because there’s nothing there to fix."
Posts: 15748
Joined: Dec. 14 2004
From: Washington DC
RE: Space-X Falcon Heavy Launch (in reply to Piwin)
quote:
There's some interesting work on small localised shields. I think it's already been successfully tested.
Yeah I was referring to protection for the small facility and eventually the city not the entire planet....but thanks for jumping on those links! I think also people need to understand that we ALL are exposed to radiation all the time anyway, despite protections, and there are so many different types that it’s really impossible to account for exact amounts of radiation doses everybody receives. For example I saw somewhere that cigarette smokers get tons more radiation than any astronauts!
What needs to be built is a radiation shield for my yam megafarts.
Using Freeman Dyson's concept of nuclear explosions behind a vast space vessel, if a shield could be built carefully enough to allow my intense gas explosions to power the vessel forward without subjecting the explorers to the Intergalactic Dutch Oven Syndrome or IDOS, then I volunteer to be the energy source.
I looked up a couple of things about terraforming mars, and it might even be possible to "smash" meteorites into mars containing metals to try and "re-activate" the magnetosphere of mars, as this is supposedly how the magnetosphere of our planet was activated. I also read the links, quite interesting stuff... melting ice from the pole caps would release CO2 and eventually thicken the atmosphere. Or we send stephen on a rocket with his yams and make him thicken the atmosphere with his farts (+ provide methane as fuel for the spaceship). he would also plant yams on martian ground to increase O2-levels in the atmosphere.
Yes, but the book is more detailed and closer to the actual science.
The problems if living on Mars are more difficult than the cavalier attitude of the Space-X venture. We'll see. I hope we're talking about it on Richards 105 birthday.
RE: Space-X Falcon Heavy Launch (in reply to estebanana)
I see great potential in the Faulkin Heavy Project. Not only can the magnificent propulsion source be used for the journey, but once there its by-products can be used to enrich the soil!
I was obviously fooling around. radiation e.g. is a big problem that needs to be considered when planning on staying on mars for a longer period of time. to ensure living on mars you can't get past terraforming, and this would take centuries at the very least. so yeah, let's wait for ricardo's 105th
Posts: 3488
Joined: Jan. 20 2004
From: Austin, Texas USA
RE: Space-X Falcon Heavy Launch (in reply to jalalkun)
Shielding the Mars pioneers from ionizing radiation is necessary because it disrupts synapses, and indeed entire cells in the brain. Large enough doses lead to cognitive decline. The effects are noticeable in some people who receive radiation treatments for brain cancer. Animal experiments indicate that high enough levels of damage can be long lasting, if not permanent.
Our magnetosphere shelters us from the full force of the solar wind, but a few particles leak through. We have evolved to survive the lifetime dose, pretty well. Shielding alternatives that I know of cost weight, the main nemesis of the rocket designer. Each ounce of payload weight is multiplied by the weight of the required additional structure, and a very heavy penalty in required fuel, fuel tankage, etc.
The Apollo astronauts survived the Van Allen belt and translunar space without visible long term effects. I recollect reports of occasional visual light flashes, tentatively attributed to ionizing radiation. However, the possibility of a large solar flare was a worrying prospect. Radiation exposure was monitored by instrumentation on the spacecraft, but above a certain threshold the medical officer (often my brother) was to be notified. I never asked him what, if anything, they might have done.
I seriously doubt that a practical threshold of safe radiation exposure is known. There are legal guidelines in the USA, generally considered to be very conservative. For example, people who work near high power radar transmitters are required to wear X-ray badges. If their exposure exceeds a certain threshold, they are removed from the environment for a period of time, and management are required to make engineering changes to lower the radiation level.
Space travel introduces two more variables: how much risk are you willing to take to save weight? and how do you quantify the risk relative to the level of exposure to high energy particles? The first question is an ethical one, the second scientific.
I am reminded of a conversation I had with my brother. While we were visiting them he came home one day saying he had been battling with the engineers. They were specifying the backup life support system for the Apollo spacecraft. The engineers were badgering him with the question, "What is the minimum amount of oxygen required to sustain human life?"
My brother responded that the answer was unknown to medical science.
"Well, can't medical science find out?"
"No," he replied.
"Why not?"
"We take an oath not to intentionally kill anybody."
Of course the oath reads, "First, do no harm." How you quantify the risk of radiation damage without doing harm to anybody is a vexed question. Animal studies are a fairly blunt instrument if you're trying to quantify the effects on human cognition.
"Anything you do can be fixed. What you cannot fix is the perfection of a blank page. What you cannot fix is that pristine, unsullied whiteness of a screen or a page with nothing on it—because there’s nothing there to fix."
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