SpaceX to send privately crewed spacecraft beyond the moon next year

Not only that, how will they tell the world that it's not possible to go to the moon since the apollo missions were fake. Ha! This will only create more conspiracies.

It's such a refreshing change to have a world leading expert on Van Allen radiation here on ATS. Pray tell, how does Van Allen radiation affect moon trips? In your own words, not from a wacky conspiracy website.... And with the math to back it up?

It is exicitng to know that SpaceX wants to do this, and I think it is great. I just hate to see so many pessimistic people posting in here as well as when I talk with others in the real world. People saying something can't be done is half the problem with why we aren't going past low earth orbit these days. Put all the doubts aside and we should cheer this on. Yes, it is a risk, but it also has a reward. Honestly I am really surprised we haven't gone back to the moon since when we last did.

I say, if it can be reasonably done, do it. Stop beating around the bush. It's time to s*** or get off the pot. I do agree that the timeline seems a bit sudden but I think it should and will be done within the next 5 years. Hell, if I could take the ride, I would in a heartbeat!

originally posted by: Naturallywired

originally posted by: RAY1990
a reply to: Naturallywired

Belt is just a namesake, think of it like a layer of gobstopper that you really don't like...

Ideally you want to pass through it extremely fast, spending a minute in the microwave would be more appealing than a minute in the Van Allen belt.

It's not a good place to be.

See! Right there, you say "Pass through it" I say " go over it; it's just a belt.

The Van Allen radiation belt is not a "belt" like you'd wear around your waist.

There are diagrams and descriptions available on the internet.

The Van Allen is structured more like the layer of an onion, or like the atmosphere itself. The major difference is that this layer is not evenly distributed around the Earth like earth's atmosphere; the Van Allen is much thinner at the poles than it is around the equator. It is this structure that defines the "beltness" of the field.

Lead may effective shielding against radiation, but it is impractical for use in spacecraft due to lead's weight. Beryllium was the shield material of choice, I believe, used for Apollo.

The other key to surviving the radiation of the Van Allen belts is speed; You pass through the thinnest part of the belt you can (based on your optimal trajectory to the Moon) and you do it as fast as you can, thus limiting your exposure.

Again, all of this is in the histories, if anyone would just take the time to look it up!

My question is this:

It took the Saturn V booster to lift the Apollo missions with sufficient velocity to make those missions survivable.

The physics have not changed, and so the mission requirements are still the same.

Is Musk proposing to develop a man-rated booster with at least the power of the Saturn V in just a year or two?

Good freaking Luck!

a reply to: Bhadhidar

Lead isn't a good shield in many respects because the radiation that hits it knocks off more particles and actually generates even more (google bremsstrahlung).

The Saturn's were massive but they were lifting a much heavier payload than will be involved here. Electronics has created a lot of replacements for mechanics, there's no lander, and there's no need to build in the capacity for rocks to bring home. The Apollo spacecraft also had a massive amount of redundancy built in - if one system failed there was a back up, so if you can reduce the amount of equipment you don't need to take by making the stuff you do have reliable then you cut back a lot on the weight.

As for the OP, I think it's fantastic - but let's hope this has been in the pipeline for a while, a year seems very tight!

a reply to: Bhadhidar

Still a BELT. And there is a overpass. Prove me wrong.

originally posted by: Bhadhidar

originally posted by: Naturallywired

originally posted by: RAY1990
a reply to: Naturallywired

Belt is just a namesake, think of it like a layer of gobstopper that you really don't like...

Ideally you want to pass through it extremely fast, spending a minute in the microwave would be more appealing than a minute in the Van Allen belt.

It's not a good place to be.

See! Right there, you say "Pass through it" I say " go over it; it's just a belt.

The Van Allen radiation belt is not a "belt" like you'd wear around your waist.

There are diagrams and descriptions available on the internet.

The Van Allen is structured more like the layer of an onion, or like the atmosphere itself. The major difference is that this layer is not evenly distributed around the Earth like earth's atmosphere; the Van Allen is much thinner at the poles than it is around the equator. It is this structure that defines the "beltness" of the field.

Lead may effective shielding against radiation, but it is impractical for use in spacecraft due to lead's weight. Beryllium was the shield material of choice, I believe, used for Apollo.

The other key to surviving the radiation of the Van Allen belts is speed; You pass through the thinnest part of the belt you can (based on your optimal trajectory to the Moon) and you do it as fast as you can, thus limiting your exposure.

Again, all of this is in the histories, if anyone would just take the time to look it up!

My question is this:

It took the Saturn V booster to lift the Apollo missions with sufficient velocity to make those missions survivable.

The physics have not changed, and so the mission requirements are still the same.

Is Musk proposing to develop a man-rated booster with at least the power of the Saturn V in just a year or two?

Good freaking Luck!

I don't need to prove anything, look it up, we already made it to the moon.

originally posted by: Naturallywired
a reply to: Bhadhidar

Still a BELT. And there is a overpass. Prove me wrong.

Your "overpass" exists at the north and south poles.

Do some research and find out why launching from either pole is impractical for a moonshot.

a reply to: BiffWellington


Crazy rich probably , if you can buy everything you do not want another car or house , you want a to enjoy a experience that only very few people are able to.

a reply to: the owlbear

I think it is reasonable to be somewhat cautious about jumping on a round the Moon cruise with Space X, just at the moment, given the number of exploding rockets they have dealt with. That being said, caution and outright terror are entirely different things, and I for one would be up for a trip around the Moon, if it meant using a proven platform that launches reliably, using a known set up, absent any tweaks or experimental gear.

originally posted by: LightSpeedDriver
a reply to: Naturallywired

It's more a bag than a belt. Imagine a region of space so toxic to humans that to pass through it on the way to the Moon without serious shielding materials (think Lead) would be a serious hazard to your health. And that's just the way there...

Dense metals such as lead are a very bad type of shielding for the type of cosmic radiation found in the Van Allen Belts. The radiation can knock particles out of the atoms of the metal, with those particles causing a secondary radiation called Bremsstrahlung.

Fibrous materials -- such as was used in the insulating material between the inside and outside skins of the Apollo capsule -- works better for that type of radiation.

Plastics (such as polyethylene) also make a good shielding for the type of cosmic particle radiation found in space, and are currently being studied for use in long-term manned missions, such as a mission to Mars:

Plastic Could Protect Astronauts from Deep-Space Radiation

a reply to: Soylent Green Is People

It was intended as an example only but probably isn't a good or accurate one for cosmic rays instead of (medical) radiation sources. However, the following from Wikipedia (yeah, I know...) tells us that they "don't know" either.

Link to Health threat from cosmic rays

None of these strategies currently provide a method of protection that would be known to be sufficient[48] while conforming to likely limitations on the mass of the payload at present (around $10,000/kg) launch prices. Scientists such as University of Chicago professor emeritus Eugene Parker are not optimistic it can be solved anytime soon.[48] For passive mass shielding, the required amount could be too heavy to be affordably lifted into space without changes in economics (like hypothetical non-rocket spacelaunch or usage of extraterrestrial resources) — many hundreds of metric tons for a reasonably-sized crew compartment. For instance, a NASA design study for an ambitious large spacestation envisioned 4 metric tons per square meter of shielding to drop radiation exposure to 2.5 mSv annually (± a factor of 2 uncertainty), less than the tens of millisieverts or more in some populated high natural background radiation areas on Earth, but the sheer mass for that level of mitigation was considered practical only because it involved first building a lunar mass driver to launch material.

Do they even have a human-rated rocket and spacecraft? If anything, the first commercial human spaceflight should be simply a few orbits around the Earth.

originally posted by: LightSpeedDriver
a reply to: Soylent Green Is People

It was intended as an example only but probably isn't a good or accurate one for cosmic rays instead of (medical) radiation sources. However, the following from Wikipedia (yeah, I know...) tells us that they "don't know" either.

Link to Health threat from cosmic rays

None of these strategies currently provide a method of protection that would be known to be sufficient[48] while conforming to likely limitations on the mass of the payload at present (around $10,000/kg) launch prices. Scientists such as University of Chicago professor emeritus Eugene Parker are not optimistic it can be solved anytime soon.[48] For passive mass shielding, the required amount could be too heavy to be affordably lifted into space without changes in economics (like hypothetical non-rocket spacelaunch or usage of extraterrestrial resources) — many hundreds of metric tons for a reasonably-sized crew compartment. For instance, a NASA design study for an ambitious large spacestation envisioned 4 metric tons per square meter of shielding to drop radiation exposure to 2.5 mSv annually (± a factor of 2 uncertainty), less than the tens of millisieverts or more in some populated high natural background radiation areas on Earth, but the sheer mass for that level of mitigation was considered practical only because it involved first building a lunar mass driver to launch material.

The issue becomes important when only long-duration (months or years) spaceflights outside the Earth's protection are considered, and that is due to the length of time exposed to the radiation. The longest Apollo flights lasted only one to two weeks, while the Space shuttle and space station get protection from the magnetic field surrounding the Earth.

The potential SpaceX trip around the Moon mentioned in the OP would not be long enough to require huge amounts of shielding. The exposure time would be within acceptable risk limits for the limited shielding that SpaceX capsule provides.

originally posted by: BiffWellington
Wow. What must it be like to be an individual with the means to buy a trip around the moon just for the fun of it?

I think that is popularly known as "F you" money

I dont think id be up for one of the first trips around the moon, nor would i go if it cost me a majority of my money however, a trip around the moon? Ohhhh yes please!

originally posted by: the owlbear

originally posted by: schuyler

originally posted by: the owlbear
SpaceX is awesome, don't get me wrong, but didn't two of their last three supply missions to the ISS fail?
Unless Elon is willing to hop on board with me, there is NO WAY I'd even consider going around the moon on one of his ships.

Same goes for Branson and Bezos for that matter.

How fortunate that you won't be forced to go! I'm guessing many people don't share your fears, so the fact that you have them is more like a personal issue.

Sorry, it's the simple fact that if the financial backers aren't willing to take the risk, I won't either.

Sorry, but they already have. Musk has received "substantial deposits" for the flight. So much for that argument.

originally posted by: schuyler

originally posted by: the owlbear

originally posted by: schuyler

originally posted by: the owlbear
SpaceX is awesome, don't get me wrong, but didn't two of their last three supply missions to the ISS fail?
Unless Elon is willing to hop on board with me, there is NO WAY I'd even consider going around the moon on one of his ships.

Same goes for Branson and Bezos for that matter.

How fortunate that you won't be forced to go! I'm guessing many people don't share your fears, so the fact that you have them is more like a personal issue.

Sorry, it's the simple fact that if the financial backers aren't willing to take the risk, I won't either.

Sorry, but they already have. Musk has received "substantial deposits" for the flight. So much for that argument.

So why isn't Elon himself taking the 1st flight? Hmmmm?

originally posted by: RAY1990
a reply to: PassiveInductor

Nuclear Thermal Rockets

Thought you'd be interested.

I appreciate the link -- very interesting indeed!

I am struck by this one particular paragraph (towards the middle of the article, at the start of the "History" section):

Development of such engines started under the aegis of the Atomic Energy Commission in 1955 as Project Rover, with work on a suitable reactor starting at Los Alamos National Laboratory and Area 25 in the Nevada Test Site. Four basic designs came from this project: KIWI, Phoebus, Pewee and the Nuclear Furnace. Twenty rockets were tested.

Check it out! Twenty rockets tested -- in 1955! That was a long time ago. This was all being thought through carefully more than 60 years ago! So it seems like we have the knowledge and competencies. What is it then? We don't have the desire?

Fortunately, SpaceX seems to be taking this seriously, and perhaps can make rapid progress.

I really think they can do it. Thanks for the info Ray.

a reply to: PassiveInductor

Such nuclear rockets have a relatively low thrust to weight ratio. And then there is the issue of radioactive fallout in the case of a failure.

a reply to: PassiveInductor

At the time we were seeing a massive expansion in nuclear weaponry and power generation - it was seen as an amazing new resource. The teensy weensy problems of all that fall-out, the risk of catastrophic accidents and the threat of global annihilation kind of put the dampeners on it.

a reply to: BenSisko

SpaceX to send privately crewed spacecraft beyond the moon next year

I hope they do.

I remember the night when Apollo 11 landed... I was young and completely sensationalized by the entire visit.
I hope that it happens again before I croak.