Radiation and life support

[Dalhousie]

On another board (not hoax-related) a poster (not a HB) has claimed that current life support technology will not work beyond Earth orbit because of the much higher radiation levels, requiring a whole campaign of testing in lunar orbit, L5 etc., starting with unmanned missions.

I know of no evidence to support this assertion and am extremely sceptical.  But, to be certain, does anyone here know if this was this ever discussed during the lead up to Apollo and were any problems ever encountered?

[ka9q]

There's no reason why a life support system that works in earth orbit shouldn't work in deep space. The only consideration, as you say, is the radiation environment. There's a fairly steady stream of extremely high energy particles called cosmic rays that are almost impossible to stop, but fortunately their rate is low enough to not be a serious short-term health concern.

The sun emits a much heavier stream of charged particles called the "solar wind" but they're usually weak enough to be stopped by the spacecraft structure or minimal shielding. The real problem are the occasional "coronal mass ejections", large masses of charged particles thrown off irregularly by the sun that can be quite energetic. Depending on how much risk you're willing to accept, this could be a serious problem for a long interplanetary mission.

Shielding charged particles is ideally done with lighter elements, especially hydrogen. One of the common suggestions is to place the water and rocket propellant tanks around the living area.

[Luke Pemberton]

The real problem are the occasional "coronal mass ejections", large masses of charged particles thrown off irregularly by the sun that can be quite energetic.

You could set yourself up for some quote mining here. CMEs are not that occasional, they occur quite frequently. It's a certain type of CME that creates the occasional energetic solar storms akin to the August 1972 event and the 2003 Halloween storm. The most recent literature that I have read from the SOHO research describes a correlation with 'CME speed' and the probability of a solar storm.

If this speed  is greater than that of the solar wind then a favourable charge distribution occurs in the solar plasma that shock drives protons to GeV energies. My main desk top computer is in another country right now, and that is where all the literature I have on this subject is stored (bad planning on my part). If I recall correctly, 99% of CMEs have a speed less that that of the solar wind, so the conditions to drive protons to GeV energies are rare.

Another issue, and this is me getting on my hobby horse, is that solar flares are different to these rare CME events. A certain antipodean hoaxer attributes proton radiation levels from such CME events to every H-alpha event in the NOAA record. There are many more issues with his calculations and how he treats flares, but he never got past base 1 with Jay and others at the IMDB regarding the correlation between proton fluxes and H-alpha events.

Since our friend at YouTube is allowed to invoke NOAA data, I'm still waiting for him to invoke this page from the NOAA source he is so keen on. It gives a really good overview of the rarity of such events. There's plenty of interesting data in the NOAA archives, if you are prepared to dig, and it shows that the proton flux levels in space are not awash with GeV protons that often.

NOAA Space Weather Cycles

An S5 event is the most extreme event and may not even occur in a cycle. The 1859 Carrington event is one such example and proves to be an interesting case study when considering our antipodean friend and the IMDb debacle.

After that public mauling he claimed that it was impossible to correlate H-alpha events with proton fluxes before 1972 because there was no proton data before 1972, and Jay was just being a big poopy face again by asking questions that he could not possibly answer. Of course, he was royally found out by Jay, and once he realised that he could not correlate H-alpha data with proton fluxes he attacked Jay's line of questioning.

This of course begs the question: What data has our antipodean been using to calculate radiation exposures if there is no proton data before 1972?

There is proton data from before 1972, and our antipodean friend knows this because he is using data from a pre-1972 CME event which is based on proton data gathered with weather balloons. He has royally dodged the IMBd question by accusing Jay of asking for the impossible, but conveniently forgets the data he uses is derived from proton data.

Which is why I invoke the Carrington event, a pre-space age, pre particle-physics age CME event. How do we know that this was a powerful CME event? The answer can be from ground based records and correlating them with ice core samples.

Sorry for the digression.

[Dalhousie]

Thanks for the comments.  let me reiterate and expand so there is no misunderstanding.

1 The question was not on a hoax board (but general space one).

2 The statement was not by a HB (but someone with a general interest in space.

3 The issue is nothing to do with radiation effects on the body, communications or electronics, but on life support systems

4 The person seems to think that the BEO environment is sufficiently different to LEO (especially WRT radiation) that experience with life support systems gained in LEO cannot be extrapolated to BEO (e.g. on a Mars mission).

I know of no such evidence (and am 95% confident that there isn't) but was hoping that there would be some relevant Apollo era literature on this.

Thanks! Dalhousie

[ka9q]

Okay, in that case I can't think of any reason why a life support system that works in low earth orbit wouldn't also work anywhere in the solar system. You provide oxygen, remove water and carbon dioxide, and regulate temperature and pressure.

About the only difference would be the thermal environment; in low earth orbit you are going in and out of sunlight over a dozen times per day, while in interplanetary space you are in continuous sunlight. That's an issue for any spacecraft, and it's nothing special for one with a crew.

[smartcooky]

..... the (1859) Carrington event, a pre-space age  pre particle-physics age CME event. How do we know that this was a powerful CME event? The answer can be from ground based records and correlating them with ice core samples.

I found this interesting, so I looked it up

http://www.history.com/news/a-perfect-solar-superstorm-the-1859-carrington-event


"That night, telegraph communications around the world began to fail; there were reports of sparks showering from telegraph machines, shocking operators and setting papers ablaze. All over the planet, colorful auroras illuminated the nighttime skies, glowing so brightly that birds began to chirp and laborers started their daily chores, believing the sun had begun rising. Some thought the end of the world was at hand, but Carrington’s naked eyes had spotted the true cause for the bizarre happenings: a massive solar flare with the energy of 10 billion atomic bombs. The flare spewed electrified gas and subatomic particles toward Earth, and the resulting geomagnetic storm—dubbed the “Carrington Event”—was the largest on record to have struck the planet. "


I shudder to think what the effect would be if one of these happened today!

[Luke Pemberton]

..... the (1859) Carrington event, a pre-space age  pre particle-physics age CME event. How do we know that this was a powerful CME event? The answer can be from ground based records and correlating them with ice core samples.

I found this interesting, so I looked it up

http://www.history.com/news/a-perfect-solar-superstorm-the-1859-carrington-event


"That night, telegraph communications around the world began to fail; there were reports of sparks showering from telegraph machines, shocking operators and setting papers ablaze. All over the planet, colorful auroras illuminated the nighttime skies, glowing so brightly that birds began to chirp and laborers started their daily chores, believing the sun had begun rising. Some thought the end of the world was at hand, but Carrington’s naked eyes had spotted the true cause for the bizarre happenings: a massive solar flare with the energy of 10 billion atomic bombs. The flare spewed electrified gas and subatomic particles toward Earth, and the resulting geomagnetic storm—dubbed the “Carrington Event”—was the largest on record to have struck the planet. "


I shudder to think what the effect would be if one of these happened today!

There is little in recent history to compare with the Carrington event, even the 1972, 1989 and 2003 storms were 'small' in comparison. The description you quote is why the hoax crowd do not understand the radiation problem. Solar flares are really quite localised events on the surface of the Sun, whereas solar storms are due to a specific type of CME event.

It's the latter that would cause problems for astronauts on an EVA or a capsule in space. The 1972 event, which the hoax fraternity cite, would have caused significant problems for an EVA and certainly made the astronauts in the CM ill. The research I have read estimates that the astronauts would have received 50 rem in the CM had they been in space when the 1972 event erupted.

NASA does not help its cause with websites like  'sickening solar flares.' They should be called 'sickening CME shock driven solar storms.' 

I really do need to get my computer and gather all the information. I have a paper that lists the dates of Solar Proton Events right back to 1950s, and this categorically shows that no Solar Proton Events occurred during an Apollo Mission.

{EDIT: Typo}

[Noldi400]

Thanks for the comments.  let me reiterate and expand so there is no misunderstanding.

1 The question was not on a hoax board (but general space one).

2 The statement was not by a HB (but someone with a general interest in space.

3 The issue is nothing to do with radiation effects on the body, communications or electronics, but on life support systems

4 The person seems to think that the BEO environment is sufficiently different to LEO (especially WRT radiation) that experience with life support systems gained in LEO cannot be extrapolated to BEO (e.g. on a Mars mission).

I know of no such evidence (and am 95% confident that there isn't) but was hoping that there would be some relevant Apollo era literature on this.

Thanks! Dalhousie

If the individual isn't an HB, he seems to have overlooked the fact that we do indeed have experience with BEO life support systems - 9 manned lunar missions (6 involving surface EVAs).  I would think that the evidence is simply that there is no mention of unforeseen problems with life support caused by radiation.

[Dalhousie]

If the individual isn't an HB, he seems to have overlooked the fact that we do indeed have experience with BEO life support systems - 9 manned lunar missions (6 involving surface EVAs).  I would think that the evidence is simply that there is no mention of unforeseen problems with life support caused by radiation.

Exactly, so that is 9 CSM and 8 LM flights, Add Zond 4-8 and we have 22 missions providing life support experience BEO