The knotty problem of human quarantine - and what about exposure of humans during a robotic sample return?

This section may seem controversial, because, after all, the idea for Apollo surely was that quarantine would protect Earth. But as we saw, the Apollo regulations have never been debated publicly, as they were published on the day of launch to prevent the delays that would result from a public discussion of them. So, even if those were applied perfectly, with present updated knowledge, would they protect Earth?

You might well think this is only an problem for humans returning to Earth. How is human quarantine an issue for a robotic sample return?

Well, when you think it over some more, we have to think about what we do in the case of accidental exposure of humans to the materials returned from Mars. This could happen in many ways:

It doesn't matter much how they got in contact with the Mars samples, whether that happens on Mars or on Earth, so the situation is rather similar actually. If that happens to anyone, surely they would have to be quarantined too just as for astronauts that contact the materials on Mars?

It's the same also if the sample is returned to the ISS or to the Moon and examined by astronauts there. An astronaut exposed in the ISS or on the Moon is much the same as a sample handler exposed in a facility on Earth. If they contact the Mars sample, they become a potential carrier of any life that is in it. It's an issue in any scenario that has humans in close proximity to the samples and with some possiblity of an accident or intentional act leading to them contacting the samples.

So you can't really separate out the procedures for return of astronauts from Mars and for robotic return of a sample, unless you can guarantee that there is no possibility at all of human contact with the materials in the sample.

An example of a return that could keep this clear separation between robots and humans would be a return to a satellite above GEO. So long as it is studied only robotically and any material returned from the satellite to Earth is sterilized, then there is no way humans can contact any life in the sample. I cover this in the section If likely to be of greater astrobiological interest - return samples to above GEO

But, so long as humans can contact the sample, accidentally or through intent, then there will have to be provisions in place to deal with that situation. So then, the ethical and legal issues are similar to the case of an astronaut who visits Mars.

First, what kind of a hazard are we talking about here. If you haven't come across the scientific papers and workshops and studies on this issue before, the chances are you're first thought will be of the "Andromeda strain" or some other science fiction scenario. In that case it's viruses from outer space. But as we've seen in this book, viruses aren't a likely problem for humans going to Mars, because they generally have to be adapted to their host, or something closely related. Any life on Mars has never encountered humans before so can't be adapted to us (though it may be capable of genetic transfer to our microbes)

The situation is rather similar to the forward direction of contamination of Mars by Earth life, with the additional complication that we have to look at effects on higher animals and humans, as well as human activities.

We have already looked at the many ways that Mars life could be hazardous to humans and also to the biosphere of the Earth, so here is a quick summary.

You might think "surely we know how to do this", looking back at Apollo. Couldn't we just handle it as they did, put the astronauts in quarantine for a few weeks on return to Earth. But those quarantine precautions never had any peer review. They were published on the day of launch. And they were not even applied properly at the time, as we saw above in Example of Apollo sample return - learning from our mistakes in the past (above). Buzz Aldrin noticed ants found their way into the quarantine facilities while he was in quarantine. Earlier, the command module hatch was opened when they landed, and dust from the Moon surely went into the sea at that point, and before that, the vents were opened to the atmosphere after re-entry, and there were other breaches of protocols as well. It's thought nowadays to be more useful as an example of what can go wrong.

What if we did this today, better, applying the rules perfectly and using modern technology ? Would a three weeks quarantine, or even a ten years quarantine protect Earth? There was no opportunity for anyone to discuss such questions at the time of Apollo. But the situation is changed. These issues would have to be debated at length today. There is simply no possibility at all, in the world as it is now, of avoiding public debate, as they did for Apollo.

So what sort of issues are there?

If we were to attempt to use quarantine today, for humans who have been in contact with the returned samples, or for astronauts returning from Mars, then problems with this approach include:

Well in practice, I think it is pretty clear that if anyone who has been exposed to the sample becomes seriously ill, they will be rushed to hospital and not permitted to die in the quarantine facilities. If you try quarantine in orbit, they will be returned to Earth as soon as they encounter any really serious health issue, especially if it requires surgery.

Could you ethically keep them inside anyway, if they get seriously ill in the quarantine facilities? It's different perhaps if you know for sure that it is a hazard for Earth to take them out. But if you don't know that for sure?

In practice, they might well be taken out of quarantine just for cases of minor discomfort, if the chance of the sample being hazardous to Earth was still thought to be very low. This was another of the lessons from Apollo. Carl Sagan wrote about this, in his "Cosmic Connection"::

"The one clear lesson that emerged from our experience in attempting to isolate Apollo-returned lunar samples is that mission controllers are unwilling to risk the certain discomfort of an astronaut – never mind his death – against the remote possibility of a global pandemic. When Apollo 11, the first successful manned lunarlander, returned to Earth – it was a spaceworthy, but not a very seaworthy, vessel – the agreed-upon quarantine protocol was immediately breached. It was adjudged better to open the Apollo 11 hatch to the air of the Pacific Ocean and, for all we then knew, expose the Earth to lunar pathogens, than to risk three seasick astronauts. So little concern was paid to quarantine that the aircraft-carrier crane scheduled to lift the command module unopened out of the Pacific was discovered at the last moment to be unsafe. Exit from Apollo 11 was required in the open sea."

At the very least it's a very tricky ethical and legal area. Even if they consent beforehand to be left to die there to protect Earth, can you hold them to that in the event that it happens, especially if you have no idea whether there is some extra terrestrial cause? It might well be some Earth based illness that needs to be diagnosed in the advanced facilities of a modern hospital to save their lives.

Then there's what Carl Sagan called "The vexing problem of the latency period", again from "Cosmic Connection"

"There is also the vexing question of the latency period. If we expose terrestrial organisms to Martian pathogens, how long must we wait before we can be convinced that the pathogen-host relationship is understood? For example, the latency period for leprosy is more than a decade."

Also though, all that is based on the assumption that we need to protect humans from diseases of humans and that nothing else matters.

If quarantine is going to be effective as a way of protecting Earth, we have to think through such questions. It's obviously not going to be an effective method to protect Earth, if we have a policy that mission planners can drop any of the requirements whenever there is any problem that impacts on the humans involved.

Yet, surely human rights and health have top priority? Even if all the scientists and workers with a risk of contacting a sample sign a voluntary agreement to not be taken out of quarantine in any circumstances, even in event of serious illness and threat to life, can they legally, be held to such an agreement? It seems to conflict with basic human rights.

What if they change their mind once their life is threatened, or if it becomes clear there is no way to sterilize them of a serious threat to the environment of Earth and they have to stay in there for the rest of their life?

Incidentally it's also similar for people who volunteer on a one way mission to Mars. Apart from issues of forward contamination, what if they want to come back to Mars later on? That's like someone who agreed to stay in the quarantine facility changing their mind once they discover they have to stay there for weeks, months, years or even the rest of their life to protect Earth.

For all these reasons I think there is almost no point in attempting to use quarantine to protect Earth or to protect humans on Mars. It's largely symbolic and would give a false sense of security. It doesn't matter where you do the quarantine either, on Mars, or the journey back, or in orbit around Earth, or on the Moon, or back on Earth, none of that helps, so long as you accept that the humans involved have to have the right to return to Earth and to get medical treatment and help in the event of life threatening conditions, or to change their mind and make the decision to exit any quarantine facilities whatever their previous decision was, and whatever legal documents they might have signed.

For the same reason, I can't see how it can work for robotically returned samples either, unless you can somehow ensure that there is no chance at all of accidental exposure of humans to the materials.

I think that the answer here is that there is no substitute for knowing what is in the samples before they are returned to Earth. For as long as you don't know if there is life in them, or don't know what it's capabilities are, then you need to sterilize any samples returned here.