قالب وردپرس درنا توس
Home / Science / Probably 2040 Before Mars samples returned safely and legally – and probably will not answer astrobiology questions

Probably 2040 Before Mars samples returned safely and legally – and probably will not answer astrobiology questions

The BBC has just reported that ESA has signed a Memorandum of Understanding to collaborate with NASA on a Mars sample return (see Agencies to Return Stones from Mars). I hope that does not change the focus for ESA from in-situ research to sample return. This expensive NASA program is more like an astrobiology technology demo than an astrobiology mission. It is unlikely to solve any of the main questions in astrobiology, but when they return an unstructured sample, there is so much legal and technical implication in protecting the Earth's environment that it is very unlikely that they will be ready to return a sample for 2040. It is quite possible that it will not be possible until 2050 or later.

This is based on estimates of the likely timing of the establishment by the NRC and on Margaret Race's investigation of the required legal processes. What makes protecting the Earth's environment so legally and technically complex is that, until we know what life is like on Mars, they must design a facility that can contain every possible form of astrobiology from Mars, if that is the only one Life that we know is on earth.

Well, if Mars were like the earth, if it had life everywhere, wherever there was organic matter, astrobiologists would be thrilled with such a mission, and if it did not land in a very cold, dry desert they are bound to give back some life in the rehearsal. But Mars is different from Earth in many ways, making this simple scenario unlikely. First, it is predicted to be swamped with organs falling into dust, meteorites, and comets, which would overwhelm both today's life and the few remaining vestiges of past life, if they exist. On Earth, there are almost all places where there are organic substances, also past life or traces of past life.

It is then expected that both life in the past and present on Mars will be very difficult to detect.

Today's life could be anywhere on Mars, but only occasionally in cheap thin salt lakes and scattered spores in the dust. The past life could be back, but in hard-to-find deposits because they may have been left only in short warm periods of hundreds of thousands to a million years or so in the distant past. They would be several meters underground and perhaps only in certain places like deltas or hydrothermal springs. Any past life that has been near the surface for hundreds of millions or billions of years is long gone. Although ionizing radiation has not been sterilized for thousands of years, over billions of years it would completely transform all amino acids and nucleotides in any surface organism from life. Most of it disintegrated into water vapor and gases.

It would not be so important if there were not the cost and complexity of this mission. It might be useful to have a low-cost technology demo. Chris McKay suggested landing a mission on Mars, collecting a handful of dust and sending it back to surface for a few days, a simple low-cost mission. This is the only suggestion for a sample return from an astrobiologist that I have seen. But his suggestion was not heard.

Instead, they went to this monster of a mission that traveled across Mars, trying to pick a perfect set of samples according to geological and non-astrobiological criteria and then put them in heaps as sample caches. A decade later, another expensive successor rover comes to collect them. It may be necessary to travel over much of the same land again, but it's only up to you to pick up the samples and bring them back to Earth.

Everything else due to new missions to Mars had to be annulled by NASA ̵

1; this elaborate and expensive mission is possible not just for a decade, but for two decades. Meanwhile, with its TGO, ESA has been able to detect traces of trace gases in the atmosphere in tiny tracks, and their ExoMars are able to drill. They seem to be making progress towards a possible in situ astrobiology mission in the not-too-distant future. It would be very unfortunate to refrain from focusing on a demonstration of the demo technology that has proven to be such a sink for NASA's finances for Mars.

Then, after all, the process of planetary protection for a sample return is so complex that we could be, legally and practically, happy to have all of the Mars 2020 samples returned before 2040. This is not possible through COSPAR.

Maybe the idea is that the legal process can be set aside as for Apollo? If anyone thinks so, Margaret Race's study makes it clear that such abbreviations are no longer allowed when it comes to laws protecting the environment on Earth.

I will explain how I get to this estimate from 2040 earliest date, and you can look at it and see if you agree or see how it could be shortened. But first, let's start by explaining why astrobiologists consider it little more than a technology demo for their discipline.


Modern Mars has a steady influx of organic matter from meteorites, comets, and interplanetary dust. Sufficient for 60 ppm, averaged to a depth of 100 meters (see page 10 of this article)

There are no large deposits of organics from antiquity there or we would have discovered them. The young Mars was potentially almost as habitable as Earth, but not very long compared to Earth. It may never have developed photosynthesis, and if so, it may have been too late in its history to deposit thick deposits before it became too dry for abundant life.

There may be evidence of past life there, maybe the old hydrothermal springs, maybe in mud layers, in deltas, there are many places to look for it. But it is urgent to drill or otherwise get lucky, the right layer exposed quickly enough by a meteorite or by wind erosion, because the organic components are completely destroyed for billions of years of time. Most of the past organic matter on or near the surface will be long gone and covered with organic matter from interplanetary space.

There may be life on Mars today, but it is on the verge of habitability. It is a planet that used to be very livable, but although it now seems so dry and sterile, there is evidence of habitats that may live in conditions that have been marginally livable for billions of years, with occasional periods of the atmosphere thickening short and life spreads a bit. Hundreds of millions of years in the future, the earth can become so hot that only a few heat-resistant life forms dwell in high caves in mountains. Mars may be an example of a similar "Swansong Biosphere," but this time life lives on a planet so cold that life can barely survive there. The most habitable areas of the Martian surface are probably similar to some of the least habitable areas of the world, our coldest, driest deserts. Nevertheless, life can be there.

Today's Mars is not completely uninhabitable. It has confirmed liquid brine sheets. They may all be too cold or too salty, but they could also have habitable brines and even fresh liquid water trapped under the ice in tiny amounts. Tiny amounts, but a swimming pool for a microbe, as Nilton Renno put it.

There could also be spores in the dust. Most of these proposed habitats are in the high latitudes. But even in equatorial regions there are several possibilities for life. None of this can be cached by Mars 2020 and returned to Earth, except by chance, because it can not see it.

The reason they say that this is a technology demo and not an astrobiologically oriented mission is because there are none that are capable of uniquely recognizing life in situ, and because they are not looking for life, both Astrologers have the highest priority.

If Mars 2020 found source rocks that match the Tissinth and ALH84001 meteorites on Mars, it would drill into them and return the cores as their top priority.

The result is likely to be as controversial as those meteorites and does not solve any of the major astrobiological questions about Mars. And this is a best-case scenario as these rocks were sent to Earth at least one meter below the Earth's surface.

Meanwhile, it would not be able to discover life among all meteorite organics. Astrobiologists have warned in many articles before.

If the samples returned do not have much astrobiological interest, this will be exactly what they have been predicting all the time.

Mars 2020 could drill a sample to return only a few inches on the side of a bit of endolithic life in a rock and not know it's there because it can not detect it. It could travel on biofilms, a few inches below the sand it rides on every day, and again there's no way to know it's there.

There could be almost untouched organic substances from ancient Mars two meters below its tracks and again. I would not know that, and there would be no way to reach them, if they knew that.

The Mars 2020 sample tubes are not even completely sterilized (they allow a small chance of a viable microbe in the tubes)

In my opinion, they should not call it an astrobiology mission. You can call it a geology mission, the samples would be great for geologists. As far as astrobiology is concerned, it would be more appropriate to refer to it as an astrobiological technological demonstration. A demo to show how they could return interesting interests to astrobiologists in the future, after sending in situ astrobiology tools to Mars.

That's no problem. This is of interest for astrobiology. The problem is that they have prioritized this sample survey mission to the extent that it is favored over many proposals for astrobiological instruments that are unlikely to fly until sample return is completed.

It is so expensive and difficult mission that they simply do not have the budget to do in-situ astrobiological study of Mars at the same time as a sample return mission. It is a double – decade mission, Mars 2020, to cache the samples and return their successors so that the obligation to rehearse the prospect of another 20 years delay before the first true in situ astrobiological missions to Mars since Viking in the 70s. No one seems to be involved in astrobiology missions on Mars in the near future. And it's not a private mission right now, Kickstarter or Crowdfunding could not raise enough money for an in-situ lander on Mars yet.

Priority for the sample return mission was set high enough for NASA to drop a satellite that was due to launch optical communication in 2022 to receive 800 gigabytes of data per day from Mars. It would have returned missions to Mars more data each day than any data returned from the New Horizons Pluto flyby. This would have made a huge difference to any mission to Mars – for example, the high-resolution orbit imagers could return hundreds of images per day, and rovers on the surface could return multiple gigabytes of 3D panoramas several times a day. You have canceled this on the basis that a Mars example return mission can be performed without this ability. They decided that since it was not absolutely necessary for a sample return, and because the budget is tight (as it always is), it's not their priority at that time.

For the mission, see

For the decision to annul it, as not essential to a Mars sample return:

SAMPLE RETURNS WOULD NOT SHOW THAT MARS 'LIFE FOR EARTH OR EARTH LIFE IS SAFE FOR MARS [19659013] This should be a preliminary mission to verify that it is okay to send people to Mars. But this mission would not prove that Martian life is safe for our astronauts or the Earth's environment. Nor would it prove that Earth's microbes on Mars would do any harm.

It would not even tell us if there is life in the rocks that Mars is drilling in 2020. It could drill a sample cache of a few inches on the side of a piece of life and not find it.

It will not be able to dig out the saline layer that is a few inches below its tracks as it travels over the desert sands and possibly only biofilms that make it habitable for mortality – and it will not be in the Be able to test the dust to see if there are spores in it just below the surface.

Also, it would not be sufficiently sterilized to approach all places on Mars suspected of having sols that might be habitable.

In our understanding of what the Martian or Earth biospheres might do with each other, it would not bring us any closer to a Martian biosphere, and if they collide.

To find it, one needs a correct in situ detection of life – not organic, not high c13 / c12 ratios (Tissint Meteorite has that), not just chirality (carbonaceous chondrites have that). Astrobiologists emphasize that we need a dedicated set of life-recognition tools with multiple simultaneous detection methods to validate each other.

You can certainly do it. MOXIE alone is an instrument that only generates oxygen, does not have to move, and on a rover that does not need oxygen – it could be on any stationary lander like Insight. That's 15 kg, enough for 3-6 astrobiology instruments. The entire range of instruments on Curiosity is 75 kg and that's enough for a dozen to two dozen astrobiology instruments, if the focus was on astrobiology as for Viking – and learn from the mistakes of Viking.

It's the only way. And the ability to drive around and drill in depth.

Otherwise, you will probably only find the organic matter that constantly bombards Mars with meteorites, comets, and interplanetary dust


The planetary Scientist Chris McKay of NASA Ames spans the worlds of astro-physics and astrobiology (he has studied physics, has a doctorate in astro-physics and has since made many research in astrobiology). He is involved in mission planning for Mars and you can find his name on many of the articles in this subject area of ​​extremophiles, life on Mars, Mars-analogous habitats, planetary protection and the search for life in our solar system. He has also written works on Mars Terraforming.

He recommends that we just grab a sample of the Martian soil to show what we can do and bring it back to Earth. Spend a day on the surface. Design the easiest cost-effective way to return a sample from Mars, not a Mars 2020, not a Rover. Just grab it and come back. In this interview he says

" The first thing is to get a mission that draws a heap of loose muck, puts it in a box and brings it to Earth .If I were an astronaut, what? I would be worried, are not the rocks, it's the dirt, the discovery of perchlorate in the dirt worries me, it's poisonous, and the second concern is the fact that it so surprised us No prediction or premonition that there would be any perchlorate in the soil, the fact that it has completely surprised us makes me wonder if there are any other surprises in the ground, I would even be surprised if there were no more surprises You do not need a precise landing, you do not need a rover, you land, take some earth and make it back to Earth, the ground time on Mars could take a day. "[19659047] "… I have been saying for many years that the sample yield should be motivated by a combiner ion of human exploration and science. The science community, I think, does a disservice to itself by arguing that there will only be a single sample return in the history of the universe, so it must be perfect. And a sample return mission that is not perfect should not be considered. I do not understand where the logic is behind it. Let's take a first sample and do a quick and easy sample to demonstrate the key technologies. It builds enthusiasm for the idea of ​​return trips to Mars. It would also facilitate a return to a second example, both programmatically and technically. This argument falls on deaf ears when I try to set it up in the community. "

One of his main concerns is that there is currently no agreement between NASA's Mars strategy and astrobiology, close to the beginning and towards the end (emphasis added):

" When we search for life, seek we after life. I said that until exhaustion in the Mars community. The geologists win hand in hand if they are firmly anchored in the Mars program. The favorite trick is to form a committee to decide what to do. The people who are put in the committee are of course people who are funded to study stones. Therefore, the committee recommends that we study stones. They will say that these rocks will give us the context to search for life on Mars. Then you say, well, that's not true. But NASA's headquarters will say that they asked the science community, and they told us to do that. It's kind of circular. The reason why the committee told you that – it's because you put together a committee of people studying stones. It's almost a catch-22. "

" … Currently, there is no match between the Mars strategy and the Astrobiology . What we have learned from studying Mars is that astrobiology has to go underground. You have to start drilling. Curiosity has an exercise and it has problems and we are now very careful with it. We have to send back to this horse and a bigger exercise. "

In this interview, I do not believe Chris McKay points out that his mission" Grab Sample Return of Dirt from Mars "will likely be astrobiological. Interestingly enough, he sees it as interesting to consider the conditions in the current Mars muck understand future missions on the surface, and in particular for human missions, since it is believed that the muck also contains human-damaging chemicals a technology demo to show that we can send a sample back from Mars at a later date, once we know how to intelligently select the samples.


For astrobiologists who talk about the need for on-site searches first see


The re The practical and practical problems are enormous and do not seem to have been addressed or even at all. Based on Margaret Race's legal analysis and published estimates of the time required to set up a Mars Sample Receiving Facility to meet the likely required specifications, they could almost certainly not return the sample by 2040.

It would not be an option to ignore legal requirements, not today. Back then, at the time of Apollo, they were able to publish the Earth Protection Regulations on the day Apollo 11 launched, so nobody had time to disagree or even study them. That would not be allowed today – and these old rules were abolished long ago and generally accepted to be largely symbolic and most useful in showing how such things can go wrong.

Such a short cut to the legal process would not be allowed today. There is a heightened awareness of environmental issues that we did not have in the 1960s and many treaties and domestic legal requirements that have since been added.

It could not be done under COSPAR either. A sample return from a comet or meteorite may be because it can show that there is no risk to the Earth's environment because we always allow samples of such objects to enter our atmosphere. But they can not use the same reasoning for a Mars sample return. The previous studies have carefully studied this, and the influx of Mars from meteorites is not a sample return. In fact, it is not easy for life to get from the Martian surface to the ejecta or survive the journey to Earth. There are effects on Mars every one or two million years able to send rocks to Earth, but most are in the high southern highlands, the meteorites come from at least one meter below the surface, and most of them spends Thousands of years in transit, and the largest meteorites are expected to have a diameter of 60 cm before they enter the Earth's atmosphere, with the outer layers removed by ablation in the fireball of reentry.

So it has to be treated as potentially dangerous to the Earth's environment. The requirements for a sample return facility have increased with each review. Originally in studies in the 1990s, it was a simple glove box in a Biocontainment Level 4 facility. These requirements were met by the discovery of ultramicrobial bacteria, the exploration of the minimum possible size of extraterrestrial microbes (estimated at about 50 nanometers, a quarter of the minimum size for modern Earth life) and the discovery of how easily abilities can be transferred through lateral gene transfer when life by GTAs of the order of 10 nm.

The latest European Space Foundation study required a $ 500 million facility with unprecedented design requirements to prevent particles as small as 50 nanometers or larger from escaping (one quarter of the 200 nm resolution limit for a diffraction-limited optical microscope ). The latest study by the ESF left open the possibility that future studies could further increase the requirements

What makes it so expensive and the process of licensing so complex is that we must prove that it protects the earth from any conceivable alien biochemistry at a time when the only biochemistry we know is on Earth. We would build the same facility to get an unsterilized sample from a Habitat in the Proxima Centauri system!

The plant must also be operational and operational at least two years before the mission to collect the sample from Earth is commenced. Preliminary studies indicated that it could take up to 7 to 10 years to become operational, followed by an estimated 5-6 years to familiarize themselves with the procedures

. But the legal situation would also need to be cleared before the mission can be started. It is also unlikely that the plant will be built until the legal requirements are met.

Margaret Race has studied in detail the legal processes that must be completed before we can return a sample from Mars to Earth

Prior to a sample return, we must achieve several years in this order

  • : Formal Environmental Impact Statement for NEPA + quarantine laws to enter into force with a broad public consultation. The average time period for an EIS in the 12 months to 30 September 2016 was 46 months.
  • Several years: Review of the President on possible large-scale environmental impact under other national laws.
  • Can do, besides the other work: international treaties that must be negotiated, and national laws of other countries

Margaret Race does not estimate a total time for all this. Roughly estimated, a decade would be optimistic to complete the whole thing.

  • 7 – 10 years: construction of the plant
  • 2 years: operation before start (minimum requirement, more likely 5-6 years)
  • 2 – 4 years: collecting and returning the sample
    (if we are Mars From time to time, the successor rover must retrace at least part of the way from Mars 2020 to find the samples in lowered tubes from time to time in small caches.

That add up to an additional 11 – 20 years after the legal process is completed, 21 to 30 years in total The process of building and testing the plant alone could take 20 years if we go by estimates there.

That means, if we want, that a sample will return to Earth by 2040 should we begin to lose no time in 2018. In fact, it's probably already too late to reach a start date of 2040. It would not be a big surprise if it did by 2050 or later would be delayed by legal delays or delays in the construction of the plant and its commissioning.

In addition, in a span of two decades, it takes to pass all the laws, then approve the plant, build them, and test our understanding of Mars through in-situ searches could evolve to the point Where we prove that Martian life is harmless and the whole process discovered was unnecessary.

But it is also possible that during this time we will find life on Mars that would be dangerous to the Earth's environment. The reason why the system would be required by law is due to this possibility.

Apollo's experience shows that we need to be very careful when our reclamation measures are more than just a symbolic measure. We also have many examples that have made the protection of the environment visible to the general public and our elected officials.

If accepted, then it is true that such a procedure has detailed impact assessments and this public engagement has been promoted at every stage of the process. In any case, whatever you think is right or wrong, it is the situation we are in.

For legal analysis

For the timeframe for the construction of the facility from the NRC study

For details the most recent study of the ESF from 2012 with the requirements of 50 nm and ideally 10 nm

So, what can we do?

I think if this mission actually takes place, they will surely either choose to sterilize the samples or (19659002) you could do so through COSPAR without you issuing numerous laws or designing a sample recirculation facility on Earth need to build that has never been tested before.

Sicher, wenn Sie mit der Aussicht konfrontiert werden Bevor sie die Mission starten, mehrere Gesetze erlassen und die Probe nicht bis 2040 oder 2050 zurückgeben können, werden sie die Entscheidung treffen, alle Materialien, die zur Erde zurückgebracht werden, stattdessen zu sterilisieren und zurückzusenden Jahrzehnt früher in th e 2030s


Dies ist für die Situation, in der wir denken, dass die Probe potenziell Leben enthalten könnte, aber dass, wenn sie es tut, wir nicht genug über dieses Leben wissen, um etwas darüber zu sagen oder seine Fähigkeiten.

In dieser Situation denke ich, dass wir, da wir überhaupt keine Erfahrung im Umgang mit außerirdischer Biologie haben, es besser tun, die Proben überhaupt nicht zur Erde zurückzubringen. Was wäre, wenn wir es stattdessen zu einer Teleroboter-Anlage über GEO bringen würden? Ich habe diesen Ort gewählt, weil es die Bahn ist, die von der Erde oder dem Mond an irgendeinem Punkt im Cislunarraum am weitesten entfernt ist.

Dies hat auch den großen Vorteil, dass es weit außerhalb der Reichweite von Erdorbitalen liegt von LEO oder MEO (mittlere Erdumlaufbahn). Jeglicher Abfall von den GEO-Satelliten selbst wird sich langsam bewegen, da sie relativ zueinander stationär sind. Daher werden Kollisionen mit einer niedrigen relativen Geschwindigkeit ausgeführt und können keine Trümmer zu viel höheren Umlaufbahnen schicken. Es ist auch weit von der Erde und vom Mond in Bezug auf Delta v, und es ist eine dynamisch stabile Umlaufbahn langfristig. All dies scheint es bei weitem zu dem sichersten Ort zu machen, an den man es zurückgeben könnte. Es ist auch leicht zugänglich von der Erde.

Der offensichtliche äußere Kreis weißer Punkte in diesem Bild zeigt die Satelliten in GEO zusammen mit den Orbitaltrümmern auf der Friedhofsbahn über GEO. Beachten Sie, dass es relativ zur Erdoberfläche stationär ist, so dass alle Satelliten dort eine sehr geringe relative Bewegung haben. Satelliten in GEO sind am Ende ihres Lebens auf diesen "Friedhofsbogen" 300 Kilometer höher zurückgezogen. Für weitere Bilder siehe hier die Orbitaltrümmer-Galerie.

Ich schlage vor, ein guter Ort, um eine Probe vom Mars zurückzubringen, wäre ein paar tausend Kilometer, vielleicht zehntausend Kilometer über GEO. Weit weg von GEO oder der Friedhofsbahn. Am weitesten kann man im cislunaren Raum vom Mond oder von der Erde in Bezug auf Delta v sein.

Du brauchst mehr als einen Kilometer pro Sekunde, um von dort entweder zum Mond oder zur Erde zu gelangen. Es ist jedoch leicht von der Erde aus zu erreichen, was es relativ einfach machen sollte, telerobotische Geräte dorthin zu schicken


Dieses Video zeigt die Orbitaltrümmer in Bewegung und aus verschiedenen Blickwinkeln.

Wie bei der vorherigen Idee könnten wir einige Proben sofort zur Erde zurückbringen, solange wir sie zuerst sterilisieren. Das sollte die Geologen zufriedenstellen. Ich schlage vor, diese Proben aus dem gleichen Grund wie zuvor mit ionisierender Strahlung zu sterilisieren, weil das ohnehin auf dem Mars passiert, und auch für Astrobiologen einige Hinweise wie Chiralität und komplexe Chemie bewahren würden, wenn es dort vorher Leben gegeben hätte sterilisiert. Es ist auch leicht, die Geologen zu berücksichtigen, die bereits beim Studium von Marsmeteoriten die ionisierende Strahlung der Reise vom Mars zur Erde entwirren.

Wenn sich die unsterilisierten Proben recht schnell als unschädlich erweisen, geben wir sie einfach als zurück ist (vielleicht sterilisiert sie, um sicher zu sein), so wie wir es mit den Mondfelsen gemacht haben. Dies spart Jahre Gesetzgebung (wahrscheinlich ein Jahrzehnt oder länger, um alle Gesetze zu bestehen) und Hunderte von Millionen von Dollar für die Planung, Bau und Betrieb einer Einrichtung, die nie benötigt wird.

Zurück zu oben GEO vereinfacht den gesamten Prozess

  • Dafür braucht man keine neuen Gesetze . Es kann innerhalb aller existierenden Gesetze durchgeführt werden, wie auch für Beispielrückgaben von Kometen und Asteroiden. This eliminates the need for many years going through legal processes, and perhaps even into decades, just passing all the legislation to return it to Earth
  • You don't have any concern about the staff not using the right protocols because it is all operated from Earth. Nothing the staff can do, by mistake, laziness or attempts to cut corners can lead to life from the spacecraft above GEO escaping into the environment of Earth.
  • There is no risk of sample release to the environment of Earth as a result of natural disasters, human error, etc such as hurricanes, or earthquakes, lapses of protocol, design issues, or even terrorists, or the fiery heat of entering the Earth's atmosphere from orbit.
  • Saves half a billion dollars of up front cost – the Earth based sample receiving facility has to be built and up and running before the sample return mission is launched. This way, all the missions to study the sample above GEO can be treated as extended missions. That's equivalent to an entire new Discovery class mission. The mission to retrieve the sample to above GEO corresponds to a stage we might well do anyway, to retrieve the capsule before return to Earth to deal with the possibility of sample container breach in transit from Mars.
  • If the samples are rapidly shown to be of no great astrobiological interest – as most astrobiologists expect at present – you can just sterilize them and return them to Earth and don't need to do any other special handling, but treat them like the Mars meteorites. This is a huge cost saving. In this case you don't have to study it telerobotically in GEO, but just sterilize the whole thing and return it to Earth as in the previous suggestion.

It also has the great advantage that we design for what we discover as the mission progresses. There is no need to design an all purpose "swiss knife" of a faculty able to deal with all conceivable biochemistries. For instance if it is viable early life, based on RNA or even just primitive autopoetic cells, it might be easy to establish at an early stage that there is no possible hazard for Earth at all. In that case again, perhaps it doesn't need to be studied in a biohazard containment facility at all, but just protected to keep Earth life out of the sample. We don't need to establish that all life on Mars is safe for Earth, just that there is no hazardous life in the sample itself.

On the other hand, we might decide it needs extreme caution . For instance, we might do that if it is some exotic form of life which is not based on DNA at all, or if we decide that it is has a much more complex genome than any Earth microbe, billions of years advanced on us and we can't figure out what it does.

Also, this is a big plus when you consider the natural human inclination to ignore low probability risks of extreme events – if we do need precautions – the planners and staff will know it is potentially hazardous and will take great care. They would never do something the equivalent of opening a hatch because the astronauts might get seasick. They will design a protocol that really does work, and think through all eventualities, and take great care to make sure that it is going to work and be effective, and is not just a symbolic gesture.

In short, the three possibilities are:

  • If we find possible life and precautions are neededwe apply them based on knowledge, not trying to second guess any possible extraterrestrial biology. Everyone is highly motivated to take suitable precautions
  • If we find life that is so "feeble" that no precautions are neededthen there is no need to build what would then be a totally unnecessary facility and the legislation will surely be simpler and at any rate passed easily with no opposition.
  • If it has no great astrobiological interestwe sterilize the sample and return it to Earth.

So then the main remaining question is – is this idea to return a sample to above GEO itself safe against accidents? Is there any risk of any of the material in the sample getting to Earth?

So, first, the only thing that could damage and release the sample above GEO is an impact but there wouldn't be any risk from spacecraft debris, as any debris in GEO or the graveyard orbit a few hundred kilometers above GEO wouldn't travel far because of their low relative velocity. So the only real chance of an impact leading to release of the material from the sample, would be from natural debris from asteroids and comets. Assuming it has thrusters to position itself as a satellite, then it could also maneuver to avoid such hazards, just like the ISS, but it might be an issue detecting small debris at that distance from Earth and its radar systems. It would of course have Whipple shields to protect from micrometeorites.

So, is there any chance that a natural meteorite hitting a spacecraft above GEO, with Whipple shields, and able to "dodge debris", could send viable life to Earth from the satellite? I leave this for experts to look into in detail, if the idea seems to have merit.

Another question to look at is, is there any chance of a failure to retrieve the sample to above GEO. Well there, the approach would be similar to the Asteroid Redirect mission. So – the intermediate stage would be, perhaps, to return it to a Distant Retrograde Orbit. This is an orbit that is stable over time periods of centuries, and is within easy reach of GEO in terms of delta v. It's an orbit that is in synchrony with the Moon, so a 28 day orbit around Earth, but it is also highly elliptical. The satellite orbits Earth more slowly when further away than the Moon and faster when it is closer to Earth, and so as seen from the Moon it seems to orbit it in a retrograde fashion. It's a more stable orbit than a prograde orbit around the Moon and has the advantage that it can be as large as you like in diameter, even continue all the way to LEO in a retrograde orbit around the Moon. But it's also a prograde orbit around Earth so it's easy to get from it to GEO

As a 28 day orbit around Earth, DRO is also far more accessible to a spacecraft from Mars than LEO, assuming it doesn't do aerobraking in Earth's atmosphere, or return directly in a fast re-entry to Earth.

This calculation is for the opposite direction, from Earth to Mars, but it gives a good idea. The authors find that you need a delta v of 3.29 km / sec from DRO to LMO (Low Mars Orbit) compared to 5.758 from LEO to LMO. The delta v would be similar for a flight from LMO to Earth. The main drawback is that the delta v depends on the position of the Moon at the time of departure from Earth, so optimal trajectories repeat only once or twice a month.

This is actually similar to ideas in the literature to return the Mars sample to DRO around the Moon, and then for astronauts to retrieve it and return it to Earth. The only difference is that my suggestion here is to retrieve it robotically, rather than asking astronauts to retrieve it manually, and then return it to above GEO instead of to LEO.

See this suggestion by Lockheed Martin to use astronauts to retrieve a Mars sample from DRO using the Orion spaceship (once ready). Other proposals though assume a fast re-entry to Earth's atmosphere at 12 km / sec (see for instance page 49 of this report). It would have a higher delta v requirement than that of course.

See also my

Source link