We're a student team planning to grow life on Mars. We've designed a greenhouse that could go to Mars and grow lettuce. We've submitted our proposal to Mars One as part of their competition for a spot on their lander in 2018, and if we win, we'll get to do this.

Having passed the technical round, the final round is a popularity contest. Votes are collected from Facebook, G+ and Twitter as only the most popular project will fly in 2018. More information on our project and on how to vote is on our website: www.lettuceonmars.com

We're up for questions on our proposal or general discussion on space colonisation, which we think is really cool.

We're not Mars One or acting on their behalf in any way.

The whole team will be passing through here today so we'll try and make sure that the best person answers the question, though we're a small team so we all did a bit of everything.

Suzi: Team Leader, COSPAR and implemented project Hector: Initiated the project, Electronics Mate and Annabelle:Plant Research Alex, Barbara, Janki: Mechanical Engineering students, "designing the box"

EDIT : Thanks for all the questions, it's been an awesome day! We hope you guys some great conversation, we really enjoyed it! If you have any more questions, you can email: [email protected] or contact us on fb/g+/twitter.

Proof: http://imgur.com/bxL7vUK

Comments: 1567 • Responses: 71  • Date: 

brainburger1134 karma

Currently NASA expends considerable effort to avoid sending anything alive to Mars, on its probes, to comply with a 1967 UN treaty.


Will your trial be exempt from these restrictions? How can you guarantee that the Martian environment won't be contaiminated?

lettuceonmars438 karma

Janki: (Part 2: How can you guarantee that the Martian environment won't be contaminated?)

You can't really guarantee anything, but the idea here is that we minimise the risk absolutely as much as possible. So here are a few of the things that we're doing:

  • Using HEPA filters, which will stop, for example, bacteria or viruses getting in or out of the greenhouse through the airlock.

    • The lettuce will be incinerated upon completion.
    • The project will take place as a semi-closed system. We are only extracting some gases from the environment.

astoriabeatsbk79 karma


lettuceonmars26 karma

Janki: We should have used cabbage just so that we could say that!!

lettuceonmars107 karma

Janki: (Part 1: Will your trial be exempt from these restrictions?)

On Mars One's website they state: Mars One will take the required actions to prevent environmental contamination caused by the importation of Earth life (humans and their companion organisms). Mars One has begun discussions with the ICSU Committee on Space Research’s (COSPAR’s) panel on planetary protection and the COSPAR panel on exploration to identify the measures that need to be taken with respect to prevent this contamination. Prof. Dr. John D. Rummel of the COSPAR panel of planetary protection is one of our advisers. Based on discussions with these panels, Mars One will acquire the necessary systems and take the required and necessary actions to protect Mars.

I don't think that this isn't the most official resource: http://www.space.com/25767-nasa-mars-greenhouse-rover-plant-experiment.html but seems as thought the current regulations will need to be changed.

maaaatttt_Damon16 karma

Arent we sending humans on this trip? Are human's not alive?

lettuceonmars78 karma

Hector: The 2018 lander is a probe, and will not be carrying humans. The Mars One colony is scheduled for the 2020s, though an up-scaled version of the design we are using could be used for any kind of human Mars colony or long-duriation mission.

IMO a full-scale greenhouse module will probably be launched, landed, and made operational remotely before humans arrive on Mars.

lettuceonmars21 karma

Janki: The 2018 mission is just a lander :)

lettuceonmars13 karma

Suzanna: Our payload will be subject to these regulations, and the microbial burden will be minimised in line with these regulations, even the surface of the lettuce seeds will be sterilised to this standard. Where these rules become less clear is around sending a viable life form (lettuce seeds) to another planet. As this has never been done before, the rules are fuzzier. We cannot obviously sterilise the seeds or that would defeat the point. As a point of reference all Mars missions have carried some Microbes with them, it is impossible to completely prevent taking any life at all with us anywhere with certainty, so the regulations deal in taking all reasonable steps to minimise the chance of contaminating Mars and preventing Scientists from identifying life if it exists there. I fully understand that any proposal sending a viable life form contains an element of risk, but we have minimised this by careful design. If selected our project may well lead to international discussion about how best to implement planetary protection rules when sending viable life forms, but this debate needs to happen anyway before we can send people. I believe this miniscule risk is worth it, for the chance to make real steps forward in developing the technology to allow us to colonise other planets.

buttfartington566 karma

Don't you think popular vote by people who are potentially scientifically illiterate is an irresponsible use of space exploration time and resources?

lettuceonmars219 karma

Janki: I feel as though one of the main aims of Mars One is to engage the public and promote an interest in space exploration. The competition itself was open to University students, not large space organisations. Though all of the teams in this competition have good science behind them, I don't think that that was the main aim here. It could be argued that one of the reason that space projects don't have a larger budget is because the public doesn't care. Hopefully, in this way everyone can get involved with one of the most exciting ideas of our generation: Exploring Mars!

lettuceonmars138 karma

Suzanna - No I don't think that. Space is the common heritage of all mankind, to deprive people of a say in its future would be profoundly unjust. The current governments that ultimately fund space exploration are not necessarily scientifically literate, but they make decisions about our future. If we are spending other people's money, they should have a voice in how it is spent.

lettuceonmars27 karma

Hector: Space colonisation means the average person, who is also willing to go, has a chance to go to space. They'll need to learn a lot but we need to give them a chance to achieve that goal. People learn new things all the time. The need for food is pretty understandable too; a self-sufficient colony needs to grow its own food.

bold_algorithm340 karma

Are you afraid that the Mars Lettuce will evolve into an aggressive, hostile, intelligent plant that will see humans as a rival species, and try to destroy us? How can you prevent such a circumstance?

lettuceonmars272 karma

Janki: Yes, this was a great concern to us. The all-powerful "Mars Lettuce" haunted our dreams whilst we were still trying to come up with a solution to this. Ultimately we prevent this by using HEPA filters in the airlock and incinerating the lettuce upon completion.

nicomac146 karma

is the incineration on/off switch located on the outside of the greenhouse to prevent the lettuce from inadvertently hitting it?

lettuceonmars121 karma

Janki: Yes, don't worry it's on the outside ;)

Damany309 karma

Why lettuce and not, say, soy or corn?

lettuceonmars507 karma

Mate: We have chosen lettuce for a number of reasons.

First and most important: it is widely used as a test plant for closed systems. It is growing currently in Mars simulation experiments on Earth, and even on the ISS in orbit. So we have a lot of data on how lettuce will behave on Mars, but nearly no such data about corn.

Secondly, lettuce is wholly edible, while we only eat the seeds of soy and corn, and we throw most of the plants away. So lettuce converts nutrients to edible material with low waste.

Third, lettuce grows fast and is easy to fit into a micro greenhouse: its basically edible within 4 weeks of germination. For corn we would need to wait months, and design a huge greenhouse that could house that big plant

Damany115 karma

What are the caloric returns of lettuce rather than corn? Dumb guy question, but people say lettuce is calorically negative - it takes more calories to consume than you get from eating it. Is this a myth? Surely, you have looked at this, and the answer is favourable for lettuce?

Also: Is there something about corn or soy that makes it not work in space?

Also two: Thanks for doing the AMA. This is fascinating to me.

lettuceonmars138 karma

Mate: We are doing this AMA because we are fascinated by it too, and also because we need your votes to make it fly! Visit our page on www.lettuceonmars.com and support us by voting on facebook and twitter, if you like our project.

To answer your questions: You are right, lettuce is not particularly nutritious. Its high in fiber, and is fresh and juicy, but thats about it. It is a proof of concept at the moment. Since this is an unmanned mission, noone is actually going to eat it for now, but if lettuce works, we can take other plants next time. The knowledge gained from growing lettuce now will be invaluable to future colonists.

I don't know of any particular reason why corn or soy would not work. They are a lot harder to grow than lettuce, and introduce other problems I mentioned above. So we start with lettuce, because its easy, and move on to more difficult plants when we get the basics right.

dkmdlb205 karma

Do you really think Mars One is going to send a probe to Mars in less than 4 years?

lettuceonmars59 karma

Janki: I think that it's an ambitious goal, buts it's possible and the only thing we can do it hope that it happens. It's completely out of our hands.

Jon-Osterman156 karma

If I try to answer any of the questions addressed to you here, will you guys respond with "lettuce do the talking"?

lettuceonmars222 karma

bamcomics95 karma

Suppose you succeed and all move on to find great careers.

How on Earth do you put this on a resume and have them believe you?

lettuceonmars104 karma

Janki: Haha that would be amazing! We made sure that we put our pictures on the website ;) Personally, I'd carry around the designs like they were primary school certificates.

syntaxvorlon57 karma

Can I suggest that under your skills on your CVs you include "Xeno-horticulture?"

lettuceonmars22 karma

Janki: Haha that's perfect

AchillesWay23 karma

You still have those? If you had to ask me right now I'm not sure I know where my degree certificate would be!

lettuceonmars40 karma

Janki: Haha I meant in that I'd wave them around and say "Look what we did!" to absolutely everyone :D I'd probably frame something to keep in my room too


How old are you? What's your university? What's your major?

lettuceonmars144 karma

Janki: Hiya, our team is made up of a bunch students from undergraduates to post doc, so 19-30 but we're mostly in our 2nd/3rd year. Together we've got Aero/Astro Engineering, Mechanical Engineering, Electronic Engineering and Biological Sciences. We're at the University of Southampton.

kirity52 karma

Hasn't it already been proven that we are able go grow plants in space? What specific environment does growing lettuce on Mars achieve that couldn't be replicated on earth. Except the low gravity.

lettuceonmars75 karma

Mate: You are right, we can grow plants in space because we have already tried that. Lettuce is growing at this very moment on the ISS as part of the NASA VEGGIE project. But that is not on Mars.

No one has ever grown anything on Mars, only in Mars analog setups on Earth. These models are not perfect and each only simulate a part of the Martian environment.

Gravity and radiation are the two really tricky ones. Creating cosmic radiation artificially is no small task, other teams usually use simpler radiations, which are not perfect substitutes.

Gravity is equally challenging, we can use centrifuges but those have severe limits themselves.

So we are not only going to see if plants can actually grow on Mars, and not only in imperfect simulations, but we will also answer a very important second question:

Can plants from Earth grow using resources from Mars?

We are going to answer that by filtering CO2 from Martian air and feeding it to our lettuce seedlings there. This is again something that we cannot reproduce on Earth.

CocaineIsTheShit44 karma

How about some Mars weed?

lettuceonmars68 karma

Hector: The main focus of this project though is to grow crop plants, for food. Hemp can be used for food as well, but it is rather large for the current greenhouse dimensions. The design, when scaled up, could grow larger plants however.

yoyoyo_its_me19 karma

how will the lower light conditions effect the lettuces' ability to differentiate between their growing season and vernalization period?

edit - also why not Arabidopsis thaliana, as in, what ruled it out? the inability to research mutations in second and third generations?

lettuceonmars11 karma

Janki: Mate should be able to answer the first part of your question when he gets back from work this evening but I can answer the second part.

We had initially also considered using Arabidopsis ourselves. However we ultimately chose lettuce because:

  • It is studied better as a model plant in small greenhouse systems, while Arabidopsis is used more in developmental studies and genetics.

  • Since Mars One intends to grow lettuce in the future, it would be valuable to show that lettuce can grow well on Mars.

  • Lettuce is a familiar plant, it makes it easier to engage and further the public’s interest in Space, inline with the spirit of Mars One.

jumpup19 karma

just wondering, whats the point of growing it on mars, couldn't you simulate the same effects in orbit or on earth?

i mean what do you hope to accomplish by sending it to mars that would have so much added value?

also, could you elaborate on how you are planning on keeping the lettuce sustained during the trip?

lettuceonmars18 karma

Hector: First the lettuce will be stored as frozen seeds for the trip to Mars, and the seed can survive the temperature variations. All the growth happens on the Martian surface. We can test some aspects of growth on Earth, or in orbit, but in order to completely validate all aspects of the design it should be tested on Mars. Simulation in orbit will not, for example, test out the open-system we’re using, and it will subject the plants to Earth-orbit levels of radiation and sunlight rather than the levels on the Martian surface. Simulation of radiation levels and gravity at the same time is particularly difficult. A human presence the design needs to be scaled up from here, and validation of the smaller design on Mars is a key step in getting a larger design tested out.

TwitchTV_Subbort18 karma

Do you have a link to other contenders? It wouldnt be right to blindly vote for yours (and make it a popularity contest) and not see what else there is. I like the idea just cant vote for something when you don't know what the competition is.

Damany13 karma

Another question: Let's say someone from NASA calls you and says they have allocated 50 pounds/25 kilograms to you on the next manned Mars mission. They will take whatever you tell them to. What would you recommend to make the life of colonists the easiest?

lettuceonmars17 karma

Mate: If NASA does that, then we need to hire a large chunk of UK space agency and a number of other companies to start with :D

If we were to recommend anything, then we would recommend systems which utilize Martian resources to decrease reliance on imports from Earth.

Our current 2kg greenhouse will filter CO2 from the Martian atmosphere and feed it to the plants. A 25kg greenhouse could use additional local resources, like gathering water ice and using that for water. In the long run, the Mars colony should sustain itself.

Damany2 karma

Thanks Mate, you have been awesome with sharing knowledge.

So I could be wrong but it seems like either energy or food would be the two things you would want on Mars. Beyond the basic survival level would you, as a solo colonist, invest spare resources in energy or food? It seems like you are leaning toward food...

lettuceonmars8 karma

Mate: I would ask someone with the proper knowledge about managing a whole colony on Mars. Keeping a simple lettuce plant alive is hard enough!

lettuceonmars16 karma

Hector: That partly depends on what else the mission is bringing, but things like an extra inflatable greenhouse would be helpful. This would help increase the growing space or plant variety, and would provide more supplies and larger margins for error, which is very important at that kind of distance from Earth!

Damany8 karma

You mention plant variety. If it isn't lettuce what is the next best option?

lettuceonmars12 karma

Hector: The other option we'd considered was cress, which happens to be a lot smaller than lettuce, and in that case we'd probably have a lot more of those plants growing.

Damany7 karma

So why is cress worse than lettuce?

lettuceonmars14 karma

Mate: watercress is simply less well studied. There is some new research on it, but lettuce has a history in Mars simulations, so our life is a lot easier with it.

lettuceonmars12 karma

Mate: we considered other plants too, like:

onions - also wholly edible and tested in some simulations. We have more resources for lettuce at our local university though.

tomatoes - another popular test subject, but is harder to grow than lettuce

Arabidopsis - the lab rat of plants. But its mostly used in genetics and plant development studies, lettuce is more popular in Mars simulations.

algae - my personal favourite with the highest nutrient density from any plant ever. But unfortunately they would have problems during taxi to Mars.

Chansinho13 karma

which one of your team would be the most willing to eat a lab-grown burger with martian lettuce?

lettuceonmars15 karma

Janki: Since Alex and Barbara aren't here yet, I'd like to nominate them. They both LOVE cooking!

wongct12 karma

Where do you get the funding?

lettuceonmars12 karma

Hector: We'll get university funding for our experiment if it gets selected. The launch and lander are covered by Mars One.

AchillesWay11 karma

What nutrients do you need in the soil to grow lettuce?

lettuceonmars32 karma

Mate: We are not taking soil as that would introduce a range of problems, mostly with planetary protection. Instead, we are growing these plants using aeroponics. So we are going to suspend the seedlings and spray them with a spray of nutrient rich water. I can copy in here the composition of our spray if you are interested. - Mate

AchillesWay13 karma

Yes please.

lettuceonmars33 karma

Mate: sorry for the poor quality of the copy. I've taken this from our technical review. Its based on published solutions by other research groups. Each chemical is followed by a concentration in uM. This is a bog standard salt solution used for aeroponics. This one is diluted enough to prevent salt gathering on leaves, but its still adequate for plant growth. I must stress that this is our current soup but not the final one, so it might change after some testing:

Ca(NO3)2 1250

KNO3 1250

MgSO4 500

KH2PO4 250

CuSO4 0.08

MnCl2 4.6

ZnSO4 0.19

Na2MoO4 0.12

H3BO3 11.56


TheDirector118 karma

What kind of payload limitations do you have and what are the major problems arising from this? Good Luck

lettuceonmars7 karma

Hector: There were payload limitations regarding mass (2kg), physical dimensions (130 x 200 x 370 mm), data transmitted, and power consumption. We also need to comply with COSPAR to prevent the release of biological material into the Martian environment.

Power supply limits mean we have to monitor the consumption within the greenhouse, and ensure the design is well insulated so that we didn't take heat from the lander, another limitation. Also, there are bandwidth restrictions which limit the number of photographs we can send back.

Planetary protection is achieved using a HEPA filter, which will stop, for example, bacteria or viruses getting in or out of the greenhouse in addition to other measures.

Janki: As mass increases quickly with the amount of material used we had to keep the greenhouse small so that we would be able to carry the volume of water necessary. However, we are using a small cultivar of lettuce, which would only require a small volume of space to grow.

Tinie_Snipah8 karma


lettuceonmars8 karma

Janki: Neither, the university provides funding for us to build the payload and Mars One allows our project to go on their lander.

ArchangelPT7 karma

Will you use mars dirt and water or bring your own?

lettuceonmars15 karma

Janki: Initially, we had considered using soil and water from Mars since there will be 2 additional experiment payloads on the lander for soil sample collection and water extraction. However, interfacing with them would be complicated and we wanted to make sure that our project could run independent of the outcome of the others. So, our lettuce seeds will be grown using an aeroponic system (spraying the roots with a nutrient solution) using water and nutrients that we will bring with us.

ArchangelPT7 karma

But you'll try to use the local resources as much as possible right?

lettuceonmars6 karma

Janki: Definitely! Using more of the local resources means that we have less stuff that we need to take up with us. And course in the future, space colonies would need to be as self sufficient as possible so it's important for us to do that. In addition, taking things up to space is expensive and there's a strict weight limit on our payload. However, we also need to compromise between project success and resource use which is why we're going for the simpler option here.

lettuceonmars3 karma

Hector: If we get through the the competition and Mars One were OK with it, we could make an alteration to the design allow some of the water extracted by the other payloads to be used in the Greenhouse.

However, in the interests of keeping the system fail-safe it would be best not to make it entirely dependent on the other payloads, so the greenhouse would still have an internal water supply.

Damany6 karma

So, if we are talking about life on Mars, your greenhouse needs to adjust for the extra distance to get the requisite sunlight to grow the lettuce. How have you modified it? More reflective surfaces or something? Does/ will the quality of the produce suffer with the weaker light?

lettuceonmars8 karma

Mate: Sunlight on Mars is about 50% as strong as the average sunlight around here. This should just be enough for lettuce to grow, but we are adding some backup LED lights to make sure everything works out well. Low light might induce growth problems like etiolation. We want to avoid that.

PointOfFingers6 karma

Are you taking photos from one side or do you have a way to spin the lettuce and view it from every angle?

lettuceonmars6 karma

Hector: The current design has a fixed camera inside the greenhouse, so that will provide one angle. It may be possible to use the lander's camera to take a photograph from outside the greenhouse too, however.

ahmedmonk3 karma

So what is your overall goal that you want to reach with this project??? Say you successfully plant the lettuce on Mars, what's the next step?? What do you want to prove??

lettuceonmars4 karma

Mate: The main goal of this project is to prove that plants from Earth can be grown on Mars.

Secondly, we want to prove that plants on Mars can be grown by using some local resources.

The next step will be to upscale the greenhouse in a future mission, and grow actual food that future colonists can eat.

nicecleatswannaruck1 karma

Reading the title reminded me of this article on the Washington Post and this MIT research paper - TD;DR: over-reliance of lettuce crops may raise Oxygen in ambient air to dangerously high levels.

I understand that the crew potentially habitating Mars will need more than Lettuce to survive, but how do you think we'll approach the challenge of perpetuating a microbiome for settlers?

lettuceonmars2 karma

Hector: The issue raised by MIT was that oxygen could not be differentiated from nitrogen in venting. However, the same technology that can enriche the nitrogen to carbon dioxide ratio of the Martian atmosphere in the greenhouse - membrane gas separation - can be used to separate nitrogen from oxygen, which will solve the issue for future Mars settlers.

abutthole1 karma

Would success with this have any implications for future terraforming of Mars?

lettuceonmars2 karma

Hector: It is about half the required technology demonstrated. COSPAR is only opposed with releasing organisms or biological matter outside the greenhouse; venting the oxygen out into the Martian atmosphere is OK as long as we keep viruses and bacteria from getting out. This is achieved using the HEPA filters. So, you could use a lot of scaled-up greenhouses for terraforming Mars. The other part of Martian terraforming, however, is building up the atmosphere; you'd need a method to sublimate the carbon dioxide frozen into the soil, which requires a different system.

teramut0 karma

Many people have asked why lettuce, so I'll make the stupid question: why Mars? Wouldn't it be easier to grow it on Earth?

(simulating martian conditions)

lettuceonmars1 karma

Janki: This was our entry into a University Competition for a spot on the Mars One lander. We can test most of the conditions on Earth separately, but not altogether.

boss187911-5 karma

have u tried growing weed??

lettuceonmars5 karma

Mate: Our setup could grow most plants, including cannabis, but we do not plan to use it for that. Food is an absolute requirement for future Mars colonists, so we focus on that.