Our BRIC-19 space-flown seedlings and the corresponding Earth-grown seedlings arrived back to our lab in Madison Wisconsin safe and sound. Their trip back from the Space Station began when the astronauts removed our samples from the freezer on the ISS and packed them into a cold bag, which was then placed into SpaceX’s Dragon capsule along with many other research items from the space station. The Dragon and its precious payload left the space station and after re-entry made its splashdown in the Pacific where a barge retrieved the capsule.
After unpacking in Houston, our BRIC-19 samples made their way back to Kennedy Space Center (KSC) by truck. Then, I met the NASA team at KSC to unpack our science from the BRIC space hardware; this was the moment of truth! We carefully opened the petri dish holders and had a first look at our space-grown plants and the ground-grown controls. We were thrilled to see that every one of the 40 petri plates in our experiment had excellent growth and no contamination. Fantastic!
We couldn’t have been happier with the results so far, but now back in the Gilroy Lab in UW-Madison critical work begins analyzing the shape and size of each BRIC-19 plant in addition to assessing the differences in gene expression.
Gilroy Lab postdoc Won-Gyu Choi will meticulously isolate the RNA from the seedlings in each petri plate, test its quality, and then the biotech center on campus will run an analysis called RNA seq. From this we will get the raw data about gene expression; this snapshot will allow comparison of how wild type plants regulate their growth in microgravity compared to seedlings which have a gene involved in plant mechanical responses that is always on or always off. Likewise, the GeneLab portion of BRIC-19 will allow comparison of the gene expression of a number of varieties (ecotypes) of Arabidopsis so that we can discover if one type of plant is more suited for growth in microgravity.
The were a number of news reports published when our seedlings were returned. It was great fun talking to the press about our work, the reporters did a great job communicating the details of our space biology research! Check out these published write-ups:
UW team’s plants return to Earth after growing in space (University Communications)
Out of this world: Fitchburg researchers send plants to space (Fitchburg Star)
UW-Madison botany researchers explore plant growth in space (Daily Cardinal)
Plants return to Earth after growing in space (Science Daily)
I just have to share some fantastic images of astronaut Reid Weisman actuating the fixative onto our space-grown Arabidopsis seedlings. This task was completed on-orbit on October 2. Many thanks to NASA for the outstanding photos!
The actuation for one of our pre-flight tests (called the Payload Verification Test, PVT) had issues back in May. The actuator is like a caulking gun mechanism which pushes a pin into the canister, plunging the fixative onto the petri plate inside which holds our seedlings. In May for our PVT one of the actuations stuck partway; when a tool malfunctions during PVT it is a big deal. After NASA did a bunch of further tests with the tool, it was determined that it was an isolated incident and that the tool and hardware should perform OK in flight. And it did!
Right now our four BRIC canisters are stored in the -80 freezer on the space station. At the end of the week, our BRIC-19 experiment will be packed into a cold bag for return to Earth inside the Dragon capsule. Unberthing of the Dragon is now scheduled for Saturday, October 25. Hopefully our experiment will be back to Kennedy Space Center in Florida by the end of next week.
It’s Sunday evening and we couldn’t be happier! The rain slowly tapered off during Saturday afternoon and then the clouds began to break up and at about 10:35 pm on Saturday we received the word that the weather was OK for a launch. So, we drove to Kennedy Space Center and when we arrived, we realized that it was a perfectly clear and still night with the constellations laid out above us in a cloudless sky. In short, a great night for a launch!
At about 1:15 am we drove to the causeway across the Banana river at Kennedy Space Center. This spot is only a few miles away from the launch pad and has great views of the rocket. Exactly on cue at 1:52 am SpaceX 4 lit up the area as its engines ignited and the rocket rose off the pad and climbed into the night sky. A few seconds later, a rumbling wall of sound hit us. Rocket launches are amazing to watch but this one was even more special as we knew our experiment was sitting inside the Dragon capsule on top of that ball of sound and fire! We watched until the rocket’s glow disappeared into the night sky and the rumble faded and was eventually lost in the sounds of the river.
High fives all around but no time to celebrate yet. Five am and we were at the Space Station Processing Facility prepping our control samples for integration. 7 am, the NASA team arrived and over the next few hours we got our control samples into their PDFUs and assembled into their BRICs. Then we said our goodbye’s to the NASA team and headed back to our hotel. The only thing left to do was to pack for the trip home tomorrow morning. But first there’s one tradition that I suspect we observed along with many groups around the world who have been working on this SpaceX4 Cargo Resupply Mission. We broke open a bottle of champagne and then promptly fell asleep.
Back in Madison, we were glad to hear that the Dragon capsule docked successfully with the ISS on Tuesday morning. Our experiment was unpacked from the cold bag and hopefully our seedlings are growing as I type this. We will be picking up our samples from Kennedy Space Center once they come back from the International Space Station at the end of October.
It’s Saturday September 20th and the Gilroy lab team is back at Kennedy Space Center. SpaceX 4’s launch target was 2:53 am, so of course we were waiting on at KSC to see the rocket climb majestically into the sky. It was raining hard and the clouds were pretty dense but if you are in the spaceflight business, you have to be an optimist. So we were waiting, incessantly checking the online launch progress feed and willing the weather to break.
About an hour before the launch time early this morning, SpaceX decided there was no chance of going and scrubbed the launch. The weather was violating two launch rules: there were thick clouds and “disturbed” weather. That was better than earlier in the day when there were seven “no go” conditions, including the cryptically named Mill Field Rule (something about electrical charge buildup on the ground from the weather) but even one “no go” really does mean no go.
We are watching the weather again today and will be at KSC again for the next launch attempt at 1:52 am Sunday morning. So, why are we back at Kennedy Space Center now rather than sleeping? It’s time to set up the next set of samples so that if we scrub again tonight we are ready for attempt #3 early on Tuesday. Although you have to be an optimist to work in the world of spaceflight, you also have to plan for setbacks.
Today the Gilroy Lab team awoke at 4am to get to the Space Station Processing Facility (SSPF) building at Kennedy Space Center (KSC). We had a 6 am Pre-Task Flight Integration meeting with the NASA team who places our experiment into the space hardware. However, we had spent all yesterday setting up our samples and had to arrive at the SSPF today a bit earlier to apply the finishing touches. Yesterday we made 40 Petri plates each freshly planted with 64 Arabidopsis seeds. Twenty plates will go into the BRIC hardware to be launched into space but we always make a duplicate set, just in case something goes wrong and we have to set the whole thing up again. Space flight means you plan for just about everything to go wrong, just to ensure it won’t.
The Petri dishes had been sitting under lights overnight, a treatment we use to synchronize seed germination once they are on board the International Space Station (ISS). However, it is necessary to cool them down in the fridge before they go into the BRIC spaceflight hardware. The cold prevents the plants from growing for the 4 days it takes to get to the ISS (two days till launch, and then two days in transit to the ISS). The astronauts will unload them from the Dragon capsule and allow them to warm up to room temperature and then they will germinate. In our case the room temperature just happens to be in a room orbiting about 250 miles above our heads!
The timing of integration is key because we do not want to plant too far in advance of launch or the seeds will germinate even in the cold and then our experiment will be ruined. Our BRIC-19 experiment is “late stowage” which means it will be packed into a cold bag and placed into SpaceX’s Dragon capsule as late as possible prior to launch (about a day before). That might sound simple but it’s actually a huge challenge for the NASA team to decide when to conduct integration, because more than one delay or “scrub” of the launch means that our experiment may sit around too long to guarantee no germination till it is on the ISS. With more than 2 days of delays, an entire sample set will have to be tossed and replaced with a new one that we need to have already prepared.
Here’s the tricky part: NASA has only so much spare hardware for our experiments and in our case it is the number of extra PDFU (Petri Dish Fixation Units), the casettes that each of our samples sits inside of, which is critical. Not only do we need enough (20) for the samples going into space but additionally, every experiment needs a control. In our case, our control will be a mirrored set of PDFUs containing plants that we will grow on Earth at 1x gravity. We will put these inside Kennedy Space Center’s ISS Environmental Simulator (ISSES), a growth chamber that controls its temperature to be identical to that of the ISS. So now we need a total 40 PDFUs (ground control and flight). That’s a lot of PDFUs.
We play some tricks to extend our PDFU stocks. Our samples are good for 2 consecutive days of launch attempts, that is, if the launch is cancelled on day 1 our sample is still good for the next day’s launch attempt. After 2 days we have to replace everything. So the game we play is to integrate our control samples 2 days after our flight samples. If the flight is delayed 2 days, our controls are swapped for our old flight samples and we make new controls. Therefore with a rolling window of launch attempts we will always have a new set of samples that can be turned over every 2 days for flight. That’s even more PDFUs! We have enough PDFUs for up to 3 scrubs; after that we have to get “creative” and recycle the old PDFUs.
So, a rocket launch really is rocket science and as we all know rocket science is hard. Getting everything perfect in the rocket and having acceptable weather for a launch is a huge challenge and it is amazing how regularly rockets actually go up. For CRS-4, the launch schedule has been very fluid as everyone tries to hit the magic combination of hardware readiness, weather and usable launch window. We’re currently on for 2:16 am EST on September 20th with a backup at 1:53am the following morning. So we’re all peering at the weather, and planning how to deal with every contingency. Fortunately, we know that the teams at SpaceX and at NASA are amazing and so the only reason to lose any sleep over the whole thing is the need to get up at 2:00 am on Saturday to watch the launch. But for the sake of our sanity, how about everyone reading this blog please “cross your fingers” that SpaceX’s CRS-4 WILL launch on Saturday morning!
The Gilroy Lab has been again fortunate to secure NASA funding for a second experiment studying the growth of Arabidopsis plants in microgravity on the International Space Station (ISS). This experiment is called BRIC-19: Test Of Arabidopsis Space Transcriptome II (TOAST II) and GeneLAB. Similar to BRIC-17, we will use the BRIC (Biological Research In Canisters) hardware with our plants growing in petri plates inside PDFU (Petri Dish Fixation Units) as we did for BRIC-17. Our experiment will launch on September 19, 2014, tucked inside SpaceX’s Dragon capsule as part of the CRS-4 (cargo resupply mission #4). The Dragon will berth with the ISS two days later on September 21, 2014, at which point the astronauts will unpack our BRICs into the ISS and our experiment will begin.
So, what exactly will we be investigating during our second foray to the ISS?
The first half of our BRIC-19 experiment is TOAST II. Just as the lack of weight on board the International Space Station causes astronauts to lose bone mass, the weightless environment causes plants to lose their supporting structures. For the plant this means they grow long and thin in space, lacking to some degree the thickened and strengthened cell walls that they use to hold themselves up on Earth. The reason the plants are stronger on Earth is that they sense the mechanical forces generated by their own weight and lay down support materials in response to these signals. In space, the signals are gone and so the plants don’t produce the support materials. As astronaut Don Pettit (who grew the famous Space Zucchini!) put it: Plants “get lazy” in space.
Part of the machinery that lets the plant sense and respond to these mechanical forces on Earth is a group of genes called the “TOUCH” genes, so named because they are switched on in response to touch. One of these genes, named TOUCH 2, or TCH2, looks to be an important hub for a lot of information processing in the plant and so we think that the product of the TCH2 gene, i.e., the TCH2 protein, is a key regulator of the plant’s ability to sense mechanical forces such as its own weight. Dr. Janet Braam’s research group in Rice University has been able to make mutant plants with forms of TCH2 that is either always “on” or always unable to trigger touch responses. Dr. Braam very generously shared these mutants with us and so we now have plants that have this master mechanical response trigger always on or off. The plan is to compare the ‘always on’ and ‘always off ‘ to a normal plant growing in space and see if activating the touch response pathway even in the mechanically “silent” world of spaceflight can help restore growth that is more like what we normally see on Earth. We will look not only at the plants’ growth but also at their transcriptomes (the expression level of every gene in the plant) to see if the growth and gene expression of have the hallmarks of being at 1 x gravity, even in the weightlessness of space.
The other half of our BRIC-19 experiment is called GeneLAB, an exciting new program in NASA where data from experiments on the International Space Station is rapidly released to the entire research community to allow as many people as possible to study the dataset for insight into how spaceflight affects biology. The Gilroy Lab has the honor of sending the first GeneLAB experiment to the ISS!
The idea behind our GeneLAB work is that many plant biologists use the “lab rat” of plant research, Arabidopsis thaliana (also known as Mouse Ear Cress), to perform their experiments in space. This is a small, extremely well studied plant which has an enormous range of tools to help dissect its functions down to the level of genes and chemicals. Arabidopsis grows naturally in many places around the world and although Arabidopsis thaliana from Poland or China is all ‘Arabidopsis’, the plants in each area have diverged a little bit from each other and so there are varieties of Arabidopsis local to each area. These varieties are called ‘ecotypes’ and each is a little different from the next. So the question we want to answer is, do the different ecotypes used by researchers respond differently to spaceflight? If they do, which ecotype you use for your experiment might be critically important! The way to test this possibility would be to grow different ecotypes on the Space Station and compare them to the same ecotypes grown under the same conditions on Earth. Our GeneLAB experiment is to investigate this idea using three commonly used ecotypes of Arabidopsis. The ecotypes are all named after where they were found and collected, so the ones we will use are named Ws (Wassilewskija, collected in Belarus), Cvi (from the Cape Verdi Islands) and Ler (Landsberg erecta, orginally from Poland). In addition we will be using the Columbia ecotype (from Columbia Missouri, USA) in our TOAST II experiment, giving us a 4-way comparison of ecotype responses. As with TOAST II, we will look at the growth of the plants and then look at the patterns of genes that are switched on and off in each ecotype in response to growing in space.
If all goes as planned, we should get our ISS-grown BRIC-19 samples for analysis following the Dragon splashdown when the capsule returns to earth from the ISS in late October, 2014.
While a major research effort in the Gilroy Lab involves studying how plants grow in microgravity on the ISS, equally huge is ongoing plant research on the ground here in our lab at UW-Madison.
Last week, Won-Gyu’s paper on calcium signaling in Arabidopsis was published in the Proceedings of the National Academy of Science (PNAS). He discovered that when roots are hit locally with salt stress, a calcium wave quickly spreads from the point of stress throughout the whole plant. This calcium wave plays a role in how plants communicate within themselves to coordinate a response.
UW-Madison communications posted a write-up about our calcium research today. Feel free to ask a question or to leave a comment below. Enjoy!
In the past few months, the Gilroy Lab space biology research team has been busy analyzing data from our space-grown and Earth-grown control plants from our BRIC-17 TOAST experiment. Excitingly, we now have a full set of RNAseq data! The RNAseq is important to our analysis because it will give us insight into the differences in gene expression of plants grown in microgravity compared to ones grown on Earth and allow us to ask our big question: “Do plants grown on the ISS look like plants experiencing low oxygen stress on Earth”?
We presented some of our preliminary results at the American Society of Gravitational and Space Research meeting in Orlando at the end of last year. This meeting is the primary venue for space biology researchers to report their results to the rest of the space research community, a community that includes NASA-funded researchers who work for universities or for private companies. This was a fantastic meeting that included not only physicists and biologists who conduct research in microgravity but also NASA employees who run the research programs and engineers who develop hardware for research on the ISS. Hanging out with rocket scientists is an incredible amount of fun!
As a reminder, here are the primary questions we wanted to investigate for our BRIC-17 TOAST experiment growing plants on the space station. For more details about rationale and preliminary data leading to this experiment, see the “Experiment” details page.
- Do hypoxic (low oxygen) conditions develop in plants grown in microgravity aboard the ISS?
- Does cax2, a plant lacking a protein which transports calcium, allow for improved plant growth under these conditions?
First, we wanted to quantify any size differences between the plants grown in microgravity compared to ones grown on Earth. For this, Won-Gyu lined up the seedlings from each petri plate and took digital images. With help from an image analysis program, he measured the total size of each seedling and took individual size measurements from each shoot and each root.
It turns out that the cax2 mutant seedlings from the Space Station do show different sizes of roots and shoots, so it looks like at least some of our ideas about low oxygen stresses in space may be correct.
Second, Won-Gyu looked at changes in the expression of specific genes, genes which we know have altered expression levels in a plant experiencing low oxygen stress thanks to other Earth-based plant research. He did this analysis by isolating RNA from our seedlings and using quantitative PCR (qPCR) to detect how much RNA was present. Looking at the amount of transcribed message (mRNA) from these specific genes will give us insight into the magnitude of hypoxia experienced by plants grown in microgravity compared to Earth-grown seedlings. Again, it turns out that the level of some, but not all, genes related to low oxygen stress on Earth are altered in spaceflight and are different in the cax2 mutants from the Station. We are now in the the most exciting aspect of research; it looks like some of our predictions are correct but the plants are telling us something extra that we need to try and understand.
These qPCR experiments investigated a few select genes already characterized to be involved in the plant hypoxic response. However, the RNAseq data allows us to explore how spaceflight affected the levels of all 27,000 genes present in Arabidopsis. This RNAseq analysis is going to be the way we will tease apart what was going on to these plants aboard the ISS. As you can imagine, this set of data is huge (for the computer geeks out there, we have about 1 terabyte of raw data to sift through). Analyzing these results is in progress, but we hope to finish the work by the time spring arrives in Madison!