字幕列表 影片播放 列印英文字幕 SpaceX just had its first commercial launch with its Falcon Heavy and landed all three of its reusable rockets. But there’s no rest for SpaceX, it's now launching another mission, sending up numerous science experiments including one by high school students aiming to study DNA repair in microgravity. They’re also sending up tissue chips, a science fiction sounding technology which you may remember from our conversation with expert Dr. Liz Warren, who spoke about this during our Cal Academy night. SpaceX CRS17 will be utilizing it’s reusable Falcon 9 rocket, which can both deliver cargo and land safely back down on Earth. But landing them isn’t easy. It’s a meticulous step-by-step process. The booster is essentially a large autonomous robot, whose onboard internal computers successfully land the rocket. The booster can either land on the ground or at sea, on the company’s droneship, Of Course I Still Love You, an interesting name for a boat, but also a nod to a famous science fiction novel, The Player of Games. Now, they make it look easy, 10. but it took many, many failures before SpaceX managed to successfully land its first rocket back in December 2015. Since then, SpaceX has made multiple successful landings. I bet you want to know how it works. Well, after the rocket reaches an altitude of roughly 80km, the first and second stage separate, the latter continuing on its way to deliver the payload. In order to reorient itself, the first stage turns on its cold engine thrusters in preparation for its re-entry burn. Following this, its 3 engines propel the booster towards the landing site, allowing for a controlled descent. Small, heat-resistant wings called grid fins are deployed to help guide the rocket as it continues its descent. From here the engine's landing burn begins, slowing it down. And finally, the booster's landing legs unfold for a successful touchdown. Yes, these landings are one of the reasons that SpaceX launches are so exciting to watch. But we can’t forget about all the innovative science payloads delivered to the ISS U.S. National Laboratory. What’s great about the ISS is that at its heart, it’s an international collaboration of science where anyone can submit an experiment, like these students from Minnesota who won the 2018 Genes in Space contest, where students from grades 7-12 compete to have their proposed DNA experiment conducted on the ISS. Last year’s winning team was David Li, Michelle Sung, Aarthi Vijayakumar, and Rebecca Li. We got in touch with Aarthi to walk us through their project. So our proposal was based off our interest in the increased risk of cancer that astronauts face in space because of the space radiation that can damage their DNA even when they're on the International Space Station. So the team worked to find a way to study how cells repair their DNA in microgravity and submitted their proposal for the contest. So what we're doing is we have yeast cells that we will use CRISPR Cas9 to induce a break in to simulate that space radiation and then we’ll allow the cells some time to repair themselves. And then we amplify their DNA on the mini PCR And based on the resulting sequence we can see if they repaired their DNA correctly or not. [00:15:09][20.9] So basically, they’ll be creating duplicates of the repaired DNA using a miniPCR. As for analyzing the data, they’ll be using the minION sequencer which provides real-time analysis by taking the DNA strands and using an electric current to determine the order of the bases within each DNA strand. The students will then take this information and determine whether the DNA sequence was changed due to damage and if the cells were then able to repair the DNA correctly. After becoming finalists, the team spent months working with mentors from MIT to build their proof of concept for the final judging panel. That meant bringing their proposal to life, by replicating the realistic timeframe that the astronauts would have onboard the ISS as well as using readily available materials. Until the conference, we had just not necessarily been restricted that way. And we didn't have to think about how much of this chemical can you take on the ISS? Can you control the heat conditions for these cells? Things like that so that was a really good experience for us. The results will hopefully provide more insight into whether or not astronaut DNA repairs itself the same way in space as it does on Earth. Their project is also making history as the first time a student-designed DNA sequencing project will be tested on the ISS. But until you know Until we got chosen to send it up, it became a little bit more real. And now it's you know it's tangible, it's in the near future and we're really going to see it launch and it feels really good. That's something that we could come up with and work with so many cool people can actually benefit astronauts and benefit other people in the future. But it’s not just about astronaut DNA. There are also four experiments being sent to the ISS U.S. National Laboratory by NCATS & the National Institutes of Health that aim to gain a better understanding of how the human body and organs function, with the ultimate goal of improving human health on Earth. Tissue chips, also known as organs-on-chips, are small devices that contain human cells grown on an artificial scaffold to model the structure and function of human tissues and organs. These tissue chip models provide an efficient way to study the mechanisms behind disease and test potential new treatments. One tissue chip study is investigating how microgravity and other factors affect kidney function, since kidney problems occur more frequently in astronauts. Another study is using tissue chips to model the lungs and bone marrow to analyze how the immune system responds to infection in microgravity. A third study is examining the impact of spaceflight on musculoskeletal disease biology using a tissue chip joint model with cartilage and bone tissues. The last tissue chip study is focused on the blood-brain barrier and aims to shed light on the mechanisms behind neurological disorders like Alzheimer’s. While those are the experiments focusing on human health, others like NASA JPL’s Orbiting Carbon Observatory 3 will concentrate on tracking the distribution of carbon dioxide on Earth by collecting measurements on specific types of atmospheric CO2. This will give scientists more insight into carbon sources and storage sinks, which could help in predicting the impact of growing atmospheric heat retention as well as controlling its variability. The OCO3 will be robotically installed on the Japanese Experiment Module-Exposed Facility. Whether they be small or large, all these investigations help to highlight the incredible partnerships ongoing in space to keep pushing the boundaries of what we know of life in microgravity. There are plenty of upcoming launches coming up, so if there’s a specific one you’d like us to cover, let us know down in the comments below and make sure to subscribe to Seeker to get your rocket launch news. Thanks for watching.
B1 中級 這就是美國宇航局和SpaceX公司下一次CRS-17任務的機載設備|發射倒計時 (This Is What the Next NASA and SpaceX CRS-17 Mission Has On Board | Countdown To Launch) 2 0 林宜悉 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字