Placeholder Image

字幕列表 影片播放

  • 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.

  • Theyre 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 well 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, theyll be creating duplicates of the repaired DNA using a miniPCR.

  • As for analyzing the data, theyll 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.

SpaceX just had its first commercial launch with its Falcon Heavy and landed all three

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

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
影片單字