ダンゴイカがＩＳＳへ、頭足類にとっての小さな一歩

【ワシントンＡＦＰ＝時事】ダンゴイカやクマムシを載せた米宇宙開発企業スペースＸのロケットが３日、国際宇宙ステーション（ＩＳＳ）に向けて打ち上げられた。（写真はダンゴイカの幼体。米航空宇宙局＜ＮＡＳＡ＞提供）
　「ファルコン９」ロケットは、米航空宇宙局（ＮＡＳＡ）が３日午後１時２９分（日本時間４日午前２時２９分）にフロリダから打ち上げた。搭載された無人宇宙船「ドラゴン」は、打ち上げの約１２分後に切り離され、５日にＩＳＳにドッキングする予定。
　載せられたダンゴイカ（学名：Ｅｕｐｒｙｍｎａ　ｓｃｏｌｏｐｅｓ）は、バクテリアと宿主生物の相互作用に対する無重力の影響を研究するために使用される。ＩＳＳに到着後、何匹かを１２時間バクテリアにさらし、残りはそのままにする。研究は地球に戻ってから行われる。
　実験の主任研究員であるジェイミー・フォスター氏は、「人を含む動物は、微生物に頼って健康な消化器系と免疫系を維持している」と述べた。「こうした有益な相互作用を宇宙旅行がどのように変化させるかは、十分分かっていない」
　実験は、宇宙での長期滞在ミッションに参加する宇宙飛行士の健康を守る技術の開発に役立つと考えられている。
　ロケットには、クマムシや綿花、携帯用超音波診断装置、微小重力下で宇宙飛行士を苦しめる腎臓結石の形成について研究するための小型人工腎臓も搭載されている。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2021/06/04-12:19）

A SpaceX rocket took off Thursday for the International Space Station carrying supplies for scientific experiments, including some surprising passengers -- squids and virtually indestructible microorganisms called tardigrades.
The rocket, leased by NASA, launched from Florida at 1:29 pm local time (1729 GMT). The Dragon capsule detached from the Falcon 9 rocket about 12 minutes after take-off and is scheduled to dock at the ISS on Saturday.
Young specimens of the species Euprymna scolopes, known as bobtail squid, are on board for the trip, so scientists can study the effect of zero gravity on the interactions between bacteria and their host organisms.
Some of the squids will be exposed to bacteria once on board the ISS, while others will be left alone. After 12 hours, the specimens are preserved until their return to Earth, where they will be studied.
Animals, including humans, rely on our microbes to maintain a healthy digestive and immune system, said Jamie Foster, the principal investigator in the experiment, in a statement. We do not fully understand how spaceflight alters these beneficial interactions.
The experiment could help scientists in the future to develop techniques to protect the health of astronauts participating in long-duration missions in space.
Also on board the SpaceX rocket will be tardigrades, also known as water bears -- microscopic organisms that can withstand extreme radiation, sizzling heat, the coldest temperatures of the universe and decades without food.
The grub-like, eight-legged animals can come back from being dried out to a lifeless husk for decades, withstand near-zero pressure in outer space and the crushing depths of the Mariana Trench.
An Israeli probe that was later revealed to be carrying tardigrades crash-landed on the Moon in 2019, and if they survived the explosion, scientists think they might still be alive today -- though no rescue mission is currently planned to bring them home.
Spaceflight can be a really challenging environment for organisms, including humans, who have evolved to the conditions on Earth, said scientist Thomas Boothby.
One of the things we are really keen to do is understand how tardigrades are surviving and reproducing in these environments and whether we can learn anything about the tricks that they are using and adapt them to safeguard astronauts.
The rocket will also carry cotton, a portable ultrasound device and a miniaturized human kidney to study the formation of kidney stones that tend to afflict astronauts in microgravity.