NASA has observed a bizarre effect of human space flight: blood going backwards in astronauts’ veins and clotting*.
The observations could have serious implications* for plans to send astronauts to Mars and to allow tourism in space.
An unnamed astronaut on the International Space Station was carrying out an ultrasound on their body – guided by experts on the ground. An ultrasound is a scan to study inside the body.
Similar tests before the astronaut went to space came back normal.
But the scan taken in space revealed a clot* of blood, shocking NASA doctors.
“We were not expecting this. This has never been reported before,” said NASA scientist Karina Marshall-Goebel, speaking to The Atlantic.
The astronaut didn’t have any clot-related symptoms, but was given blood-thinning medication for the rest of their time in orbit to prevent more clots forming.
This clotting and reverse flow was declared a new risk for humans in spaceflight, which will have to be better understood and planned for before astronauts can spend months or years in space, or before regular people can go to space for holidays or to live and spend extended periods in reduced gravity.
NASA researchers observed the jugular veins of 11 astronauts on the ISS using ultrasounds.
And in five of those 11 astronauts, blood flow in the jugular vein had stalled*.
“Sometimes it was sloshing back and forth a bit, but there was no net-forward movement,” Ms Marshall-Goebel explained.
The jugular vein is one of the most important parts of the body.
It runs between the heart and the head, draining deoxygenated* blood from the brain.
This “draining” process is essential to reduce pressure in the brain.
Stalled blood flow in veins is really rare, and is typically only seen in legs – often after long plane flights.
Blood that doesn’t move normally through the body is a major concern because it can lead to clotting, which can cause more serious problems like damage to the lungs.
The blood in the jugular vein also began moving in the opposite direction (from the heart towards the head) for two astronauts.
NASA scientists described this as “extremely abnormal”, and said that the blood may have switched directions due to a blockage.
A similar phenomenon* has been observed on Earth for patients with tumours* that force blood to find a different route to the heart.
“It’s almost like a detour,” explained Ms Marshall-Goebel.
This strange condition vanished when the astronauts returned to Earth.
“I think it was probably scary for everybody.
“But I think the fact that we found this now is really, really good news, because if you know this is a risk factor of spaceflight, it’s something that you can monitor* and prevent,” said Ms Marshall-Goebel.
As part of the same research, astronauts on the space station placed their legs in a special chamber with lower air pressure to suck more blood into their lower legs as would happen in Earth’s gravity. The chamber improved blood flow to the legs in 10 of 17 tests but worsened it in two.
This article was first published in The Sun and is republished here with permission.
THE LONG TRIP TO MARS
The finding that space travel can do weird things to humans’ blood and the way it flows around the body will have to be planned for as we look to space tourism and long-distance space travel in the future.
US President Donald Trump has ordered NASA to get humans to Mars by 2033.
The closest that Earth and Mars would ever be to each other as they separately orbit the Sun is a distance of 54.5 million kilometres but that’s rare. The average distance is 225 million kilometres.
Spacecraft that have already been to Mars without astronauts have taken 128-333 days, which would be a very long time for a human to be in a cramped spacecraft.
SpaceX boss Elon Musk believes his Interplanetary Transport System (ITS) could manage the journey in just 80 days, eventually reducing travel time to just 30 days.
Russian cosmonaut Valery Polyakov holds the record for the longest continuous trip into space, with nearly 438 consecutive* days in orbit aboard the Mir space station, from January 1994 to March 1995. He trained very hard before the trip to be as fit and strong as possible and wore a pressure suit while in space to force blood into his legs.
- clotting: the action of thickening to form a lump
- implications: the conclusions or answers you can arrive at without actually being told
- clot: liquid thickened to form a lump
- stalled: slowed or stopped completely
- deoxygenated: without oxygen in it
- phenomenon: thing we notice
- tumours: a type of growth or lump
- monitor: watch
- consecutive: one after another
- What did they give the astronauts to prevent another clot forming?
- In what situation would blood go in reverse on Earth?
- What were the results of the trial of the pressure chamber for astronauts’ legs?
- How far is it from Earth to Mars?
- How long did Valery Polyakov stay in space for on his long trip?
LISTEN TO THIS STORY
1. Create a space first aid kit
If you were an astronaut on the ISS, what would you pack in a first aid kit? Think about the health issues in today’s story, then think about other effects that space travel and living on the space station could have on your health. Also think about what types of accidents you could have in zero gravity. What would you pack to help you when things go wrong? List all of the items you would pack and, for each item, write a sentence explaining why you would pack this and what might happen to make you need it.
Time: allow 25 minutes to complete this activity
Curriculum Links: English, Science, Health and Physical Education
After reading the story, do you think that it is safe to start space tourism? Write arguments for and against people going on space holidays.
Time: allow at least 20 minutes to complete this activity.
Curriculum Links: English, Science, Critical and Creative Thinking
Wondrous Wow Words
After reading the article, with a partner, highlight as many wow words or ambitious pieces of vocabulary that you can find in yellow. Discuss the meanings of these words and see if you can use them orally in another sentence.
HAVE YOUR SAY: Does this make you more or less keen to go to space? Would you go if you could?
No one-word answers. Use full sentences to explain your thinking. No comments will be published until approved by editors.