Hydrogen leak delays Discovery launch

Join Our Community of Science Lovers!

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American



On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


The space shuttle Discovery is still on the ground this morning, after NASA postponed last night’s scheduled launch because of a hydrogen leak. Liftoff is now tentatively scheduled for Sunday night.

The mission was to have dropped off the final pieces of the International Space Station's (ISS) solar arrays that capture energy from the sun, and parts for its urine recycling system that would expand the ISS’s capacity from three to six crew members. It was sidelined after engineers discovered a leak in the gaseous hydrogen venting system outside of the external fuel tank. That system carries excess hydrogen away from the launch pad, and an accumulation of gas could have caused an explosion at launch.

NASA techs will examine the leak today and meet at 4 p.m. EDT to discuss its status.  

Discovery's launch date was previously pushed back by nearly a month to evaluate possible safety concerns surrounding valves that control the flow of hydrogen gas from the main engines to the external fuel tank. Those worries aren’t related to the latest mishap, NASA spokesperson William Johnson told Bloomberg News.

“It’s completely different,” he told the newswire.

Hydrogen vent line connects to the external tank for space shuttle Discovery/NASA TV

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe