Nasa Artemis - live: Space agency’s Moon rocket launch in doubt again amid yet another leak

Nasa is going to try and head back to the Moon – again.

The space agency will launch its Space Launch System rocket as part of the Artemis programme that one day hopes to put humans back onto the lunar surface.

But first it must contend with the technical problems that caused the initial launch, on Monday, to be postponed.

The space agency now hopes that those issues are fixed and that it will be able to launch the rocket in a new two-hour launch window that opens at 2.15pm local eastern time, or 7.15pm in the UK, on Saturday.

If successful, the spacecraft will launch off Earth and around the Moon, before heading back down to our planet 42 days later. This time, the Orion crew capsule is empty – but if this journey is successful, then a trip with humans on board is to come.

Key Points

• Nasa is ‘go’ for launch

• Weather unlikely to stand in way

Launch director says decision has not yet been made

16:08 , Andrew Griffin

Charlie Blackwell-Thompson, the launch director, has received the recommendation to scrub the launch but has not yet made a decision, according to Nasa’s live stream. She will not yet decide that today’s launch has been scrubbed.

She still has some further conversations she wants to have about the rocket, Nasa said. It did not say what those conversations were: it’s possible they relate not to whether the rocket will go today (that seems very unlikely) but what will happen to it after, and whether Nasa will try to launch tomorrow or give up and roll the rocket back to its assembly building.

Engineering team says ‘no go’ to today’s launch

15:57 , Andrew Griffin

Engineering teams have presented their belief that today’s launch is “no go” – it should be scrubbed. They only recommend that to Nasa’s leaders, who must make the final decision, but you can probably guess what that decision is going to be.

Leak could require major work, reporter says

15:53 , Andrew Griffin

The leak is coming from inside the engine compartment, which can’t be easily accessed, according to NBC’s Tom Costello.

That has two main consequences. The first and most immediate is that a scrub sounds likely. But it might also suggest that it has to be fixed by being rolled back to the assembly building – which would mean Nasa wouldn’t be able to use tomorrow’s backup window, and might have to wait until October or even longer.

Nasa promises update ‘shortly'

15:49 , Andrew Griffin

On Nasa’s live stream, viewers have just been told that engineers are updating the launch director about the latest news, and that there should be an update “shortly”. Again, that update is likely to be the announcement that the launch is scrubbed – but there’s always hope.

Nasa asks people to ‘stand by'

15:44 , Andrew Griffin

Nasa’s main account has tweeted about the problems, alongside a message asking people to “stand by” and keep watch on its YouTube channel. That might be an indication that an update is coming, or it might. (At this point, any update is almost certainly going to be the announcement that the launch is scrubbed; it’s getting harder and harder to see how there will be time to go today.)

What options does Nasa have?

15:40 , Andrew Griffin

Engineers are still troubleshooting the problem, and trying to find a fix. But this, from space writer Eric Berger, is a good summation of the options if today is written off.

Rolling back to the VAB (the vehicle assembly building) would be a big and unfortunate move, and mean that the launch could be delayed into October. But it is looking increasingly likely.

Third time unlucky

15:29 , Andrew Griffin

The third attempt to fix the hydrogen leak has failed. Neither upping the temperature or upping the pressure has worked.

This leak appears to be stubborn and difficult to fix. (Hydrogen is notoriously so: it’s very small and able to escape out of even the smallest leak.)

Even if engineers were to come up with another way of sealing it up, and it worked, the amount of time left to actually make use of the launch window later is rapidly dwindling.

It does feel like today’s launch will be scrubbed. We’ll let you know as soon as anything is confirmed.

Hydrogen flowing back in

15:17 , Andrew Griffin

Here’s the moment of truth: hydrogen is on its way back into the rocket. Will it stay there, or leak out?

(In the meantime, engineers are also racing to get other tasks done. All this delay could mean that even if the leak is fixed, there isn’t enough time to be ready before the launch window closes.)

Nasa says engineers are working hard

15:07 , Andrew Griffin

Nasa says its engineers are still working hard to fix the problem:

It doesn’t feel like good news, overall. Even if this is fixed, then it has already caused a big delay, and other work should have happened by now. But sometimes, with rocket launches, everything seems bad and then it quickly turns around: Nasa and many other people will be hoping for that today.

Plan C is plan A

15:01 , Andrew Griffin

Engineers have a plan to fix the problem. And it turns out to be plan A: warming up the quick disconnect in the hope that everything will seat properly and seal up the leak.

This was the first plan, but engineers then switched the plan B of to trying to pressurise it into place. Now plan C is going back to plan A and seeing if that might work after all.

It’s already been warming up for 15 minutes while the new plan was being set, so there’s 15 minutes to go – and then we’ll see again whether this has made everything work.

Again: all of this may have an impact on the planned launch time, since everything proceeds according to a tight schedule. There’s some wiggle room – but if there is a liftoff then it may be some time into the two hour launch window.

Plan to fix leak has failed

14:40 , Andrew Griffin

Engineers tried waiting for the temperature to change, they tried making the pressure change. But the leak has not changed: it’s still leaking.

That plan has been written off and engineers will now look for something else to try and get the rocket going today.

Here’s a picture that shows the problem section:

Fingers crossed as engineers try again

14:33 , Andrew Griffin

With an important seal loose, engineers have a plan: increase the pressure, and hope that it gets the seal back into the quick disconnect fitting, where it should be, so that the leak will stop. That pressure has been increased – and now it’s a matter of crossing fingers and hoping the leak is fixed.

Leak not fixed after all

14:08 , Andrew Griffin

As more hydrogen flows through the seal, it’s leaking again. Engineers are going to switch it back off again and see if they can get the seal to get back into place.

Again, all of this is very much unplanned; with a two-hour window, there’s space for some delays, but not loads.

Leaking seal appears to have fixed itself

13:32 , Andrew Griffin

As engineers had hoped, the leaking seal appears to have sealed itself: hydrogen is flowing again. Engineers had hoped that warming it up would force it back in properly, and that seems to have happened.

It’s not clear yet what that will have on the launch window.

Moon rocket could explode without care

12:50 , Andrew Griffin

While we’re waiting for updates, it’s worth revisiting this piece from Jon Kelvey – what’s at stake when Nasa “scrubs” a launch, and what might happen if it didn’t? (Spoiler: a lot.)

Problem is similar to one that ended launch last time

12:47 , Andrew Griffin

On Monday, the launch was pulled because of a hydrogen leak. Now there appears to be another one.

This is coming from a different place – the quick disconnect at the heart of this problem has been fine in all the previous fillings of the rocket.

Artemis launch hit by first big problem

12:32 , Andrew Griffin

The countdown clock just started, but there’s already an issue, as engineers take a look at a liquid hydrogen leak that has appeared as the rocket has started being filled up. Here’s the latest update from Nasa:

“Engineers detected a liquid hydrogen leak in a quick disconnect cavity and have stopped flowing the propellant to the core stage while they troubleshoot. Launch controllers are attempting to warm up the quick disconnect to attempt to reseat it to get a tight seal. Liquid oxygen flow is continuing.”

In short, that means that there’s a leak in one of the attachments, and engineers are now trying to work out whether they can fix it. The quick disconnect will take 30 minutes to warm up and it might reseat and seal the leak then.

Weather still looking OK

11:41 , Andrew Griffin

The weather isn’t great in Florida this morning. (But it’s good enough to start filling up the rocket, which has now begun.)

But things are still looking good for later. There’s a 60% chance of favourable conditions when the window opens, which goes up to 80% by the end of the launch window.

Weather looks favourable – mostly

11:12 , Andrew Griffin

The weather does not look likely to ruin today’s launch. The chances aren’t great – but they are favourable, overall.

You can read about Nasa’s weather forecast here.

11:11 , Andrew Griffin

Nasa has said today’s launch is a “go”. That doesn’t mean we’ll definitely get one – any kind of technical or weather problems could still lead to it being scrubbed – but everything is progressing as it should be, for now.

Hello and welcome...

10:13 , Andrew Griffin

... to The Independent’s live coverage of Nasa’s Artemis launch.

It’s the second time it will try and head back to the Moon, after major technical problems postponed a planned launch on Monday.