SpaceX's Starship rocket has returned to Earth on its fourth test flight, landing in the Indian Ocean
"Splashdown confirmed! Congratulations to the entire SpaceX team on an exciting fourth flight test of Starship!" the company says
SpaceX founder Elon Musk says: "Despite loss of many tiles and a damaged flap, Starship made it all the way to a soft landing in the ocean!"
Earlier, the booster was brought back down to the Gulf, to hover just above the water
That’s a big step forward from previous test flights when the booster was destroyed in flight
This fourth test flight follows three earlier tests that had varying degrees of success
You can follow our live stream of the launch by pressing the Play button at the top of this page
The Starship rocket is due to launch in less than five minutes now from SpaceX's base in Boca Chica, Texas.
There's a lot of hope pinned on this mission after three failed test flights.
As a reminder, you can watch the launch live by clicking the Play button at the top of our live page.
Jonathan Amos
Science correspondent
Image source, ReutersSpaceX develops its technology in a different way from how many people might expect it to be done. The rocket company's philosophy is to "test early, break it and learn".
SpaceX is not worried if something doesn't work perfectly straight out of the box. So don't be surprised if this mission does not tick off all the steps described above.
For SpaceX, success will be judged on what it manages to get right over and above what happened to Starship previously.
This means seeing the booster and the Ship get significantly further along in the planned mission profile.
If the booster can get much closer to performing the controlled hover above Gulf waters, it will be chalked up as a win.
Likewise, if the Ship can survive the intense heat of atmospheric re-entry and make it intact through to the Indian Ocean (with a controlled or uncontrolled contact with the water), SpaceX will be delighted.
Rebecca Morelle
Science editor
Keep an eye on the performance of the booster's 33 engines. It's where it all starts. Getting them to fire together is a big deal.
SpaceX looks to have got on top of this, judging by test flights two and three. But the rocket company has had difficulty managing these power units following separation, during the phase where the booster is asked to come back towards the Gulf coast.
Fuel lines and valves have become clogged.
Upgrades on this flight will aim to address previous shortcomings.
Watch also the separation, or staging, process itself. The Ship lights its engines before the two halves of the vehicle come apart. A slotted ring between the two sections allows hot exhaust gases from the Ship's engines to escape easily, and not damage the top of the booster.
On today's flight, this staging ring will be deliberately discarded after separation to reduce weight on the booster and help with its return manoeuvres. We might get to see it fall away.
Image source, ReutersIn its latest update, SpaceX says it's hoping to launch Starship at 07:50 local time (12:50 GMT, 13:50 BST) from its base in southeast Texas - but that time could change.
Starship was originally expected to launch at 07:00, but the timing has been delayed a couple of times since.
Posting on X, the company adds that the weather conditions are 95% favourable.
Remember: you can watch the launch live by clicking the Play button at the top of this page.
Rebecca Morelle
Science editor
Today's planned flight profile is broadly similar to earlier test missions.
Starship will launch out over the Gulf of Mexico, in the direction of the Atlantic Ocean and southern Africa.
The Super Heavy booster will once again get things off the ground and power upwards for two minutes and 41 seconds.
The Ship will then separate and use its six engines to push on to space.
SpaceX wants the Super Heavy booster to try to fly back to near the coast of Texas and come down vertically, to hover just above the Gulf's waters.
It will then be allowed to topple over and sink. This is a prelude to later attempts to land back at the launch pad on future tests.
Meanwhile, the ship should be flying out over the Caribbean at this stage.
It will shut down its engines a little under eight and a half minutes into the flight, at an altitude of perhaps 150km (90 miles), moving at more than 20,000km/h (12,400mph). The Ship will then cruise around the Earth.
At 39 minutes after lift-off, the Ship should be falling back through the atmosphere to another controlled hover just above seawater, but in the Indian Ocean, west of Australia.
SpaceX says, external the team have started loading the propellant - or "prop" for short - into Starship.
All being well, we've got just over half an hour to go before lift-off. Stay with us.
Rebecca Morelle
Science editor
The top half of Starship is called simply...the Ship. It's got six engines at its base, again burning methalox.
It's the business end of the system in the sense that it's inside the Ship that satellites would be stowed or a crew would sit.
Elon Musk, SpaceX CEO, says Starship should be able to put 150 tonnes - and more - of payload in a low-Earth orbit just a few hundred kilometres up.
Workhorse rockets today can do no more than about 20-30 tonnes to a similar altitude, and those vehicles are in part, or wholly, expendable: you need a new vehicle, or elements of a new vehicle, every time you launch.
Image source, .Jonathan Amos
Science correspondent
Starship comes in two halves.
The bottom segment - the Super Heavy booster - does the job of getting everything off the ground. At its base are 33 engines, burning a mix of liquid methane and liquid oxygen.
Engineers refer to the combination as methalox. Firing in unison, the cluster of engines should produce in excess of 70 meganewtons of thrust.
To put that in context: Nasa's biggest rocket - the Space Launch System, or SLS - produces 39 meganewtons off the pad, and that's over 20% more than the old space shuttle system could generate.
Starship is by far the most powerful launch system we've ever seen.
Image source, .
Emily Atkinson
Live reporter
Hello and welcome to our live coverage, as we prepare to see Elon Musk’s Starship rocket make its fourth attempt at launching - and returning - from the skies, beyond Earth’s atmosphere.
It follows previous attempts in March this year, and April and November last year.
SpaceX says today’s test flight will focus on demonstrating the rocket’s ability to return Starship to Earth at the end of the vehicle’s flight.
Lift-off from the Texan coastal town of Boca Chica is scheduled to occur within a two-hour window, starting at 07:00 local time (12:00 GMT; 13:00 BST).
SpaceX has suggested 07:50 would be the moment.
If the entrepreneur can get Starship working as designed, it will be revolutionary. A fully and rapidly reusable rocket capable of putting more than a hundred tonnes of payload in orbit in one go would radically lower the cost of space activity, and enable new types of space activity.
Our science correspondent, Jonathan Amos, and science editor, Rebecca Morelle, have highlighted key moments to look out for before and during the launch.
We'll have a live stream of the launch at the top of this page, that will go live around 30 minutes ahead of lift-off.