*

Launch pad leak, then cloudy weather push back Starship's

10th

flight

*

Three Starship failures in 2025 raise stakes for rocket's

latest

test

*

SpaceX seeks progress in ship's heat shield, steering

flaps

(Updates SpaceX calls off launch for the day)

By Joey Roulette

WASHINGTON, Aug 25 (Reuters) - Elon Musk's SpaceX

postponed the 10th launch of its Starship rocket due to cloudy

weather in Texas on Monday, another slight delay in its efforts

to overcome development setbacks and achieve several long-sought

milestones essential to the Mars rocket system's reusable

design.

The 232-feet (71-metres) tall Super Heavy booster and its

171-feet (52-metres) tall Starship upper half, which together

make it taller than New York's Statue of Liberty, sat on a

launch mount at SpaceX's Starbase rocket facilities ahead of

liftoff time that had been moved back a few times because of

gloomy weather.

The rocket was filled with millions of pounds of propellant

and set to launch when SpaceX around 8:00 p.m. EST (0000 GMT)

opted to call off the day's launch and turn the operation into a

launch rehearsal, considering the weather forecast would remain

unfavorable throughout the launch window.

SpaceX will try to launch Starship on Tuesday at 7:30 p.m.

(2130 GMT)

A liquid oxygen leak at the Starship launchpad had nixed a

Sunday launch attempt, billionaire Musk wrote on X overnight,

adding SpaceX would try again on Monday. Musk on Monday appeared

on SpaceX's live stream for a brief chat about Starship's design

and its role in ferrying humans to Mars.

Development of SpaceX's next-generation rocket, key to the

company's powerful launch business and Musk's goal to send

humans to Mars, has faced repeated hiccups this year.

NASA hopes to use the rocket as soon as 2027 for its first

crewed moon landing since the Apollo program.

SpaceX's Starlink satellite internet business, a major

source of company revenue, is also tied to Starship's success.

Musk aims to use Starship to launch larger batches of Starlink

satellites, which have so far been deployed by SpaceX's

workhorse Falcon 9 rocket, into space.

"In about 6 or 7 years, there will be days where Starship

launches more than 24 times in 24 hours," Musk said on Sunday,

replying to a user on X.

This year, two Starship testing failures early in flight,

another failure in space on its ninth flight, and a massive test

stand explosion in June that sent debris flying into nearby

Mexican territory have tested SpaceX's capital-intensive

test-to-failure development approach, in which new iterations of

rocket prototypes are flown to their technical limits.

That ethos is markedly different from SpaceX's rivals such

as Jeff Bezos' Blue Origin, whose New Glenn rocket made an

operational debut in January following years of on-the-ground

development and testing. The new Vulcan rocket from United

Launch Alliance, co-owned by Boeing ( BA ) and Lockheed Martin ( LMT )

, had a similar upbringing before its 2024 debut.

With SpaceX's approach, testing failures early in Starship's

flight prevent the company from gathering vital technical data

needed to advance the rocket's design.

Still, SpaceX, which Musk expects to record around $15.5

billion in revenue this year, has continued to swiftly produce

new Starships for test flights at Starbase, a sprawling and

rapidly growing rocket industrial complex. The area was made a

municipality in May by local voters, many of them SpaceX

workers.

Starship's setbacks underscore the technical complexities of

the latest iteration. The ship is packed with far more

capabilities than predecessor models such as increased thrust, a

potentially more resilient heat shield and stronger steering

flaps crucial to nailing its atmospheric reentry - key traits of

its rapidly reusable design that Musk has long pushed for.

SpaceX has a lengthy to-do list for Starship's development

before the rocket begins routine missions envisioned by Musk.

That includes demonstrating safe returns from space, payload

deployments in orbit and complex in-space propellant refueling

which is crucial to its moon mission assignments for NASA.

Whenever Starship can launch, the rocket system will liftoff

from Texas and separate in half dozens of miles in altitude,

with its Super Heavy booster returning for a water landing off

the Texas coast, while Starship ignites its own engines to blast

further into space.

In space, Starship will attempt to deploy mock Starlink

satellites and reignite an engine along its suborbital path

around the globe. Atmospheric reentry over the Indian Ocean will

test its exterior steering flaps and an array of experimental

heat shield tiles as the ship blazes through intense friction

and heat.