Nasa prepares for third attempt at Artemis lunar rocket launch

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Nasa's Space Launch System (SLS) rocket with the Orion spacecraft atop resting on launch pad 39B as final preparations are made for the Artemis I mission at Nasa's Kennedy Space Center on Monday.

Two previous launch attempts for Nasa's Space Launch System were aborted because of fuel line leaks and other technical problems that Nasa has since resolved.

PHOTO: AFP

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- Ground teams at Kennedy Space Centre prepared on Tuesday for a third try at launching National Aeronautics and Space Administration’s (Nasa) towering, next-generation Moon rocket, the debut flight of the United States space agency’s Artemis lunar programme, 50 years after Apollo’s last Moon mission.

The 32-storey tall Space Launch System (SLS) rocket was due to blast off from Cape Canaveral, Florida, at 1.04am EST (2.04pm Singapore time) on Wednesday to send its Orion capsule on a 25-day voyage around the Moon and back without astronauts aboard.

Nasa flight-readiness crews were eager for success after 10 weeks beset by engineering difficulties, two hurricanes and two trips from the spacecraft’s hangar to its launch pad.

Two previous launch attempts, on Aug 29 and Sept 3, were

aborted because of fuel line leaks

and other technical problems that Nasa has since resolved.

While moored to its launch pad last week,

the rocket endured fierce winds and rain from Hurricane Nicole,

forcing a two-day flight postponement.

Post-storm inspections found the hurricane had torn off a strip of ultra-thin protective sealant from Orion’s exterior, but Nasa officials said on Monday night the damage was minor and posed negligible risk to the launch.

Weather is always a factor beyond Nasa’s control.

The latest forecast on Monday called for a 90 per cent chance of favourable conditions during Wednesday’s two-hour launch window, according to the US Space Force at Cape Canaveral.

Dubbed Artemis I, the mission marks the first flight of the SLS rocket and the Orion capsule together, built under Nasa contracts with Boeing and Lockheed Martin, respectively.

It also signals a major change in direction for Nasa’s post-Apollo human spaceflight programme, after decades focused on low-Earth orbit with space shuttles and the International Space Station.

Named for the Greek goddess of the hunt - and Apollo’s twin sister - Artemis aims to return astronauts to the moon’s surface as early as 2025.

Twelve astronauts walked on the moon during six Apollo missions from 1969 to 1972, the only spaceflights yet to place humans on the lunar surface.

But Apollo, born of the US-Soviet space race during the Cold War, was less science-driven than Artemis.

The new moon programme has enlisted commercial partners such as billionaire Elon Musk’s SpaceX and the space agencies of Europe, Canada and Japan to eventually establish a long-term lunar base as a stepping stone to even more ambitious human voyages to Mars.

Getting the SLS-Orion spacecraft off the ground is a key first step.

Its first voyage is intended to put the 2.6-million-kg vehicle through its paces in a rigorous test flight, pushing its design limits to prove the spacecraft is suitable to fly astronauts.

If the mission succeeds, a crewed Artemis II flight around the Moon and back could come as early as 2024, followed within a few more years by the programme’s first lunar landing of astronauts, one of them a woman, with Artemis III.

Billed as the most powerful, complex rocket in the world, the SLS represents the biggest new vertical launch system the US space agency has built since the Saturn V of the Apollo era.

Barring last-minute difficulties, the launch countdown should end with the rocket’s four main R-25 engines and its twin solid-rocket boosters igniting to produce 3.99 million kg of thrust, sending the spacecraft streaking skyward.

About 90 minutes after liftoff, the rocket’s upper stage will propel Orion out of Earth orbit on course for a 25-day flight that brings it to within 96km of the lunar surface before sailing 64,374km beyond the Moon and back to Earth.

The capsule is expected to splash down in the Pacific on Dec 11.

Although no humans will be aboard, Orion will carry a simulated crew of three – one male and two female mannequins – fitted with sensors to measure radiation levels and other stresses that real-life astronauts would experience.

A top objective for the mission is to test the durability of Orion’s heat shield during re-entry as it hits Earth’s atmosphere at 39,429km per hour, or 32 times the speed of sound, on its return from lunar orbit – much faster than re-entries of capsules returning from the space station.

The heat shield is designed to withstand re-entry friction expected to raise temperatures outside the capsule to nearly 2,760 deg C.

More than a decade in development with years of delays and budget overruns, the SLS-Orion spacecraft has so far cost Nasa least US$37 billion (S$50.6 billion), including design, construction, testing and ground facilities.

Nasa’s Office of the Inspector-General has projected total Artemis costs will run to US$93 billion by 2025.

Nasa defends the programme as a boon to space exploration that has generated tens of thousands of jobs and billions of dollars in commerce. REUTERS

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