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NASA: Premature shutdown of new mega-rocket during Saturday demo traced to hydraulic system


NASA have traced the cause of the premature shutdown of the Space Launch System‘s engines during a demo firing on Saturday to its hydraulic system.

Engineers said that overly ‘conservative’ test parameters had been introduced that caused the mega-rocket’s systems to go into shut down after just over a minute.

Despite initial concerns, the core stage of the 213 feet (65m) -tall rocket — which sports four ‘RS-25’ engines at its base — was undamaged by the test firing.

More powerful than the Apollo-era Saturn V rockets, the Space Launch System (or SLS) will also launch with two smaller solid rocket boosters attached to its side.

The mega-rocket was intended to return humanity to the lunar surface this decade — and is hoped will still launch on an unmanned orbit of the Moon in November. 

This trip — intended to put both the rocket and an attached Orion crew capsule through its paces — will begin from the Kennedy Space Center in Florida.

However, NASA experts are reportedly undecided as to whether they should subject the rocket to another test firing before it is shipped across the country.

NASA have traced the cause of the premature shutdown of the Space Launch System's rocket engines (pictured) during a demo firing on Saturday to its hydraulic system

NASA have traced the cause of the premature shutdown of the Space Launch System’s rocket engines (pictured) during a demo firing on Saturday to its hydraulic system

Engineers said that overly 'conservative' test parameters had been introduced that caused the mega-rocket's systems to go into shut down after just over a minute. Pictured, the SLS core stage undergoing an engine test firing at the Stennis Space Center in Mississippi on Saturday

Engineers said that overly ‘conservative’ test parameters had been introduced that caused the mega-rocket’s systems to go into shut down after just over a minute. Pictured, the SLS core stage undergoing an engine test firing at the Stennis Space Center in Mississippi on Saturday

The ‘hotfire’ test of the RS-25 engines was conducted by NASA and SLS contractor Boeing’s engineers on Saturday at the Stennis Space Center in Mississippi.

For the duration of the firing, the core stage of the rocket was anchored to the B-2 test stand — a massive steel structure in the confines of the launch facility.

The SLS was fuelled up with more than 700,000 gallons of liquid hydrogen and oxygen propellant for the demo — such that should have allowed the rocket engines to fire for eight minutes in total, equal to the time it would take to get into space.

SLS programme manager John Honeycutt of NASA’s Marshall Space Flight Center in Alabama said during a press conference that the core stage and RS-25 engines ‘performed perfectly’, BBC News reported.

‘We’ve learned from the data that the shutdown did occur as the result of a couple of test parameters we had set on the hydraulic system that’s powered by the core stage auxiliary power units,’ Mr Honeycutt continued.

‘What we’ve done for this test programme, in order to protect the flight hardware, is intentionally be a little conservative with our test parameters.’

The hydraulic system is responsible for the pivoting of the four main engines in-flight, allowing the rocket to be steered.

‘On auxiliary power unit 2, we saw a low indication on the hydraulic reservoir level, and the hydraulic pressure. Those two “low cuts” went through their checks over a series of milliseconds,’ explained Mr Honeycutt.

‘And on the three checks that it took, it stayed low and it sent the command to the flight computer to advance the shutdown.’

As the shutdown was initiated by limits introduced specifically for the engine test, such would not cause an issue in the event of a real launch. 

Despite initial concerns, the core stage of the 213 feet (65m) -tall rocket ¿ which sports four 'RS-25' engines at its base, pictured here during the test ¿ was undamaged by the firing

Despite initial concerns, the core stage of the 213 feet (65m) -tall rocket — which sports four ‘RS-25’ engines at its base, pictured here during the test — was undamaged by the firing

More powerful than the Apollo-era Saturn V rockets, the Space Launch System (or SLS ¿ pictured) will also launch with two smaller solid rocket boosters attached to its side

More powerful than the Apollo-era Saturn V rockets, the Space Launch System (or SLS — pictured) will also launch with two smaller solid rocket boosters attached to its side

SLS programme manager John Honeycutt said during a press conference that the core stage and RS-25 engines 'performed perfectly' during the test (pictured) , BBC News reported

SLS programme manager John Honeycutt said during a press conference that the core stage and RS-25 engines ‘performed perfectly’ during the test (pictured) , BBC News reported

Saturday’s demo was to be the final test before the launch of the SLS as part of NASA Artemis programme, which plans to place astronauts back on the Moon by the year 2024 — the first time humanity has taken steps on Earth’s satellite since 1972.

Despite concerns that the space agency will miss their self-imposed deadline, NASA chief Jim Bridenstine is confident the test issue will not cause significant delays.

‘Is it within the realm of possibility to launch [Artemis-1] by 2021? Yes, it is still within the realm of possibility,’ he told BBC News, adding that NASA was on track to return to the Moon by 2024, where they plan to sustain a programme of exploration.

He also said that Nasa was hitting the milestones needed to meet the 2024 date for astronauts returning to the Moon.

'We've learned from the data that the shutdown did occur as the result of a couple of test parameters we had set on the hydraulic system that's powered by the core stage auxiliary power units,' Mr Honeycutt continued. Pictured: the test of the four RS-25 engines

'We've learned from the data that the shutdown did occur as the result of a couple of test parameters we had set on the hydraulic system that's powered by the core stage auxiliary power units,' Mr Honeycutt continued. Pictured: the test of the four RS-25 engines

‘We’ve learned from the data that the shutdown did occur as the result of a couple of test parameters we had set on the hydraulic system that’s powered by the core stage auxiliary power units,’ Mr Honeycutt continued. Pictured: the test of the four RS-25 engines

The so-called 'hotfire' test of the RS-25 engines was conducted by NASA and Boeing engineers on Saturday at the Stennis Space Center in Mississippi

The so-called ‘hotfire’ test of the RS-25 engines was conducted by NASA and Boeing engineers on Saturday at the Stennis Space Center in Mississippi

‘It must be said — and this is so important, that we have strong, bipartisan, apolitical support for the Artemis programme,’ added Mr Bridenstine, who is an outgoing appointee of the Trump administration.

While little is known at present about incoming President Joe Biden’s thoughts on the space programme, the US Democratic party expressed broad support for the planned return to the lunar surface prior to 2020 election.

Mr Bridenstine said that he believed NASA can present the new administration with options for space exploration that they can buy into.

‘These are not programmes for one term, these are programmes that need to withstand multiple administrations,’ he concluded. 

The mega-rocket is intended to return humanity to the lunar surface this decade ¿ and is hoped will still launch on an unmanned orbit of the Moon in November. Pictured, an artist's impression of the Space Launch System blasting off on a mission

The mega-rocket is intended to return humanity to the lunar surface this decade — and is hoped will still launch on an unmanned orbit of the Moon in November. Pictured, an artist’s impression of the Space Launch System blasting off on a mission

WHAT IS NASA’S SPACE LAUNCH SYSTEM?

Nasa’s Space Launch System, or SLS, is an advanced launch vehicle that will ‘provide the foundation for human exploration beyond Earth’s orbit’, according to the space agency.

Launching with unprecedented thrust power, SLS will carry crews of up to four astronauts in the agency’s Orion spacecraft on missions to explore deep-space destinations.

Offering more payload mass, volume capability and energy to speed missions through space than any current launch vehicle, SLS is designed to evolve over several decades to keep up with modern technologies and payloads.

Nasa's Space Launch System, or SLS, is an advanced launch vehicle that will 'provide the foundation for human exploration beyond Earth’s orbit', according to the space agency (artist's impression)

Nasa’s Space Launch System, or SLS, is an advanced launch vehicle that will ‘provide the foundation for human exploration beyond Earth’s orbit’, according to the space agency (artist’s impression)

These include robotic scientific missions to places like the Moon, Mars, Saturn and Jupiter. 

The rocket’s first launch, which will be unmanned, is set for 2020 at Nasa’s Kennedy Space Centre in Florida. 

The initial configuration for what SLS can carry past low-Earth orbit and on to the moon is more than 26 metric tons, with a final configuration of at least 45 metric tons.

Nasa intends to send humans to ‘deep-space’ destinations such as Mars and the moon aboard the SLS, with a date for a mission to the red planet set for the 2030s.



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