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The leaning tower of Nasa

  Nasa’s $1 billion (£720 million) Mobile Launcher rocket tower is ‘leaning’, according to the space agency.
During recent upgrades to the 350-foot (106-metre) structure, Nasa added a number of connecting arms, but it appears the extensions have put the tower on a slight tilt.
Nasa has acknowledged ‘some deflection and imperfections’ in the column but says the launcher is ‘structurally sound’ and does not need any design modifications.
The Mobile Launcher cost $234 million (£167 million) to build and is currently undergoing renovations worth $678 million (£485 million) to prepare it for the maiden launch of Nasa’s Space Launch System mega-rocket in 2019.
The lean likely means the already well over-budget tower won’t be used for more than one or two launches due to safety concerns, experts claim.
This in-part because the structure, housed at Nasa’s Kennedy Space Centre near Cape Canaveral, Florida, would need yet another upgrade after the rocket’s initial launch to accommodate larger payloads.
It may be cheaper for Nasa to build an entirely new tower, which would cost around $300 million (£214 million), according to a recommendation from the agency’s Aerospace Safety Advisory Panel.
Speaking on the Mobile Launcher’s structural issues, a Nasa spokesperson told NasaSpaceFlight that the tower’s ‘leaning/bending’ was expected, and will not require corrective work.
‘Nasa’s mobile launcher is structurally sound, built to specifications, and does not require a design change or modifications. As expected, the mobile launcher is not perfectly still,’ they said.
The launch tower was originally built to prop up the launch of Nasa’s human exploration spacecraft Ares-1, but the flight was cancelled by President Barack Obama in October 2010 as part of his Nasa authorisation bill.
Since 2011, the Mobile Launcher has undergone a number of upgrades to prepare for the agency’s significantly larger Space Launch System megarocket, which is set to take astronauts to Mars in the 2030s.
The Nasa spokesperson said: ‘The first surveys of the tower in 2011 indicated some deflection and imperfections, which is not unusual for big steel construction of this magnitude.
‘This is likely due to a combination of welding the different levels and modifying them one at a time from the mobile launcher’s original design for the Ares rocket, changes introduced in the structure during these modifications, and the additional mass.
‘There is no data that indicates a structural issue directly attributed to these imperfections (neither caused by the imperfections or causing the imperfections).’ But while the tilt may not require a structural correction, it may limit the number of launches the Mobile Launcher is capable of safely supporting.
‘While Nasa seems to believe this lean is not enough to require additional construction, it will likely mean that the Mobile Launcher won’t be used for more than one or two launches,’ Popular Mechanics reporter Avery Thompson wrote.
News of the Mobile Launcher’s lean comes after Nasa completed one of its first full-throttle tests of a Space launch System (SLS) RS-25 engine.
The 260-second engine firing at Stennis Space Center in Mississippi represented the toughest test yet for the hardware, which will power the SLS’s first unmanned flight in 2019.
In a statement, Nasa said: Operators powered one of Nasa’s Space Launch System (SLS) engines up to 113 percent thrust level, the highest RS-25 power level yet achieved.
‘The test lasted 260 seconds with power levels at 113 percent for 50 seconds of the test. This was the third full-duration test conducted on the A-1 Test Stand at Stennis this year.
‘Four RS-25 engines will help power SLS at launch, supplying a combined 2 million pounds of thrust and working in conjunction with a pair of solid rocket boosters to provide more than 8 million pounds of thrust.’
Increased engine performance is crucial for enabling SLS missions to deep space as the rocket, currently being built, evolves over the coming decades to carry astronauts and heavy cargo on a single flight.
The SLS was designed for missions beyond low-Earth orbit carrying crew and cargo to the moon or beyond.
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.
The rocket, set to take it’s maiden flight in 2019, will eventually carry humans on the Orion spacecraft.
Over the next year, engineers plan to add additional 3D printed parts to the RS-25 engine to reduce waste and costs associated with the SLS.



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