The first SLS mobile launcher is leaning

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Though NASA says it is not a problem, they have now revealed that the very expensive mobile launcher to be used for the first unmanned SLS launch in 2019, is leaning slightly.

The notes spoke of engineers being concerned about a lean towards the North – which would be towards the rocket when mated – with the angle of the leaning claimed to be seen as increasing when the Vertical Stabilizer porch was installed. It was also claimed the ML Tower is twisting and this issue increased when the porch was installed. This was cited as the reason additional arm installations onto the Tower were placed on hold, until the leaning-twisting issue is understood. Next in line for installation are the ICPS (Interim Cryogenic Propulsion Stage) Umbilical Arm, the Crew Access Arm and the two Vehicle Stabilizer Arms.’s Philip Sloss took the concerns to NASA to ask for clarifications. NASA responded, saying “the ML leaning/bending was not the cause of the delay in the install of the Crew access arm. These are unrelated.” However, they did expand on the specific issue, mainly to note it is understood and does not currently require any additional mitigation or modification to the ML.

“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,” a NASA spokesperson added.

Note that this mobile launcher is not compatible with the second SLS launch, which would be the first manned flight in 2023. NASA will either have to modify it significantly at great costs, or build another, discarding this launcher after only one use.


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  • geoffc

    The combined cost of the two SLS mobile towers, appears to be more than the cost to SpaceX of developing the Falcon Heavy.

    Something is wrong here. We all know it. Will Congress admit it? I doubt it.

  • Mark H.

    I’ll be surprised if it is ever used at all

  • Localfluff

    Is it leaning left or is it leaning right?
    That kind of somewhat orbital mechanics is decisive for the political survival of this pretend-to-do-something-jobs program. Or rather maybe the question should be, towards which jobs program state is it leaning?

    “Leaning” in any direction means it remains a slave to gravity in any case.

  • Richard M

    “The combined cost of the two SLS mobile towers, appears to be more than the cost to SpaceX of developing the Falcon Heavy.”

    Actually, The combined cost of the two SLS mobile towers, appears to be more than TWICE the cost to SpaceX of developing the Falcon Heavy. ($912 million + $300 million = $1.212 billion, versus “over half a billion dollars” for FH)

  • Kirk

    A week ago Dick Eagleson wrote that we will know SLS is on the ropes when it become a public laughingstock and the subject of jokes on late night TV. Eric Berger’s “by the numbers” tweet is a step in that direction.

  • Ted

    The A.C. Gilbert Company – maker of world famous Erector Set toys says the error with the tower is due to a failure of not reading the instructions. “Erector Set Toys were designed with a maximum height of 30 inches not 300 feet!” Besides that how do you keep track of all those little nuts an bolts.

    However the supplier of Lincoln Logs says that have a low cost replacement almost ready. It can easily handle the 300 foot level and although just a one time fix it’ll burn light a volcano after launch be able to be seen for miles and miles!

    Or, we can just let the government do it.

  • Localfluff

    Countdown to the first crewed SLS+Orion launch:
    $41 000 000 000
    $40 999 999 999
    $40 999 999 998
    $40 999 999 997
    Halt the countdown! Restart at:
    $43 000 000 000
    $42 999 999 999

    Are you making that up to cover up the really ugly truth?

  • Localfluff

    I’m at least glad they renamed it from Ares. This SLS thingy would’ve given Mars a bad name.

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