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From the reddit discussion: "I read an article on the SLS/Orion. They had a problem with vibrations making screens unreadable. It would have cost millions of d

From the reddit discussion: "I read an article on the SLS/Orion. They had a problem with vibrations making screens unreadable. It would have cost millions of dollars to dampen the pod vibrations so the pilots could read their instruments. Then a scientist realized that if you changed the monitor refresh rate to match the vibrations, the screens looked perfectly clear. The million dollar fix was abandoned for a 10 cent accelerometer that adjusted the refresh rate automatically. I see no reason why spacex couldn't use this solution to make the screens useful in the rigor of flight."

rbanffy 12y ago
The SLS/Orion used a solid-rocket first stage. Vibrations were, at one point, risking the lives of the crew. IIRC, a very heavy dampener was added to the original design, further reducing effective launch capacity. I assume the liquid fuel engines on the F9 offer a much less bumpy ride.
- mikeash 12y ago
  One really starts to wonder at NASA's obsession with solid rockets for manned launchers. I get it for the Space Shuttle, they were cornered and gave it a shot, but surely it's obvious now that it's a bad idea.
  - ak217 12y ago
    The obsession comes from political connections of ATK Thiokol. (I don't mean to accuse NASA bureaucrats of corruption. What I think happens is that NASA and partners come up with a design and take it to Congress for funding. Congress asks for more design choices. Curiously, the design that uses certain contractors receives funding, and the other ones don't.)
    - tanzam75 12y ago
      The politics of the SRBs are absolutely disgusting and date back to the original choice of Thiokol in the 1970s. Thiokol won the contract for the space shuttle SRBs because James Fletcher was the head of NASA. Fletcher had previously been president of the University of Utah. He thus had connections with Thiokol, and also with Senator Jake Garn (R-Utah). There were four bids for the SRBs. NASA engineers selected the Aerojet bid, which came in at the lowest price. Fletcher overruled his own engineers and picked Thiokol. Because Thiokol was located in landlocked Utah, their SRBs would have to be delivered in pieces and reassembled at the Cape, using O-rings to seal the joints. The failure of the O-rings in cold weather then killed the 7 astronauts on Challenger. To add insult to injury, Aerojet had been planning to manufacture the SRBs in Florida, in one piece, shipping them to the Cape by barge. Hence, no assembly, no O-rings, and no dead astronauts. To add further insult to injury, James Fletcher was reappointed NASA Administrator after the Challenger explosion! Jake Garn became one of only two Congressmen to fly into space.
      - mikeash 12y ago
        "The space sickness he experienced during the journey was so severe that a scale for space sickness was jokingly based on him, where 'one Garn' is the highest possible level of sickness." At least some sort of revenge was had upon him.... Looks like he flew before the Challenger explosion. I wonder if he ever realized how close to death he came on his own flight, and his own role in it.
      - deleted 12y ago
        [deleted]
tanzam75 12y ago
As clever as that may be, it is still a workaround for a problem that shouldn't even exist. Astronauts on Soyuz and Shenzhou do not have any problem with vibrations making the screen unreadable. That's because they don't have a vibration problem. Soyuz and Shenzhou are launched on liquid rocket boosters. Similarly, astronauts on Dragon won't have any problem seeing the screen due to vibrations. The Falcon 9 is also an all-liquid rocket. The reason that SLS/Orion will vibrate so badly is that it uses solid rocket boosters. The SLS uses SRBs because it is required to use shuttle-derived components. The shuttle used SRBs because they were cheaper than the proper solution of designing liquid rocket boosters. This sums up, in a nutshell, what's wrong with the American space program. A budget expedient from the 1970s is forcing technical workarounds well into the 21st century.
- criley2 12y ago
  You're being downvoted but you're absolutely correct. Even today, in the 21st century, the US Congress mandates Solid Rocket Boosters in all NASA heavy lifters, as a Congressional mandate with strong oversight on design to ensure compliance. The reason is purely political. There is no engineering or scientific benefit to SRB's, not a single one. But there are benefits to propping up SRB companies with NASA purchase mandates that we source ICBM stuff from.

rbanffy 12y ago

The SLS/Orion used a solid-rocket first stage. Vibrations were, at one point, risking the lives of the crew. IIRC, a very heavy dampener was added to the original design, further reducing effective launch capacity. I assume the liquid fuel engines on the F9 offer a much less bumpy ride.

mikeash 12y ago
One really starts to wonder at NASA's obsession with solid rockets for manned launchers. I get it for the Space Shuttle, they were cornered and gave it a shot, but surely it's obvious now that it's a bad idea.
- ak217 12y ago
  The obsession comes from political connections of ATK Thiokol. (I don't mean to accuse NASA bureaucrats of corruption. What I think happens is that NASA and partners come up with a design and take it to Congress for funding. Congress asks for more design choices. Curiously, the design that uses certain contractors receives funding, and the other ones don't.)
  - tanzam75 12y ago
    The politics of the SRBs are absolutely disgusting and date back to the original choice of Thiokol in the 1970s. Thiokol won the contract for the space shuttle SRBs because James Fletcher was the head of NASA. Fletcher had previously been president of the University of Utah. He thus had connections with Thiokol, and also with Senator Jake Garn (R-Utah). There were four bids for the SRBs. NASA engineers selected the Aerojet bid, which came in at the lowest price. Fletcher overruled his own engineers and picked Thiokol. Because Thiokol was located in landlocked Utah, their SRBs would have to be delivered in pieces and reassembled at the Cape, using O-rings to seal the joints. The failure of the O-rings in cold weather then killed the 7 astronauts on Challenger. To add insult to injury, Aerojet had been planning to manufacture the SRBs in Florida, in one piece, shipping them to the Cape by barge. Hence, no assembly, no O-rings, and no dead astronauts. To add further insult to injury, James Fletcher was reappointed NASA Administrator after the Challenger explosion! Jake Garn became one of only two Congressmen to fly into space.
    - mikeash 12y ago
      "The space sickness he experienced during the journey was so severe that a scale for space sickness was jokingly based on him, where 'one Garn' is the highest possible level of sickness." At least some sort of revenge was had upon him.... Looks like he flew before the Challenger explosion. I wonder if he ever realized how close to death he came on his own flight, and his own role in it.
    - deleted 12y ago
      [deleted]

tanzam75 12y ago

As clever as that may be, it is still a workaround for a problem that shouldn't even exist. Astronauts on Soyuz and Shenzhou do not have any problem with vibrations making the screen unreadable. That's because they don't have a vibration problem. Soyuz and Shenzhou are launched on liquid rocket boosters. Similarly, astronauts on Dragon won't have any problem seeing the screen due to vibrations. The Falcon 9 is also an all-liquid rocket. The reason that SLS/Orion will vibrate so badly is that it uses solid rocket boosters. The SLS uses SRBs because it is required to use shuttle-derived components. The shuttle used SRBs because they were cheaper than the proper solution of designing liquid rocket boosters. This sums up, in a nutshell, what's wrong with the American space program. A budget expedient from the 1970s is forcing technical workarounds well into the 21st century.

criley2 12y ago
You're being downvoted but you're absolutely correct. Even today, in the 21st century, the US Congress mandates Solid Rocket Boosters in all NASA heavy lifters, as a Congressional mandate with strong oversight on design to ensure compliance. The reason is purely political. There is no engineering or scientific benefit to SRB's, not a single one. But there are benefits to propping up SRB companies with NASA purchase mandates that we source ICBM stuff from.