Value chain · CLM-0998
In plain terms
With the top of a five-kilometre section of the satellite two hundred degrees Fahrenheit hotter than the bottom, the estimate has its free end bending by about eight or about eighty metres during construction. The report's text says eight metres and its own chart says about eighty; the report does not say which is right.
The claim as recorded
Grumman's 1978 estimate for the Boeing Phase I aluminium satellite module, cantilevered from the construction base, gives slope and tip deflection against module length to 5.5 km for gradients of 100, 200 and 300 degF between upper and lower members, with an expected gradient of about 120 degF: the plots read 0.8 degrees of slope and about 80 m of deflection at the full 5.4 km length for 200 degF, while the prose states "the tip deflection relative to the base is 8 meters; the slope is 0.8 degrees".
Evidence behind this: T3-contractor "preliminary estimate", which the page says will be re-evaluated; and the page's prose and its plots disagree by a factor of ten.
Scope and limits
THE PROSE AND THE PLOTS DISAGREE: 8 m against about 80 m at the length where the slope reaches 0.8 degrees; recorded, not resolved. A uniform-curvature cantilever with 0.8 degrees of tip slope over 5.4 km deflects 38 m, matching neither exactly, so the plots are not a simple uniform-curvature pair either. Aluminium Phase I structure, superseded by graphite in Phase II; a construction-phase boundary condition.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
Printed p.28, normalised: "The module structure was cantilevered from the construction base... The results show that for a temperature difference between upper and lower members of 200 degF the tip deflection relative to the base is 8 meters; the slope is 0.8 degrees. Updated thermal data will be used to reevaluate these estimates." Printed p.27, from the render: slope in degrees against module length, straight lines, the 200 degF line reaching about 0.83 degrees at 5.5 km. Printed p.29, from the render: deflection in metres against module length, the 200 degF curve reaching about 80 m at 5.4 km, "EXPECTED delta-T ~ 120 degF" marked.
Basis: metres of tip deflection; degrees of slope; degF of gradient; km of module length
Related records
- Answers question
- QST-013 not published in this release
Cite this
energyaperture.com/c/clm-0998
CLM-0998, Energy Aperture, as of 1978.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-456
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