Methods for Calculating Motion Induced Interruptions as Applied to a Space Capsule After Splashdown

The introduction of calculation methods for motion induced interruptions (MII) in 1984 introduced a new way to quantify human factors in addition to the motion sickness index (MSI). The 1990 Graham method for calculating MII uses a combination of a vessel's acceleration and roll to determine a "tipping" factor to calculate MII per minute. The Applebee-Baitis (AB) method considered that the motions are implicitly considered in accelerations, and therefore did not require roll to calculate MII. This thesis examines and analyzes the differences between the AB and Graham methods and compares their results for a unique hull form shape, a cylindrical capsule, in rough seas to determine which method is preferred. Two tests were performed by the Naval Surface Warfare Center, Carderock Division (NSWCCD) for the National Aeronautics and Space Administration (NASA) on the Orion Crew Exploration Vehicle (CEV) in post-splashdown conditions. A one-quarter scale model of the CEV was tested at the Aberdeen Test Center in Aberdeen, Maryland. Direct comparison of the analyzed data, MII sensitivity to location, and scaling analyses are examined and future work to further the application of MII calculation methods are proposed. The symmetry of the capsule leads to the assumption that roll and pitch-dominant MII calculations should be on the same order of magnitude. They are not because both MII methods only take roll-motions into account. The inclusion of both pitch and roll motions for the MII calculations is proposed as future work. The Graham method was found to be the more appropriate calculation because it is more conservative, and therefore preferred in the context of crew safety.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Ocean Engineering

Department dc:contributor.department

Aerospace and Ocean Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2013

Author dc:creator

• Hanyok, Lauren Watson

Chair dc:contributor.committeechair

• McCue-Weil, Leigh S.

Committee members dc:contributor.committeemember

• Belknap, William Forrest
• Brown, Alan J.

• motion induced interruptions
• unique hull form
• space capsule
• accelerations
• human factors

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:78

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/19252