Analysis of Use of Manipulators for Assembly of the International Space Station (ISS)
- Paper number
IAC-07-B3.3.05
- Author
Dr. Elizabeth Bains, National Aeronautics and Space Administration (NASA)/Johnson Space Center, United States
- Coauthor
Mr. Shakeel Razvi, National Aeronautics and Space Administration (NASA), United States
- Year
2007
- Abstract
The International Space Station (ISS) is a complex structure of modules, truss segments, mating adaptors, storage platforms, etc., that is being assembled on-orbit. Manipulators are used to attach many of these components, which are connected by a variety of mechanisms, called berthing mechanisms. The manipulator must position the incoming element within a capture envelop so that a capture latch or bolts can connect the two elements. The manipulator must hold the incoming element until hard mating is complete to avoid the risk of having an element loosely attached when jets are used for attitude control of the ISS. Significant pre-mission analysis is performed to ensure that the operation is feasible in the on-orbit environment and also to ensure that loads within the system are acceptable during nominal and off-nominal operations. These analyses include both crew-in-the-loop tests (CIL) and batch simulations. The CIL tests are performed with a high fidelity mockup of the on-orbit crew interface coupled to a high fidelity integrated simulation of the manipulator and the contact dynamics of the berthing mechanism. The mockup provides the manipulator control, any available feedback from the berthing mechanism, any available out-the-window or camera views, and any available additional berthing cues. These tests cover crew control of the manipulator until the incoming element is within the envelope of the capture latch or bolts since this phase requires significant crew assessment of and response to available cues. The batch simulations focus on loads calculations, using the same integrated manipulator/berthing mechanism contact dynamics used in the CIL tests but also including the capture latch or bolting phase. These pre-mission analyses have, in many cases, identified operational or software changes required to ensure successful berthing. This paper describes the types of analyses that are performed for ISS berthing operations. Selected examples of the results of these analyses demonstrate the types of changes identified by those analyses.
- Abstract document