Engineering topics

Mockovciak, J., Jr.

Publications and source records attributed to Mockovciak, J., Jr..

4 records

NASA NTRS1982

Advanced service equipment

Orbiter-based service equipment needs/usage are identified by considering a broad spectrum of on-orbit operational scenarios associated with three primary mission events: initial launch, revisits, and Earth return. Nominal and alternate modes of operation, contingency situations (as remote manipulator system inoperative), and Orbiter close proximity operations are included. Satellite classes considered are direct delivery and servicing of the orbiter, low Earth orbiter/propulsion, sorties and DOD, geosatellites, and planetary and other satellites.

Mockovciak, J., Jr.↗

NASA NTRS1982

Servicing costs for representative service missions

User cost for three satellite services were assessed. The three missions are: advanced X-ray astrophysics facility (AXAF) revisit; upper atmosphere research satellite (UARS) revisit: and solar maximum mission (SMM) Earth return. Service scenarios for the missions to identify service equipment needs and on orbit usage were developed. The AXAF revisit is a service mission involving a contamination sensitive satellite. Following servicing and checkout, the spacecraft is redeployed from the orbiter. The total user charges for revisit missions is from 5 to 10% less than the cost to build and relaunch a replacement satellite. It is indicated that satellite servicing from the Orbiter is cost effective.

Mockovciak, J., Jr.↗

NASA NTRS1980

Operational factors affecting microgravity levels in orbit

Microgravity levels desired for proposed materials processing payloads are fundamental considerations in the design of future space platforms. Disturbance sources, such as aerodynamic drag, attitude control torques, crew motion and orbital dynamics, influence the microgravity levels attainable in orbit. The nature of these effects are assessed relative to platform design parameters such as orbital altitude and configuration geometry, and examples are presented for a representative spacecraft configuration. The possible applications of control techniques to provide extremely low acceleration levels are also discussed.

Olsen, R. E.↗

NASA NTRS1977

Satellite power system LEO vs GEO assembly issues

A strawman crystal-silicon 5-GW Satellite Power System (SPS) concept formed the basis of a study of construction concepts for building a complete SPS in low earth orbit (LEO) or geosynchronous orbit (GEO). Construction scenarios were evolved, including factory-in-space concepts and operations. Design implications imposed on the SPS satellite as a consequence of in-orbit assembly operations, and related attitude control requirements during assembly in LEO or GEO environments, were also evaluated. Results are presented indicating that complete assembly of an operational SPS in LEO, followed by transport to GEO, does not appear technically desirable. The best mix, however, of LEO versus GEO construction activity remains to be resolved.

Mockovciak, J., Jr.↗