Engineering topics

Gibbins, Martin N.

Publications and source records attributed to Gibbins, Martin N..

5 records

NASA NTRS1991

Systems integration and demonstration of advanced reusable structure for ALS

The objective was to investigate the potential of advanced material to achieve life cycle cost (LCC) benefits for reusable structure on the advanced launch system. Three structural elements were investigated - all components of an Advanced Launch System reusable propulsion/avionics module. Leading aeroshell configurations included sandwich structure using titanium, graphite/polyimide (Gr/PI), or high-temperature aluminum (HTA) face sheets. Thrust structure truss concepts used titanium, graphite/epoxy, or silicon carbide/aluminum struts. Leading aft bulkhead concepts employed graphite epoxy and aluminum. The technical effort focused on the aeroshell because the greatest benefits were expected there. Thermal analyses show the structural temperature profiles during operation. Finite element analyses show stresses during splash-down. Weight statements and manufacturing cost estimates were prepared for calculation of LCC for each design. The Gr/PI aeroshell showed the lowest potential LCC, but the HTA aeroshell was judged to be lower risk. A technology development plan was prepared to validate the applicable structural technology.

Gibbins, Martin N.↗

NASA NTRS1990

Reusable structure for the Advanced Launch System

The U.S. Advanced Launch System (ALS) effort has been established to reduce the cost of payload mass to orbit and increase launch reliability. One approach to reducing costs of primarily expendable launch vehicles is to recover and reuse the most costly elements (i.e., the main engines and the avionics hardware); this is the mission of the propulsion/avionics (P/A) module. This study was conducted to identify material and design options for P/A module structure. A critical structural element is the aeroshell which: (1) provides the reentry aerodynamic surface, (2) shields other subcomponents from reentry heating, and (3) absorbs touchdown loads. Two P/A module types are required for the ALS: one that flies a high-temperature return from orbit profile and another that flies a cooler suborbital profile. For system cost benefits, common structure is desired for both types. A design concept is developed for a honeycomb sandwich structure that can survive the suborbital-reentry heating rates and the return-from-orbit heating rates with an ablative thermal protection system. Thermal analyses show that structural temperatures from aerodynamic heating are within material capabilities. Stress analyses indicate the structural design can support the critical loads.

Gibbins, Martin N.↗

NASA NTRS1988

Hypervelocity impact damage assessment for Space Station

To inhibit damage and limit the probability of penetration of the Space Station pressure wall by micrometeoroids and orbital debris, a shield placed away from the wall is used to form a double wall. To determine shield effectiveness and assess impact damage, existing test data were reviewed and additional testing was performed for Space Station double wall designs. Empirical spallation and penetration functions derived from the data show that shield thickness and impact angle affect the damage to the wall. Thick shields reduce wall damage for low angle impacts but increase damage for oblique impacts. Multilayer insulation between the shield and wall reduces impact damage to the wall. A relationship between impact velocity and spall damage to the wall is demonstrated. Preliminary test results on Li-Al shield material indicate possible improved effectiveness over Al shields.

Coronado, Alex R.↗

NASA NTRS1988

Space Station pressure wall repair techniques

Space Station components are susceptible to hypervelocity impact damage from orbital debris and meteoroids. An especially vulnerable and critical space station component is the module pressure wall. Even with shielding, sufficiently large impacting particles can create penetrations ranging from pinholes to large jagged holes. This paper describes pressure wall damage repair patches along with procedures and tools for performing the repair. One patch incorporates an aluminum foil protected from the jagged hole edge with a Kevlar or foam pad. An adhesive holds the patch in place. Another patch uses a stiff plate held away from the damaged area by a low durrometer rubber ring which also seals the plate edge. An adhesive will also secure this patch in place. Procedures were developed to prepare the punctured wall surface and apply the patch under weightless and unpressurized conditions. The procedures were tested in a laboratory and in the MSFC Neutral Buoyancy Simulator with models of the patches and tools.

Gibbins, Martin N.↗

NASA NTRS1987

Repairing Holes in Pressure Walls

Patches and easy-to-use tools yield pressure-tight seal. Repairer lifts patch from repair kit with hook-and-pile-tipped tool and positions it over puncture hole. With tool, even gloved repairer easily manipulates patch without damaging it.

Mori, Paul Bruce Y.↗