Engineering PapersSearch

SEARCH · Engineering Papers

Results for “Launcher”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5

NASA Affordable Vehicle Avionics (AVA): Common Modular Avionics System for Nano-Launchers Offering Affordable Access to Space

Small satellites are becoming ever more capable of performing valuable missions for both government and commercial customers. However, currently these satellites can only be launched affordably as secondary payloads. This makes it difficult for the small satellite mission to launch when needed, to the desired orbit, and with acceptable risk. NASA Ames Research Center has developed and tested a prototype low-cost avionics package for space launch vehicles that provides complete GNC functionality in a package smaller than a tissue box with a mass less than 0.84 kg. AVA takes advantage of commercially available, low-cost, mass-produced, miniaturized sensors, filtering their more noisy inertial data with realtime GPS data. The goal of the Advanced Vehicle Avionics project is to produce and flight-verify a common suite of avionics and software that deliver affordable, capable GNC and telemetry avionics with application to multiple nano-launch vehicles at 1 the cost of current state-of-the-art avionics.

Guidance Navigation and Control

Surface Hardness Testing of Mobile Launcher 1 (ML-1) Vehicle Support Posts (VSP) Following Artemis I Launch Exposure

Following the successful launch of Artemis I on November 16th, 2022 (Fig 1), a surface hardness assessment was performed on the eight primary VSPs (Figs. 2, 3) located on the Zero Deck of the ML. This assessment was performed as part of an instrument investigation for strain gauges installed on VSP interior surfaces that had a “strange reaction”. This report does not address the VSP strain gauge investigation, but rather VSP structural integrity for future service (Artemis II, III, …). Surface hardness measurements were taken to assess the strength of the ASTM A148 steel castings to confirm thermal exposure from launch had not reannealed the VSPs. However unlikely, it is possible high temperature may have heated and tempered (reannealed) the VSPs, resulting in a change of built-in stresses. This loss in built-in stress may explain the change in off-set measured by the strain gauges. Initial hardness measurements were made at two interior surfaces of VSPs near the strain gauges and the corresponding exterior surfaces (engine hole-facing). Field hardness measurements on the exterior, engine hole surface-facing surfaces for all eight VSPs ranged from 175 to 226 HB/P, well below the minimum hardness of 302 Brinell (HB). Opposing interior surface hardness measurements near strain gauges ranged from 264 to 358 HB/P. In all cases for flight VSPs, a drop in interior-to-exterior hardness ranging from 70 to 132 HB/P was measured. Surface hardness measurements were then made on the two spare VSPs not exposed to launch temperatures for baseline comparison. These two spare VSPs had a drop in Brinell hardness from interior to exterior surfaces ranging from 3 to 17 HB/P. The large interior-to-exterior delta hardness for eight flight VSPs but not for the two spare VSPs suggests launch exposure temperatures softened the exterior surfaces, raising two questions: 1) Are the VSPs compromised for future use, and 2) How deep is the exterior surface softening effect? To address concerns of low surface hardness values at non-critical exterior surfaces, additional field surface hardness measurements were taken at high-stress locations on VSP3: Both door jams, back radius, and internal left and right radius near the base. These values came in well above the required minimum hardness (317 to 365 HB/P). For a more representative pre-launch versus post-launch surface hardness comparison, VSP Acceptance Data Packages (ADPs) were reviewed, and hardness measurements were made at the same eight original locations on VSP3 where hardness measurements were made at the foundry. To determine the degree of softening, 1/8” of material was machined away at three exterior surfaces of engine hole-facing side (Fig. 4). A significant increase in surface hardness was measured ranging from 50 to 86 HB/P. Values at these three locations were still slightly below the required minimum hardness, so an additional 1/8” material was machined away, and hardness values were retaken. At the ¼” depth, hardness values increased to 321 to 324 HB/P. These values fall above the required minimum, concluding surface hardness testing. Rationale for VSP continued use was reached with no restrictions during a Chief Engineering Review based on hardness values exceeding minimum at critical locations and subsurface locations for VSP #3.

Artemis I

Mount mechanisms for the Saturn 5/Apollo mobile launcher at John F. Kennedy Space Center

A support system was designed to resist hurricane wind loads at the launch pad and to allow the supported structural frame to expand and contract freely under wide ranges of temperature. This system consists of six mount mechanisms devised to meet the previously stated requirements plus a load-carrying capacity for each of 3.2-million kilograms (7-million pounds) downward and 1.6-million kilograms (3.5-million pounds) upward. A similar but lighter system of six mount mechanisms was designed for use in the sheltered environment of the vehicle assembly building. Each requirement and design result is discussed, and each mount mechanism is defined by location and type with references to visual presentations.

Balke, H. A.

Rotating mobile launcher

Apparatus holds remotely piloted arm that accelerates until launching speed is reached. Then vehicle and counterweight at other end of arm are released simultaneously to avoid structural damage from unbalanced rotating forces.

Gregory, T. J.

Advanced ion thruster and electrochemical launcher research

The theoretical model of orificed hollow cathode operation predicted experimentally observed cathode performance with reasonable accuracy. The deflection and divergence characteristics of ion beamlets emanating from a two grid optics system as a function of the relative offset of screen and accel grids hole axes were described. Ion currents associated with discharge chamber operation were controlled to improve ion thruster performance markedly. Limitations imposed by basic physical laws on reductions in screen grid hole size and grid spacing for ion optics systems were described. The influence of stray magnetic fields in the vicinity of a neutralizer on the performance of that neutralizer was demonstrated. The ion current density extracted from a thruster was enhanced by injecting electrons into the region between its ion accelerating grids. Theoretical analysis of the electrothermal ramjet concept of launching space bound payloads at high acceleration levels is described. The operation of this system is broken down into two phases. In the light gas gun phase the payload is accelerated to the velocity at which the ramjet phase can commence. Preliminary models of operation are examined and shown to yield overall energy efficiences for a typical Earth escape launch of 60 to 70%. When shock losses are incorporated these efficiencies are still observed to remain at the relatively high values of 40 to 50%.

Wilbur, P. J.

Exosat/Delta - Demonstrated short-term backup launcher capability through international cooperation

The instrumentation, performance parameters, Delta launch implementation, and development program of the Exosat, launched in February 1983 are described. The X ray satellite was integrated into the Delta vehicle over a three month period, and will survey mainly previously observed X ray objects by directing its detectors at them just before they are occulted by the moon. The 120 kg science package, powered by 260 W of power from solar panels, include low- and medium-energy imaging devices. The spacecraft was originally intended for Ariane launch, but scheduling conflicts, plus the need for a polar-type orbit, dictated the use of the Western Space and Missile Center. Maintenance of Delta compatibility throughout the development of the Exosat facilitated the transfer of launch vehicles, as did full existing documentation of the spacecraft and familiarity between the ESA and NASA managers of the development and launch programs, respectively.

Ganoung, J. K.

Orbit on demand - Structural analysis finds vertical launchers weigh less

Structural considerations arising from favored design concepts for the next generation on-demand launch vehicles are explored. The two emerging concepts are a two stage fully reusable vertical take-off vehicle (V-2) and a horizontal take-off, two stage subsonic boost launch vehicle (H-2-Sub). Both designs have an 1100 n. mi. cross-range capability, with the V-2 orbiter having small wings with winglets for hypersonic trim and the H-2-Sub requiring larger, swept wings. The rockets would be cryogenic, while airbreathing initial boosters would be either turbofans, turbojets and/or ramjets. Dynamic loading is lower in the launch of a V-2. The TPS is a critical factor due to thinner leading edges than on the Shuttle and may require heat-pipe cooling. Airframe structures made of metal matrix composites have passed finite element simulations of projected loads and can now undergo proof-of-concept tests, although whisker-reinforced materials may be superior once long-whisker technology is developed.

Taylor, A. H.