Pterodactyl: Thermal Protection System for Integrated Control Design of a Mechanically Deployed Entry Vehicle

The need for precision landing of high mass payloads on Mars and the return of sensitive samples from other planetary bodies to specific locations on Earth is driving the development of an innovative NASA technology referred to as the Deployable Entry Vehicle (DEV). A DEV has the potential to deliver an equivalent science payload with a stowed diameter 3 to 4 times smaller than a traditional rigid capsule configuration. However, the DEV design does not easily lend itself to traditional methods of directional control. The NASA Space Technology Mission Directorate (STMD)s Pterodactyl project is currently investigating the effectiveness of three different Guidance and Control (G&C) systems actuated flaps, Center of Gravity (CG) or mass movement, and Reaction Control System (RCS) for use with a DEV using the Adaptable, Deployable, Entry, and Placement Technology (ADEPT) design. This paper details the Thermal Protection System (TPS) design and associated mass estimation efforts for each of the G&C systems. TPS is needed for the nose cap of the DEV and the flaps of the actuated flap control system. The development of a TPS selection, sizing, and mass estimation method designed to deal with the varying requirements for the G&C options throughout the trajectory is presented. The paper discusses the methods used to i) obtain heating environments throughout the trajectory with respect to the chosen control system and resulting geometry; ii) determine a suitable TPS material; iii) produce TPS thickness estimations; and, iv) determine the final TPS mass estimation based on TPS thickness, vehicle control system, vehicle structure, and vehicle payload

Pterodactyl: Trade Study for an Integrated Control System Design of a Mechanically Deployable Entry Vehicle

This paper presents the trade study method used to evaluate and downselect from a set of guidance and control (G&C) system designs for a mechanically Deployable Entry Vehicle (DEV). The Pterodactyl project was prompted by the challenge to develop an effective G&C system for a vehicle without a backshell, which is the case for DEVs. For the DEV, the project assumed a specific aeroshell geometry pertaining to an Adaptable, Deployable Entry and Placement Technology (ADEPT) vehicle, which was successfully developed by NASAs Space Technology Mission Directorate (STMD) prior to this study. The Pterodactyl project designed three different entry G&C systems for precision targeting. This paper details the Figures of Merit (FOMs) and metrics used during the course of the projects G&C system assessment. The relative importance of the FOMs was determined from the Analytic Hierarchy Process (AHP), which was used to develop weights that were combined with quantitative design metrics and engineering judgement to rank the G&C systems against one another. This systematic method takes into consideration the projects input while simultaneously reducing unintentional judgement bias and ultimately was used to select a single G&C design for the project to pursue in the next design phase

An Interesting Correspondence: A Discussion Between C. E. W. Dorris and Miss Nora Yount (Christians) and A. E. Clement, W. H. Lovell, Chas. B. Galloway, and Geo W. Nackles (Methodists).

https://digitalcommons.acu.edu/crs_books/1092/thumbnail.jp

Mechanically-Deployed Hypersonic Decelerator and Conformal Ablator Technologies for Mars Missions

The concept of a mechanically deployable hypersonic decelerator, developed initially for high mass (~40 MT) human Mars missions, is currently funded by OCT for technology maturation. The ADEPT (Adaptive, Deployable Entry and Placement Technology) project has broad, game-changing applicability to in situ science missions to Venus, Mars, and the Outer Planets. Combined with maturation of conformal ablator technology (another current OCT investment), the two technologies provide unique low mass mission enabling capabilities otherwise not achievable by current rigid aeroshell or by inflatables. If this abstract is accepted, we will present results that illustrate the mission enabling capabilities of the mechanically deployable architecture for: (1) robotic Mars (Discovery or New Frontiers class) in the near term; (2) alternate approaches to landing MSL-class payloads, without the need for supersonic parachute or lifting entry, in the mid-term; and (3) Heavy mass and human missions to Mars in the long term

Adaptable, Deployable Entry and Placement Technology (ADEPT) Overview of FY15 Accomplishments

ADEPT is an atmospheric entry architecture for missions to most planetary bodies with atmospheres: Current Technology development project funded under STMD Game Changing Development Program (FY12 start); stowed inside the launch vehicle shroud and deployed in space prior to entry; low ballistic coefficient (less than 50 kilograms per square meter) provides a benign deceleration and thermal environment to the payload; High-temperature ribs support three dimensional woven carbon fabric to generate drag and withstand high heating

A Neptune Orbiter Concept Using Drag Modulated Aerocaptue (DMA) and the Adaptable, Deployable Entry and Placement Technology (ADEPT)

Conceptual Neptune orbiter was designed for the purpose of assessing mission feasibilityBuilt off of the 2017 Pre-Decadal Study, but adapted for drag modulation aerocapture.Science payload includes: Narrow Angle camera, Doppler Imager, Magnetometer, Atmospheric Probe (w/ ASI, Nephelometer, Mass Spectrometer). Baseline concept of operations releases probe prior to orbit insertion, but investigations are ongoing to assess the feasibility of bringing the probe to orbit before release

Self-assembly in solution of a reversible comb-shaped supramolecular polymer

We report a single step synthesis of a polyisobutene with a bis-urea moiety in the middle of the chain. In low polarity solvents, this polymer self-assembles by hydrogen bonding to form a combshaped polymer with a central hydrogen bonded backbone and polyisobutene arms. The comb backbone can be reversibly broken, and consequently, its length can be tuned by changing the solvent, the concentration or the temperature. Moreover, we have proved that the bulkiness of the side-chains have a strong influence on both the self-assembly pattern and the length of the backbone. Finally, the density of arms can be reduced, by simply mixing with a low molar mass bis-urea

The Virion Host Shut-Off (vhs) Protein Blocks a TLR-Independent Pathway of Herpes Simplex Virus Type 1 Recognition in Human and Mouse Dendritic Cells

Molecular pathways underlying the activation of dendritic cells (DCs) in response to Herpes Simplex Virus type 1 (HSV-1) are poorly understood. Removal of the HSV virion host shut-off (vhs) protein relieves a block to DC activation observed during wild-type infection. In this study, we utilized a potent DC stimulatory HSV-1 recombinant virus lacking vhs as a tool to investigate the mechanisms involved in the activation of DCs by HSV-1. We report that the release of pro-inflammatory cytokines by conventional DC (cDC) during HSV-1 infection is triggered by both virus replication-dependent and replication-independent pathways. Interestingly, while vhs is capable of inhibiting the release of cytokines during infection of human and mouse cDCs, the secretion of cytokines by plasmacytoid DC (pDC) is not affected by vhs. These data prompted us to postulate that infection of cDCs by HSV triggers a TLR independent pathway for cDC activation that is susceptible to blockage by the vhs protein. Using cDCs isolated from mice deficient in both the TLR adaptor protein MyD88 and TLR3, we show that HSV-1 and the vhs-deleted virus can activate cDCs independently of TLR signaling. In addition, virion-associated vhs fails to block cDC activation in response to treatment with TLR agonists, but it efficiently blocked cDC activation triggered by the paramyxoviruses Sendai Virus (SeV) and Newcastle Disease Virus (NDV). This block to SeV- and NDV-induced activation of cDC resulted in elevated SeV and NDV viral gene expression indicating that infection with HSV-1 enhances the cell's susceptibility to other pathogens through the action of vhs. Our results demonstrate for the first time that a viral protein contained in the tegument of HSV-1 can block the induction of DC activation by TLR-independent pathways of viral recognition