Organizational Unit:
Aerospace Systems Design Laboratory (ASDL)
Aerospace Systems Design Laboratory (ASDL)
Permanent Link
Research Organization Registry ID
Description
Previous Names
Parent Organization
Parent Organization
Organizational Unit
Includes Organization(s)
ArchiveSpace Name Record
Publication Search Results
Now showing
1 - 6 of 6
-
ItemSizing of an Entry, Descent, and Landing System for Human Mars Exploration(Georgia Institute of Technology, 2006-09) Christian, John A., III ; Wells, Grant William ; Lafleur, Jarret M. ; Manyapu, Kavya ; Verges, Amanda ; Lewis, Charity ; Braun, Robert D.The human exploration of Mars presents many challenges, not least of which is the task of entry, descent, and landing (EDL). Because human-class missions are expected to have landed masses on the order of 40 to 80 metric tons, significant challenges arise that have not been seen to date in robotic missions. This study provides insight into the challenges encountered as well as potential solutions through parametric trade studies on vehicle size and mass. Aerocapture and entry-from-orbit analyses of 10 and 15 m diameter aeroshells with a lift-to-drag ratio of 0.3 or 0.5 were investigated. Results indicate that in the limit, a crew capsule used only for descent could have an initial mass as low as 20 t. For larger landed payloads, such as a 20 t surface power system, a vehicle with an initial mass on the order of 80 t may be required. In addition, no feasible EDL systems were obtained with the capability to deliver more than approximately 25 t of landed payload to the Mars surface for initial masses less than 100 t. This suggests that an aeroshell diameter of 15 m may not be sufficient for human Mars exploration.
-
ItemMars Entry, Descent, and Landing Parametric Sizing and Design Space Visualization Trades(Georgia Institute of Technology, 2006-08) Alemany, Kristina ; Wells, Grant William ; Theisinger, John ; Clark, Ian G. ; Braun, Robert D.Entry, descent, and landing (EDL) is a multidimensional, complex problem, which is difficult to visualize in simple plots. The purpose of this work is to develop a systematic visualization scheme that could capture Mars EDL trades as a function of a limited number of variables, such that programmatic design decisions could be effectively made with insight of the design space. Using the Mars Science Laboratory (MSL) as a basis, contour plots have been generated for key EDL figures of merit, such as maximum landed elevation and landed mass as a function of four input parameters: entry mass, entry velocity, entry flight path angle, and vehicle L/D. Additionally, sensitivity plots have been generated in an attempt to capture the effects of varying the fixed input parameters. This set of EDL visualization data has been compiled into a Mars EDL handbook to aid in pre-phase A design space exploration and decision making.
-
ItemAn Evaluation of Ballute Entry Systems for Lunar Return Missions(Georgia Institute of Technology, 2006-08) Clark, Ian G. ; Braun, Robert D. ; Theisinger, John ; Wells, Grant WilliamThis study investigates the advantages and feasibility of using ballutes for Earth entry at lunar return velocities. Using analysis methods suitable for conceptual design and assuming a CEV type entry vehicle, multiple entry strategies were investigated. Entries that jettison the ballute after achieving low Earth orbit conditions were shown to reduce heating rates to within reusable thermal protection system limits. Deceleration was mitigated to approximately four g's when a moderate amount of lift was applied subsequent to ballute jettison. Primary ballute size drivers are the thermal limitations and areal densities of the ballute material. Performance requirements for both of those metrics were generated over a range of total ballute system masses. Lastly, preliminary investigation of a lower mass cargo variant of the CEV allowed for additional reduction of ballute system mass. However, ballute system mass as a percentage of the total entry mass was shown to be relatively independent of the entry mass.
-
ItemAn Entry Handbook for the Conceptual Design of Mars Missions(Georgia Institute of Technology, 2006-05) Wells, Grant William ; Braun, Robert D.The purpose of this investigation is to investigate trends in Mars entry, descent and landing conceptual mission design and propose a method of presenting this information as a handbook for conceptual design. The premise of the project is that Mars entry, descent and landing can be parameterized with five variables: (1) entry mass, (2) entry velocity, (3) entry flight path angle, (4) vehicle aeroshell diameter, and (5) vertical lift-to-drag ratio. For combinations of these input parameters, the following trajectory information will be determined: peak deceleration, peak heat rate, heat load, and the altitude at which Mach 2 is reached (for parachute deployment).
-
ItemEntry Descent and Landing Challenges of Human Mars Exploration(Georgia Institute of Technology, 2006-02) Wells, Grant William ; Lafleur, Jarret M. ; Verges, Amanda ; Manyapu, Kavya ; Christian, John A., III ; Lewis, Charity ; Braun, Robert D.Near-term capabilities for robotic spacecraft include a target of landing 1 - 2 metric ton payloads with a precision of about 10 kilometers, at moderate altitude landing sites (as high as +2 km MOLA). While challenging, these capabilities are modest in comparison to the requirements for landing human crews on Mars. Human Mars exploration studies imply the capability to safely land 40 - 80 metric ton payloads with a precision of tens of meters, possibly at even higher altitudes. New entry, descent and landing challenges imposed by the large mass requirements of human Mars exploration include: (1) the potential need for aerocapture prior to entry, descent and landing and associated thermal protection strategies, (2) large aeroshell diameter requirements, (3) severe mass fraction restrictions, (4) rapid transition from the hypersonic entry mode to a descent and landing configuration, (5) the need for supersonic propulsion initiation, and (6) increased system reliability. This investigation explores the potential of extending robotic entry, descent and landing architectures to human missions and highlights the challenges of landing large payloads on the surface of Mars.
-
ItemDevelopment of a Planetary Entry System Synthesis Tool for Conceptual Design and Analysis(Georgia Institute of Technology, 2005-06) Kipp, Devin M. ; Dec, John A. ; Wells, Grant William ; Braun, Robert D.A Planetary Entry Systems Synthesis Tool, with applications to conceptual design and modeling of entry systems has been developed. This tool is applicable to exploration missions that employ entry, descent and landing or aerocapture. An integrated framework brings together relevant disciplinary analyses and enables rapid design and analysis of the atmospheric entry mission segment. Tool performance has been validated against Mars Pathfinder flight experience and has direct relevance to future NASA robotic and human space exploration systems.