Lunar Landing Trajectory Design for Onboard Hazard Detection and Avoidance

The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing the software and hardware technology needed to support a safe and precise landing for the next generation of lunar missions. ALHAT provides this capability through terrain-relative navigation measurements to enhance global-scale precision, an onboard hazard detection system to select safe landing locations, and an Autonomous Guidance, Navigation, and Control (AGNC) capability to process these measurements and safely direct the vehicle to a landing location. This paper focuses on the key trajectory design issues relevant to providing an onboard Hazard Detection and Avoidance (HDA) capability for the lander. Hazard detection can be accomplished by the crew visually scanning the terrain through a window, a sensor system imaging the terrain, or some combination of both. For ALHAT, this hazard detection activity is provided by a sensor system, which either augments the crew s perception or entirely replaces the crew in the case of a robotic landing. Detecting hazards influences the trajectory design by requiring the proper perspective, range to the landing site, and sufficient time to view the terrain. Following this, the trajectory design must provide additional time to process this information and make a decision about where to safely land. During the final part of the HDA process, the trajectory design must provide sufficient margin to enable a hazard avoidance maneuver. In order to demonstrate the effects of these constraints on the landing trajectory, a tradespace of trajectory designs was created for the initial ALHAT Design Analysis Cycle (ALDAC-1) and each case evaluated with these HDA constraints active. The ALHAT analysis process, described in this paper, narrows down this tradespace and subsequently better defines the trajectory design needed to support onboard HDA. Future ALDACs will enhance this trajectory design by balancing these issues and others in an overall system design process

MSL Entry, Descent and Landing Performance and Environments

A viewgraph presentation on the MARS Science Laboratory (MSL) Entry, Descent and Landing (EDL) performance and environments is shown. The topics include: 1) High Altitude and Precision Landing; 2) Guided, Lifting, Ballistic Trade; 3) Supersonic Chute Deploy Altitude; 4) Guided, Lifting, Ballistic Landing Footprint Video; 5) Transition Indicator at Peak Heating Point on Trajectory; 6) Aeroheating at Peak Heating Point on Trajectory Nominal, No Uncertainty Included; 7) Comparison to Previous Missions; 8) Pork Chop Plots - EDL Performance for Mission Design; 9) Max Heat Rate Est (CBE+Uncert) W/cm2; 10) Nominal Super Chute Deploy Alt Above MOLA (km); 11) Monte Carlo; 12) MSL Option M2 Entry, Descent and Landing; 13) Entry Performance; 14) Entry Aeroheating and Entry g's; 15) Terminal Descent; and 16) How An Ideal Chute Deployment Altitude Varies with Time of Year and Latitude (JSC Chart)

Human Mars Entry, Descent and Landing Architecture Study: Rigid Decelerators

Several technology investments are required to develop Mars human scale Entry, Descent, and Landing (EDL) systems. Studies play the critical role of identifying the most feasible technical paths and high payoff investments. The goal of NASA's Entry, Descent and Landing Architecture Study is to inform those technology investments. In Phase 1 of the study, a point design for one lifting-body-like rigid decelerator vehicle, was developed. In Phase 2, a capsule concept was also considered to determine how it accommodated the human mission requirements. This paper summarizes the concept of operations for both rigid vehicles to deliver a 20-metric ton (t) payload to the surface of Mars. Details of the vehicle designs and flight performance are presented along with a packaging, mass sizing, and a launch vehicle fairing assessment. Finally, recommended technology investments based on the analysis of the rigid vehicles are provided

Human Mars Entry, Descent and Landing Architecture Study (EDLAS): Rigid Decelerators

Develop two evolutionary rigid vehicle concepts to deliver human-scale payloads (20 metric tons) to the surface of Mars: Capsule; Lifting body, mid-range lift-to-drag ratio (Mid L/D). Determine vehicle configurations for various mission flight phases. Determine vehicle performance: Integrated system mass; Ability to meet landing constraints; Payload packaging and surface access. Provide technology investment recommendations to NASAs Space Technology Mission Directorate

PL&HA and SPLICE Overview

Guidance, Navigation and Control (GN&C) technologies for precise and safe landing are essential for future robotic science and human exploration missions to solar system destinations with targeted surface locations that pose a significant risk to successful landing and subsequent mission operations. These Entry, Descent and Landing (EDL) technologies are a part of the NASA domain called PL&HA (Precision Landing and Hazard Avoidance) and are considered high priority capabilities within the space technology roadmaps from NASA and the National Research Council (NRC). The PL&HA technologies promote and enable new missions concepts to solar system destinations