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Entry, Descent, and Landing Flight Sensors and Ground-Testing Technologies

Description:

Scope Title:

Measurement of Electron Number Density in High-Speed Flows Produced in Ground-Test Facilities

Scope Description:

Understanding the spacecraft environment during the high-speed planetary entry phase of a mission requires accurate modeling of thermal nonequilibrium formation and relaxation mechanisms and knowledge of high-speed chemical kinetics under conditions of thermal nonequilibrium. At high entry velocities and temperatures, the chemical mechanisms may be driven by electron impact processes, where ionization can reach several percent of the flow field, accelerating reaction kinetics and electronic state excitation that is responsible for radiative heating of spacecraft. At lower velocities, the formation of low concentrations of electrons (10-8  to 10-4 mole fraction) can still play a role in kinetics but also causes radio blackout during the entry phase. Data regarding electron formation in shock waves can be obtained through ground tests in shock tube facilities, and early-stage ionization models may be validated against flight data based on available radio blackout data. NASA is seeking methods to measure electron number densities with good temporal resolution in shock tube facilities to better quantify these phenomena. Characteristics of the diagnostics being sought include the following:

  • High speed (>1 MHz) measurement of ne.
  • Low spatial resolution (<5 mm resolution in the direction of motion).
  • Line-integrated or point measurements are acceptable.
  • Nonintrusive diagnostics are preferable.
  • Measurement ranges spanning 2 to 3 orders of magnitude between 1012 and 1023 m-3 over pathlengths of 10 to 50 cm.

Expected TRL or TRL Range at completion of the Project: 2 to 4

Primary Technology Taxonomy:

  • Level 1 09 Entry, Descent, and Landing
  • Level 2 09.X Other Entry, Descent, and Landing

Desired Deliverables of Phase I and Phase II:

  • Analysis
  • Prototype
  • Hardware

Desired Deliverables Description:

Phase I Goals: Assessment study of potential diagnostic techniques, including the approach to identify a product solution that meets performance aspects and stays within cost constraints.

Phase II Goals: Prototype diagnostic system demonstration in a relevant environment with hardware delivery to NASA.

State of the Art and Critical Gaps:

Electron number density measurement in a shock-heated test gas using Stark broadening has been demonstrated in the NASA Ames Electric Arc Shock Tube (EAST) facility. Specifically, the electron density was obtained by measuring Stark width of atomic hydrogen across a range of operating pressures and velocities in the shock tube. The desired measurement ranges and characteristics described in this solicitation improve upon past measurements obtained in EAST.

Relevance / Science Traceability:

Understanding radiative heating environments and validation of analytical tools used in spacecraft design are crucial for supporting NASA's future robotic and human exploration missions. Ground testing at more extreme environments to support these missions will challenge existing capabilities, and there is a strong need now to advance diagnostic techniques beyond the current state of the art. The Mars Sample Return program's Sample Retrieval Lander (high-mass entry) and Earth Entry System, along with the Artemis program's high-speed crewed Earth return, are all examples of entry vehicles that will experience aerothermal heating, and accurate modeling of the radiation is needed.

References:

  1. B. Cruden, "Electron Density Measurement in Reentry Shocks for Lunar Return," Journal of Thermophysics and Heat Transfer, Vol. 26, No. 2, April-June 2012.
  2. J. Grinstead, et al., "Ames Electric Arc Shock Tube (EAST): Optical Instrumentation and Facility Capabilities," 2nd International Workshop on Radiation of High Temperature Gases in Atmospheric Entry, held 6-8 September 2006 at University "La Sapienza," Rome, Italy. Edited by A. Wilson. ESA-SP Vol. 629, Nov. 2006.

Scope Title:

Component Technologies for Lidar Sensors and In Situ Navigation Beacons Applicable to Guidance, Navigation, and Control (GN&C) for Precise Safe Landing

Scope Description:

NASA is seeking the development of hardware component technologies for advanced lidar sensors and in situ navigation beacons that will be utilized within entry, descent, and landing (EDL) and deorbit, descent, and landing (DDL) GN&C systems for precise safe landing on solid solar system bodies, including planets, moons, and small celestial bodies (e.g., asteroids and comets). The EDL phase applies to landings on bodies with atmospheres, whereas DDL applies to landings on airless bodies. For many of these missions, EDL/DDL represents one of the riskiest flight phases. NASA has been developing technologies for precision landing and hazard avoidance (PL&HA) to minimize the risk of the EDL/DDL phase of a mission and to increase the accessibility of surface science targets through precise and safe landing capabilities. One flight instrumentation focus of PL&HA technology has been in the development of lidar technologies that provide either terrain mapping (range point cloud) capability or direct velocity measurement. A second instrumentation focus of lunar landings, for instance, is the development of in situ ground and orbital sensors, such as beacons for precision landing. The continued maturation of these technologies is targeting (1) multimodal operation (i.e., combining mapping and velocimetry functions); (2) reduction of size, mass, and power; and (3) multicomponent integration.

This solicitation is requesting specific system-level hardware components, rather than complete solutions. To be considered, the proposals must include a hardware element and show a development path to operation within the applicable EDL/DDL spaceflight environment (radiation, thermal, vacuum, vibration, etc.). The specific system-level hardware component technologies desired include:

 

1. Advanced lidar hardware component technologies that can significantly improve functionality of existing lidar sensors and/or reduce size, mass, and power.

The desired hardware component technologies include, but are not limited to, laser transmitter, beam-steering system/method, photonics integrated circuits, focal plane array, etc., that when integrated into a complete lidar system could improve system performance in any or all of the following EDL/DDL applications:

  • Hazard Detection and Avoidance: Operation from 1 km to 500 m slant range to map a 100-m-diameter landing area, detect hazardous terrain features greater than 30 cm radius, and register their locations in a sensor/vehicle reference frame to better than 10 cm precision.
  • Terrain Relative Navigation: Operation from 20 km to 2 km altitude to generate surface elevation data that can be compared with known surface topography features to determine the vehicle position relative to a landing location to less than 50 m.
  • Velocity and/or Altitude Sensing: Operation from 20 km range down to less than 10 m with (1) velocity as high as 2 km/sec along the line of sight (LOS) with a precision on order of 20 cm/sec (1-sigma) at 20 km altitude and 2 cm/sec at 2 km altitude, and (2) altitude data with better than 2 m precision, 1-sigma.

Proposed technologies must address operation in presence of vehicle dynamics and motions (e.g., velocity, attitude variations, vibration).

 

2. Navigation receivers compatible with planned navigation services.

NASA is investing in and pursuing deployment of lunar communication and navigation services through the Lunar Communications Relay and Navigations Systems (LCRNS) and LunaNet Interoperability Specifications releases. Through this and other beacon development efforts, NASA is deploying these services to provide navigation support to vehicles on and around the Moon. Development is needed of user terminals that can receive the reference navigation signals and messages to perform localization of the user. These can be integrated into a lander to support external positioning, velocity, and timing updates prior to, during, and post descent phases of flight, reducing the reliance and increasing the robustness of lander navigation. NASA is seeking proposals on technologies enabling low size, weight, and power (SWaP) LunaNet Navigation-compatible receivers with accurate clock references to provide a solution to a potential user.

Expected TRL or TRL Range at completion of the Project: 4 to 6

Primary Technology Taxonomy:

  • Level 1 09 Entry, Descent, and Landing
  • Level 2 09.X Other Entry, Descent, and Landing

Desired Deliverables of Phase I and Phase II:

  • Analysis
  • Prototype
  • Hardware
  • Software

Desired Deliverables Description:

The following deliverables are desired for Phase I: (1) Hardware demonstrations of sensor components and applicable support hardware, and/or (2) analysis and software simulations of component proofs of concept within simulated environments. Responses must show a path for the proposed capabilities to be compatible with the environmental conditions of spaceflight.

The following deliverables are desired for Phase II: (1) Hardware demonstrations of sensor components and applicable support hardware, and (2) analysis of components in laboratory or relevant environment (depending on TRL). Phase II products will need to demonstrate a path for the capabilities to be compatible with the environmental conditions of spaceflight.

State of the Art and Critical Gaps:

Missions to solar system bodies must meet increasingly ambitious objectives requiring highly reliable precision landing and hazard avoidance capabilities. Examples of these capabilities include precise measurements of vehicle relative proximity, velocity, and orientation, as well as high-resolution elevation maps of the surface during the descent to the targeted body. While current technologies may be available with this functionality, a key part of this solicitation is to address compatibility with the spaceflight environment and to pursue component technologies to improve upon the current state of the art.

Relevance / Science Traceability:

GN&C/PL&HA technologies for precise safe landing are critical for future robotic science and human exploration missions to locations with hazardous terrain and/or pre-positioned surface assets (e.g., cached samples or cargo) that pose significant risks to successful spacecraft touchdown and mission surface operations. The PL&HA technologies enable spacecraft to land with minimum position error from targeted surface locations, and they implement hazard-avoidance diverts to land at locations safe from lander-sized or larger terrain hazards (e.g., craters, rocks, boulders, sharp slopes, etc.). PL&HA has maintained consistent prioritization within the NASA and National Research Council (NRC) space technology roadmaps for more than a decade. An element of PL&HA capabilities has already been utilized in the Mars 2020 lander, and several others will be demonstrated on upcoming Commercial Lunar Payload Services (CLPS) missions.

References:

  1. A. Martin, et al. (2018), "Photonic integrated circuit-based FMCW coherent LiDAR," Journal of Lightwave Technology, vol. 36, no. 19, 4640-4645, Oct.1, 2018, doi: 10.1109/JLT.2018.2840223.
  2. C.V. Poulton, A. Yaacobi, D.B. Cole, M.J. Byrd, M. Raval, D. Vermeulen, and M.R. Watts (2017), "Coherent solid-state LIDAR with silicon photonic optical phased arrays," Opt. Lett. 42, 4091-4094.
  3. F. Amzajerdian, G.D. Hines, D.F. Pierrottet, B.W. Barnes, L.B. Petway, and J.M. Carson (2017), “Demonstration of coherent Doppler lidar for navigation in GPS-denied environments,” Proc. SPIE 10191, Laser Radar Technology and Applications XXII, 1019102.
  4. Andrew E. Johnson and Tonislav I. Ivanov, “Analysis and Testing of a LIDAR-Based Approach to Terrain Relative Navigation for Precise Lunar Landing,” AIAA 2009.
  5. Farzin Amzajerdian, Vincent E. Roback, Alexander E. Bulyshev, Paul F. Brewster, William A. Carrion, Diego F. Pierrottet, Glenn D. Hines, Larry B. Petway, Bruce W. Barnes, and Anna M. Noe, “Imaging flash lidar for safe landing on solar system bodies and spacecraft rendezvous and docking,” Proc. SPIE Vol 9465 (2015).
  6. Nikolas Trawny, Andres Huertas, Michael Luna, Carlos Y. Villalpando, Keith E. Martin, John M. Carson III, Andrew E. Johnson, Carolina Restrepo, Vincent E. Roback, “Flight testing a Real-Time Hazard Detection System for Safe Lunar Landing on the Rocket-powered Morpheus Vehicle,” Proc. of AIAA Science and Tech. Forum, 2015.
  7. Lunar Communications Relay and Navigation Systems (LCRNS) homepage: https://esc.gsfc.nasa.gov/projects/LCRNS
  8. "LunaNet: Empowering Artemis with Communications and Navigation Interoperability," https://www.nasa.gov/feature/goddard/2021/lunanet-empowering-artemis-with-communications-and-navigation-interoperability Oct. 2021.

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