Bo J. Naasz

Asteroid Redirect Robotic Mission: Robotic Boulder Capture Option Overview

The National Aeronautics and Space Administration (NASA) is currently studying an option for the Asteroid Redirect Robotic Mission (ARRM) that would capture a multi-ton boulder (typically 2-4 meters in size) from the surface of a large (is approximately 100+ meter) Near-Earth Asteroid (NEA) and return it to cislunar space for subsequent human and robotic exploration. This alternative mission approach, designated the Robotic Boulder Capture Option (Option B), has been investigated to determine the mission feasibility and identify potential differences from the initial ARRM concept of capturing an entire small NEA (4-10 meters in size), which has been designated the Small Asteroid Capture Option (Option A). Compared to the initial ARRM concept, Option B allows for centimeter-level characterization over an entire large NEA, the certainty of target NEA composition type, the ability to select the boulder that is captured, numerous opportunities for mission enhancements to support science objectives, additional experience operating at a low-gravity planetary body including extended surface contact, and the ability to demonstrate future planetary defense strategies on a hazardous-size NEA. Option B can leverage precursor missions and existing Agency capabilities to help ensure mission success by targeting wellcharacterized asteroids and can accommodate uncertain programmatic schedules by tailoring the return mass.

NASA's Asteroid Redirect Mission concept development summary

This paper summarizes key findings of Asteroid Redirect Mission pre-formulation concept development efforts, including mission architecture and design drivers, flight system concepts and trades, advanced solar electric propulsion component and system options, and asteroid capture option trades and risk reduction efforts. This paper also provides a summary of concept development findings with a focus on extensibility to future mission applications and risk reduction and early testing of astronaut extra-vehicular activities.

A Guidance and Navigation Strategy for Rendezvous and Proximity Operations with a Noncooperative Spacecraft in Geosynchronous Orbit

The feasibility and benefits of various spacecraft servicing concepts are currently being assessed, and all require that servicer spacecraft perform rendezvous, proximity operations, and capture operations with the spacecraft to be serviced. There are many high-value commercial and military spacecraft located in geosynchronous orbit (GEO) which may be candidates for servicing, but GEO is a regime in which rendezvous and capture operations are not commonplace; further, most GEO spacecraft were not designed to be cooperative rendezvous targets, and some may even be completely nonfunctional and therefore potentially tumbling. In this work we present elements of a guidance and navigation strategy for rendezvous and proximity operations with a noncooperative spacecraft in GEO. Translational Δv is assessed for a passively safe co-elliptic rendezvous approach sequence that is followed by injection into a safety ellipse about a noncooperative tumbling spacecraft and, ultimately, final approach to capture. Covariance analysis is presented for a simulation of range and bearing measurements throughout the rendezvous and proximity operations sequence.

Proximity Operations for the Robotic Boulder Capture Option for the Asteroid Redirect Mission

In September of 2013, the Asteroid Robotic Redirect Mission (ARRM) Option B team was formed to expand on NASAs previous work on the robotic boulder capture option. While the original Option A concept focuses on capturing an entire smaller Near-Earth Asteroid (NEA) using an inflatable bag capture mechanism, this design seeks to land on a larger NEA and retrieve a boulder off of its surface. The Option B team has developed a detailed and feasible mission concept that preserves many aspects of Option As vehicle design while employing a fundamentally different technique for returning a significant quantity of asteroidal material to the Earth-Moon system. As part of this effort, a point of departure proximity operations concept was developed complete with a detailed timeline, as well as DeltaV and propellant allocations. Special attention was paid to the development of the approach strategy, terminal descent to the surface, controlled ascent with the captured boulder, and control during the Enhanced Gravity Tractor planetary defense demonstration. The concept of retrieving a boulder from the surface of an asteroid and demonstrating the Enhanced Gravity Tractor planetary defense technique is found to be feasible and within the proposed capabilities of the Asteroid Redirect Vehicle (ARV). While this point of departure concept initially focuses on a mission to Itokawa, the proximity operations design is also shown to be extensible to wide range of asteroids.

An environment for hardware-in-the-loop formation navigation and control

Recent interest in formation flying satellite systems has spurred a considerable amount of research in the relative navigation and control of satellites. Development in this area has included new estimation and control algorithms as well as sensor and actuator development specifically geared toward the relative control problem. This paper describes a simulation facility, the Formation Flying Test Bed (FFTB) at NASA Goddard Space Flight Center, which allows engineers to test new algorithms for the formation flying problem with relevant GN&C hardware in a closed loop simulation. The FFTB currently supports the inclusion of GPS receiver hardware in the simulation loop. Support for satellite crosslink ranging technology is at a prototype stage. This closed-loop, hardware inclusive simulation capability permits testing of navigation and control software in the presence of the actual hardware with which the algorithms must interact. This capability provides the navigation or control developer with a perspective on how the algorithms perform as part of the closed-loop system. In this paper, the overall design and evolution of the FFTB are presented. Each component of the FFTB is then described. Interfaces between the components of the FFTB are shown and the interfaces to and between navigation and control software are described. Finally, an example of closed-loop formation control with GPS receivers in the loop is presented.

The HST SM4 Relative Navigation Sensor System: Overview and Preliminary Testing Results from the Flight Robotics Lab

The upcoming Hubble Space Telescope (HST) Servicing Mission 4 (SM4) includes a Relative Navigation Sensor (RNS) experiment which uses three cameras and an avionics package to record images, and estimate in real-time the relative position and attitude (aka “pose”) during the Shuttle capture and deployment of the telescope. RNS recently completed its third and final phase of testing at the Marshall Space Flight Center Flight Robotics Laboratory. This testing utilized flight spare cameras, engineering development unit avionics and flight pose algorithms to estimate the pose of a Hubble mockup mounted to the Flight Robotics Laboratory (FRL) Dynamic Overhead Target Simulator (DOTS). The mockup was moved through a variety of flight-like lighting conditions and trajectories. In this paper we present pose estimation results from the third phase of RNS FRL testing.