Lawrence G. Lemke

The 2005 MARTE Robotic Drilling Experiment in Río Tinto, Spain: Objectives, Approach, and Results of a Simulated Mission to Search for Life in the Martian Subsurface

The Mars Astrobiology Research and Technology Experiment (MARTE) simulated a robotic drilling mission to search for subsurface life on Mars. The drill site was on Peña de Hierro near the headwaters of the Río Tinto river (southwest Spain), on a deposit that includes massive sulfides and their gossanized remains that resemble some iron and sulfur minerals found on Mars. The mission used a fluidless, 10-axis, autonomous coring drill mounted on a simulated lander. Cores were faced; then instruments collected color wide-angle context images, color microscopic images, visible-near infrared point spectra, and (lower resolution) visible-near infrared hyperspectral images. Cores were then stored for further processing or ejected. A borehole inspection system collected panoramic imaging and Raman spectra of borehole walls. Life detection was performed on full cores with an adenosine triphosphate luciferin-luciferase bioluminescence assay and on crushed core sections with SOLID2, an antibody array-based instrument. Two remotely located science teams analyzed the remote sensing data and chose subsample locations. In 30 days of operation, the drill penetrated to 6 m and collected 21 cores. Biosignatures were detected in 12 of 15 samples analyzed by SOLID2. Science teams correctly interpreted the nature of the deposits drilled as compared to the ground truth. This experiment shows that drilling to search for subsurface life on Mars is technically feasible and scientifically rewarding.

Scientific exploration of near-Earth objects via the Orion Crew Exploration Vehicle

A study in late 2006 was sponsored by the Advanced Projects Office within NASAs Constellation Program to examine the feasibility of sending the Orion Crew Exploration Vehicle (CEV) to a near-Earth object (NEO). The ideal mission profile would involve two or three astronauts on a 90 to 180 day flight, which would include a 7 to 14 day stay for proximity operations at the target NEO. This mission would be the first human expedition to an interplanetary body beyond the Earth-Moon system and would prove useful for testing technologies required for human missions to Mars and other solar system destinations. Piloted missions to NEOs using the CEV would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific investigations of these primitive objects. The main scientific advantage of sending piloted missions to NEOs would be the flexibility of the crew to perform tasks and to adapt to situations in real time. A crewed vehicle would be able to test several different sample collection techniques and target specific areas of interest via extra-vehicular activities (EVAs) more efficiently than robotic spacecraft. Such capabilities greatly enhance the scientific return from these missions to NEOs, destinations vital to understanding the evolution and thermal histories of primitive bodies during the formation of the early solar system. Data collected from these missions would help constrain the suite of materials possibly delivered to the early Earth, and would identify potential source regions from which NEOs originate. In addition, the resulting scientific investigations would refine designs for future extraterrestrial resource extraction and utilization, and assist in the development of hazard mitigation techniques for planetary defense.

MARTE: Technology development and lessons learned from a Mars drilling mission simulation

29 pages, 21 figures, 2 tables.-- ISI Article Identifier: 000250768000006.-- Special issue: Mining Robotics.

Mars Sample Return using commercial capabilities: Propulsive Entry, Descent, and Landing

This paper describes a critical portion of the work that has been done at NASA, Ames Research Center regarding the use of the commercially developed Dragon capsule as a delivery vehicle for the elements of a high priority Mars Sample Return mission. The objective of the investigation was to determine entry and landed mass capabilities that cover anticipated mission conditions. The “Red Dragon” Mars configuration uses supersonic retro-propulsion, with no required parachute system, to perform Entry, Descent, and Landing (EDL) maneuvers. The propulsive system proposed for use is the same system that will perform an abort, if necessary, for a human rated version of the Dragon capsule. Standard trajectory analysis tools are applied to publically available information about Dragon and other legacy capsule forms in order to perform the investigation. Trajectory simulation parameters include entry velocity, flight path angle, lift to drag Ratio (L/D), landing site elevation, atmosphere density, and total entry mass. In addition, engineering assumptions for the performance of the propulsion system are stated. Mass estimates for major elements of the overall proposed architecture are coupled to this EDL analysis to close the overall architecture. Three, Type 1 synodic launch opportunities, beginning with the 2022 opportunity, define the arrival conditions. Results are given for a system reflecting a nominal baseline set of the analysis parameters as well as sensitivities to those parameters. The EDL performance envelope includes landing altitudes between 0 and -4 km referenced to the Mars Orbiter Laser Altimeter datum as well as minimum and maximum atmosphere density. Total entry masses between 7 and 10 mt are considered with architecture closure occurring between 9.0 and 10 mt. Propellant mass fractions for each major phase of the EDL - Entry, Terminal Descent, and Hazard Avoidance - have been derived. A useful payload mass of 2.0 mt is provided and includes mass and growth allowance for a Mars Ascent Vehicle (MAV), Earth Return Vehicle (ERV), and mission unique equipment. The useful payload supports an architecture that receives a sample from another surface asset and sends it directly back to Earth for recovery in a high Earth orbit. The work shows that emerging commercial capabilities as well as previously studied EDL methodologies can be used to efficiently support an important planetary science objective. The work has applications for human exploration missions that will also use propulsive EDL techniques.

Mars Sample Return using commercial capabilities: Mission architecture overview

Mars Sample Return (MSR) is the highest priority science mission for the next decade as recommended by the recent Decadal Survey of Planetary Science. This paper presents an overview of a feasibility study for a MSR mission. The objective of the study was to determine whether emerging commercial capabilities can be used to reduce the number of mission systems and launches required to return the samples, with the goal of reducing mission cost. The major element required for the MSR mission are described and include an integration of the emerging commercial capabilities with small spacecraft design techniques; new utilizations of traditional aerospace technologies; and recent technological developments. We report the feasibility of a complete and closed MSR mission design using the following scenario that can start in any one of three Earth to Mars launch opportunities, beginning in 2022: A Falcon Heavy injects a SpaceX Red Dragon capsule and trunk onto a Trans Mars Injection (TMI) trajectory. The capsule is modified to carry all the hardware needed to return samples collected on Mars including a Mars Ascent Vehicle (MAV); an Earth Return Vehicle (ERV); and hardware to transfer a sample collected in a previously landed rover mission, such as the Mars 2020 rover, to the ERV. The Red Dragon descends to land on the surface of Mars using Supersonic Retro Propulsion (SRP). After previously collected samples are transferred to the ERV, the single-stage MA V launches the ERV from the surface of Mars to a Mars phasing orbit. The MA V uses a storable liquid, pump-fed bi-propellant propulsion system. After a brief phasing period, the ERV, which also uses a storable bi-propellant system, performs a Trans Earth Injection (TEl) burn. Once near Earth the ERV performs Earth and lunar swing-bys and is placed into a Lunar Trailing Orbit (LTO)an Earth orbit, at lunar distance. A later mission, using a Dragon and launched by a Falcon Heavy, performs a rendezvous with the ERV in the lunar trailing orbit, retrieves the sample container and breaks the chain of contact with Mars by transferring the sample into a sterile and secure container. With the sample contained, the retrieving spacecraft, makes a controlled Earth re-entry preventing any unintended release of pristine Martian materials into the Earths biosphere. Other capsule type vehicles and associated launchers may be applicable. An MSR launch in 2022 becomes the preferred option if the Mars 2020 rover is the previous sample caching vehicle. The analysis methods employed standard and specialized aerospace engineering tools. Mission system elements were analyzed with either direct techniques or by using parametric mass estimating relationships (MERs). The architecture was iterated until overall mission convergence was achieved on at least one path. Subsystems analyzed in this study include support structures, power system, nose fairing, thermal insulation, actuation devices, MA V exhaust venting, and GN&C. Best practice application of loads, mass growth contingencies, and resource margins were used. For Falcon Heavy capabilities and Dragon subsystems we utilized publically available data from SpaceX; published analyses from other sources; as well as our own engineering and aerodynamic estimates. Earth Launch mass is under 11 mt, which is within the estimated capability of a Falcon Heavy, with margin. Total entry masses between 7 and 10 mt were considered with closure occurring between 9 and 10 mt. Propellant mass fractions for each major phase of the EDL - Entry, Terminal Descent, and Hazard Avoidance were derived. An assessment of the entry condition effects on the thermal protection system (TPS), currently in use for Dragon missions, showed no significant stressors. A useful mass of 2.0 mt is provided and includes mass growth allowances for the MA V, the ERV, and mission unique equipment. We also report on alternate propellant options for the MA V and options for the ERV, including propulsion systems; crewed versus robotic retrieval mission; as well as direct Earth entry. International Planetary Protection (PP) policies as well as verifiable means of compliance with both forward and back contamination controls, will have a large impact on any MSR mission design. We identify areas within our architecture where such impacts occur. This work shows that emerging commercial capabilities can be effectively integrated into a mission to achieve an important planetary science objective.

A Micro-Meteorological mission for global network science on Mars: a conceptual design

Abstract The Mars Micro-Meteorological Station (“μ-Met”) mission is designed to provide the global surface pressure measurements required to help characterize the Martian general circulation and climate system. Measurements of surface pressure distributed both spatially and temporally, coupled with simultaneous measurements from orbit, will enable the determination of the general circulation, structure and driving factors of the Martian atmosphere as well as the seasonal CO 2 cycle. The influence of these atmospheric factors will in turn provide insight into the overall Martian climate system. With the science objective defined as the long-term (at least 1 Mars year) globally distributed measurement of surface atmospheric pressure, a readily achievable and low-cost network mission has been designed. The μ-Met mission utilizes microsensors coupled with a robust and lightweight surface station to deliver 16 μ-Met stations to Mars via a Med-Lite launch vehicle. The battery powered μ-Met surface stations are designed to autonomously measure, record and transmit the science data via a UHF relay satellite. Entry, descent and landing is provided by an acroshell with a new lightweight ceramic thermal protection system, a parachute and an impact absorbing structure. The robust lander is capable of surviving the landing loads imposed by the high altitude landing sites required in a global network. By trading the ability to make many measurements at a single site for the ability to make a single measurement at many sites, the μ-Met mission can provide truly global meteorological science.