Mars Exploration Rover | EPFL Graph Search

NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, Spirit and Opportunity, exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface and geology; both landed on Mars at separate locations in January 2004. Both rovers far outlived their planned missions of 90 Martian solar days: MER-A Spirit was active until March 22, 2010, while MER-B Opportunity was active until June 10, 2018. Objectives The mission's scientific objective was to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. The mission is part of NASA's Mars Exploration Program, which includes three previous successful landers: the two Viking program landers in 1976 and Mars Pathfinder probe in 1997. The scientific objectives of the Mars Exploration Rover mission were to: *Search for and characterize a variety of rocks and soils that hold clues to past water ac

Preliminary Design of a Lunar Reconnaissance Drone

Thomas Pfeiffer, Erik Uythoven

In this report, a preliminary design study of a compact lunar reconnaissance drone module which will assist exploration rovers is presented. It is designed to assist future exploratory rover missions in difficult environments such as PSRs or extreme topographies. Although similar concepts have been validated on Mars by NASA’s Ingenuity helicopter, only few such ideas exist for lunar applications. The main challenges of this project lie in the propulsion system to be used, the thermal system of the drone (due to extreme temperatures) and the 3D mapping of the lunar surface using a flash lidar system. These aspects were studied in detail with promising results: For a drone with a weight of 20 kg, 1 kg of green monopropellant is sufficient to cover a distance of a least 1 km before it needs refuelling. In this report, it is assumed that the lightweight flash lidar technology should be developed enough to allow for 10 cm resolution at 50 m flight altitude. This feasibility and initial design study sets a foundation for lunar drones and exploration of the Moon using flying spacecrafts, although many open questions remain to be solved and detailed designs to be performed.

2022

Super-resolution microscopy live cell imaging and image analysis

Tomas Lukes

Novel fundamental research results provided new techniques going beyond the diffraction limit. These recent advances known as super-resolution microscopy have been awarded by the Nobel Prize as they promise new discoveries in biology and live sciences. All these techniques rely on complex signal and image processing. The applicability in biology, and particularly for live cell imaging, remains challenging and needs further investigation. Focusing on image processing and analysis, the thesis is devoted to a significant enhancement of structured illumination microscopy (SIM) and super-resolution optical fluctuation imaging (SOFI)methods towards fast live cell and quantitative imaging. The thesis presents a novel image reconstruction method for both 2D and 3D SIM data, compatible with weak signals, and robust towards unwanted image artifacts. This image reconstruction is efficient under low light conditions, reduces phototoxicity and facilitates live cell observations. We demonstrate the performance of our new method by imaging long super-resolution video sequences of live U2-OS cells and improving cell particle tracking. We develop an adapted 3D deconvolution algorithm for SOFI, which suppresses noise and makes 3D SOFI live cell imaging feasible due to reduction of the number of required input images. We introduce a novel linearization procedure for SOFI maximizing the resolution gain and show that SOFI and PALM can both be applied on the same dataset revealing more insights about the sample. This PALM and SOFI concept provides an enlarged quantitative imaging framework, allowing unprecedented functional exploration of the sample through the estimation of molecular parameters. For quantifying the outcome of our super-resolutionmethods, the thesis presents a novel methodology for objective image quality assessment measuring spatial resolution and signal to noise ratio in real samples. We demonstrate our enhanced SOFI framework by high throughput 3D imaging of live HeLa cells acquiring the whole super-resolution 3D image in 0.95 s, by investigating focal adhesions in live MEF cells, by fast optical readout of fluorescently labelled DNA strands and by unraveling the nanoscale organization of CD4 proteins on a plasma membrane of T-cells. Within the thesis, unique open-source software packages SIMToolbox and SOFI simulation tool were developed to facilitate implementation of super-resolution microscopy methods.

Czech Technical University in Prague2017

SOFI Simulation Tool: A Software Package for Simulating and Testing Super-Resolution Optical Fluctuation Imaging

Stefan Geissbuehler, Theo Lasser, Marcel Leutenegger, Tomas Lukes, Azat Sharipov

Super-resolution optical fluctuation imaging (SOFI) allows one to perform sub-diffraction fluorescence microscopy of living cells. By analyzing the acquired image sequence with an advanced correlation method, i.e. a high-order cross-cumulant analysis, super-resolution in all three spatial dimensions can be achieved. Here we introduce a software tool for a simple qualitative comparison of SOFI images under simulated conditions considering parameters of the microscope setup and essential properties of the biological sample. This tool incorporates SOFI and STORM algorithms, displays and describes the SOFI image processing steps in a tutorial-like fashion. Fast testing of various parameters simplifies the parameter optimization prior to experimental work. The performance of the simulation tool is demonstrated by comparing simulated results with experimentally acquired data.

Public Library of Science2016

Super-resolution microscopy live cell imaging and image analysis

Tomas Lukes

Czech Technical University in Prague2017