Over the past decade, the FAA Surveillance and Broadcast Services (SBS) program has upgraded air traffic surveillance capabilities and services using satellite-enabled technology. The primary tool for these improvements is Automatic Dependent Surveillance-Broadcast (ADS-B). The FAA business case for the SBS program, originally developed in 2007, relied on several safety and efficiency benefit mechanisms. Some of the most beneficial applications concerned providing services to regions without previous surveillance coverage, including a large non-radar region within the Gulf of Mexico. ADS-B Out is an example of cooperative surveillance; consequently, operator equipage is necessary for controllers to provide the proposed enhanced services. A major part of the SBS program was an ADS-B Out mandate in much of US controlled airspace that became official in May of 2010, with a compliance date of January 1, 2020. Equipage compliance in the Gulf of Mexico differed by operator type/airspace and those differences are reflected in when benefits were delivered. This study presents analyses performed to (a) revalidate previously reported benefits among low-altitude helicopter operators in Gulf of Mexico and (b) examine benefits for high-altitude air traffic now that the ADS-B mandate is in effect. In both scenarios, the primary benefit claim was an increase in airspace capacity. The analyses indicate that changes were made to increase capacity and measurements indicate that the capacity is being used.

The Mars 2020 entry, descent, and landing architecture resembles closely that of MSL. Due to the inherent similarity between both missions, Mars 2020 will make use of heritage technology and spare parts of Mars Science Laboratory (MSL), including the Terminal Descent Sensor. The Terminal Descent Sensor collects instantaneous altitude and velocity measurements of the vehicle using a six narrow-beam line of sight Doppler altimeter/velocimeter. For MSL, it was shown that the system is robust enough for one beam to be temporarily obscured by the jettisoned heatshield. In this paper, we further evaluate the system's robustness and EDL performance in the event of beam failure. This assessment was done by means of Monte Carlo dispersion analysis. In each simulation it is assumed that one of the six beams does not collect measurements. Further analysis was conducted to evaluate system performance by employing a measurement collection scheme that leads to a lower loss of measurements. Analysis demonstrated that in the event of beam failure the TDS provides degraded altitude and velocity measurements. The largest degradation in performance is seen when the nadir pointing beam does not collect altitude measurements, resulting in timeline degradation, higher altitude errors, and a higher vertical velocity at touchdown. Results showed, however, that measurements provided by the TDS to the navigation filter are sufficient to still ensure a survivable touchdown if the system employs the original beam sequences or opts to use an alternate sequence in the event that a hardware failure is discovered during the inter-planetary cruise to Mars.

Building upon the success of the Mars Science Laboratory (MSL) landing and surface mission, the Mars 2020 project is a flagship-class science mission intended to address key questions about the potential for life on Mars and collect samples for possible Earth return by a future mission. [1] Mars 2020 will also demonstrate technologies needed to enable future human expeditions to Mars. Utilizing the groundbreaking entry, descent, and landing (EDL) architecture pioneered by the MSL, [2] [3] Mars 2020 will launch in July 2020 and land on Mars in February 2021. Like its predecessor, Mars 2020 will deliver its rover payload to the Martian surface through the use of Apollo-derived entry guidance, a 21.45 meter supersonic Disk-Gap-Band parachute, a Descent Stage powered by throttleable Mars lander engines, and the signature Sky Crane maneuver. While Mars 2020 inherits most of its EDL architecture, software, and hardware from the MSL, a number of changes have been made to correct deficiencies, improve performance, and increase the robustness of the system. For example, Mars 2020 will take advantage of the favorable atmospheric conditions of the 2020 launch opportunity to deliver a larger and more capable rover than has landed on Mars to date. A primary focus in developing the Mars 2020 EDL system has been mitigating residual risks identified after the landing of the MSL. The Advanced Supersonic Parachute Inflation Research Experiment (ASPIRE) was performed to address new concerns about the stresses experienced by parachute canopies during inflation. Other risk reduction activities include investigating possible interactions between the parachute deployment system and the inertial measurement unit (IMU) which could lead to IMU saturation, researching the effects of airborne dust on radar ground measurements, and site-specific gravity modeling for improved fuel usage. Several enhancements were added for Mars 2020 to improve performance. The addition of Terrain Relative Navigation (TRN) allows the system to land at sites with more hazardous terrain, enabling scientists to select from locations which have previously been considered inaccessible. Mars 2020 will utilize a Range Trigger for initiating parachute deployment, which reduces landing ellipse sizes by 40% compared to the Velocity Trigger approach used on the MSL. New EDL Camera hardware will capture high resolution and high frame rate images and videos of key events, such as parachute deployment and rover touchdown. Finally, the Mars Entry, Descent, and Landing Instrumentation 2 (MEDLI2) sensor suite will build upon the successful MSL MEDLI experiment with the addition of heatshield pressure sensors tuned for the supersonic flight regime and backshell instrumentation. The team has faced new and unexpected challenges throughout development. Notably, the failure of the flight heatshield during a static load test has prompted the fabrication of a new unit. Also, in accommodating the first ever Mars Helicopter under the rover belly pan, the EDL design has been further constrained by reduced ground clearances. Despite these challenges, much of the EDL-related hardware and software have already been delivered, and the EDL verification and validation program is on track to be completed on schedule prior to launch in July 2020.

In 2012, the Mars Science Laboratory (MSL) landed safely on the surface of Mars using a supersonic Disk-Gap-Band (DGB) parachute, which was structurally qualified for flight via a subsonic wind tunnel test program. Results of the Low-Density Supersonic Decelerators (LDSD) program have called into question the methodology and principles that form the foundation of the MSL subsonic test program. LDSD discovered that quasi-static subsonic proof loading a parachute via ground testing may not provide canopy stresses that sufficiently bound the stresses experienced during a rapid supersonic inflation at Mars. Additionally, deeper scrutiny of the materials and structural margins present in previously successful supersonic DGBs indicated that the MSL parachute flew with lowest margins of any previous parachute. These factors have increased the perceived risk of reusing a heritage MSL DGB parachute design with a subsonic test program for Mars 2020. To reduce this risk, a series of risk reduction steps were initiated starting in 2016. First, two parachute assemblies have been pursued in parallel: a Build-to-Print (BTP) MSL parachute, designed and manufactured by Pioneer Aerospace Corporation, which maintains the heritage of the successful MSL parachute, and a strengthened parachute, designed and manufactured by Airborne Systems North America, which uses higher strength materials throughout the parachute assembly but maintains the same overall size as the MSL parachute. Second, each parachute system was tested in a subsonic wind tunnel to examine the canopies in their fully inflated state and assess the workmanship of each canopy. Finally, full-scale parachutes from each vendor will experience at least one supersonic inflation at Marsrelevant Mach numbers and atmospheric densities at Earth via a supersonic sounding rocket test campaign. This paper presents high-level details regarding the risk reduction strategy, the two candidate parachute configurations, the ground test program, and the supersonic flight test program, and brief results from each of the test programs.

NASA’s Mars 2020 mission is charged with responding to the highest priority objectives of the 2011 planetary sciences decadal survey, conducting extensive in-situ science on the surface of the Red Planet, and carrying important cross-agency human precursor technologies. The mission concept was predicated on and enabled by leveraging the Curiosity rover engineering design, successful Sky Crane landing systems, and other elements from the Mars Science Laboratory project into a new mission with new payload elements. High-heritage paradigms are unusual for flagship science missions and can be difficult to execute as the realities of spacecraft development intervene. However the project has had good success to-date from concept through formulation and into early implementation. This paper will describe the general approaches developed and used by the Mars 2020 Project team at NASA’s Jet Propulsion Laboratory (JPL).

The Mars 2020 (M2020) Council of Atmospheres (CoA) is a joint engineering and science team that is tasked with assessing atmospheric risk associated with entry, descent and landing (EDL). This paper presents the teams, tools, and processes involved in generating the atmospheric data that are used in EDL performance simulations. The overall methodology used by the M2020 CoA is largely the same as the Mars Science Laboratory CoA [1]. Mars Mesoscale Model 5 (MMM5) at Oregon State University and Mars Regional Atmospheric Modeling System (MRAMS) at the Southwest Research Institute are mesoscale models that generate atmospheric parameters, such as wind and density profiles, at the candidate landing sites and at the time of M2020 EDL. Preliminary analysis shows that atmospheric conditions at the candidate landing sites do not significantly affect EDL performance. In fact, simulating EDL with mesoscale winds, instead of generic engineering winds, produces smaller landing ellipses. The M2020 CoA is preparing for the third landing site workshop in January 2017 by evaluating the candidate landing sites at nominal atmospheric conditions, assessing the affects of dust events on EDL performance, and tuning the mesoscale models as more data is received.

Well before Curiosity's successful landing at Gale Crater on the night of 5 August 2012, the entry, descent, and landing team had to contend with a number of development challenges that threatened the system architecture, the spacecraft's performance, and its safety. Given the ambitiousness of the landing system, perhaps it comes as no surprise that these challenges existed in all phases of system development, spanning design, testing, and operations and across all portions of flight from the top of the atmosphere through touchdown. These challenges, which included hardware, software, and flight dynamics issues, required a variety of different responses and wide range of expertise within the team. The ways the team answered the challenges were the difference between success and failure in both reaching the launch pad and reaching the surface of Mars.

On August 5th, 2012, at 10:31 PM PDT, the Mars Science Laboratory (MSL) rover Curiosity landed safely within Gale Crater. Her successful landing de-pended not only upon the flawless execution of the numerous critical activities during the seven minute entry, descent, and landing (EDL), but also upon the operational preparations and decisions made by the flight team during approach, the final weeks, days, and hours prior to landing. During this period, decisions made by the flight team balanced operational risk to the spacecraft in flight with any resulting risks incurred during EDL as a result of those decisions. This pa-per summarizes the operations plans made in preparation for Approach and EDL and the as flown decisions and actions executed that balanced the operational and EDL risks and prepared the vehicle for a successful landing.

On 6 August 2012, the Curiosity rover successfully touched down on the Martian surface setting off the most ambitious surface exploration of this planetary body. Preceding this significant step were years of design, development, and testing of the Curiosity Entry, Descent, and Landing system to prepare for the most complex landing endeavor ever attempted at Mars. To address the numerous challenges, the approach and implementation of the overall Entry, Descent, and Landing verification and validation program relied on its decomposition into three distinct domains: flight dynamics, flight system and subsystem verification and validation. The test and analysis scope, the venues, and the processes utilized were tailored to each of these domains, and are discussed in greater detail. The overall lessons learned and conclusions described herein can serve as a pathfinder for the Entry, Descent, and Landing system testing approach and implementation of future Mars landed missions.

This paper discusses the Mars Science Laboratory telecommunications configuration for ultrahigh-frequency relay data and direct-to-Earth X-band semaphore tones during entry, descent, and landing, as well as the configuration of the Mars Reconnaissance orbiter, Mars Odyssey orbiter, and the Deep Space Network. Actual link performance will be compared with a priori predictions, including signal strength, Doppler shift, plasma blackout, and the range and angles between the Mars Science Laboratory and orbiting relay assets. Predictions were generated using telecom link budgets and models developed at the Jet Propulsion Laboratory. These data were also integrated into the mission's primary end-to-end entry, descent, and landing performance simulation, Program to Optimize Simulated Trajectories II which enabled telecom predictions based on Monte Carlo results of entry, descent, and landing simulations.

The successful Mars Science Laboratory entry, descent, and landing returned a wealth of in situ data that, when combined with orbiter remote sensing data and numerical modeling results, can be used to determine the state of the atmosphere. The entry atmosphere reconstruction included data from several sources: 1) temperature and pressure data from the Mars Reconnaissance Orbiter and Mars Climate Sounder instrument, 2) density derived from the Mars entry, descent, and landing instrument suite, 3) density derived from the vehicle's inertial measurement unit and knowledge of the vehicle aerodynamics, and 4) numerical mesoscale model results. No single data set is sufficient to understand the atmospheric state along the path flown by the spacecraft. Rather, the reconstructed profile of density is pieced together from the available data, along with some assumptions and inferences. The strategy used to combine the various data sets required a clear understanding of each source's strengths and weaknesses. The various data sets appear consistent and reinforce each other. From these data sets, a novel approach to anchoring reconstructed pressure data in the upper altitudes to observed data near the Gale Crater landing site is presented. The paper also describes how the anchoring technique, along with using postflight adjustments to mesoscale model data and in situ measurements are used to reconstruct the atmospheric state along the trajectory. The final reconstructed profile is compared with preflight predictions and implications of the new approach and lessons learned are also discussed.

On August 6, 2012, the Mars Science Laboratory rover, Curiosity, successfully landed on the surface of Mars. The Entry, Descent and Landing (EDL) sequence was designed using atmospheric conditions estimated from mesoscale numerical models. The models, developed by two independent organizations (Oregon State University and the Southwest Research Institute), were validated against obser-vations at Mars from three prior years. In the weeks and days before entry, the MSL “Council of Atmospheres” (CoA), a group of atmospheric scientists and modelers, instrument experts and EDL simulation engineers, evaluated the latest Mars data from orbiting assets including the Mars Reconnaissance Orbiter's Mars Color Imager (MARCI) and Mars Climate Sounder (MCS), as well as Mars Odyssey's Thermal Emission Imaging System (THEMIS). The observa-tions were compared to the mesoscale models developed for EDL performance simulation to determine if a spacecraft parameter update was necessary prior to entry. This paper summarizes the daily atmosphere observations and comparison to the performance simulation atmosphere models. Options to modify the at-mosphere model in the simulation to compensate for atmosphere effects are also presented. Finally, a summary of the CoA decisions and recommendations to the MSL project in the days leading up to EDL is provided.

This paper discusses the MSL telecommunications configuration for UHF relay data during EDL, as well as the configuration of NASA's Mars Reconnaissance Orbiter and Mars Odyssey. Actual link performance will be compared to a priori predictions including signal strength, Doppler shift, UHF plasma blackout, and the range and angles between MSL and UHF relay assets. Predictions were generated using telecom link budgets and models developed at JPL. These data were also integrated into MSL's primary end-to-end EDL performance simulation, NASA Langley's Program to Optimize Simulated Trajectories II (POST2), which enabled telecom predictions based on Monte Carlo results of EDL simulations.

Energy metabolism is complex, and is broadly categorized into 3 components: substrate utilization, oxidative phosphorylation and ATP transfer and utilization. Whilst an area of intense research, our understanding of energy metabolism in health and disease remains limited, primarily due to inherent difficulties in measuring the various processes involved. With the advent of hyperpolarization using the dynamic nuclear polarization (DNP) technique, magnetic resonance spectroscopy (MRS) utilizing 13C-labelled tracers allows for the non invasive visualization of energy metabolism in the intact organism from mouse to man. We hypothesized that long term diabetes would induce alterations in carbohydrate metabolism in the kidney and heart in a model of spontaneous non obese type 2 diabetes, the Goto Kakisaki (GK) rat.