Henry S. Wright

Design of the ARES Mars Airplane and Mission Architecture

Significant technology advances have enabled planetary aircraft to be considered as viable science platforms. Such systems fill a unique planetary science measurement gap, that of regional-scale, near-surface observation, while providing a fresh perspective for potential discovery. Recent efforts have produced mature mission and flight system concepts, ready for flight project implementation. This paper summarizes the development of a Mars airplane mission architecture that balances science, implementation risk and cost. Airplane mission performance, flight system design and technology maturation are described. The design, analysis and testing completed demonstrates the readiness of this science platform for use in a Mars flight project.

The Mars airplane: a credible science platform

Significant technology advances have enabled planetary aircraft to be considered as viable science platforms. Such systems fill a unique planetary science measurement gap, that of regional-scale, near-surface observation, while providing a fresh perspective for potential discovery. Recent efforts have produced mature mission and flight system concepts, ready for flight project implementation. This work summarizes the development of a Mars airplane mission architecture that balances science, implementation risk and cost. Airplane mission performance, flight system design and technology readiness are described.

A Design Comparison of Atmospheric Flight Vehicles for the Exploration of Titan

Titan, the largest moon of Saturn, is one of the most scientifically interesting locations in the Solar System. With a very cold atmosphere that is five times as dense as Earth s, and one and a half times the surface pressure, it also provides one of the most aeronautically fascinating environments known to humankind. While this may seem the ideal place to attempt atmospheric flight, many challenges await any vehicle attempting to navigate through it. In addition to these physical challenges, any scientific exploration mission to Titan will most likely have several operational constraints. One difficult constraint is the desire for a global survey of the planet and thus, a long duration flight within the atmosphere. Since many of the scientific measurements that would be unique to a vehicle flying through the atmosphere (as opposed to an orbiting spacecraft) desire near-surface positioning of their associated instruments, the vehicle must also be able to fly within the first scale height of the atmosphere. Another difficult constraint is that interaction with the surface, whether by landing or dropped probe, is also highly desirable from a scientific perspective. Two common atmospheric flight platforms that might be used for this mission are the airplane and airship. Under the assumption of a mission architecture that would involve an orbiting relay spacecraft delivered via aerocapture and an atmospheric flight vehicle delivered via direct entry, designs were developed for both platforms that are unique to Titan. Consequently, after a viable design was achieved for each platform, their advantages and disadvantages were compared. This comparison included such factors as deployment risk, surface interaction capability, mass, and design heritage. When considering all factors, the preferred candidate platform for a global survey of Titan is an airship.

Measurements from an Aerial Vehicle: A New Tool for Planetary Exploration

Aerial vehicles fill a unique planetary science measurement gap, that of regional-scale, near-surface observation, while providing a fresh perspective for potential discovery. Aerial vehicles used in planetary exploration bridge the scale and resolution measurement gaps between orbiters (global perspective with limited spatial resolution) and landers (local perspective with high spatial resolution) thus complementing and extending orbital and landed measurements. Planetary aerial vehicles can also survey scientifically interesting terrain that is inaccessible or hazardous to landed missions. The use of aerial assets for performing observations on Mars, Titan, or Venus will enable direct measurements and direct follow-ons to recent discoveries. Aerial vehicles can be used for remote sensing of the interior, surface and atmosphere of Mars, Venus and Titan. Types of aerial vehicles considered are airplane “heavier than air” and airships and balloons “lighter than air.” Interdependencies between the science measurements, science goals and objectives, and platform implementation illustrate how the proper balance of science, engineering, and cost, can be achieved to allow for a successful mission. Classification of measurement types along with how those measurements resolve science questions and how these instruments are accommodated within the mission context are discussed.

Design of a long endurance Titan VTOL vehicle

Saturns moon Titan promises insight into numerous key scientific questions, many of which can be investigated only by in situ exploration of its surface and atmosphere. This paper presents research on a vertical takeoff and landing (VTOL) vehicle designed to conduct a scientific investigation of Titans atmosphere, clouds, haze, surface, and any possible oceans. Multiple options for vertical takeoff and horizontal mobility were considered. A helicopter was baselined because of its many advantages over other types of vehicles, particularly in that it has access to hazardous terrain and the ability to perform low speed aerial surveys. Using a nuclear power source and the atmosphere of Titan, a turbo expander cycle produces the 1.9 kW required by the vehicle for flight and mission operations, allowing it to sustain a long range, long duration mission that could travel over a thousand kilometers. The turbo expander power source can increase the lifespan and quality of science for planetary aerial flight to an extent that the limiting factor for the mission life is not available power but the life of the mechanical parts. This design is the first to investigate the implications of this potentially revolutionary technology on a Titan aerial vehicle

Mars 2020 Entry, Descent and Landing Instrumentation (MEDLI2)

This paper will introduce Mars Entry Descent and Landing Instrumentation (MEDLI2) on NASAs Mars2020 mission. Mars2020 is a flagship NASA mission with science and technology objectives to help answer questions about possibility of life on Mars as well as to demonstrate technologies for future human expedition. Mars2020 is scheduled for launch in 2020. MEDLI2 is a suite of instruments embedded in the heatshield and backshell thermal protection systems of Mars2020 entry vehicle. The objectives of MEDLI2 are to gather critical aerodynamics, aerothermodynamics and TPS performance data during EDL phase of the mission. MEDLI2 builds up the success of MEDLI flight instrumentation on Mars Science Laboratory mission in 2012. MEDLI instrumentation suite measured surface pressure and TPS temperature on the heatshield during MSL entry into Mars. MEDLI data has since been used for unprecedented reconstruction of aerodynamic drag, vehicle attitude, in-situ atmospheric density, aerothermal heating, transition to turbulence, in-depth TPS performance and TPS ablation. [1,2] In addition to validating predictive models, MEDLI data has highlighted extra margin available in the MSL forebody TPS, which can potentially be used to reduce vehicle parasitic mass. MEDLI2 expands the scope of instrumentation by focusing on quantities of interest not addressed in MEDLI suite. The type the sensors are expanded and their layout on the TPS modified to meet these new objectives. The paper will provide key motivation and governing requirements that drive the choice and the implementation of the new sensor suite. The implementation considerations of sensor selection, qualification, and demonstration of minimal risk to the host mission will be described. The additional challenges associated with mechanical accommodation, electrical impact, data storage and retrieval for MEDLI2 system, which extends sensors to backshell will also be described.

A Comparison of Aerial Platforms for the Exploration of Titan

Exploration of Titan, envisioned as a follow -on to the highly successful Cassini -Huygens mission, is described in this paper. A mission blending measurements from a dedicated orbiter and an in -situ aerial explorer is discussed. Summary description of the science rationale and the mission architecture, including the orbiter, is provided . The mission has been sized to ensure it can be accommodated on an existing expendable heavy -lift launch vehicle. A launch to Titan in 2018 with a 6 -year time of flight to Titan using a combination of Solar Electric Propulsion and aeroassist (direct entry and aerocapture) forms the basic mission architecture. A detailed assessment of different platforms for aerial exploration of Titan has been performed. A rationale for the selection of the airship as the baseline platform is provided. Detailed description of the airship, its subsystems, and its operational strategies are provided.

Multidimensional analysis of autonomous aerial observation systems (AAOS) for scientific, civil, and defense applications

Better knowledge of the atmosphere, ocean and land are needed by a wide range of users spanning the scientific, civil and defense communities. Observations to provide this knowledge will require aerial systems with greater operational flexibility and lower life-cycle costs than are currently available. Persistent monitoring of severe storms, sampling and measurements of the Earth’s carbon cycle, wildfire monitoring/management, crop assessments, ozone and polar ice changes, and natural disaster response (communications and surveillance) are but a few applications where autonomous aerial observations can effectively augment existing measurement systems. User driven capabilities include high altitude, long range, long-loiter (days/weeks), smaller deployable sensor-ships for in-situ sampling, and sensors providing data with spectral bandwidth and high temporal and three-dimensional spatial resolution. Starting with user needs and considering all elements and activities required to acquire the needed observations leads to the definition of autonomous aerial observation systems (AAOS) that can significantly complement and extend the current Earth observation capability. In this approach, UAVs are viewed as only one, albeit important, element in a mission system and overall cost and performance for the user are the critical success factors. To better understand and meet the challenges of developing such AAOSs, a systems oriented multi-dimensional analysis has been performed that illuminates the enabling and high payoff investments that best address the needs of scientific, civil, and defense users of Earth observations. The analysis further identifies technology gaps and serves to illustrate how investments in a range of mission subsystems together can enable a new class of Earth observations.