Damon Landau

• PhD
• Systems Engineer at Jet Propulsion Laboratory

The prospect that the five major moons of Uranus could host subsurface oceans makes them high‐priority targets for future exploration. Different techniques can be used to search for deep oceans in these objects. Here, we focus on ocean detection and characterization from measurements of the moons' response to the gravitational tides and librations...

The most recent Planetary Science and Astrobiology Decadal Survey has proposed Uranus as the target for NASA’s next large-scale mission. The interior structure and atmosphere of the planet are currently poorly understood, and objectives for investigating Uranus’s deeper regions and composition are highly ranked. Traditionally, gravity science has s...

Future missions to Enceladus would benefit from multi-moon tours that leverage \(V_\infty \) on resonant orbits to progressively transfer between moons. Such resonance hopping trajectories present a vast search space for global optimization due to the different combinations of available resonances and flyby velocities. The proposed multi-objective...

The scientific value of a Uranus Orbiter and Probe mission is driven by the amount of data relayed from the probe and the diversity of satellite observations. For probe entries, key design choices include release of the probe on approach or from orbit, and orbiter equatorial crossing inside or outside of Uranus' rings, all while ensuring sufficient...

The question of how many impulses is necessary to optimize a transfer-type maneuver has remained open for decades. Recently, the introduction of optimal switching surfaces revealed the existence of iso-impulse trajectories with differing numbers of impulses for fixed-time rendezvous maneuvers. In this paper, the multiplicity of minimum-Δv impulsive...

We study the multiplicity of minimum-∆v impulsive trajectories for long-time-horizon problems. One notable feature of these extremal impulsive trajectories is that many of the impulses are applied at a specific position, highlighting the significance of what we coin as "impulse anchor positions." We demonstrate that for long-time-horizon maneuvers...

Star is a mission design tool that globally searches for patched-conic trajectories that satisfy a set of user-defined constraints. It has been used to develop dozens of mission concepts at the Jet Propulsion Laboratory spanning multi-target rendezvous, sample return, multiple gravity assists (ballistic, high- and low-thrust), central-body switch t...

Future missions to Enceladus would benefit from multi-moon tours that leverage V-infinity on resonant orbits to progressively transfer between moons. Such "resonance family hopping" trajectories present a vast search space for global optimization due to the different combinations of available resonances and flyby speeds. The proposed multi-objectiv...

Interstellar objects (ISOs) are fascinating and under-explored celestial objects, providing physical laboratories to understand the formation of our solar system and probe the composition and properties of material formed in exoplanetary systems. This paper will discuss the accessibility of and mission design to ISOs with varying characteristics, i...

Interstellar objects are a category of comets and asteroids that offer a unique scientific opportunity to answer fundamental scientific questions about the origin of solar system volatiles, the compositions of exo-solar systems, and the transfer rates of material between solar systems. However, they are also difficult to reach due to their high ene...

Europa is a premier target for advancing both planetary science and astrobiology, as well as for opening a new window into the burgeoning field of comparative oceanography. The potentially habitable subsurface ocean of Europa may harbor life, and the globally young and comparatively thin ice shell of Europa may contain biosignatures that are readil...

With the discovery of 1I ’Oumuamua and 2I Borisov, interstellar objects (ISOs) have been thrust into the forefront of planetary science, and the robotic exploration of ISOs is now of significant interest. With current propulsion technology, rendezvous with these objects is likely infeasible, and thus the maximum science return results from a combin...

Using the "statite," or static-satelite, concept -- an artificial satellite capable of hovering in place using a solar sail -- this work proposes to create a dynamic orbital slingshot in anticipation of Interstellar Objects (ISOs) passing through our solar system. The existence of these ISOs offers a unique scientific opportunity to answer fundamen...

Exoplanet discoveries since the mid-1990’s have revealed an astounding diversity of planetary systems. Studying these systems is essential to understanding planetary formation processes, as well as the development of life in the universe. Unfortunately, humanity can only observe limited aspects of exoplanetary systems by telescope, and the signific...

This article is the second of a three-part series in which we present the results of a study exploring concepts for improving communications and tracking capabilities of deep space SmallSats. In Part I, we discussed SmallSat direct-to-earth links and SmallSat communications equipment, and provided recommendations for future work. In Part II, we foc...

Robotic exploration of the solar system using small satellites (SmallSats) is gaining popularity because of SmallSats’ lower cost and faster development cycle compared to primary science missions. A potential obstacle for deployment of SmallSats in deep space is the limitation associated with the communications link imposed by SmallSats' frugal pow...

This paper analyzes the advancements to the Julia Language 1.1 Ephemeris and Physical constants Reader including the addition of gravitational modeling. Originally written in MATLAB, this Julia Language program is intended to be used in for trajectory design. Written in an open-source coding language, this ephemeris reader can output the state of p...

We propose that the Gateway elements be 'scarred' to accommodate future demonstration and investigation of artificial gravity (AG) at human scale. We show how this could be done using the Gateway elements already envisioned, with minimal additional developments and minimal interference with other Gateway functions. The resulting flight data would b...

This paper aims to identify the best approaches for exploring planetary bodies with very long orbital periods, i.e., bodies that approach Earth only once in a lifetime. This includes long-period comets (LPCs), and the newly discovered classes of Manx comets and interstellar objects (ISOs). Long-period comets are high scientific value targets, as in...

The current aim of NASA's Journey to Mars is a stepwise approach towards landing humans on the Red Planet, culminating in a sustained presence. There are many recent studies on how this could be achieved in an evolvable and affordable manner. Most architectures begin with crewed missions to Phobos or Mars orbit in the mid-2030‘s, progress toward sh...

When designing a mission, the addition of a maneuver at the right spot often improves the utility of an otherwise mediocre trajectory. However, the additional degrees of freedom of finding the best maneuver location can severely complicate automated broad-search algorithms. A computationally efficient formulation that reduces the maneuver design sp...

The new JPL Small-Body Automatic Mission-Design System comprises two main elements: a database of pre-computed mission options to all known asteroids and comets, and an inter- active web interface that can be used to design transfers to each small body. The system is kept current with the JPL small-body orbit catalog, is publicly available, and can...

The primary objective of this Airbus Defence and Space funded, Pre-Phase-0 study was to make an early assessment of the feasibility of a combined NEO/space weather monitoring system based on interplanetary Cubesats. During this study the original concept of surveying and in-situ visits of NEOs had to be de-scoped to just a survey system as the orig...

The removal of 123 pieces of debris from the Sun-synchronous LEO environment is accomplished by a 10-spacecraft campaign wherein the spacecraft, flying in succession over an 8-yr period, rendezvous with a series of the debris objects, delivering a de-orbit package at each one before moving on to the next object by means of impulsive manoeuvres. Thi...

We consider the problem of optimally transferring a spacecraft from a starting to a target asteroid. We introduce novel approximations for important quantities characterizing the optimal transfer in case of short transfer times (asteroid hops). We propose and study in detail approximations for the phasing value φ, for the maximum initial mass m* an...

With the development of in situ resource utilization, a propellant production plant on the Moon could be used to extract oxygen from the lunar regolith, or could produce hydrogen and oxygen from ice deposits. These propellants may then be transported to LEO via cislunar ferries to supply spacecraft bound for interplanetary destinations. Alternative...

Artificial gravity has long been proposed to limit the harmful effects of the micro-gravity environment on human crews during mission to Mars. A tethered spacecraft spinning at 4 rpm (to avoid motion sickness) provides an attractive configuration. However, if the spacecraft is required to spin down for impulsive maneuvers and then spin up for inter...

Recent technology advancements in microelectric propulsion will enable the next generation of small spacecraft to perform trajectory and attitude maneuvers with significant ΔV requirements, provide thrust over long mission durations, and replace reaction wheels for attitude control. These advancements will open up the class of mission architectures...

We investigate the use of nuclear-electric propulsion for human missions to Mars. Employing a patched-conic solution as our initial guess, low-thrust trajectories are designed via a continuation method. We determine the propulsion requirements for a reusable human transportation system, in which a single vehicle makes a round trip between the Earth...

Recent technology advancements in Micro Electric Propulsion (MEP) will enable the next generation of small spacecraft to perform trajectory and attitude maneuvers with significant ΔV requirements, provide thrust over long mission durations, and replace reaction wheels for attitude control. These advancements will open up the class of mission archit...

We present the methods and results of the Jet Propulsion Laboratory team in the 5th Global Trajectory Optimization Competition. Our broad-search strategy utilized several recently developed phase-free metrics for rapidly narrowing the search options. Two different, adaptive, branch-and-prune strategies were employed to build up asteroid sequences u...

This paper summarizes the results of a 2014 KISS workshop that identified a wide variety of ways that the technologies (and their near-term derivatives) developed for the proposed Asteroid Redirect Mission (ARM) would beneficially impact the Nation’s space interests including: human missions to Mars and its moons, planetary defense, orbital debris...

NASA is currently studying an Asteroid Redirect Mission (ARM) concept that could capture an entire 2 to 12 m asteroid or boulder from a larger asteroid and place it in orbit around the Moon. Once at the Moon, astronauts would be sent to visit the asteroid or boulder and use it as a test bed for developing technologies and procedures needed for deep...

Although a gravity-assist tour of the Uranian moons would be desirable component of a Uranus mission, such tours are especially challenging due to its distance from the Sun and the planet's very high obliquity (97.77°). The high obliquity means that the initial orbits at Uranus tend to be very highly inclined (60°-80°), except in the rare case of a...

This paper describes a simple semi-analytic model for mass-optimized interplanetary solar electric low-thrust trajectories. A description is given of a model that accurately and quickly determines the performance of circular-coplanar low-thrust transfers with a series of simple empirical and physics-based relationships that can be implemented easil...

Ion propulsion enables planetary missions that would otherwise be unaffordable in a cost-capped program. Two such missions are described here.

In 2010 and 2011 NASA and Keck Institute for Space Studies sponsored inves-tigations into the feasibility of identifying, capturing, and returning an entire (al-beit small) NEA to the vicinity of Earth, and concluded that a 40-kW solar elec-tric propulsion system launched on an Atlas 551 provided sufficient propulsion to control an asteroid's traje...

The human exploration of Phobos and Deimos or the retrieval of a surface sample launched to low-Mars orbit presents a highly constrained orbital transfer problem. In general, the plane of the target orbit will not be accessible from the arrival or departure interplanetary trajectories with an (energetically optimal) tangential burn at periapsis. Th...

2011 AG5 is a Potentially Hazardous Asteroid roughly 140 m in diameter. The current orbit determination, based on 213 optical measurements from 2010-Nov-08.6 to 2011-Sep-21.4, allows for the possibility of an Earth impact on 2040-Feb-05.2 with probability 0.2%. The 2040 potential impact is a 17:10 resonant return from a 2023 Earth encounter, where...

Crewed missions to near-Earth objects (NEOs), as well as reconnaissance for hazard reduction, for science, and for resource exploitation, require in situ robotic precursor missions. Because potential crewed mission targets have multiple requirements, even quite high probabilities for each single requirement lead to a need for multiple targets to be...

A human mission to Mars would likely involve several vehicle elements that are staged near Earth, and the choice of staging location can significantly affect the efficiency and robustness of a Mars exploration campaign. The key figures of merit are overall {increment}V, departure windows, backup opportunities, and contingency options. These charact...

We design a new version of a cycler orbit between Earth and Mars (known as the Aldrin cycler) in which we use low thrust to reduce the encounter velocities. We show that by reducing the encounter velocities at both planets, the propellant needed by the taxis to perform hyperbolic rendezvous can be significantly reduced. If the V-infinity reduction...

Several Hall thrusters (e.g. BPT-4000, BHT-600, SPT-100, etc.) are able that operate with useful thrust at the sub-kilowatt power levels that would be available from solar arrays at Jupiter distance. We have found that a combination of a multi-kilowatt thruster (e.g. the BPT-4000) for the interplanetary trajectory with a sub-kilowatt thruster (e.g....

We propose the development of an Interplanetary Sample Canister (ISC) for the Mars Sample Return (MSR) mission using CubeSat and Microfabricated Electrospray Propulsion (MEP) technology to enable a lower cost MSR mission.

A comparison of Earth departures from Earth-Moon L2, lunar orbit, high-Earth orbit, and low-Earth orbit is presented. The choice of departure staging node strongly affects vehicle designs, crew contingency options, and mission backup opportunities.

Efficient methods to transfer among a variety of Mars orbits is presented. Emphasis is placed on connecting arrival and departure interplanetary trajectories to an arbitrary circular target orbit for a hybrid human/robotic Mars sample return mission.

This report describes the results of a study sponsored by the Keck Institute for Space Studies (KISS) to investigate the feasibility of identifying, robotically capturing, and returning an entire Near-Earth Asteroid (NEA) to the vicinity of the Earth by the middle of the next decade. The KISS study was performed by people from Ames Research Cent...

The report of the US Planetary Science Decadal Survey (PSDS), released in draft form March 7, 2011, identifies several mission concepts involving travel to high-priority outer solar system (OSS) destinations. These include missions to Europa and Jupiter, Saturn and two of its satellites, and Uranus. Because travel to the OSS involves much larger di...

This paper describes the results of a study into the feasibility of identifying, robotically capturing, and returning an entire Near-Earth Asteroid (NEA) to the vicinity of the Earth by the middle of the next decade. The feasibility of such an asteroid retrieval mission hinges on finding an overlap between the smallest NEAs that could be reasonably...

Earth departure options such as the location for deployment, aggregation, and crew rendezvous as well as the type of propulsion leveraged for each mission phase effect overall mission performance metrics such as number of critical maneuvers, mass of propellant to achieve departure, and initial mass required in low Earth orbit. This paper identifies...

The diverse physical and orbital characteristics of near-Earth asteroids provide progressive stepping stones on a flexible path to Mars. Beginning with cislunar exploration capability, the variety of accessible asteroid targets steadily increas-es as technology is developed for eventual missions to Mars. Noting the poten-tial for solar electric pro...

Attitude solutions for spin-stabilized rigid spacecraft are presented that are direct functions of the torque and angular momentum vectors in the body and in the inertial frame. Two solutions are found: an approximate solution and an exact algebraic solution. Unfortunately, in applications, the algebraic method is not practical because the torque a...

The combination of lunar gravity assists for Earth escape and ∼1.25 yr. of SEP V-infinity leveraging effectively boosts the performance of a given launch vehicle. Two methods are available to establish a launch period with lunar gravity assists, where the energy achievable with lunar escape has been character-ized as a function of right ascension,...

An article from the Soviet newspaper, Pravda, is presented, which discusses issues related to missions to Mars. The type of vehicle needed for a Martian mission is examined, including the propulsion system, construction of the vehicle in earth orbit, living quarters, safety considerations, and the landing vehicle. Options for the mission route and...

The use of Solar Electric Propulsion (SEP) can provide significant benefits for the human exploration of near-Earth asteroids. These benefits include substantial cost savings - represented by a significant reduction in the mass required to be lifted to low Earth orbit - and increased mission flexibility. To achieve these benefits, system power leve...

We examine human missions to the Martian moons, Phobos and Deimos, that use hybrid chemical and solar-electric propulsion trajectories. Chemical propulsion is used where the orbit dynamics favor an impulsive maneuver and this efficiency offsets the inefficiency of the lower specific impulse of chemical systems. Solar-electric propulsion at power le...

Near-Earth Objects (NEOs) are exciting targets for exploration; they are relatively easy to reach but relatively little is known about them. With solar electric propulsion, a vast number of interesting NEOs can be reached within a few years and with extensive flexibility in launch date. An additional advantage of electric propulsion for these missi...

The disparate design problems of selecting an electric propulsion system, launch vehicle, and flight time all have significant impacts on the cost and robustness of a mission. The effects of these system choices combine into a single optimization of the total mission cost, where the design constraint is a required spacecraft net (nonelectric propul...

There have been many proposed technologies and architectures to extend a human presence beyond the Moon. Solar electric propulsion (SEP) provides the capability to implement a wide variety of missions with relatively low injected mass to low-Earth orbit. Because of its broad applicability this technology can enable progressively ambitious steps tow...

This poster will present the results from an extensive search for trajectories in 2015-2035 to over 7,000 Near Earth Asteroids. Both chemical propulsion and electric propulsion trajectories are examined in three mission classes: (1) robotic rendezvous missions, (2) robotic sample return missions, and (3) human explorations missions. Many of the acc...

The Neptune System Explorer (NSE) mission concept study assessed opportunities to conduct Cassini-like science at Neptune with a radioisotope electric propulsion (REP) based spacecraft. REP is based on powering an electric propulsion (EP) engine with a radioisotope power source (RPS). The NSE study was commissioned under the Joint Radioisotope Elec...

This poster will present an architecture for human missions to near-Earth asteroids in the mid 2020s using Solar Electric Propulsion (SEP). This concept relies on taking existing, flight-proven technologies from unmanned spaceflight and scaling them up to higher power levels for human spaceflight. When applied to human spaceflight, the robustness o...

Judicious swingbys of the Galilean satellites can capture a spacecraft into Jupiter orbit without requiring a propulsive Jupiter-orbit-insertion maneuver. A single flyby of Ganymede is sufficient to capture into a 1-year orbit at Jupiter with an arrival V-infinity of 3 km/s or less, while a double flyby of Callisto and Gany-mede or of Ganymede and...

On April 15th, at the Kennedy Space Center, President Obama announced his new goals for NASA's human spaceflight activities. One of the most exciting challenges that he gave to NASA was a human journey to an asteroid in 2025 as part of a path the leads to human Mars missions in the 2030s. This poster presents the results from a trajectory search fo...

Solar electric propulsion (SEP) trajectories to Saturn using multiple gravity assists are explored for the joint NASA and ESA Titan Saturn System Mission study. Results shows that these new trajectories enable greater performance compared to chemical propulsion with similar gravity assists or SEP without gravity assists. This paper describes the me...

In 2008, NASA and ESA commissioned a study of an international flagship-class mission to Titan, Saturn, and Enceladus consisting of a NASA orbiter and two ESA in situ elements, a montgolfière hot air balloon and a lake lander. This paper provides an overview of the trajectory design for this mission, which consists of a solar electric interplanetar...

A procedure to produce a large variety of trajectories to Uranus and Neptune is presented. A small set of exceptional trajectories emerges from this broad search and expands the range of missions available to these planets. Payload mass increases dramatically when a Jupiter flyby is available, and the choice of gravity-assist sequence has a greater...

We present an implementation of a Flexible Path architecture for human exploration beyond Earth orbit using Solar Electric Propulsion (SEP). Human missions with combined SEP and chemical propulsion to asteroids and Mars are possible by evolving existing Hall Thruster and solar array technologies to power levels of 100s of kW. We present two archite...

We compare a variety of mission scenarios to assess the strengths and weaknesses of options for Mars exploration. The mission design space is modeled along two dimensions: trajectory architectures and propulsion system technologies. We examine direct, semi-direct, stop-over, semi-cycler, and cycler architectures, and we include electric propulsion,...

Traditional methods of producing artificial gravity rely on thrusting through the center of mass of the spacecraft, which entails a crew cabin that is either large (in length) increasing mass, or tethered to the propellant tanks requiring reconfiguration during maneuvers. An alternative approach requires offset thrusting, but allows a mass-competit...

NASA's Jet Propulsion Laboratory has conducted a study focused on the analysis of appropriate margins for deep space missions using solar electric propulsion (SEP). The purpose of this study is to understand the links between disparate system margins (power, mass, duty cycle, etc.) and their impact on overall mission performance and robustness. It...

The disparate design problems of selecting an electric propulsion system, launch vehicle, and flight time all have significant impacts on the cost and robustness of a mission. The effects of these system choices combine into a single optimization of the total mission cost, where the design constraint is a required spacecraft neutral (non-electric p...

A guidance algorithm was used to examine the space rendezvous process from a low-circular orbit departure, to final docking of a space vehicle taxi, with the cycler. The algorithm tracked the desired approach profile, allowing the taxi, to dock within 10 cm of the approach axis at a speed of 7 cm per second. It was observed that the docking procedu...

We present an architecture for the human exploration of Mars. This architecture is characterized by the use of parking orbits at Earth and gravity assists at Mars. An interplanetary transfer vehicle cycles from Earth orbit to Mars flyby and back, eliminating the need to launch transfer vehicles from the surfaces of Earth and Mars. Necessary develop...

Earth–Mars trajectories with low energy requirements that also limit the (transfer) time a crew spends in interplanetary space are essential to the design of cost-effective, minimal-risk missions. We compute optimal V trajectories with constraints on the transfer time of flight for launch years 2009 through 2022. We further explore the consequences...

We compute optimal low-thrust transfers (with constant thrust and constant specific impulse) between Earth and Mars over a range offlight times (from 120 to 270 days) and launch years (between 2009 and 2022). Unlike impulsive transfers, the mass-optimal trajectory depends strongly on the thrust and specific impulse of the propulsion system. A low-t...

We present cycler and semi-cycler trajectories to transport crews from Earth to a Mars base and back It is assumed that the Mars base should never be abandoned and that the cycler vehicles safely and comfortably transport twelve people at a time. Since these cycler vehicles involve a significant investment, as few as possible should be built. We ex...

Earth-Mars cycler trajectories (cyclers) could play an important role in a future human transportation system to Mars. A particular cycler that repeats every two synodic periods and has one intermediate Earth encounter is very promising. In a circular-coplanar model it requires no propulsive maneuvers, has 153-day transfer times between Earth and M...

We present an architecture for the human exploration of Mars. This architecture is characterized by the use of parking orbits at Earth and gravity assists at Mars. An interplanetary transfer vehicle cycles from Earth orbit to Mars flyby and back, eliminating the need to launch transfer vehicles from the surfaces of Earth and Mars. Necessary develop...

We construct a cycler (with acceptable transfer times and moderate encounter velocities) by patching a series of three-synodic-period semicycler trajectories together. The cycler employs high-efficiency low-thrust propulsion for trajectory maintenance and correction (thus making it a "powered" cycler). Even though the propellant usage is not insign...

Mars human-mission scenarios can incorporate a parking orbit at either Earth or Mars. In many cases the parking orbit is not conveniently oriented with respect to the interplanetary leg (e.g., returning to Earth from a parking orbit at Mars). A method to reorient the spacecraft's orbit around a planet for a roundtrip mission is described. This meth...