Asteroid Redirect Mission Research Articles

Capacity of Sun-driven lunar swingby sequences and their application in asteroid retrieval

For deep-space mission design, the gravity of the Sun and the Moon can be first considered and utilized. Their gravity can provide the energy change for launching spacecraft and retrieving spacecraft as well as asteroids. Regarding an asteroid retrieval mission, it can lead to the mitigation of asteroid hazards and an easy exploration and exploitation of the asteroid. This paper discusses the application of the Sun-driven lunar swingby sequence for asteroid missions. Characterizing the capacity of this technique is not only interesting in terms of dynamic insights but also non-trivial for trajectory design. The capacity of a Sun-driven lunar swingby sequence is elucidated in this paper with the help of the "Swingby-Jacobi" graph. The capacity can be represented by a range of the Jacobi integral that encloses around 660 asteroids currently cataloged. To facilitate trajectory design, a database of Sun-perturbed Moon-to-Moon transfers, including multi-revolution cases is generated and employed. Massive trajectory options for spacecraft launch and asteroid capture can then be explored and optimized. Finally, a number of asteroid flyby, rendezvous, sample-return, and retrieval mission options enabled by the proposed technique are obtained.

Near-Earth Asteroid Capture via Using Lunar Flyby plus Earth Aerobraking

Capturing Near-Earth Asteroids (NEAs) in the Earth-Moon system is a potential method of future space exploration and resource utilization. In order to make the captured NEA easily rendezvoused by spacecrafts, it is expected to capture the asteroid in a low-energy and low-inclination orbit. Lunar flyby and Earth aerobraking have been proved to be effective energy-saving methods in asteroid retrieval missions. Based on the Earth aerobraking capture strategy, if a lunar flyby process is performed before the asteroid enters the atmosphere, the thermal ablation of the asteroid in the atmosphere is expected to be alleviated. This paper proposes a lunar flyby plus Earth aerobraking method to capture an NEA. Using Geostationary Transfer Orbit (GTO) as the target orbit, the efficiency of three different capture strategies (direct capture strategy, Earth aerobraking capture strategy and lunar flyby plus Earth aerobraking capture strategy) are compared. Compared to the Earth aerobraking capture strategy, simulation results show that the main advantage of the lunar flyby plus Earth aerobraking capture strategy is that the mass loss ratio can be reduced (15 real asteroids are used as examples and mass loss ratio can be reduced by 0.98–3.39%). For example, for an asteroid with a diameter of 5 m, the mass is about 170.17 tons (with a density of 2.6g/cm3), reducing the mass loss ratio by 1% means that 1701.7 kg of the asteroid materials can be saved. Meanwhile, if the asteroid has a suitable phase for lunar flyby, while reducing the mass loss ratio, the fuel consumption can also be reduced. Furthermore, the conditions that do not require maneuvering between the lunar flyby and Earth aerobraking are preliminarily discussed. During the preliminary design stage of asteroid retrieval missions, compared with the Earth aerobraking capture strategy, lunar flyby plus Earth aerobraking capture strategy provides a potentially effective option for reducing the mass loss and the fuel consumption.

Astrobiology as a NASA Grand Challenge

Are we alone is a question whose ambition can only be met with a NASA-led global collaboration. In this white paper, we describe how this makes The Search for Life Beyond Earth a new Grand for NASA. As described in the White House Office of Science and Technology Policy and the White House National Economic Council, Grand Challenges are ambitious but achievable goals that harness science, technology, and innovation to solve important national or global problems and that have the potential to capture the public's imagination. NASA had identified an Grand Challenge centered on the Asteroid Retrieval Mission, which was closed out in June, 2017. Here, we explain how NASA's next Grand could be focused on The Search for Life Beyond Earth, with a flagship-scale mission in Astrophysics as its centerpiece.

On asteroid retrieval missions enabled by invariant manifold dynamics

In recent years, the retrieval of entire asteroids has received significant attention, with many approaches leveraging the invariant manifolds of the Circular-Restricted Three-body Problem to capture an asteroid into a periodic orbit about the L1 or L2 points of the Sun–Earth system. Previous works defined an ‘Easily Retrievable Object’ (ERO) as any Near-Earth Object (NEO) which is retrievable using these invariant manifolds with an impulsive Δv of less than 500m∕s. We extend the previous literature by analysing the Pareto fronts for the EROs discovered for the first time, using high-performance computing to lift optimisation constraints used in previous literature, and modifying the method used to filter unsuitable NEOs from the NEO catalogue. In doing so, we can demonstrate that EROs have approximately the same transfer cost for almost any possible transfer time, including single-impulse transfers, which could offer significant flexibility to mission designers. We also identify 44 EROs, of which 27 are new, and improve on previously-known transfer solutions by up to 443m∕s, including 17 new capture trajectories with Δv costs of less than 100m∕s.

Location and stability of distant retrograde orbits around the Moon

ABSTRACT Recently has grown the interest of placing natural or artificial objects in the neighbourhood of the Moon. We numerically investigate a region of retrograde orbits around the Moon associated with the C Family of periodic orbits and the quasi-periodic orbits that oscillate around them (Broucke 1968; Winter 2000). We have given continuity to Winter (2000) investigations by introducing a more realistic dynamical scenario, one based on the four-body Sun–Earth–Moon–particle problem. Our results showed that the region of stability diminished to approximately 4 ${{\ \rm per\ cent}}$, the original size encountered for the circular-restricted three-body problem (CRTBP), mainly due to the Sun’s gravitational perturbations. None the less, the size of the region continues to be significant and we were able to found distant retrograde orbits (DROs) around the Moon with eccentricity following e = 2.259 63 × 10−6a + 0.238 45 (standard error of 1 ${{\ \rm per\ cent}}$) and semimajor axis values of the initial osculating orbits, varying between 110 000 and 185 000 km, remaining stable for a time span of 104 lunar periods. This set of distant orbits from the Moon are characterized by a narrow range of acceptable initial positions (0.8–0.83) and velocities of ∼0.5, in the rotating Earth–Moon frame. The out of plane amplitude oscillations of $\pm 15\, 000$ km presented by these DROs are a natural outcome of the significant Moon’s inclination of 5.15°. Some results presented on this work can be useful for lunar missions, such as the ones that would require prolonged stays around the satellite and use stable distant orbits as ‘parking’ orbits, such as the advanced concepts of NASA’s Asteroid Redirect Mission, proposed a few years ago.

Trajectory Design for Asteroid Retrieval Missions: A Short Review

In simple terms, an asteroid retrieval mission envisages a spacecraft that rendezvous with an asteroid, lassos it and hauls it back to the Earth’s neighbourhood. Speculative engineering studies for such an ambitious mission concept appeared in scientific literature at the beginning of the space age. This early work employed a two-body dynamical framework to estimate the Δv costs entailed on hauling an entire asteroid back to Earth. The concept however has experienced a revival in recent years, stimulated by the inclusion of a plan to retrieve a small asteroid in NASA’s 2014 budget. This later batch of work is well aware of technological limitations, and thus envisages a much more level-headed space system, capable of delivering only the most minimal change of linear momentum to the asteroid. As a consequence, the design of retrieval trajectories has evolved into strategies to take full advantage of low energy transfer opportunities, which must carefully account for the simultaneous gravitational interactions of the Sun, Earth and Moon. The paper revises the published literature up to date, and provides a short literature survey on the historical evolution of the concept. This literature survey is particularly focused on the design of asteroid retrieval trajectories, and thus the paper provides a comprehensive account for; the endgame strategies used so far, the different dynamical models and the trajectory design methodologies.

Optimization of low-thrust trajectory for a mission to the asteroid 433 Eros with Earth gravity assist

Subject of this paper is the design of a space robotic mission to the asteroid 433 Eros. The mission aims to grab a boulder from its surface and transport it inside the Earth’s Hill sphere. This kind of mission was chosen to develop a method of analysis of all the opportune trajectories for a sample-return mission, using a generic Near-Earth asteroid as 433 Eros. This work was inspired by NASA’s Asteroid Redirect Mission, which was cancelled in 2017 due to lack of funding, and whose purpose was to transfer a boulder from the surface of a Near-Earth asteroid to a stable lunar orbit, where it could be further analysed both by robotic probes and by a future manned mission. The propulsion system used for the theorized mission consists of three autonomous ion thrusters fully adjustable in magnitude and direction of thrust. Furthermore, during the return flight an Earth gravity assist is used to increase the mass of boulder that the spacecraft can transport towards Earth. Selecting the same time window of the ARM, different trajectories, separately for the outbound and inbound flights, are calculated using indirect methods. Subsequently, a plausible interpretation of the different performances of the calculated trajectories is given, considering both the solar electric power available to the spacecraft and the geometric configuration of the bodies involved. At the end of this process, all the calculated trajectories for the outbound and inbound flights are compared, and possible final solutions for the mission are discussed.

NASA's Asteroid Grand Challenge: Strategy, Results, and Lessons Learned

Beginning in 2012, NASA used a strategic process to identify broad societal questions, or grand challenges, that are well suited to the aerospace sector and align with national priorities. This effort generated NASA's first grand challenge, the Asteroid Grand Challenge (AGC), a large-scale effort using multidisciplinary collaborations and innovative engagement mechanisms, that focused on finding and addressing asteroid threats to human populations. In April 2010, President Barack Obama announced a mission to send humans to an asteroid by 2025. This resulted in the agency's Asteroid Redirect Mission (ARM) to leverage and maximize existing robotic and human efforts to capture and reroute an asteroid, with the goal of eventual human exploration. The AGC, initiated in 2013, complemented ARM by expanding public participation, partnerships, and other approaches to find, understand, and overcome these potentially harmful asteroids. This article describes a selection of AGC activities implemented from 2013 to 2017 and their results, excluding those conducted by NASA's Near-Earth Object Observations Program and other organizations. The strategic development of the initiative is outlined as well as initial successes, strengths, and weaknesses resulting from the first 4 years of AGC activities and approaches. Finally, we describe lesson learned and areas for continued work and study. The AGC lessons learned and strategies could inform the work of other agencies and organizations seeking to conduct a global scientific investigation with matrixed organizational support, multiple strategic partners, and numerous internal and external open innovation approaches and audiences.

Long term evolution of distant retrograde orbits in the Earth-Moon system

This work studies the evolution of several Distant Retrograde Orbits (DROs) of varying size in the Earth-Moon system over durations up to tens of millennia. This analysis is relevant for missions requiring a completely hands off, long duration quarantine orbit, such as a Mars Sample Return mission or the Asteroid Redirect Mission. Four DROs are selected from four stable size regions and are propagated for up to 30,000 years with an integrator that uses extended precision arithmetic techniques and a high fidelity dynamical model. The evolution of the orbit’s size, shape, orientation, period, out-of-plane amplitude, and Jacobi constant are tracked. It has been found that small DROs, with minor axis amplitudes of approximately 45,000 km or less decay in size and period largely due to the Moon’s solid tides. Larger DROs (62,000 km and up) are more influenced by the gravity of bodies external to the Earth-Moon system, and remain bound to the Moon for significantly less time.

Synergies between human space exploration and science in the asteroid redirect mission and the potential Italian participation in the asteroid redirect robotic mission phase⋆

In 2010, the study proposal called Asteroid Retrieval Mission (ARM) was selected by the Keck Institute for Space Studies (KISS) at the California Institute of Technology (Caltech). ARM had, as its main goal, the ambition to give a feasible, and realistic from a budget standpoint, destination to NASA Human Space Exploration (HSE) after the International Space Station (ISS), fulfilling President Obama’s goal to have astronaut reach and interact with an asteroid (NEO) by 2025. ARM was formulated exploiting synergies between HSE and science, and with benefits also for technology development and in-space validation. In 2013, ARM, renamed Asteroid Redirect Mission, became a NASA program with the support of the White House. The Italian Space Agency (ASI) expressed interest to participate in the robotic phase of ARM, called Asteroid Redirect Robotic Mission (ARRM). This presentation, given at the XIII National (Italian) Congress of Planetary Sciences, had the goal to introduce ARM to the Italian scientific community to gather proposals for the possible Italian participation in NASA ARRM, such as ASI payloads that could be possibly hosted on NASA ARRM.

Integrating Public Deliberation into Engineering Systems: Participatory Technology Assessment of NASA’s Asteroid Redirect Mission

ABSTRACTWe discuss an experiment employing participatory technology assessment (pTA), a public deliberation method for eliciting lay citizen input prior to making decisions about science and technology to inform upstream engineering decisions concerning technical aspects of NASA’s Asteroid Initiative. In partnership with NASA, the Expert and Citizen Assessment of Science and Technology network conducted a pTA forum on NASA’s Asteroid Initiative in 2014. The goal of the exercise was to assess citizens’ values and preferences about potential asteroid detection, asteroid mitigation, and exploration-based technologies associated with NASA’s Initiative. This article discusses the portion of the forum that focused on the Asteroid Redirect Mission, an effort to redirect an asteroid into lunar orbit that astronauts can study. The forum sought public input on two options for performing the mission that NASA included in technical assessments to make a down select decision: Option A to capture a 10-meter-diameter asteroid; or Option B to redirect a several-meters-diameter boulder from the surface of a larger asteroid. We describe the values and perceptions participants had about Option A and B, how these results were used by NASA managers, and the impact the results of the pTA had on the down select.

Rotational and translational considerations in kinetic impact deflection of potentially hazardous asteroids

Kinetic impact may be the most reliable and easily implemented method to deflect hazardous asteroids using current technology. Depending on warning time, it can be effective on asteroids with diameters of a few hundred meters. Current impact deflection research often focuses on the orbital dynamics of asteroids. In this paper, we use the ejection outcome of a general oblique impact to calculate how an asteroid’s rotational and translational state changes after impact. The results demonstrate how small impactors affect the dynamical state of small asteroids having a diameter of about 100m. According to these consequences, we propose using several small impactors to hit an asteroid continuously and gently, making the deflection mission relatively flexible. After calculating the rotational variation, we find that the rotational state, especially of slender non-porous asteroids, can be changed significantly. This gives the possibility of using multiple small impactors to mitigate a potentially hazardous asteroid by spinning it up into pieces, or to despin one for future in-situ investigation (e.g., asteroid retrieval or mining).

An investigation of the low-ΔV near-Earth asteroids (341843) 2008 EV5 and (52381) 1993 HA

Context. The Asteroid Redirect Mission (ARM) under development by NASA is being planned to collect a multi-meter boulder from a near-Earth asteroid (NEA), and to bring it to the cis-lunar space in the mid-2020’s for future study and exploitation by a crewed mission. The MarcoPolo-M5 project is being proposed in 2016 for the M5 mission opportunity by ESA, to bring back to Earth a sample from a very primitive D-type NEA. As D-types are very rare within the NEA population, considerable effort is still in progress to characterize easily accessible targets with unknown surface composition, in order to discover further asteroids that belong to this taxonomic group. Aims. We aim to further characterize the physical properties of two optimal targets for sample return space missions, the low-ΔV NEAs (341843) 2008 EV5 and (52381) 1993 HA. The asteroid 2008 EV5 is the baseline target of ARM, but only one spectrum of this object exists in the literature. The asteroid 1993 HA is a very favourable target for a space mission based on its dynamical properties: here we intend to assess if it is a suitable target for MarcoPolo-M5. Methods. We obtained visible spectroscopy of 2008 EV5 with the FORS2 instrument at ESO-VLT (Paranal, Chile), at different rotational phases. We also obtained visible and near-infrared spectroscopy of 1993 HA, using the EFOSC2 and SOfI instruments at ESO-NTT (La Silla, Chile). Visible photometry of 1993 HA was carried out within the IMPACTON project at the Observatório Astronômico do Sertão de Itaparica (Itacuruba, Brazil). Results. Our new observations are in agreement with the C-type classification of 2008 EV5, which is a requirement for the ARM mission. We obtained five visible spectra which do not show any variability within the limits of noise, suggesting a homogeneous surface. We obtained the first ever spectroscopic dataset (~0.4–1.6 μm) for 1993 HA, finding a featureless, red-sloped behaviour typical of D-types (a T or X classification is also possible, with decreasing confidence). We also found that the synodic rotation period of 1993 HA is 4.107 ± 0.002 h, a value that is optimal for the execution of a sample return mission. The derived lightcurve also suggests an elongated shape (axis ratio a/b ≥ 1.71). At this stage 1993 HA does indeed seem to be the most favourable target for MarcoPolo-M5, though future observations are necessary to study it further.

The size-frequency distribution of H > 13 NEOs and ARM target candidates detected by Pan-STARRS1

We determine the absolute magnitude (H) distribution (or size-frequency distribution, SFD; N(H)∝10αH where α is the slope of the distribution) for near-Earth objects (NEO) with 13 < H < 30 and Asteroid Retrieval Mission (ARM) targets with 27 < H < 31 that were detected by the 1st telescope of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1; e.g. Kaiser et al., 2002; Kaiser, 2004; Hodapp et al., 2004). The NEO and ARM target detection efficiencies were calculated using the Greenstreet et al. (2012) NEO orbit distribution. The debiased Pan-STARRS1 NEO absolute magnitude distribution is more complex than a single slope power law - it shows two transitions - at H ∼ 16 from steep to shallow slope, and in the 21 < H < 23 interval from a shallow to steep slope, which is consistent with other recent works (e.g. Mainzer et al., 2011c; Brown et al., 2013; Harris and D’Abramo, 2015). We fit α=0.48±0.02 for NEOs with 13 < H < 16, α=0.33±0.01 for NEOs with 16 < H < 22, and α=0.62±0.03 for the smaller objects with H > 22. There is also another change in slope from steep to shallow around H = 27. The three ARM target candidates detected by Pan-STARRS1 in one year of surveying have a corrected SFD with slope α=0.40−0.45+0.33.We also show that the window for follow up observations of small (H≳ 22) NEOs with the NASA IRTF telescope and Arecibo and Goldstone radars are extremely short - on order of days, and procedures for fast response must be implemented in order to measure physical characteristics of small Earth-approaching objects. CFHT’s MegaCam and Pan-STARRS1 have longer observing windows and are capable of following-up more NEOs due to their deeper limiting magnitudes and wider fields of view.

The gas-surface interaction of a human-occupied spacecraft with a near-Earth object

NASA’s asteroid redirect mission (ARM) will feature an encounter of the human-occupied Orion spacecraft with a portion of a near-Earth asteroid (NEA) previously placed in orbit about the Moon by a capture spacecraft. Applying a shuttle analog, we suggest that the Orion spacecraft should have a dominant local water exosphere, and that molecules from this exosphere can adsorb onto the NEA. The amount of adsorbed water is a function of the defect content of the NEA surface, with retention of shuttle-like water levels on the asteroid at 1015 H2O’s/m2 for space weathered regolith at T∼300K.

Resistance forces during boulder extraction from an asteroid

Planning for NASA's Asteroid Redirect Mission (ARM) requires estimating the forces that appear during extraction of a boulder from the surface of an asteroid with unknown surface regolith properties. These forces are estimated for a vertical constant force or acceleration pull and a rolling, constant force, torque (peel) on a 4-m diameter spherical boulder using both analytic and discrete element method (DEM) models considering the effects of microgravity and regolith cohesion using Johnson–Kendall–Roberts (JKR) model. Estimates of the bulk asteroid regolith cohesion strength derived from lunar and asteroid regolith studies ranged from 25Pa to 250Pa. JKR cohesive forces at particle contacts depend on particle surface energy and effective curvature radius (particle size). DEM particle size dependent cohesion parameters are linked to estimated regolith cohesion strength by simulating shear and tension tests over a range of DEM particle surface energies resulting in the formulation of the dependence of particle surface energy as a function of cohesion strength and particle size. Maximum extraction forces occur for a vertical pull through the boulder center of mass with constant acceleration. Extraction force decreases for a constant force pull to 0.62pcS where S is the boulder surface area embedded in the regolith and pc is the cohesion strength of the regolith. Boulder extraction by peeling produces the smallest forces by up to more than a factor of 2, as the failure across the boulder surface increases progressively rather than being fully engaged as occurs during a vertical pull extraction. Variations between DEM and analytic results differed from 9% to 17% over the range of regolith cohesion values and peel extraction leverage.

Asteroid retrieval missions enabled by invariant manifold dynamics

Near Earth Asteroids are attractive targets for new space missions; firstly, because of their scientific importance, but also because of their impact threat and prospective resources. The asteroid retrieval mission concept has thus arisen as a synergistic approach to tackle these three facets of interest in one single mission. This paper reviews the methodology used by the authors (2013) in a previous search for objects that could be transported from accessible heliocentric orbits into the Earth's neighbourhood at affordable costs (or Easily Retrievable Objects, a.k.a. EROs). This methodology consisted of a heuristic pruning and an impulsive manoeuvre trajectory optimisation. Low thrust propulsion on the other hand clearly enables the transportation of much larger objects due to its higher specific impulse. Hence, in this paper, low thrust retrieval transfers are sought using impulsive trajectories as first guesses to solve the optimal control problem. GPOPS-II is used to transcribe the continuous-time optimal control problem to a nonlinear programming problem (NLP). The latter is solved by IPOPT, an open source software package for large-scale NLPs. Finally, a natural continuation procedure that increases the asteroid mass allows to find out the largest objects that could be retrieved from a given asteroid orbit. If this retrievable mass is larger than the actual mass of the asteroid, the asteroid retrieval mission for this particular object is said to be feasible. The paper concludes with an updated list of 17 EROs, as of April 2016, with their maximum retrievable masses by means of low thrust propulsion. This ranges from 2000tons for the easiest object to be retrieved to 300tons for the least accessible of them.

Directed energy missions for planetary defense

Directed energy for planetary defense is now a viable option and is superior in many ways to other proposed technologies, being able to defend the Earth against all known threats. This paper presents basic ideas behind a directed energy planetary defense system that utilizes laser ablation of an asteroid to impart a deflecting force on the target. A conceptual philosophy called DE-STAR, which stands for Directed Energy System for Targeting of Asteroids and exploration, is an orbiting stand-off system, which has been described in other papers. This paper describes a smaller, stand-on system known as DE-STARLITE as a reduced-scale version of DE-STAR. Both share the same basic heritage of a directed energy array that heats the surface of the target to the point of high surface vapor pressure that causes significant mass ejection thus forming an ejection plume of material from the target that acts as a rocket to deflect the object. This is generally classified as laser ablation. DE-STARLITE uses conventional propellant for launch to LEO and then ion engines to propel the spacecraft from LEO to the near-Earth asteroid (NEA). During laser ablation, the asteroid itself provides the propellant source material; thus a very modest spacecraft can deflect an asteroid much larger than would be possible with a system of similar mission mass using ion beam deflection (IBD) or a gravity tractor. DE-STARLITE is capable of deflecting an Apophis-class (325m diameter) asteroid with a 1- to 15-year targeting time (laser on time) depending on the system design. The mission fits within the rough mission parameters of the Asteroid Redirect Mission (ARM) program in terms of mass and size. DE-STARLITE also has much greater capability for planetary defense than current proposals and is readily scalable to match the threat. It can deflect all known threats with sufficient warning.

Nonlinear Attitude Control of Spacecraft with a Large Captured Object

This paper presents an attitude control strategy and a new nonlinear tracking controller for a spacecraft carrying a large object, such as an asteroid or a boulder. If the captured object is larger or comparable in size to the spacecraft and has significant modeling uncertainties, conventional nonlinear control laws that use exact feedforward cancellation are not suitable because they exhibit a large resultant disturbance torque. The proposed nonlinear tracking control law guarantees global exponential convergence of tracking errors with finite-gain stability in the presence of modeling uncertainties and disturbances, and it reduces the resultant disturbance torque. Furthermore, this control law permits the use of any attitude representation, and its integral control formulation eliminates any constant disturbance. Under small uncertainties, the best strategy for stabilizing the combined system is to track a fuel-optimal reference trajectory using this nonlinear control law because it consumes the least amount of fuel. In the presence of large uncertainties, the most effective strategy is to track the derivative plus proportional–derivative-based reference trajectory because it reduces the resultant disturbance torque. The effectiveness of the proposed attitude control methods is demonstrated by using results of numerical simulation based on an Asteroid Redirect Mission concept.

The LCOGT NEO Follow-up Network

AbstractLas Cumbres Observatory Global Telescope Network (LCOGT) has deployed a homogeneous telescope network of nine 1-meter telescopes to four locations in the northern and southern hemispheres, with a planned network size of twelve 1-meter telescopes at 6 locations. This network is very versatile and is designed to respond rapidly to target of opportunity events and also to perform long term monitoring of slowly changing astronomical phenomena. The global coverage of the network and the apertures of telescope available make LCOGT ideal for follow-up and characterization of Solar System objects (e.g. asteroids, Kuiper Belt Objects, comets, Near-Earth Objects (NEOs)) and additionally for the discovery of new objects.We are using the LCOGT network to confirm newly detected NEO candidates produced by the major sky surveys such as Catalina Sky Survey (CSS) and PanSTARRS (PS1&amp;2) and several hundred targets are now being followed per year. An increasing amount of time is being spent to obtain follow-up astrometry and photometry for radar-targeted objects and those on the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) or Asteroid Retrieval Mission (ARM) lists in order to improve the orbits, determine the light curves and rotation periods and improve the characterization. This will be extended to obtain more light curves of other NEOs which could be targets. Recent results have included the first period determinations for several of the Goldstone-targeted NEOs. We are in the process of building a NEO follow-up portal which will allow professionals, amateurs and Citizen Scientists to plan, schedule and analyze NEO imaging and spectroscopy observations and data using the LCOGT Network and to act as a co-ordination hub for the NEO follow-up efforts.