The Kuiper Belt is a broad, torus-shaped region in the outer Solar System beyond Neptune’s orbit. It contains primordial planetary building blocks and dwarf planets. NASA’s New Horizons spacecraft ...conducted a flyby of Pluto and its system of moons on 14 July 2015. New Horizons then continued farther into the Kuiper Belt, adjusting its trajectory to fly close to the small Kuiper Belt object (486958) 2014 MU69 (henceforth MU69; also informally known as Ultima Thule). Stellar occultation observations in 2017 showed that MU69 was ~25 to 35 km in diameter, and therefore smaller than the diameter of Pluto (2375 km) by a factor of ~100 and less massive than Pluto by a factor of ~106. MU69 is located about 1.6 billion kilometers farther from the Sun than Pluto was at the time of the New Horizons flyby. MU69’s orbit indicates that it is a “cold classical” Kuiper Belt object, thought to be the least dynamically evolved population in the Solar System. A major goal of flying past this target is to investigate accretion processes in the outer Solar System and how those processes led to the formation of the planets. Because no small Kuiper Belt object had previously been explored by spacecraft, we also sought to provide a close-up look at such a body’s geology and composition, and to search for satellites, rings, and evidence of present or past atmosphere. We report initial scientific results and interpretations from that flyby.
The New Horizons spacecraft carried three instruments that measured the space environment near Pluto as it flew by on 14 July 2015. The Solar Wind Around Pluto (SWAP) instrument revealed an ...interaction region confined sunward of Pluto to within about 6 Pluto radii. The region's surprisingly small size is consistent with a reduced atmospheric escape rate, as well as a particularly high solar wind flux. Observations from the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument suggest that ions are accelerated and/or deflected around Pluto. In the wake of the interaction region, PEPSSI observed suprathermal particle fluxes equal to about 1/10 of the flux in the interplanetary medium and increasing with distance downstream. The Venetia Burney Student Dust Counter, which measures grains with radii larger than 1.4 micrometers, detected one candidate impact in ±5 days around New Horizons' closest approach, indicating an upper limit of <4.6 kilometers(-3) for the dust density in the Pluto system.
The Kuiper Belt is a distant region of the outer Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU
, a cold classical Kuiper Belt object approximately 30 ...kilometers in diameter. Such objects have never been substantially heated by the Sun and are therefore well preserved since their formation. We describe initial results from these encounter observations. MU
is a bilobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color or compositional heterogeneity. No evidence for satellites, rings or other dust structures, a gas coma, or solar wind interactions was detected. MU
's origin appears consistent with pebble cloud collapse followed by a low-velocity merger of its two lobes.
Pluto is the only planet in our solar system that has not yet been visited by a spacecraft from Earth. Beyond the orbit of Pluto lies the Kuiper-Belt: home to many primordial objects from the ...earliest days of the formation of the solar system, preserved in a cosmic deep freeze. The Johns Hopkins University/Applied Physics Laboratory (JHU/APL) is planning the mission for the Principal Investigator, Dr. S. Alan Stern of Southwest Research Institute. The planned design of the New Horizons spacecraft, along with a discussion of the design drivers, is presented. The design lifetime of the spacecraft would be 15.25 years. Measures taken to ensure the reliable operation of the spacecraft over the life of the planned mission are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) spacecraft was designed at APL as the first Solar Terrestrial Probe in NASA's Solar Connections Program. The spacecraft ...supports the operation of four scientific remote-sensing instruments for a minimum of 2 years from a circular orbit 625 km in altitude with an inclination of 74.1 degree . TIMED has been designed with a significant amount of onboard autonomy, as it is run with a low-cost mission operations concept. The robust spacecraft with redundant subsystems features an Integrated Electronics Module that contains RF and digital subsystems in a common card cage. The TIMED GPS Navigation System uses the GPS for onboard tracking, navigation, and "event-based" commanding, and is key to the implementation of low-cost mission operations.
A space mission consists of more than just a spacecraft and scientific instruments. It also includes a ground system to support communications, command and telemetry processing and archiving, a ...mission operations team, and a launch vehicle. Before launch, all of these elements must be tested together in an integrated fashion. The Mission System Engineer is the chief architect of this system, is responsible for all technical aspects of the entire system, and directs trade studies to determine the partitioning of functions among subsystems and elements of the entire system. The TIMED mission and system were designed around a concept of low-cost mission operations. This concept was realized through the creation of a highly autonomous spacecraft, instrument operations that are decoupled from spacecraft operations, and payload (instrument) operations centers that are geographically distributed and connected through the Internet.
The Kuiper Belt is a distant region of the Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU69, a Cold Classical Kuiper Belt Object, a class of objects that ...have never been heated by the Sun and are therefore well preserved since their formation. Here we describe initial results from these encounter observations. MU69 is a bi-lobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color and compositional heterogeneity. No evidence for satellites, ring or dust structures, gas coma, or solar wind interactions was detected. By origin MU69 appears consistent with pebble cloud collapse followed by a low velocity merger of its two lobes.
In this paper we will describe the experimental results of a novel method for simulating the proton radiation of a low earth orbit with a cyclotron using a specially designed proton beam modulator. ...We will present details on the design of the proton beam modulator wheel and the experimental results of the irradiation of actual spaceflight electronic components with the modulated beam. Electronic devices on board spacecraft are generally susceptible to penetrating radiation encountered in the space environment. Since the proton radiation spectrum of a low earth orbit covers a rather wide range from 1 to 500 MeV, a proton beam range modulator was designed that simulates a proton spectrum from 5 to 120 MeV. This proton radiation energy range simulates the most damaging part of the spectrum. The spectrum from the cyclotron was mapped by means of a sodium iodide scintillator; those measurements confirmed our initial calculations of the proton spectral density and showed that the mean energy of the protons is centered at about 40 MeV. In this paper, we will present an analysis of the simulation of the low-earth-orbit proton energy spectrum and details concerning the design of the proton beam modulator. In order to verify the operation of the modulator used for simulating low-earth-orbit radiation, power conditioners using MOSFET power switches were subjected to the proton radiation. They were allowed to accumulate a total of 30 krads (Si) of proton radiation over the specified energy range.
The Pluto system was recently explored by NASA's New Horizons spacecraft, making closest approach on 14 July 2015. Pluto's surface displays diverse landforms, terrain ages, albedos, colors, and ...composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto's atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto's diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto's large moon Charon displays tectonics and evidence for a heterogeneous crustal composition, its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected.
On July 14, 2015, the New Horizons mission accomplished the first flyby of Pluto–Charon, achieving full mission success during its primary mission. Less than 4 years later, during its first extended ...mission, New Horizons flew by Arrokoth, a 36-km contact binary trans-Neptunian object in the Kuiper Belt, on January 1, 2019. Along the way, New Horizons imaged numerous distant Kuiper Belt objects, performed important heliophysics science including complex Lyman-α radiation scans, and measured the dust and zodiacal light from regions never before explored. This article provides an overview of the New Horizons spacecraft and its engineering performance, as well as potential strategies for extending the mission far beyond its original design lifetime. Details on the mass and power budgets, as well as descriptions of key innovations to meet the challenges posed by the mission, offer insight into the engineering accomplishments that led to mission success. Trended data on the power, thermal, and propulsion systems substantiate projections of the mission's potential to continue its exploration beyond the heliopause until ~2050.
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