New Horizons Attitude Control System
New Horizons is equipped with a multilayered thermal insulation system to retain heat produced by its operating electronics, keeping its shape and remaining precisely aligned for gathering data through instruments, communicating with Earth or maneuvering through space.
Small hydrazine thrusters reorient the spacecraft 100 times every second, while star trackers and an inertial measurement unit provide constant position data. All data is recorded onto two low-power solid state recorders (one primary, one backup). Once data have been transmitted back to Earth they are stored on low-power solid-state recorders that store and transmit it.
Attitude Determination
New Horizons features seven scientific instruments designed to detect various surface and atmospheric phenomena, each having their own independent computer that manages data flow.
Star trackers and an inertial measurement unit (IMU) supply constant positional information to the Guidance and Control processor on board the spacecraft; both use 12MHz Mongoose V processors. Each star tracker stores a map of 3,000 stars; approximately every 10 seconds one snaps wide-angle photos of the sky to compare with the onboard map to determine orientation; IMUs provide 100Hz motion information feedback if it indicates that its placement needs adjusting; should this happen, small hydrazine thrusters will activate to reorientation efforts.
Thrusters are used for attitude determination and trajectory course maneuvers. The spacecraft spins at 5rpm during Jupiter flybys, Pluto approaches and flybys as well as various science observations and systems checks.
Trajectory Correction Maneuvers
New Horizons will perform five propellant maneuvers from December 16 through December 31 to move itself into an orbit 100 kilometers from the lunar surface and will remain there for an entire year.
As part of their cruise mission, operators will conduct various trajectory correction maneuvers to fine-tune and reduce total energy (delta V). This process uses thrusters onboard the spacecraft to alter velocity or direction.
New Horizons mission objectives focus on Pluto and its moons, but also involve studying other Kuiper Belt objects. Scientists will gain a better understanding of planetesimal accretion processes that led to solar system bodies such as Pluto and Charon being formed as well as their geology, atmospheres and other features such as their chemical composition. New Horizons can also conduct studies of Jupiter that weren’t possible with Cassini flyby such as meteorology studies, magnetosphere mapping, dust mapping and characterizing volcanic moon Io.
Attitude Control
Step two of attitude control involves actively shifting orientation with thrusters. This process is relatively complex, as it requires that the spacecraft remain stable with respect to its orientation without significantly shifting; sensors must also detect any shifts or variations in position. Furthermore, damping systems such as hysteretic materials or viscous fluid must also be present so as to convert oscillations to heat energy and damp out oscillations effectively.
New Horizons was launched on January 6, 2006 and passed Jupiter for a gravity boost in February 2007, before making its way through the Kuiper Belt and studying its ancient remains of planet-building. New Horizons will eventually encounter mysterious object Arrokoth located a billion miles beyond Pluto for a first ever close encounter of any Kuiper Belt object – this unique encounter was photographed recently from New Horizons’ unique perch in outer solar system by New Horizons team recently!
Radio Communications
New Horizons features 16 thrusters – four 4.4 N (1.0 lbf), and twelve 0.9 N (0.2 lbf), deployed into redundant branches to assist trajectory correction maneuvers. Fine attitude control is accomplished using its onboard gyroscopes and accelerometers; additionally information from dual redundant star cameras and two Adcole Sun sensors is also gathered during mission operations.
The spacecraft is shielded from micrometeoroids by an advanced multilayer insulation system composed of 18 layers of Dacron sandwiched between Mylar plastic film and Kapton polyimide films, to protect itself against micrometeorites. Furthermore, this insulating layer helps shield its RTG reactor against excess heat produced during nuclear reactions. To ensure a uniform distribution of mass, the spacecraft underwent rigorous weighing and spin tests prior to launch. The spacecraft was launched on a solar escape trajectory, traveling past Jupiter and Pluto in 2015 to provide insight into the formation of Dwarf Planets and Kuiper Belt objects. All commands are time-tagged using Universal Time (UT), while its onboard UT to MET clock register has an onboard correlation better than +/-4 seconds for accurate timing down to submillisecond levels for science instrument timing accuracy.