Long Range Reconnaissance Imager (LORRI) is a telescope aboard the ''

New Horizons ''New Horizons'' is an Interplanetary spaceflight, interplanetary space probe launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institut ...

'' spacecraft for imaging. LORRI has been used to image Jupiter, its moons,

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...

and its

moons A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are colloquially referred to as moons, a deriva ...

, and Arrokoth since its launch in 2006. LORRI is a

reflecting telescope A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternati ...

of Ritchey-Chrétien design, and it has a main mirror diameter of 208 mm (8.2 inches) across. LORRI has a narrow field of view, less than a third of a degree. Images are taken with a

CCD CCD may refer to: Science and technology * Charge-coupled device, an electronic light sensor used in various devices including digital cameras * .ccd, the filename extension for CloneCD's CD image file * Carbonate compensation depth, a property ...

capturing data with 1024 × 1024

pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, p ...

s. LORRI is a telescopic panchromatic camera integrated with the ''New Horizons'' spacecraft, and it is one of seven major science instruments on the probe. LORRI does not have any moving parts and is pointed by moving the entire ''New Horizons'' spacecraft.

Operations

LORRI was used to calculate

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

s for Pluto and Charon. LORRI is also used for navigation, especially to more precisely determine the location of a flyby target. In 2018, ''New Horizons'' spacecraft used navigation data from LORRI for its planned flyby of Arrokoth in a couple months. During the cruise to Jupiter, LORRI data was also used to determine a value for the cosmic optical background as an alternative to other methods. At Jupiter, LORRI was used for an extensive observation campaign of Jupiter's atmosphere, rings, and moons. On August 29, 2006, the cover on LORRI was opened and it took an image in space of

Messier 7 Messier 7 or M7, also designated NGC 6475 and sometimes known as the Ptolemy Cluster, is an open cluster of stars in the constellation of Scorpius. The cluster is easily detectable with the naked eye, close to the "stinger" of Scorpius. With a d ...

(aka Ptolemy’s Cluster) for its first light image. The following year, in 2007 when it flew by Jupiter for its gravity assist, it was used to image Jupiter and its moons. LORRI also imaged the Jovian system in 2010 as part of an annual checkout confirming the operation of LORRI, taking pictures from a distance of about 16 AU. In 2015, LORRI was used to image Pluto before and during the flyby. In December 2017, LORRI took an image at a greater distance from Earth than ''

Pale Blue Dot ''Pale Blue Dot'' is a photograph of Earth taken on February 14, 1990, by the ''Voyager 1'' space probe from an unprecedented distance of over kilometers ( miles, 40.5 AU), as part of that day's ''Family Portrait'' series of images of th ...

'' by ''

Voyager 1 ''Voyager 1'' is a space probe launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and the interstellar medium, interstellar space beyond the Sun's heliosphere. It was launched 16 days afte ...

'', in this case of the Wishing Well Cluster. This cluster was also the first light image for the

Wide Field and Planetary Camera The Wide Field/Planetary Camera (WFPC) (pronounced as wiffpick (Operators of the WFPC1 were known as "whiff-pickers")) was a camera installed on the Hubble Space Telescope launched in April 1990 and operated until December 1993. It was one of ...

of the

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

, taken in May 1990.First Image Taken by Hubble's Wide Field Planetary Camera
Hubblesite.org Wishing Well cluster New Horizons

In August 2018, LORRI was able to detect Arrokoth at distance of around . A large stack of images of Arrokoth from August to December 2018 was used to confirm a closer flyby, rather than more distant by ruling out moons and rings systems to a certain level of detection. On the night of December 24, 2018 LORRI was used to take images of Arrokoth at a distance of . Three images were taken each with a half second long exposure, at a 1024x1024 pixel resolution.

Specifications

LORRI is a reflective telescope integrated with the ''New Horizons'' spacecraft. It can take

greyscale image In digital photography, computer-generated imagery, and colorimetry, a greyscale (more common in Commonwealth English) or grayscale (more common in American English) image is one in which the value of each pixel is a single sample (signal), s ...

s of astronomical targets. Specifications: *Telescope style: Ritchey-Chrétien *Aperture: 208 mm (8.2 inches) **f/12.6 **Effective

focal length The focal length of an Optics, optical system is a measure of how strongly the system converges or diverges light; it is the Multiplicative inverse, inverse of the system's optical power. A positive focal length indicates that a system Converge ...

2630 mm (103.5 inches) **Mirror substance:

Silicon Carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder a ...

*Mass: 8.8 kilograms (19.4 pounds) *Average electrical power use: 5.8

watt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work ...

s *Field of View: 0.29 degrees *Resolution: 4.95 μrad pixels *Bandpass: from about 350 nm to 850 nm *

Operating temperature An operating temperature is the allowable temperature range of the local ambient environment at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the de ...

: 148K to 313K *Sensor: E2V Technologies CCD47-20 and Analog Devices AD9807 ADC ** Frame-Transfer Back-Illuminated CCD ** Size: 13.3×13.3 mm ** Pixel size: 13×13 μm native size with 4×4 pixel on-chip binning possible ** 1024×1024 active pixels ** 12 bits ADC The mirror is made of

silicon carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder a ...

which helped support meeting the thermal requirements of the design. The instrument is a thinned backside-illuminated charge-coupled device, and captures images at a resolution of 1024 by 1024 pixels, with a variety of exposure settings. LORRI can take one picture per second and store the picture digitally as a 12-bit image, with either lossless or

lossy compression In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...

. (See also

Data compression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compressi ...

) LORRI incorporates a field-flattening lens with three elements. The design can take images at very low light levels required for the mission, including light levels 1/900 those of Earth when it is at Pluto. For the Arrokoth encounter the longest exposure time (up to ten seconds for the Pluto flyby) was increased. This was accomplished after the Pluto flyby by the team, to support taking images in even lower light levels. After the Pluto flyby, exposure times of at least 30 seconds were made possible, which was also useful for taking reconnaissance images and enabling imaging down to a magnitude of 21. LORRI is pointed by moving the entire spacecraft, which limits the exposure time. The spacecraft does not have reaction wheels and is stabilized by thrusters.

Jovian system

While passing by Jupiter in February 2007, the Jovian system was observed using LORRI and other instruments. LORRI views of the

Galilean moons The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter. They are, in descending-size order, Ganymede (moon), Ganymede, Callisto (moon), Callisto, Io (moon), Io, and Europa (moon), Europa. They are the most apparent m ...

Pluto

Due to its telescope power, LORRI was able to capture images of Pluto and its moons, offering the closer views as the spacecraft flew by the dwarf planet. File:15-143-PlutoSystem-NewHorizons-20150626.jpg, Long range view with Pluto and moons circled. (stars processed out) File:NH-LORRI-Pluto-Charon-2015-01-25.jpg, Observation of Pluto and Charon from January 2015 File:Pluto-System-June-29.png, LORRI image of Pluto and Charon in June 2015 File:NH-Pluto-20150711.jpg, Days before closest approach, LORRI views the other side of Pluto File:NH-Pluto-TombaughRegio-MountainRange-20150714-IFV.jpg, Mountain range on Pluto near

Tombaugh Regio Tombaugh Regio (), sometimes nicknamed "Pluto's heart" after its shape, is the largest bright surface feature of the dwarf planet Pluto. It lies just north of Pluto's equator, to the northeast of Belton Regio and to the northwest of Safronov ...

File:Pond on Pluto.jpg, What is thought to be a frozen pond on Pluto, about 20 miles (30 kilometers) across File:Pluto via New Horizons (composite).jpeg, Several images from LORRI composited together

Charon

15810 Arawn

In 2016 ''New Horizons'' observed the Kuiper belt object,

15810 Arawn 15810 Arawn ( provisional designation ) is a trans-Neptunian object (TNO) from the inner regions of the Kuiper belt, approximately in diameter. It belongs to the plutinos, the most populous class of resonant TNOs. It was named after Arawn, th ...

. It is the object that is pointed with an arrow. KBO 1994 JR1 by New Horizons in April 2016

486958 Arrokoth

Long-distance views

File:PIA21588 - A KBO among the Stars.jpg, LORRI image of

486958 Arrokoth 486958 Arrokoth (Provisional designation in astronomy, provisional designation ; formerly nicknamed Ultima Thule) is a trans-Neptunian object located in the Kuiper belt. Arrokoth became the farthest and most primitive List of minor planet ...

from July 2017 File:Ultima Thule approach video1.gif, Arrokoth among the stars of

Sagittarius Sagittarius ( ) may refer to: *Sagittarius (constellation) *Sagittarius (astrology), a sign of the Zodiac * Sagittarius of Gap, a 6th century bishop *Sagittarius A*, the supermassive black hole at the center of the Milky Way galaxy Ships *'' S ...

, imaged by ''New Horizons'' in late 2018. Its

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

from the spacecraft decreased from 20 to 15. File:Newhorizonschristmasthule.png, Arrokoth viewed on December 24, 2018 by LORRI

Approach views

File:UltimaThule TwoCloseups.gif, Wiggle animation of Arrokoth File:2014MU69 animation.gif, With arrows File:Detecting Ultima Thule's Size and Shape on Approach (cropped).png, Arrokoth as seen by LORRI during its approach, and released on January 1, 2019. File:NH-UltimaThule-20190102.png, Arrokoth as seen by LORRI on January 1, 2019, at distance of 18,000 miles (28,000 kilometers).

Closest views of Pluto flyby

Since LORRI had the highest magnification of the instruments, it captured the closest views of Pluto's terrain during the flyby. Its smaller field of view was panned across Pluto, capturing a stripe of the dwarf planet's terrain. Pluto - Sputnik Planum LORRI noodle top

References

External links

*
NASA LORRI gallery
* ttp://pluto.jhuapl.edu/soc/UltimaThule-Encounter/ LORRI images
NASA page showing Arrokoth picture comparing MVIC (lower resolution but color) and LORRI (greyscale but sharper), and a third image product combining the data
(January 2, 2019) {{Satellite and spacecraft instruments New Horizons Space imagers