Integrated Science Investigation of the Sun or IS☉IS, is an instrument aboard the ''
Parker Solar Probe
The Parker Solar Probe (PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+) is a NASA space probe launched in 2018 with the mission of making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii ...
'', a space probe designed to study the Sun. IS☉IS is focused on measuring energetic particles from the Sun, including
electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary partic ...
s,
protons, and
ion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...
s.
The parent spacecraft was launched in early August 2018, and with multiple flybys of Venus will study the
heliosphere
The heliosphere is the magnetosphere, astrosphere and outermost atmospheric layer of the Sun. It takes the shape of a vast, bubble-like region of space. In plasma physics terms, it is the cavity formed by the Sun in the surrounding interst ...
of the Sun from less than 4 million kilometers or less than 9 solar radii.
IS☉IS consists of two detectors, EPI-Lo and EPI-Hi, corresponding to detection of relatively lower and higher energy particles.
EPI-Lo is designed to detect from about 20 k
eV per nucleon up to 15 MeV (
mega
Mega or MEGA may refer to:
Science
* mega-, a metric prefix denoting 106
* Mega (number), a certain very large integer in Steinhaus–Moser notation
* "mega-" a prefix meaning "large" that is used in taxonomy
* Gravity assist, for ''Moon-Eart ...
electronvolt
In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the measure of an amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacu ...
s) total energy, and for electrons from about 25 keV up to 1000 keV.
EPI-Hi is designed to measure charged particles from about 1– to 200 MeV per
nucleon
In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number (nucleon number).
Until the 1960s, nucleons w ...
and electrons from about 0.5 to 6 MeV, according to a paper about the device.
The shortname includes a symbol for the Sun, a circle with a dot in it: ☉.
NASA suggests pronouncing the name as "ee-sis" in English.
Operations

By September 2018, IS☉IS had been turned on and
first light data was returned.
EPI-Hi
EPI-Hi includes:
*High Energy Telescope (1)
**HET has 16 detectors stacked
*Low Energy Telescopes (2)
**LET1 is double ended with 9 stacked detectors
**LET2 is single ended with 7 stacked detectors
The detectors are
solid-state devices.
EPI-Lo
EPI-Lo includes 8 wedge detectors, fed by 80 separate entrances.
These entrances correspond to covering a field of view over almost a full hemisphere.
EPI-Lo can record differential energy spectra for
electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary partic ...
s,
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
,
Helium-3
Helium-3 (3He see also helion) is a light, stable isotope of helium with two protons and one neutron (the most common isotope, helium-4, having two protons and two neutrons in contrast). Other than protium (ordinary hydrogen), helium-3 is th ...
,
Helium-4
Helium-4 () is a stable isotope of the element helium. It is by far the more abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on Earth. Its nucleus is identical to an alpha particle, and consis ...
,
Carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes ...
,
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
,
Neon
Neon is a chemical element with the symbol Ne and atomic number 10. It is a noble gas. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air. It was discovered (along with krypt ...
,
Magnesium
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...
,
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ...
, and
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...
.
See also
*
JEDI
Jedi (), Jedi Knights, or collectively the Jedi Order are the main heroic protagonists of many works of the '' Star Wars'' franchise. Working symbiotically alongside the Old Galactic Republic, and later supporting the Rebel Alliance, the Jedi ...
(instrument on ''Juno'' Jupiter orbiter that detects energetic particles at Jupiter)
References
{{Psp
Parker Solar Probe
Spacecraft instruments