{"id":14431,"date":"2017-08-09T20:23:03","date_gmt":"2017-08-09T12:23:03","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/station-bound-instrument-to-open-new-chapter-in-the-story-of-cosmic-rays\/"},"modified":"2017-08-09T20:23:03","modified_gmt":"2017-08-09T12:23:03","slug":"station-bound-instrument-to-open-new-chapter-in-the-story-of-cosmic-rays","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/station-bound-instrument-to-open-new-chapter-in-the-story-of-cosmic-rays\/","title":{"rendered":"Station-bound instrument to open new chapter in the story of cosmic rays"},"content":{"rendered":"
\"\"
This mosaic image of Crab Nebula, a six-light-year-wide expanding remnant of a star\u2019s supernova explosion, was taken by the Hubble Space Telescope. Recent research shows that galactic cosmic rays flowing into our solar system originate in clusters like these. Credit: NASA\/ESA\/Arizona State University<\/figcaption><\/figure>\n

Physicists are gearing up to send a re-engineered science instrument originally designed for lofty balloon flights high in Earth\u2019s atmosphere to the International Space Station next week to broaden their knowledge of cosmic rays, subatomic particles traveling on intergalactic routes that could hold the key to unlocking mysteries about supernovas, black holes, pulsars and dark matter.<\/p>\n

Fastened in the cargo bay of a SpaceX Dragon capsule, the cosmic ray observatory will be robotically connected to a port outside the space station\u2019s Japanese Kibo laboratory for a three-year science campaign sampling cosmic rays, particles accelerated to nearly the speed of light by violent and mysterious forces in the distant universe.<\/p>\n

First discovered more than a century ago, most cosmic rays are blocked by the atmosphere from reaching Earth\u2019s surface, requiring scientists to send up detectors on high-altitude balloon flights or space missions.<\/p>\n

Their name is a misnomer. Cosmic rays are not a form of light like gamma-rays or X-rays, but bits of matter sent careening through space by powerful forces elsewhere in our galaxy and beyond.<\/p>\n

\u201cCosmic rays are direct samples of matter from outside our solar system, possibly from the most distant reaches of the universe,\u201d said Eun-Suk Seo, lead scientist on the Cosmic Ray Energetics and Mass, or CREAM, instrument and a professor of physics at the University of Maryland.<\/p>\n

Scientists have flown variants of the CREAM instrument seven times on balloon research missions, logging more than six months of flight time. Engineers modified the existing science payload for the rigors of spaceflight, finishing the instrument for as little as $10 million to $20 million, Seo said, a fraction of the cost of a standalone space mission or an instrument developed from scratch.<\/p>\n

Changes to the balloon-borne instrument, managed at NASA\u2019s Wallops Flight Facility in Virginia, included making the on-board electronics more robust against radiation, and ensuring the package could survive the shaking of a rocket launch.<\/p>\n

\"\"
Eun-Suk Seo, University of Maryland professor of physics, stands in an on-campus control room. Credit: Faye Levine\/University of Maryland<\/figcaption><\/figure>\n

Dozens of stacked layers of silicon pixels, carbon targets, tungsten planes and scintillating fibers will detect particles, ranging from subatomic units of relatively light hydrogen to heavy iron, coming from deep space and determine their mass, charge and trajectory.<\/p>\n

Each cosmic ray comes with its own backstory, and the particles will reveal clues about their origins as they collide with the matter inside CREAM\u2019s detector. Scientists will trace the shower of secondary particles generated by each cosmic ray\u2019s crash into the instrument\u2019s cross section of pixels and targets.<\/p>\n

The most energetic cosmic rays can penetrate all the way to Earth\u2019s surface, but detectors on the ground only pick up the leftovers generated from collisions with oxygen and nitrogen atoms in the atmosphere, producing \u201cair showers\u201d of secondary particles the rain down on the planet.<\/p>\n

\u201cThe original cosmic rays, for you to detect them, you have to fly an instrument in space,\u201d Seo said. \u201cThat\u2019s what we are doing. We identify (cosmic rays) particle-by-particle, tell what they are, how much energy they have, and characterize them. We (sample) them directly before they are broken up in the atmosphere.\u201d<\/p>\n

CREAM will be sensitive to cosmic rays with higher energies than previous cosmic ray detectors flown in space, including the $2 billion Alpha Magnetic Spectrometer delivered to the space station on the second-to-last space shuttle flight in 2011.<\/p>\n

\u201cWhat CREAM is going to do is to extend the direct measurements to the highest energies possible, to energies that are capable of generating these gigantic air showers that can reach all the way to the ground,\u201d Seo said.<\/p>\n

Huge explosions like stellar supernovas, along with extreme gravitational forces from other cosmic phenomena, send cosmic rays shooting through space at mind-boggling velocities approaching the speed of light. One of the CREAM instrument\u2019s chief objectives is to study where the particles come from.<\/p>\n

NASA\u2019s Fermi Gamma-ray Space Telescope proved some cosmic rays come from the expanding debris remnants of supernovas, but the case is still open for other types of cosmic rays.<\/p>\n

\u201cIt\u2019s generally believed that cosmic rays originate in supernovas,\u201d Seo said. \u201cThere are other possible contributions or accelerators, pulsars, colliding galaxies, black holes, AGNs (active galactic nuclei).\u201d<\/p>\n

But some cosmic rays are believed to be too energetic to be accelerated by supernovas.<\/p>\n

\u201cA supernova is very powerful, but still it\u2019s a finite engine,\u201d Seo said.<\/p>\n

\"\"
A cutaway diagram of the CREAM instrument. Credit: University of Maryland<\/figcaption><\/figure>\n

Subatomic particles like protons are the most common type of cosmic ray at lower energies, and cosmic rays become rarer as scientists look at higher energies. But balloon science campaigns found the drop-off in particle detections at higher energies is not as steep as predicted, a result known as spectral hardening.<\/p>\n

\u201cAt high energies that are in our energy range \u2026 there are more cosmic rays than were expected from the simple supernova acceleration scenario,\u201d Seo said.<\/p>\n

Comparisons of two types of particles \u2014 protons and helium \u2014 suggest low-energy and high-energy cosmic rays could come from different sources.<\/p>\n

\u201cAt lower energies, we already know protons are the most dominant component, but as you approach this acceleration limit you expect to see this composition change,\u201d Seo said. \u201cBut this hasn\u2019t been observed yet because we are not able to do the direct measurements at that higher energy. With CREAM, we are to explore these higher energies to actually observe such composition changes to confirm such a supernova acceleration scenario.\u201d<\/p>\n

Seo said CREAM will build up statistics on the flux, or variability, of high-energy cosmic rays with continuous observations not possible on a short-duration balloon flight.<\/p>\n

\u201cBy utilizing the space station, we can increase our exposure by an order of magnitude,\u201d Seo said. \u201cIn order words, every day on the station, we will increase the statistics, and as the statistical uncertainties get reduced, and we can detect higher energies than before.\u201d<\/p>\n

One way physicists say cosmic rays could be born is during collisions between particles of dark matter, a mysterious substance that makes up about 27 percent of all the mass and energy in the universe. Only 5 percent of the universe is regular matter \u2014 stuff we can see and touch \u2014 while the rest is dark energy, an enigmatic force that helps drive the expansion of the universe.<\/p>\n

\u201cThe question of whether these are from an exotic source like dark matter has generated lots of excitement, but for us to actually know whether there is some exotic source like dark matter, or an astrophysical source like a pulsar \u2026 we will need a lot more understanding of cosmic rays,\u201d Seo said.<\/p>\n

Scientists from the United States, South Korea, France and Mexico are part of the CREAM project. The instrument weighs about 2,773 pounds (1,258 kilograms) inside the Dragon spacecraft\u2019s payload trunk.<\/p>\n

Liftoff from NASA\u2019s Kennedy Space Center in Florida is scheduled for Aug. 14.<\/p>\n

\u201cIt\u2019s a very exciting time for us in high-energy particle astrophysics, and the long development road of CREAM culminating in this space station mission has been a world-class success story,\u201d Seo said.<\/p>\n

Email the author.<\/i><\/b><\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

This mosaic image of Crab Nebula, a six-light-year-wide expanding remnant of a star\u2019s supernova explosion, was taken by the Hubble Space Telescope. Recent research shows that galactic cosmic rays flowing into our solar system originate in clusters like these. Credit: NASA\/ESA\/Arizona State University Physicists are gearing up to send a re-engineered science instrument originally designed […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[1690,2379,3214,1395,479,717,1602,316],"class_list":["post-14431","post","type-post","status-publish","format-standard","hentry","category-news","tag-astrophysics","tag-cosmic-rays","tag-cream","tag-dragon","tag-falcon-9","tag-international-space-station","tag-iss-cargo","tag-spacex"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/14431"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=14431"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/14431\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=14431"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=14431"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=14431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}