The E and B Experiment (EBEX) will measure the

cosmic microwave background radiation In Big Bang cosmology the cosmic microwave background (CMB, CMBR) is electromagnetic radiation that is a remnant from an early stage of the universe, also known as "relic radiation". The CMB is faint cosmic background radiation filling all spac ...

of a part of the sky during two sub-orbital (high-altitude) balloon flights. It is an experiment to make large, high-fidelity images of the CMB polarization anisotropies. By using a telescope which flies at over 42,000 metres high, it is possible to reduce the atmospheric absorption of microwaves to a minimum. This allows massive cost reduction compared to a satellite probe, though only a small part of the sky can be scanned and for shorter duration than a typical satellite mission such as

WMAP The Wilkinson Microwave Anisotropy Probe (WMAP), originally known as the Microwave Anisotropy Probe (MAP and Explorer 80), was a NASA spacecraft operating from 2001 to 2010 which measured temperature differences across the sky in the cosmic mic ...

. The first flight was an engineering flight over

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

in 2009. For the science flight, EBEX was launched on 29 December 2012, near

McMurdo Station McMurdo Station is a United States Antarctic research station on the south tip of Ross Island, which is in the New Zealand-claimed Ross Dependency on the shore of McMurdo Sound in Antarctica. It is operated by the United States through the Unit ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

.Blog post from a member of the EBEX science team describing the launch.
/ref>YouTube video of the EBEX launch.
/ref> It circled around the

South Pole The South Pole, also known as the Geographic South Pole, Terrestrial South Pole or 90th Parallel South, is one of the two points where Earth's axis of rotation intersects its surface. It is the southernmost point on Earth and lies antipod ...

using the polar vortex winds before landing on 24 January 2013 about 400 miles from McMurdo.Blog post describing the landing.
/ref>

Instrumentation

EBEX consists of a 1.5 m Dragone-type telescope that provides a resolution of 8 arcminutes in frequency bands centered on 150, 250, and 410 GHz. Polarimetry is achieved with a continuously-rotating achromatic half-wave plate supported by a superconducting

magnetic bearing A magnetic bearing is a type of bearing that supports a load using magnetic levitation. Magnetic bearings support moving parts without physical contact. For instance, they are able to levitate a rotating shaft and permit relative motion with ve ...

and a fixed wire grid polarizer. The wire grid is mounted at 45 degrees to the incoming light beam and transmits one polarization state while reflecting the other. Each polarization state is subsequently detected by its own focal plane with a 6 degree instantaneous field-of-view on the sky. Each of the focal planes contains up to 960

transition-edge sensor A transition-edge sensor (TES) is a type of cryogenic energy sensor or cryogenic particle detector that exploits the strongly temperature-dependent resistance of the superconducting phase transition. History The first demonstrations of the supe ...

s read out with frequency-domain

SQUID True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

multiplexing.

Temporary disappearance

The EBEX telescope was reported missing in May, 2012, while in transit from the

University of Minnesota The University of Minnesota, formally the University of Minnesota, Twin Cities, (UMN Twin Cities, the U of M, or Minnesota) is a public university, public Land-grant university, land-grant research university in the Minneapolis–Saint Paul, Tw ...

to the NASA

Columbia Scientific Balloon Facility The Columbia Scientific Balloon Facility (CSBF) (established in 1961, formerly known as the National Scientific Balloon Facility (NSBF)) is a NASA facility responsible for providing launch, tracking and control, airspace coordination, telemetry ...

Palestine, Texas Palestine ( ) is a city in and the seat of Anderson County in the U.S. state of Texas. It was named for Palestine, Illinois, by preacher Daniel Parker, who had migrated from that town. The city had a 2020 U.S. census population of 18,544, mak ...

. The driver of the truck said that the trailer had been stolen while parked at a motel in

Dallas Dallas () is the List of municipalities in Texas, third largest city in Texas and the largest city in the Dallas–Fort Worth metroplex, the List of metropolitan statistical areas, fourth-largest metropolitan area in the United States at 7.5 ...

. Scientists and employees of the trucking company searched the area and found the missing trailer parked at a truck wash near

Hutchins, Texas Hutchins is a city in Dallas County, Texas, United States. Its population was 5,338 at the 2010 census. History The area was first inhabited by families around 1860 as a trading place for immigrants who settled along the west bank of the Trinity ...

. The trailer had been opened, but no scientific equipment had been stolen and the telescope was undamaged.

Flight

EBEX launched from

Williams Field Williams Field or Willy Field is a United States Antarctic Program airfield in Antarctica. Williams Field consists of two snow runways located on approximately 8 meters (25 ft) of compacted snow, lying on top of 8–10 ft of ice, floa ...

on the Antarctic coast on 29 December 2012.

References

External links

Main (UMN) Site
{{DEFAULTSORT:E and B Experiment Physics experiments Radio astronomy Cosmic microwave background experiments Balloon-borne telescopes Astronomical experiments in the Antarctic

Instrumentation

Temporary disappearance

Flight

See also

References

External links