ANITA is also resting safely on ICE - 1/22/2009
Williams Field, Antarctica.- After a total flight time of 30 days, 15 hours, and 58 minutes, the second mission of the current NASA's long duration balloon launch campaign, was finished two days ago on January 20.
The 39 million cubic feet balloon was carrying a experiment developed by the University of Hawaii called ANITA (Antarctic Impulse Transient Antenna). consisting of a radio telescope to detect ultra-high energy cosmic-ray neutrinos by use of the Askaryan effect. This effect predicts the production of a coherent radio emission from the cascade of particles produced in a high-energy particle interaction when a neutrino passes trough the earth under the ice sheet of the Antarctic Plateau.
The mission (numbered as 590N) was launched on December 21th from the NASA long duration balloon launch site at Williams Field airport, near McMurdo base. At left can be seen a map of ANITA's path during the entire trip (click to enlarge).
As occured the last week with CREAM, the termination procedure was carried out sending the separation signal via the TDRSS satellite relay system directly from CSBF's Operations Control Center in Palestine, Texas. The payload landed 122 nautic miles SW of the Siple Dome at 13:15 UTC and according to the telemetry received it tipped over upon impact, but is in good condition as it continues to transmit data through the Iridium system.
Plans for the recovery of the instrument are under consideration.
First Up, first down. CREAM balloon flight terminated - 1/13/2009
Williams Field, Antarctica.- The first balloon launched during the current balloon campaign was also the first to be terminated on January 7th when the separation command was sent to the balloon. The balloon was carrying the CREAM (Cosmic Ray Energetics And Mass) instrument developed by the University of Maryland and NASA Wallops Flight Facility. The instrument which was built to explore the supernova acceleration limit of cosmic rays, the relativistic gas of protons, electrons and heavy nuclei arriving at Earth from outside the solar system was performing his fourth polar trip.
As you may remember from past updates, the balloon was launched from the NASA long duration balloon launch site at Williams Field airport, near McMurdo base on December 19th, 2008. After remaining three weeks at float altitudes close to 120.000 feet, just after completing the second full circle to Antarctica and while was over land, decision was taken to finish the flight.
The termination procedure was carried out sending the separation signal via the TDRSS satellite relay system at 10:27 UTC. The payload landed 560 nautic miles N-NW of McMurdo Station and according to NASA sources the telemetry data after impact suggests that the Gondola landed probably upright and with little damage. Also was informed that the critical phase of the parachute cutaway was succesfully carried out by SAPR (Semi-Automatic Parachute Release) system. Total flight time was 19 days, 13 hours, and 13 minutes.
Althought plans called for a first recovery mission of the payload using a DC-3 Bassler on January 9th, until now the mission was re-scheduled on a daily basis due to the bad weather. The next attempt will be on January 14th. This first recovery mission is vital to recover kay elements of the missions as the data vault, UTP (Universal Terminate Package), CDM (Command Data Module), and the high-gain antenna.
More information on CREAM:
::http://cosmicray.umd.edu/cream/ CREAM'S University of Maryland web site
Great discovery made by a balloon-borne mission - 1/7/2009
Latest issue of NATURE published in November 20, 2008 contains a lenghtly article on which an international team of researchers offers evidence about the discovery of a puzzling surplus of high-energy electrons bombarding Earth from space.
The discovery is a by-product of three long duration Antarctic flights of the ATIC (Advanced Thin Ionization Calorimeter) an instrument composed mainly by a ionization calorimeter with the objective of to measure the cosmic ray proton and helium spectra.
"This is a big discovery," says John Wefel of Louisiana State University. "It's the first time we've seen a discrete source of accelerated cosmic rays standing out from the general galactic background."
The team expected ATIC to tally the usual mix of particles, mainly protons and ions, but the calorimeter found something extra: an abundance of high-energy electrons.
Wefel likens it to driving down a freeway among family sedans, mini-vans and trucks "when suddenly a bunch of Ferraris bursts through the normal traffic. You don't expect to see so many race cars on the road or so many high-energy electrons in the mix of cosmic rays" During five weeks of ballooning in 2000 and 2003, ATIC counted 70 excess -that is above the usual number expected from the galactic background- electrons in the energy range 300-800 GeV. Seventy electrons may not sound like a great number, but like seventy Ferraris on the freeway, it's a significant surplus.
"The source of these exotic electrons must be relatively close to the solar system no more than a kiloparsec away" sayd Jim Adams of the NASA Marshall Space Flight Center. Why must the source be nearby? Adams explains: "High-energy electrons lose energy rapidly as they fly through the galaxy". By the time an electron has traveled a whole kiloparsec, it isn't so "high energy" any more.
High-energy electrons are therefore local. Some members of the research team believe the source could be less than a few hundred parsecs away.
"Unfortunately we can't pinpoint the source in the sky." Although ATIC does measure the direction of incoming particles, it's difficult to translate those arrival angles into celestial coordinates.
This uncertainty gives free rein to the imagination. The least exotic possibilities include, e.g., a nearby pulsar, a 'microquasar' or a stellar-mass black hole, all are capable of accelerating electrons to these energies. It is possible that such a source lurks undetected not far away. NASA's recently-launched Fermi Gamma-ray Space Telescope is only just beginning to survey the sky with sufficient sensitivity to reveal some of these objects.
An even more tantalizing possibility is dark matter: a popular yet unproven explanation for dark matter is that their particles inhabit in extra dimensions. We feel their presence via the force of gravity, but do not sense them in any other way.
How does this produce excess cosmic rays? these particles have the curious property (one of many) that they are their own anti-particle. When two collide, they annihilate one another, producing a spray of high-energy photons and electrons. The electrons are not lost in hidden dimensions, however, they materialize in the 3-dimensions of the real world where detectors like ATIC can detect them as cosmic rays.
"Our data could be explained by a cloud or clump of dark matter in the neighborhood of the solar system," says Wefel. "In particular, there is a hypothesized particle with a mass near 620 GeV which, when annihilated, should produce electrons with the same spectrum of energies we observed."
Now we must wait ans see if for example the Fermi Space Telescope may have the best chance of pinpointing the source.
"Whatever it is," says Adams, "it's going to be amazing."
To know more about the above mentioned ATIC flights you can read the flight sheet that we prepared here at Stratocat including data and pictures of the First Mission in 2000 the second one performed in 2002 and the latest, carried out in 2007. A third mission was intended in 2005 but failed due to balloon problems.
To obtain more information on ATIC and a copy of NATURE's article go to http://atic.phys.lsu.edu/
