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Delta II Rocket Coming Together for GLAST Satellite Launch
Science Today: How to Build a Future Gamma-ray Detector?
Wellness Fair to Offer Free Screenings, Options for Health

SLAC Today

Thursday - April 17, 2008

Delta II Rocket Coming Together for GLAST Satellite Launch

On Pad 17-B, the mobile service tower (left) approaches the Delta II rocket (right). The solid rocket boosters in the tower will be mated with the rocket. (Photo courtesy of NASA/Jim Grossmann.)

The Delta II 7920-H, or "Heavy," rocket that will launch the Gamma-ray Large Area Telescope (GLAST) satellite is in the process of being assembled on Launch Pad 17-B at Cape Canaveral Air Force Station, Florida.

Solid rocket boosters were recently attached to the rocket. A series of nine strap-on solid rocket motors will next be mated with the rocket to help power the first stage. Because the Delta rocket is configured as a Delta II 7920 Heavy, the boosters are larger than those used on the standard configuration.

"The Delta II is one of our most reliable launch vehicles," said Rick Harnden, GLAST Program Scientist at NASA Headquarters, Washington. "However, we'll be breathing a lot easier once GLAST has been lofted successfully into orbit."

GLAST is slated for launch from the Cape Canaveral Air Station on May 16 between 8:45 a.m.–10:40 p.m. PDT. GLAST's main instrument, the Large Area Telescope (LAT), was integrated at SLAC in 2005 and 2006 from hardware fabricated at laboratories all around the world.


(Daily Column - Science Today)

How to Build a Future Gamma-ray Detector?

An artist's conception of a future gamma-ray system. (Image courtesy of J. Buckley, University of Washington.)

Following its launch next month, the Gamma-ray Large Area Space Telescope (GLAST) will explore the non-thermal universe using gamma-rays, the most energetic form of lightmore than a million times more energetic than "medical" X-rays (energies range from 20 MeV to 300 GeV). However, at even higher energies (starting at 1 TeV), gamma rays are usually so sparse that larger detection areas are needed.

"These can only be provided by ground-based instruments," said Stefan Funk of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC).

Because gamma rays are absorbed by the atmosphere, ground-based instruments have to employ a trick to detect gamma-rays; they use Cherenkov light, optical light produced by the interaction of TeV gamma rays with the particles in the atmosphere, to trace the gamma rays. This Cherenkov light is reflected with large mirrors onto a focal plane and can then be detected with photo-sensors such as photomultipliers.

Funk and a team of national and international collaborators are studying how to best build such a future gamma-ray telescope system.

"Depending on the scientific motivation, there are a large number of parameters such as telescope spacing, photodetector size, altitude of the system and so on that can be changed in such a system," Funk said. "Before we start building, we better make sure that we get the optimal configuration."

Currently, Funk and his collaborators—including KIPAC's Seth Digel—perform detailed simulation studies to determine the optimal array parameters for such a system that would eventually help to explore the sky at the highest energies, beyond the TeV range.

Wellness Fair to Offer Free Screenings, Options for Health

(Photo - Wellness Fair)
Stanford Provost John Etchemendy scaled the recreation center's indoor rock-climbing wall during last year's Wellness Fair.

This year's Wellness Fair is scheduled for Thursday, May 1, in the Arrillaga Center for Sports and Recreation. The fair promises a day full of activities aimed at encouraging university employees to adopt healthier habits and lifestyles.

The event, which will take place from 10:00 a.m. to 3:00 p.m., will feature free health screenings to measure blood pressure, body fat, bone density, cholesterol and blood sugar levels. Activities will include the chance to scale the center's indoor rock wall, try out cardio exercise equipment, enjoy a 10-minute chair massage and watch a healthy food demonstration.

As part of the university's BeWell@Stanford initiative, the fair also will feature a floor full of booths where employees can get information on health-related products and services. And for those looking for new ways to exercise, demonstrations of Pilates, yoga, tai chi, belly dancing and other options are scheduled. The fair's "second annual battle of the sexes squash match" will be held as well.

Just outside, the Campus Bike Shop will conduct bicycle safety checks. Parking and Transportation Services will register bikes, and the Stanford Blood Mobile will be accepting donations. Organizers strongly suggest that an appointment be made to avoid waiting in long lines for blood donations and cholesterol tests. For the latter, visit the WellCall website. First-time users must register with the password "stanford." Please visit the Blood Center website to schedule a blood donation.

There will be giveaways for all participants during the event, as well as drawings for larger prizes. Additional information—including the fair's full schedule—is available at the Benefits website.


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