MOON SATELLITES HAVE BEGUN COLLECTING INFORMATION

The following excerpt is from the NASA website:

“WASHINGTON -- NASA's Gravity Recovery And Interior Laboratory (GRAIL)
spacecraft orbiting the moon officially have begun their science
collection phase. During the next 84 days, scientists will obtain a
high-resolution map of the lunar gravitational field to learn about
the moon's internal structure and composition in unprecedented
detail. The data also will provide a better understanding of how
Earth and other rocky planets in the solar system formed and evolved.


"The initiation of science data collection is a time when the team
lets out a collective sigh of relief because we are finally doing
what we came to do," said Maria Zuber, principal investigator for the
GRAIL mission at the Massachusetts Institute of Technology in
Cambridge. "But it is also a time where we have to put the coffee pot
on, roll up our sleeves and get to work."

The GRAIL mission's twin, washing-machine-sized spacecraft, named Ebb
and Flow, entered lunar orbit on New Year's Eve and New Years Day.
GRAIL's science phase began yesterday at 8:15 p.m. EST (5:15 p.m.
PST). During this mission phase, the spacecraft will transmit radio
signals precisely defining the distance between them. As they fly
over areas of greater and lesser gravity caused by visible features
such as mountains, craters and masses hidden beneath the lunar
surface, the distance between the two spacecraft will change
slightly. Science activities are expected to conclude on May 29,
after GRAIL maps the gravity field of the moon three times.

"We are in a near-polar, near-circular orbit with an average altitude
of about 34 miles (55 kilometers) right now," said David Lehman,
GRAIL project manager from NASA's Jet Propulsion Laboratory (JPL) in
Pasadena, Calif. "During the science phase, our spacecraft will orbit
the moon as high as 31 miles (51 kilometers) and as low as 10 miles
(16 kilometers). They will get as close to each other as 40 miles (65
kilometers) and as far apart as 140 miles (225 kilometers)."

Previously named GRAIL A and B, the names Ebb and Flow were the result
of a nation-wide student contest to choose new names for the
spacecraft. The winning entry was submitted by fourth graders from
the Emily Dickinson Elementary School in Bozeman, Mont. Nearly 900
classrooms with more than 11,000 students from 45 states, Puerto Rico
and the District of Columbia, participated in the contest.

JPL manages the GRAIL mission for NASA's Science Mission Directorate
in Washington. The GRAIL mission is part of the Discovery Program
managed at NASA's Marshall Space Flight Center in Huntsville, Ala.
Lockheed Martin Space Systems in Denver built the spacecraft.”

TWIN SATELITES WILL EXPLORE THE MOON

It's great we are going back to the moon. The moon may be the best place to build a permanent space station from which we can explore the solar system. The followig story about the new moon mission is an excerpt from the NASA website:

NASA Moon Mission In Final Preparations For September Launch
CAPE CANAVERAL, Fla. -- NASA's Gravity Recovery And Interior Laboratory (GRAIL), mission to study the moon is in final launch preparations for a scheduled Sept. 8 launch onboard a Delta II rocket from Cape Canaveral Air Force Station in Florida.

GRAIL's twin spacecraft are tasked for a nine-month mission to explore Earth's nearest neighbor in unprecedented detail. They will determine the structure of the lunar interior from crust to core and advance our understanding of the thermal evolution of the moon.

"Yesterday's final encapsulation of the spacecraft is an important mission milestone," said David Lehman, GRAIL project manager for NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Our two spacecraft are now sitting comfortably inside the payload fairing which will protect them during ascent. Next time the GRAIL twins will see the light of day they will be about 95 miles up and accelerating."

The spacecraft twins, GRAIL A and B, will fly a circuitous route to lunar orbit taking 3.5 months and covering approximately 2.6 million miles (4.2 million kilometers) for GRAIL-A, and 2.7 million miles (4.3 million kilometers) for GRAIL-B.

In lunar orbit, the spacecraft will transmit radio signals precisely defining the distance between them. Regional gravitational differences on the moon are expected to expand and contract that distance. GRAIL scientists will use these accurate measurements to define the moon's gravity field. The data will allow mission scientists to understand what goes on below the surface of our natural satellite.

"GRAIL will unlock lunar mysteries and help us understand how the moon, Earth and other rocky planets evolved as well," said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology in Cambridge.

GRAIL's launch period opens Sept. 8 and extends through Oct. 19. On each day, there are two separate launch opportunities separated by approximately 39 minutes. On Sept. 8, the first launch opportunity is 8:37 a.m. EDT; the second is 9:16 a.m.

JPL manages the GRAIL mission. It is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver, built the spacecraft. Launch management for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida.”