GRAIL: Another Lofty Quest (Part 9) September 21, 2011Posted by Lofty Ambitions in Science, Space Exploration.
Tags: GRAIL: Another Lofty Quest, GRAILTweetup, Museums & Archives, Nuclear Weapons
“We organize information on maps in order to see our knowledge in a new way. As a result, maps suggest explanations; and while explanations reassure us, they also inspire us to ask more questions, consider other possibilities.” – Maps of the Imagination: The Writer as Cartographer by Peter Turchi
Less than two weeks ago, NASA was launching GRAIL toward the Moon for its mapping mission. This Friday, just two days from now, a NASA weather satellite is expected to come hurling down through Earth’s atmosphere. All this has us thinking about what’s up there circling here and there without us taking much notice.
When Doug first applied to be a part of the NASA Tweetup for the GRAIL (Gravity Recovery and Interior Laboratory) mission, we didn’t know all that much about the science objectives for GRAIL. We thought it would be another opportunity to hang out with like-minded space nerds on the Space Coast. We knew our experience of watching the last two shuttle launches couldn’t be repeated, but a rocket launch would continue to amaze us. Very quickly, we learned more about the GRAIL mission and were delighted to see that it aligned with some long-standing interests that had little to do with the rocket.
Much science proceeds by increments. An experiment confirms a theory, and that hard-won information spawns new questions, new ideas to investigate. The researchers carry out this work, passing down data and lore through laboratory lineages.
The Dean of Leatherby Libraries, Doug’s boss, was a Map Librarian earlier in her career. Not long ago, Doug earned a certificate in Geographic Information Systems (GIS) from CalState-Fullerton, a move the library thought might prove useful. Even earlier, during his Ph.D., Doug had worked on a GIS-like system, a software tool that converts data into a map-based, or geographical, representation. You can’t study maps, map-making, and GIS for very long before you run into concepts like coordinate systems, GPS, and geodetics (sometimes also referred to as geodesy).
As a scientific endeavor, geodetics concerns itself with measuring our Earth. The science has moved well past its historical priority of trying to determine our planet’s diameter and shape. In 2002, GRAIL’s predecessor as a scientific tool, GRACE, opened new directions in Earth Science by producing the most accurate map of the Earth’s gravitational field ever created. One direct outcome of GRACE’s gravitational map is a much better understanding of how the earth’s ice caps and oceans respond to the gravitational field. In turn, this understanding will allow other earth scientists, in particular oceanographers and environmental scientists, to develop more accurate models of the earth’s hydrological cycle. In the same fashion, the gravity map that is created based on the data to be obtained by GRAIL about the Moon will be used to determine structural information about that orbiting mass, information such as what kind of core the moon possesses, whether it is solid or molten.
In one of those lovely coincidences that turn up time and again since starting Lofty Ambitions, the first geodetic satellite was launched from Cape Canaveral’s Launch Complex 17 (LC 17), the same site from which Doug saw GRAIL launch almost two weeks ago. Even better, that first geodetic satellite was named Anna.
ANNA arose as a collaboration between the nation’s military and its civilian aerospace agency. In fact, the name derives from the initials of involved groups: Army, Navy, NASA, Air Force. As you can imagine, there’s some debate about the positioning of each group’s name in the palindrome acronym, but that’s the order that the New York Times reported on November 1, 1962, the day after its launch.
Like GRAIL, ANNA was in fact two satellites, ANNA 1-A and ANNA 1-B. ANNA 1-A was launched on May 10, 1962, but failed to reach orbit after its second stage didn’t fire. ANNA 1-B was successfully launched on Halloween of 1962, after being delayed by the Cuban missile crisis because of Cape Canaveral’s proximity to Cuba. Again, like GRAIL, ANNA was launched on a member of the Delta family of rockets, Thor. In many ways, GRAIL and ANNA serve as bookends for LC 17. Although ANNA wasn’t the first Delta-powered science satellite launched from LC 17, it was one of the first. GRAIL was the last. There will be no more Delta launches from LC 17. That launch pad is being taken out of service.
ANNA’s primary science tool was a series of four enormously powerful strobe lights (8M candlepower) arrayed on its spherical body. The lights flashed in a prescribed sequence in response to radio signals broadcast from Earth-side stations. Photographs taken of the flashes from known positions on the earth against a background of known stars allowed scientists to determine the location of new positions via triangulation.
John Finney’s 1962 New York Times article indicates that the ANNA mission was the focus of a controversy over the desires of civilian scientists to make the mission data public and the military’s requirement for secrecy: “At one point, the military established secrecy for the project on the ground that the geodetic information provided by the satellite on intercontinental distances would permit more accurate aiming of Soviet ballistic missiles.” Later, it was decided that Soviet nuclear warheads of the era were already powerful enough that the improvements made in targeting via the new geodetic data probably wouldn’t make much difference.
During the Cold War, accurately measuring distances over the skin of the earth was a significant military endeavor. We first came into contact with this project last year at an exhibit called “Mapping the Earth During the Cold War” at the Smithsonian’s National Museum of American History. We were struck by the notion of scientists whose aim was to measure the Earth’s distances—its shape, it gravity, the distance relationship of places—all in an effort to make better targeting algorithms for Intercontinental Ballistic Missile. These scientists were, in effect, getting to know the Earth deeply in order that they could destroy it.
ANNA is still up there, endlessly orbiting the Earth, though she no longer flashes in acknowledgement of a received message.
To see the news story about ANNA’s launch, click HERE.