Random Walk Elachi (Left) and Stone at the Press Conference
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Random Walk Elachi (left) and Stone at the press conference. T HE L AB N AMES O NE OF I TS O WN Charles Elachi (MS ’69, and so knows the school well. of Caltech, and I intend to the Space Shuttle that have PhD ’71) has been named He is an expert in remote continue that tradition. My allowed scientists to see the new director of the Jet sensing, and in recognition commitment is to continue through the clouds that Propulsion Laboratory (JPL), of his work, he was one of the tradition of excellence blanket Earth. (The technol- which Caltech manages for the youngest members ever and boldness in exploring our ogy also penetrates the top NASA, effective May 1. elected to the National solar system, understanding layer of soil in arid regions, President David Baltimore Academy of Engineering. the origin of galaxies, and revealing hints of what lies made the announcement at He has long been a leader of applying that knowledge to below.) He has participated a press conference on January planetary exploration at JPL better understand the changes in a number of archaeological 31, where Elachi and Balti- and is widely respected at the on our own planet.” The new expeditions in the Egyptian more were joined by retiring Laboratory. I look forward to post brings Elachi full circle, desert, the Arabian peninsula, JPL director Edward Stone, having a close working as he recalled being inspired and the Western Chinese the Morrisroe Professor of relationship with him.” as an 11-year-old in Lebanon desert, using satellite data to Physics; and NASA adminis- “Charles Elachi brings by JPL’s launching of Ex- search for old trading routes trator Daniel Goldin. Elachi formidable talents to his new plorer 1—43 years ago to the and buried cities. Some of has served in a variety of job, as both a scientist and a day, he noted. “Maybe that’s these expeditions have been research and management leader,” said Goldin. “In a good omen for me,” he featured in National Geo- positions at JPL since 1971. addition to already being joked. He grew up to receive graphic, on PBS, and in Most recently, he has been responsible for many of JPL’s a BSc in physics from the Caltech News (“The Road head of the Space and Earth missions in solar system University of Grenoble, to Ubar,” April, 1992). He Science Programs; other exploration, Earth sciences, France, and the Dipl.Ing. in has also served as principal positions include manager for and astrophysics, he has led engineering from the Poly- investigator on numerous radar development and leader efforts to create road maps technic Institute, Grenoble, NASA research and develop- of the radar remote-sensing of our exploration strategies both in 1968, and then ment studies and flight team. decades into the future. He earned his Caltech MS and projects. He is currently the Elachi “knows JPL better is both an effective adminis- PhD in electrical engineering. team leader of the Cassini than anyone and will be best trator and a visionary.” He also earned an MBA from Titan radar experiment and a able to lead the Laboratory in Elachi said he was honored USC in 1978, and an MS in coinvestigator on the Rosetta the coming years,” Baltimore to be entrusted with the geology from UCLA in 1983. Comet Nucleus Sounder said. “Charles has an extraor- leadership of JPL. “For the Elachi is perhaps best Experiment. He is the author dinary record of accomplish- last 40 years JPL has enjoyed known for his role in the of more than 200 publica- ment in his 30 years at JPL. a tradition of excellence as a development of a series of tions on space and planetary He is an alumnus of Caltech, NASA center and division imaging radar systems for exploration, Earth observa- 2 ENGINEERING & SCIENCE NO . 4 tion from space, active microwave remote sensing, wave propagation and scattering, electromagnetic theory, lasers, and integrated S NIFF M E A T UNE optics, and he holds several patents in those fields. He has written three textbooks on remote sensing and has taught EE/Ge 157, Introduc- When Hamlet told the iorally relevant to them. tion to the Physics of Remote courtiers they would eventu- But the study likely applies Sensing, since 1982. ally “nose out” the hidden to other animals, including In 1988, the Los Angeles corpse of Polonius, he was humans, because the olfactory Times selected him as one of perhaps a better neurobiolo- systems of most living crea- “Southern California’s rising gist than he realized. Accord- tures appear to follow the stars who will make a differ- ing to research by Caltech same basic principles. After ence in L.A.” In 1989, neuroscientists, the brain placing electrodes in the Asteroid 1982 SU was creates subtle temporal codes brains of individual fishes, renamed 4116 Elachi in to identify odors. Some neu- they were subjected to recognition of his contribu- ral signals change over the sequences of 16 odor compo- tions to planetary exploration. duration of a sniff, giving nents found in foods they Elachi is the second Caltech first a general notion of the normally seek. Analyzing the alumnus to be named director type of odor, then a more signals from the mitral cells of JPL. The first, William subtle discrimination that showed that the information Pickering (BS ’32, PhD ’36), leads to precise recognition the fish could extract about a headed the lab from 1954 to of the smell. In the February stimulus became more precise 1976. ■—JP 2 issue of the journal Science, as time went by. The finding Gilles Laurent, associate was surprising because the professor of biology and signals extracted from the computation and neural receptor neurons located systems, and postdoc Rainer upstream of the mitral cells W. Friedrich, now at the Max showed no such temporal Planck Institute in Heidel- evolution. “It looks as if the berg, Germany, report that brain actively transforms certain neurons respond to an static patterns into dynamic odor through a complicated ones and in so doing, man- process that evolves over a ages to amplify the subtle brief period of time. These differences that are hard to neurons, called mitral cells perceive between static because they resemble patterns,” Laurent says. miters—the pointed hats “Music may provide a use- worn by bishops—are found ful analogy. Imagine that the by the thousands in the olfactory system is a chain of human olfactory bulb. choruses—a receptor chorus, “We’re interested in how feeding onto a mitral-cell ensembles of neurons encode chorus, and so on—and that sensory information,” each odor causes the receptor explains Laurent. “So we’re chorus to produce a chord. On February 12, NEAR Shoemaker became the first spacecraft to land on an less interested in where the Two similar odors evoke two asteroid—all the more impressive when you consider that this legless relevant neurons lie, as very similar chords, making revealed by brain mapping discrimination difficult. orbiter was never designed to land on anything. NASA’s Near Earth Asteroid studies, than in the patterns What the mitral-cell chorus Rendezvous mission, which was renamed in honor of the late Eugene of firing these neurons pro- does is to transform each Shoemaker (BS ’47), the father of planetary geology, had been in close orbit duce and in figuring out from chord it hears into a musical around the 21-mile long Eros for a year. The craft touched down at a these patterns how recogni- phrase, in such a way that the tion, or decoding, works.” difference between these gentle four miles an hour and in an orientation that allowed its solar The researchers used zebra phrases becomes greater over panels to continue to function, so jubilant scientists turned its gamma-ray fish because these animals time. In this way, odors that spectrometer back on to get a close-up analysis of Eros’s surface mineral- have comparatively few initially ‘sounded’ alike pro- ogy. In this image mosaic, taken from an orbital altitude of 200 kilometers, mitral cells and because much gressively become more easily is already known about the identified.” the arrow points to the landing site. Gene’s gotta be happy…. types of odors that are behav- In other words, when we ENGINEERING & SCIENCE NO . 4 detect a citrus smell in a garden, for example, the odor is first conveyed by the receptors to the mitral cells. This initial firing allows for little more than the generic detection of the citrus nature of the smell. Within a few tenths of a second, however, new mitral cells are recruited, leading the pattern of activity to change rapidly. This quickly allows us to deter- mine whether the citrus smell is actually a lemon or an orange. T HE I NS AND O UTS OF O VER - AND U NDERVOTES However, the individual tuning of the mitral cells first stimulated by the citrus odor does not become more specif- ic. Instead, the manner in In December, following ballots with hand-marked study is complete, it will which the firing patterns the contentious vote counting votes, lever machines, punch encompass presidential unfold through the lateral in the presidential election, cards, optical scanning elections going back to 1980, circuitry of the olfactory bulb Caltech and MIT decided to devices, and direct-recording and will examine a finer is ultimately responsible for join forces to develop a voting electronic devices (DREs), breakdown of the different the fine discrimination of the system that will be easy to which are similar to auto- technologies, and a break- odor.