 |
Image courtesy of Kamal Oudrhiri |
Kamal Oudrhiri is the radio science group manager at NASA’s Jet Propulsion Laboratory and the deputy project manager for the Cold Atom Laboratory, an Interational Space Station quantum physics facility expected to launch in 2017. Over the last decade, Oudrhiri has served in key roles on multiple NASA missions: the Mars Exploration Rovers (MER), the international Cassini mission to Saturn, the GRAIL lunar mission, the Mars Science Laboratory (MSL) and the Juno mission to Jupiter.
The New Horizon project was launched in 2006 by NASA with the mission objective to gather scientific information on Pluto. The recent images of Pluto taken by NASA’s New Horizons spacecraft have been the main topic of conversation for space enthusiasts for several months. After a 3-billion-mile journey that took more than nine years at speeds of 16.2 km/sec — 10 times faster than a bullet — New Horizons flew by Pluto and its moon on July 14, 2015 and sent back the most detailed images and science measurements ever taken of the dwarf planet and its neighboring moons. The data transmitted back to Earth included important scientific information on the atmospheres of Pluto and Charon. USC alumni, Oudrhiri (M.S. EE '00, Ph.D. ASTE), played a key role as part of New Horizons Radio Science Experiment (REX).
 |
Image courtesy of Kamal Oudrhiri |
REX is the principal instrument used to study Pluto’s atmosphere. Measuring the atmospheric composition and temperature conventionally relied on utilizing the spacecraft’s telecom system as the transmitting source, but due to the vast distance of Pluto from Earth and the limited power onboard the spacecraft (~200 Watts, the equivalent of two light bulbs) to operate REX, the source radio signal was instead transmitted from Earth using the Deep Space Network (DSN) antennas and then received by the REX receivers, enabling a reception of higher science quality signal at the spacecraft. However, this new approach posed risks due to potential interference from other ground telecommunication sources. If these interferences were to affect the signal being transmitted to the spacecraft during the closest approach to Pluto, the REX experiment could be significantly degraded or even lost. In designing the experiment, Oudrhiri and his team developed a unique capability to detect and correct any undesired interference.
Unlike missions to Mars, which are in orbit while collecting data, New Horizons was only designed to flyby Pluto for an hour at the closest approach. After waiting almost a decade, Oudrhiri and his team had a single shot at Pluto's atmosphere. Everything had to work flawlessly. As the spacecraft was closing in on Pluto, Oudrhiri’s team was already busy executing their procedures to enable multiple transmitters from the DSN antennas to beam their signals towards Pluto. From Earth, all seem to work as planned but without knowing the status of the experiment on Pluto, researchers waited painstakingly for four days for the data recorded during the Pluto encounter to be played back to Earth through one of the three, large 70 meter antennas located in California, Madrid, and Canberra. Once the data was acquired and the experiment was confirmed to be a success, the REX team could finally feel a sense of relief.
Earth’s atmosphere, including the outer limit, is about 10 percent of its radius, compared to Pluto’s atmosphere, which exceeds 350 times its size. Studying Pluto’s dynamic atmosphere will further our understanding of how this mysterious dwarf planet formed.
Oudrhiri believes innovation and technology will enable smaller spacecraft, such as CubeSats, to fly further, making it possible for university-lead projects to reach interplanetary destinations. Oudrhiri states, “I am really happy to see that my university, USC, is making great progress in building and launching small CubeSats.” USC alumni have made a big impact in space exploration, from Neil Armstrong to current NASA administrator Charlie Bolden, and Oudrhiri represents the latest of a new generation — one that will perhaps be able to explore the deep reaches of the universe.
