Caltech Space Challenge

Andrea, REVOLVE PhD Fellow participated in Caltech Space Challenge week.

The workshop brought 32 undergraduate and graduate students from all over the world to gather at Caltech and their task was to design a pre-phase A mission to Enceladus in 5 days. The participants came from different scientific backgrounds, representing engineering, science, business, graphical design, and many others. They were divided in two different groups and they were able to benefit from working under the mentorship of experienced engineers and managers from NASA’s Jet Propulsion Laboratory (JPL), Caltech (Keck Institute for Space Studies and Galcit) and private industry (Lockheed Martin, The Aerospace Corporation and Northrop Grumman).

Andrea worked in his team as the System Engineer (telecom, thermal and power subsystem dimensioning), and collaborated on the scientific instrumentation study as well as for the mission analysis concept and architecture. The opportunity to work with the other 15 people in his team, each from a different background gave him the opportunity to learn other scientific fields, and provided him with an opportunity to refine the rough work done in 5 days in order to have a more rigorous proposal and the opportunity of a conference paper (to be detailed soon). It is uncommon to have 16 people selected among several applicants working together on a mission concept!

The Workshop gave the team the opportunity to visit the Jet Propulsion Laboratory under the guide of A-team and X-team experts for half a day. The rest of the day was dedicated to classes under the mentorship of JPL engineers. During the week they enjoyed several lectures (soon to be online) on space exploration, science objectives and instrumentation. We had an afternoon of mentorship from the former JPL director Charles Elachi. He was also available to answer any technical and non-technical questions about their proposal.

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Advanced Synthesis of Reflect-Arrays

It is very likely to be that if you think about a space antenna, the image that appears in your mind is a parabola that sends electromagnetic waves toward the Earth or the deep space. An antenna, as it appears, is a metallic structure that captures and/or transmits radio electromagnetic waves. Antennas come in all shapes and sizes from little ones that can be found on your roof to watch TV to really big ones that capture signals from satellites millions of miles away (figure 1). The antennas that space satellites uses are a special bowl shaped antenna that focuses signals at a single point called a parabolic antenna. The bowl shape is what allows the antennas to both capture and transmit electromagnetic waves.

via GIPHY Figure 1 New Horizon mission spacecraft, a courtesy of jpl.nasa.gov

But what if this concept of capturing and/or transmitting electromagnetic waves would be performed in a slightly different way? Keeping in mind that a parabolic or shaped antennas exploits the geometric features of the reflecting surface to create a narrow and symmetric antenna beam, we can imagine to exploit another concept to perform this signal directivity.

The concept of a Reflect-Array is based on the fact that we want create this narrow and symmetric beam by using flat reflector, or we can say, flat antennas. This is the key point of the Reflect-Array technology. So, does not matter which kind of signal or for which application, a spacecraft would be equipped by a flat antenna.   The simple geometric shape of this kind of antenna would allow to reduce the cost of manifacturing, would allow a more flexible allocation on the spacecraft, since it can be conceived foldable, it can be lighter (reduction of mass in Space satellite is very important) and, last but not the least, it can offer a very performing and smart technology for space application.

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Figure 2: C-band Reflect-Array demonstrator, a courtesy of Thales Alenia Space France

Another milestone concept of Reflect-Array is that it is constituted by a flat panel that is printed with several metallic patches. Electromagnetic waves can be reflected in different way if they imping of different surfaces, in this case on different patches. The way the signal is reflected by every single patch will determine an ensemble of small signals that interact, they sum up or erase each other. The result is a directive narrow signal as would be produced by a traditional shaped antenna.

Figure 3: Deployment scheme of a faceted Reflect-Array, courtesy of Thales Alenia Space France.