When most people picture a spacecraft talking to Earth, they imagine a gleaming dish antenna the size of a backyard swimming pool, aimed heroically at the stars. Then Mars Cube One, better known as MarCO, came along and asked a gloriously unreasonable question: what if a spacecraft about the size of a briefcase could phone home from Mars?
That question sits at the heart of the interview topic, “Nacer Chahat Designs Antennas For Mars CubeSats.” Chahat, a NASA Jet Propulsion Laboratory antenna and microwave engineer, helped tackle one of the most stubborn problems in deep-space exploration: how to fit serious communication power into a spacecraft that has almost no room, limited energy, strict mass limits, and absolutely zero patience for mechanical drama once it is millions of miles from Earth.
The answer was not simply “make the antenna smaller.” In space engineering, that is the kind of sentence that sounds easy only until physics clears its throat. The MarCO CubeSats needed to receive data from NASA’s InSight lander during its entry, descent, and landing on Mars, then relay that information back to Earth in near real time. To do that, the spacecraft used a clever mix of deployable antennas, compact radios, precision pointing, and deep-space communication techniques. Tiny satellite, huge job. No pressure.
Who Is Nacer Chahat?
Nacer Chahat is known for his work in antenna design, spacecraft telecommunications, radar systems, electromagnetic compatibility, and deployable antenna technologies. At NASA’s Jet Propulsion Laboratory in Pasadena, California, his work has touched missions and research efforts involving CubeSats, landers, rovers, radar instruments, remote sensing, and Mars exploration.
His professional background is unusually broad. Chahat has worked across frequencies from UHF to terahertz, which means his engineering world spans everything from practical spacecraft radios to high-frequency systems used in imaging and sensing. He is also the author of CubeSat Antenna Design, a Wiley-IEEE Press book that collects lessons from JPL’s work on small spacecraft antennas. In plain English: he is one of the people you want in the room when your spacecraft is tiny, your data matters, and Mars is not exactly offering free Wi-Fi.
The interview that inspired this article focused on how antenna engineers deal with the harsh tradeoffs of deep-space CubeSats. MarCO was a perfect case study because it forced engineers to rethink what a small satellite could do. CubeSats were once mostly associated with student projects, low-Earth orbit experiments, and technology demonstrations close to home. MarCO helped move that story into interplanetary space.
Why Mars CubeSats Needed Special Antennas
MarCO consisted of two 6U CubeSats, MarCO-A and MarCO-B, launched with NASA’s InSight mission on May 5, 2018. Their job was not to land on Mars or enter orbit. Instead, they flew independently past the planet and attempted to relay InSight’s landing data back to Earth during one of the most nerve-racking events in planetary exploration: entry, descent, and landing.
InSight could communicate through existing Mars orbiters, including NASA’s Mars Reconnaissance Orbiter. But a dedicated flyby relay offered a powerful technology demonstration. If small spacecraft could provide near-real-time landing updates, future missions might bring their own communications support rather than depending entirely on orbital assets already at another planet.
That is where antennas became mission-critical. MarCO needed to receive UHF signals from InSight as the lander descended through the Martian atmosphere. Then it had to send that data across interplanetary distance to NASA’s Deep Space Network using X-band communications. The spacecraft had to point one antenna toward Mars and another toward Earth, all while operating with limited power and a body small enough to make a microwave oven look roomy.
The Antenna Problem Was a Packaging Problem
On a large spacecraft, engineers can often use bigger antennas, more power, and more forgiving hardware margins. On a CubeSat, every square centimeter becomes prime real estate. Components compete for space like passengers trying to fit luggage into an overhead bin during holiday travel.
The high-gain antenna needed to be large enough electrically to form a focused beam back to Earth. But it also had to survive launch, fit within the compact CubeSat configuration, deploy reliably in space, and remain stable during deep-space operations. A rigid dish would have been awkward. A simple patch antenna would not provide enough gain. The MarCO team needed something flat, foldable, efficient, and tough.
The Folded-Panel Reflectarray: A Flat Antenna Acting Like a Dish
The star of the MarCO antenna story is the folded-panel reflectarray, an elegant design that behaves somewhat like a parabolic dish while avoiding the bulk of a traditional curved reflector. Instead of a big bowl-shaped antenna, MarCO used flat panels patterned with carefully designed elements that controlled the phase of reflected radio waves.
In simple terms, the pattern on the antenna helped organize the outgoing signal so it behaved like it came from a much larger, more conventional high-gain antenna. It is a little like convincing a folding camping table to perform as a concert grand piano. Absurd? Yes. But with enough electromagnetic wizardry, surprisingly effective.
The MarCO high-gain antenna was designed for X-band Mars-to-Earth telecommunications, including operation around 8.425 GHz. Published technical descriptions of the antenna report a gain of about 29.2 dBic with right-hand circular polarization, while keeping the antenna mass under 1 kilogram and occupying only a small fraction of the spacecraft’s usable volume when stowed. That combination of compactness and performance is exactly what made the design important.
Why Reflectarrays Matter
A reflectarray combines ideas from reflector antennas and printed antenna arrays. Each cell or patch on the surface is engineered to shift the phase of the radio wave in a specific way. Together, those tiny features shape the beam. The result is a flat or panel-based antenna that can be easier to fold, package, and deploy than a conventional dish.
For CubeSats, reflectarrays are attractive because they can provide high gain without demanding a giant rigid structure. They also allow engineers to build antennas that stow tightly against the spacecraft. For MarCO, the panels folded against the outside of the CubeSat and deployed after launch, turning a compact spacecraft into a deep-space communicator.
UHF In, X-Band Out: The Bent-Pipe Relay
MarCO’s communication approach is often described as a “bent-pipe” relay. That phrase may sound like something from a plumber’s invoice, but in spacecraft communications it means the relay does not deeply process the data like a full communications hub. Instead, it receives the signal, converts or retransmits it, and sends it onward.
During InSight’s landing sequence on November 26, 2018, the lander transmitted status information in UHF. Each MarCO spacecraft attempted to receive that UHF data and relay it to Earth over X-band using the Iris radio system and the high-gain antenna. Because Mars and Earth were separated by light-travel time, “near real time” still meant a delay of several minutes. Space, unfortunately, refuses to install fiber broadband.
Even with that delay, the achievement was remarkable. MarCO enabled engineers on Earth to follow InSight’s descent far faster than they would have if they had waited only for later relay paths. The CubeSats turned a terrifying landing sequence into a live engineering drama with a much better signal.
The Iris Radio: A Small Box With a Big Responsibility
Antennas were only part of the system. MarCO also depended on the Iris radio, a compact deep-space transponder developed for small spacecraft. The radio provided UHF receive capability and X-band receive/transmit capability, allowing MarCO to listen to InSight and talk to Earth.
The radio and antenna system had to work together with navigation, attitude control, power, thermal management, and flight software. In deep space, nothing works alone. A high-gain antenna is useful only if the spacecraft can point it accurately. A radio is useful only if it has enough power and thermal stability. A deployment mechanism is useful only if it opens when commanded and does not decide, at the worst possible moment, to become modern art.
That is why Chahat’s work is best understood as systems engineering through the lens of antenna design. The antenna cannot be treated as a decorative add-on. It affects structure, power, pointing, mission operations, and risk.
What Made the MarCO Antenna Design So Difficult?
The MarCO antenna design had to satisfy several competing requirements at once. First, it had to fit inside or against a 6U CubeSat form factor. Second, it had to be light enough for the spacecraft’s mass budget. Third, it had to deploy after launch and remain stable. Fourth, it had to provide enough gain to communicate from Mars to Earth. Fifth, it had to survive the mechanical vibration of launch and the thermal environment of deep space.
Each requirement pushes against the others. Make the antenna larger and gain improves, but mass and packaging suffer. Make it lighter and deployment may become harder. Make the beam narrower and data transmission improves, but pointing becomes more demanding. Reduce complexity and reliability may improve, but performance may fall short. Antenna engineering is basically a long argument with tradeoffs, and the tradeoffs are very stubborn.
Deployment Is Not a Footnote
Deployable antennas are fascinating because they turn stored mechanical energy into mission capability. But they are also risky. A hinge, latch, spring, panel, cable, or release mechanism that behaves perfectly in a lab must also work after launch vibration, vacuum, temperature swings, and months of cruise.
For MarCO, folding the high-gain antenna panels flat was essential. But folding creates deployment risk. Engineers had to build confidence through modeling, testing, and careful coordination between mechanical and RF design teams. The antenna’s electromagnetic performance mattered, but so did the simple question: will it open?
RainCube, OMERA, and the Bigger Antenna Story
The interview also touched on projects beyond MarCO, including RainCube and OMERA. These projects show that MarCO was not a one-off trick. It was part of a broader movement at JPL to create deployable antennas for small spacecraft that could support communications, radar, and Earth science missions.
RainCube, short for Radar in a CubeSat, demonstrated a Ka-band radar in a compact CubeSat platform. Its deployable antenna work helped show that small spacecraft could carry instruments once associated with much larger satellites. That matters because Earth science often depends on radar observations, and smaller platforms can make missions more affordable, flexible, and repeatable.
OMERA, the One-Meter Reflectarray, pushed the idea further by exploring a larger deployable reflectarray concept. A one-meter-class antenna packed into a small spacecraft is an ambitious engineering challenge. It requires precise RF design, panel alignment, hinge mechanisms, feed placement, and structural stability. If MarCO proved a briefcase-sized relay could talk from Mars, projects like OMERA point toward a future where small satellites perform more demanding science and communication tasks.
Why MarCO Changed the Conversation About CubeSats
Before MarCO, CubeSats were already useful, but many people still viewed them as limited to Earth orbit. MarCO helped change that perception. The mission showed that small satellites could survive cruise to Mars, navigate independently, deploy antennas, communicate with the Deep Space Network, and perform a useful relay function during a major planetary landing.
MarCO did not replace large spacecraft. That is not the point. Big missions still need big systems, large instruments, powerful transmitters, and long-duration reliability. But MarCO proved that small spacecraft can be valuable companions. They can provide redundancy, targeted support, mission-specific communication, technology testing, or scout capabilities at a fraction of the scale of traditional spacecraft.
The “bring your own relay” idea is especially important. Future landers, probes, and flyby missions may benefit from small communications spacecraft designed for specific moments of high risk. During landing, minutes matter. A small relay can provide situational awareness, reduce uncertainty, and help teams understand what happened without waiting hours for data to arrive through another path.
Lessons From Chahat’s Antenna Work
The biggest lesson from Chahat’s work on Mars CubeSat antennas is that innovation often comes from constraint. If engineers had unlimited mass, unlimited space, and unlimited power, they might not need clever folded reflectarrays. But CubeSats force creativity. They demand that teams pack performance into origami-like structures, compact radios, and lean systems.
Another lesson is that antenna design is not just about radio waves. It is about mission architecture. The MarCO antennas influenced how the spacecraft oriented itself, how it relayed data, how it used power, and how it demonstrated a new operational concept. A good antenna can change what a mission is capable of doing.
Finally, MarCO shows that small spacecraft can punch far above their weight when engineers design them around a focused purpose. MarCO did not try to be a Mars orbiter, a lander, and a science observatory all at once. It had a clear mission: relay InSight landing data and demonstrate deep-space CubeSat communications. That focus made the engineering sharper.
Experiences and Reflections: What This Topic Teaches Engineers, Students, and Space Fans
One of the most inspiring parts of the MarCO antenna story is how practical it feels despite the cosmic setting. Yes, Mars is involved. Yes, radio waves are crossing millions of miles. Yes, the phrase “folded-panel reflectarray” sounds like it should come with a Ph.D. and possibly a secret handshake. But underneath the advanced engineering is a familiar problem: how do you make something important work when you do not have much room?
That problem appears everywhere. A student designing a small robot faces it. A product engineer building a wearable device faces it. A homeowner organizing a tiny garage faces it, although the consequences are usually less interplanetary. Chahat’s antenna work is a master class in designing under constraint. The limitation is not a wall; it is the shape of the puzzle.
For young engineers, MarCO is a reminder that the best solution is not always the biggest or most obvious. A traditional dish antenna would be easy to understand, but difficult to package. A flat reflectarray required deeper design work, but it fit the mission. That is a powerful engineering lesson: elegance often comes from finding the form that serves the system, not forcing the system to serve the form.
The story also teaches the value of interdisciplinary teamwork. Antenna engineers had to collaborate with mechanical engineers, thermal engineers, radio designers, flight software teams, mission planners, and navigation specialists. The antenna could not be designed in isolation. Its deployment affected mechanical layout. Its beam affected pointing. Its power needs affected operations. Its success depended on the spacecraft behaving as a complete organism, not a pile of impressive parts.
Another valuable experience from this topic is learning to respect testing. In science fiction, spacecraft unfold perfectly because the script says so. In real engineering, every hinge, panel, feed, cable, connector, and fastener earns trust through analysis and testing. MarCO’s antenna story shows that bold ideas still need boring discipline. The glamorous moment is the signal arriving from Mars; the invisible foundation is thousands of careful decisions made long before launch.
For space fans, the MarCO mission also changes the emotional scale of exploration. A spacecraft does not need to be enormous to matter. The MarCO CubeSats were small, but they had personality, purpose, and historic impact. Their nicknames, WALL-E and EVE, made them feel almost like brave little travelers. But the charm should not distract from the engineering achievement. These were not toys. They were deep-space technology demonstrators that helped prove a new model for mission support.
There is also a broader cultural lesson here. Space exploration advances not only through giant leaps but also through clever miniaturization. The future may include fleets of small spacecraft working alongside flagship missions, scouting destinations, testing instruments, relaying data, or creating distributed sensor networks. The antennas that make those spacecraft useful will be as important as their cameras, computers, and propulsion systems.
Chahat’s work invites us to see antennas differently. They are not just metal shapes bolted onto spacecraft. They are the voice of the mission. Without antennas, a spacecraft can explore but not report back. It can survive but not share. It can witness history but leave Earth waiting in silence. On MarCO, the antenna system gave a tiny spacecraft the ability to participate in one of NASA’s most dramatic Mars landings. That is not a small accessory. That is the difference between a lonely machine and a communicating explorer.
In the end, the interview topic matters because it captures a turning point. Nacer Chahat and the MarCO team helped show that small spacecraft could do meaningful work far from Earth when designed with precision, creativity, and courage. The antennas were compact, but the idea was enormous: deep-space exploration does not always need to arrive in a massive package. Sometimes it unfolds from a small box, points itself toward Earth, and says, “Message received.”
Conclusion
Nacer Chahat’s work on antennas for Mars CubeSats highlights one of the most exciting shifts in modern space engineering. The MarCO mission proved that small satellites can communicate across deep space, support planetary landings, and expand the possibilities for future exploration. By combining deployable reflectarray antennas, compact radio systems, smart mission design, and relentless testing, JPL engineers turned a pair of briefcase-sized spacecraft into historic interplanetary relays.
The story is not just about antennas. It is about the art of making ambitious missions possible with limited resources. It is about transforming constraints into inventions. And yes, it is also about proving that a small spacecraft can have a very big voice when the antenna is designed by people who know exactly how to make physics behave.
Note: This article synthesizes publicly available information from NASA/JPL mission materials, NASA technical reports, IEEE Spectrum coverage, Hackaday interview reporting, Wiley-IEEE references, NASA podcast materials, and related U.S.-based aerospace documentation. No source-link markup or citation placeholders have been inserted into the article body.
