Jacqueline Hochheiser, Corporate Communications

In a historic interplanetary feat, NASA’s Mars helicopter, Ingenuity, successfully performed the first powered flight on another planet. Ingenuity embarked on a journey to Mars aboard the Perseverance rover in hopes of furthering NASA’s research into sending humans to the red planet in the future. Despite the millions of miles Ingenuity traveled into space, the mission is closer to home than you might think in at least one important way. The RF technology aboard Ingenuity and Perseverance is the critical link allowing NASA to communicate and send flight instructions to Ingenuity from Earth.

About Ingenuity and Its Mission

Ingenuity was transported and deposited at Jezero Crater, its test location, by the Perseverance rover on February 18, 2021 after launching into space on July 30, 2020 from Cape Canaveral Air Force Station in Florida. The site of Ingenuity’s flight testing was officially named the Wright Brother’s Field in honor of the first successful flight on Earth and linking that history to the first flight on another planet.

NASA’s Jet Propulsion Laboratory (JPL) was responsible for the design, construction and operation of Ingenuity during its 30 Sol (Martian day) test window on Mars. The helicopter is part of NASA’s Mars Exploration Program, which is a long-term effort of robotic exploration to find ancient signs of life and determine the possibility of sending astronauts to the planet in the future. Ingenuity serves as a technology demonstration to confirm if flight is indeed possible in the thin Martian atmosphere.

Ingenuity. Image courtesy of NASA / JPL-Caltech

Although Mars’ gravity is only one third of Earth’s, the atmosphere is only 1% as thick, making flight especially difficult. Ingenuity was engineered with these conditions in mind, resulting in an extremely light and tiny aircraft. The helicopter stands 19 in. (0.49m) tall and weighs just 4 lbs. (1.8 kg). Ingenuity’s rotor system spans 4 ft. (1.2m) in diameter, comprised of carbon fiber counter rotating blades with foam cores. At top speed, the blades spin at about 2,400 rpm, allowing the helicopter to travel at 6.6 ft. per second (2m/sec).

These small dimensions present the challenge of engineering miniaturized onboard computers that serve as Ingenuity’s brain. To ensure the computers’ reliability, the helicopter is equipped with solar powered batteries that provide ~350W worth of charge. The batteries also provide power for Ingenuity’s internal heating system to keep its computers at operating temperature during Mars’ cold nights, which can reach as low as -130⁰ F
(90⁰ C).

The ability to explore Mars from the skies offers researchers a different perspective of the alien landscape, as well as expanding on technological capabilities for future Mars missions. Using helicopters for exploration of the red planet will provide access to areas that rovers can’t reach such as steep or slippery terrain. Ingenuity is equipped with a black-and-white and a color camera that map Mars’ surface during flight. This will help researchers create 3D images of Mars’ terrain to provide valuable insight for eventual human exploration.

Ingenuity has successfully completed four flights with more planned for the future, all aimed at pushing the helicopter’s limits.  At the time of writing, Ingenuity has achieved a maximum height of 16 ft. (5m), a maximum round-trip distance of 872 ft. (266 m), and its longest flight time of 117 seconds. It has also been successful at rotating in place while in a hover to aim its cameras at different angles and take photos. Ingenuity has also captured multiple photos of the Martian landscape while in transit, providing JPL with quality color images.

The Role of RF in Ingenuity’s Mission

Radio frequency technology played a critical role in Ingenuity’s flight testing and the relay of scientific data from these flights back to Earth. The helicopter operates autonomously, which means that NASA does not directly communicate with Ingenuity and it operates of its own accord based on pre-coded computer algorithms sent from Earth to Mars. The Perseverance rove holds a significant role in Ingenuity’s flight testing, acting as the communications liaison between NASA and the helicopter.  

Both Perseverance and Ingenuity are outfitted with X-band and VHF antennas. The X-band frequency (8 to 12 GHz) is capable of traveling over long distances, and is frequently used for space missions. VHF (3 GHz) is most commonly used as a backup for x-band communications as it is a lower frequency and cannot transmit data as quickly. In many space missions spanning millions of miles, it is often crucial to involve one or more relay satellites that will help preserve signal integrity over the vast distance.

The Mars Relay Network is a constellation of five satellites that orbit Mars to aid communication and transmission of scientific data from Mars to Earth and vice versa. Of the five satellites, NASA owns four with the fifth belonging to the European Space Agency (ESA) resulting in near constant availability of relay satellite capability regardless of Earth’s and Mars’ rotations.

Using relay satellites can also improve latency, which becomes more prevalent the farther a transmitted signal travels. Signals are not physically able to travel faster than the speed of light (186,000 miles / second), and therefore the farther it travels, the longer the latency, or delay, will be. The delay sending data to and from Mars can span from 4 minutes (35 million miles) to 24 minutes (250 million miles) depending on Earth’s proximity to Mars during each planet’s revolution around the sun.

The satellites in the Mars Relay Network. Image courtesy of NASA/ JPL-Caltech

Due to the latency of signals sent to the Ingenuity mission, NASA sends pre-coded flight instructions to the Mars Relay Network, which then transmits the signal to Perseverance and finally to Ingenuity at the scheduled flight time. From its perch 211 ft. away from Ingenuity’s launch site, Perseverance also chronicles the helicopter’s flight by capturing videos and images of each flight with its two cameras Mastcam-Z and Navcam. Ingenuity will then relay the data it logged during flight back to Perseverance, up to the Relay Network and finally back to Earth.

NASA’s Deep Space Network (DSN), an array of giant radio antennas, is responsible for sending and receiving signals to and from various space missions including Ingenuity’s. The DSN is comprised of three ground terminals around the world that are operated by JPL. The three terminals are spaced equally apart at approximately 120◦ longitude. The locations include Goldstone, near Barstow, CA, near Madrid, Spain, and near Canberra, Australia. The strategic placement of these antennas allows constant communication with spacecraft regardless of Earth’s rotation. Each array is equipped with x-band and VHF antennas.

After just four flights, Ingenuity has proved to be a huge success and presents the first of many flights and helicopters that will explore Mars’ surface. The knowledge NASA will glean from the perspective that helicopters provide will contribute to their mission to ultimately sending humans to Mars. RF technology has played an instrumental role in making NASA’s aspirations a reality and allowing near seamless communication from the ground to Ingenuity from millions of miles away.

RF Components for Space Missions

Mini-Circuits is proud to support the space industry in expanding the limits of technology for satellite communications, astronomy and space exploration. We have over thirty years of experience working with customers in upscreening RF components for space flight and have successfully designed parts into spaceborne systems with a wide range of requirements. Learn more about our in-house space upscreening capabilities, and see how Mini-Circuits can help reduce cost and save time for your project.

Sources

NASA’s Ingenuity Mars Helicopter Succeeds in Historic First Flight (NASA)

Archived: Mars Helicopter and the Future of Extraterrestrial Flight (NASA Science)

Ingenuity’s Team Waits for Data on Helicopter’s First Flight (NASA/ JPL-Caltech)

Space Communications: 7 Things You Need to Know (Danny Baird, NASA’s Space Communications and Navigation Program)

NASA to Attempt First Controlled Flight on Mars as Soon as Monday (NASA)

What is the Deep Space Network? (NASA/ JPL-Caltech)

NASA’s Ingenuity Mars Helicopter Logs Second Successful Flight (NASA Science)

NASA’s Ingenuity Mars Helicopter Flies Faster and Farther on Third Flight (NASA Science)

Ingenuity Completes its Fourth Flight (NASA Science)

What is Telemetry? How Telemetry Works, Benefits, Challenges & More (Alexandra Altvater, Stackify)