NASA Psyche flies by Mars May 15

NASA’s Psyche spacecraft flew by Mars on Friday, May 15, using the planet’s gravity to bend its path and add speed for the longer trip to the asteroid Psyche, according to NASA. The agency said before the encounter that the spacecraft would pass about 2,800 miles, or 4,500 kilometers, above the Martian surface at roughly 12,333 mph, or 19,848 kph. (science.nasa.gov) The maneuver is a standard gravity assist, but for Psyche it is the mission’s only planned planetary flyby before arrival in the main asteroid belt. The spacecraft launched on Oct. 13, 2023, aboard a SpaceX Falcon Heavy from NASA’s Kennedy Space Center in Florida. (science.nasa.gov) ### Why did a spacecraft headed to an asteroid need to swing past Mars? NASA said the Mars encounter lets mission planners save propellant by using the planet’s gravity to do part of the work that the spacecraft’s propulsion system would otherwise have to provide. Psyche uses solar-electric propulsion and xenon propellant, gradually building speed over a yearslong cruise rather than relying on one large burn. The target is 16 Psyche, a metal-rich asteroid between Mars and Jupiter that NASA describes as one of the more unusual objects in the solar system. The mission is the first NASA attempt to study an asteroid thought to contain more metal than rock or ice, with scientists using it as a way to examine material that may resemble the interior building blocks of planets. (science.nasa.gov) ### How close did Psyche come, and how fast was it moving? NASA’s May 8 mission update put closest approach at about 2,800 miles above Mars and the flyby speed at about 12,333 mph. Those numbers made the encounter close enough to reshape the spacecraft’s trajectory while still leaving room for planned imaging and instrument work during the pass. (science.nasa.gov) Friday’s flyby was designed as both a navigation event and an operations rehearsal. NASA said gravity assists also give teams a chance to practice procedures and calibrate science instruments before the spacecraft reaches its primary target. (science.nasa.gov) ### What were the Mars pictures for if the mission is not going to Mars? On May 3, Psyche photographed Mars from about 3 million miles, or 4.8 million kilometers, away, producing a thin crescent view of the planet, according to NASA. The agency said the geometry of the approach left the Sun out of frame and above the planet, while dust in the Martian atmosphere scattered sunlight and made the crescent appear extended. (science.nasa.gov) NASA said the early Mars images were primarily intended to calibrate the spacecraft’s multispectral imager and characterize its performance in flight. The mission team plans to use the imager to collect thousands of observations of Mars around the flyby, both to refine instrument settings and to rehearse the techniques it will need when the spacecraft approaches the asteroid in 2029. (science.nasa.gov) Scientific American reported on Friday that the crescent Mars image was taken during the approach phase and highlighted how the flyby doubles as a practice run for the asteroid encounter. (science.nasa.gov) ### What happens after Mars is behind it? NASA’s mission overview says asteroid Psyche’s gravity is expected to capture the spacecraft in late July 2029, with prime science operations beginning in August 2029. The spacecraft is then expected to spend about 26 months in a sequence of mapped orbits around the asteroid, taking images and gathering data on its composition, structure and magnetic field. (science.nasa.gov) Arizona State University leads the mission, while NASA’s Jet Propulsion Laboratory manages it. NASA says the next major milestone after the Mars flyby is arrival at the asteroid in 2029, when the instruments tested during this week’s encounter are scheduled to begin their main science campaign. (scientificamerican.com) (psyche.ssl.berkeley.edu) (science.nasa.gov)