NASA has delayed the launch of Psyche. Here’s why it’s a big deal

NASA and Team Psyche declined interview requests until an independent review of the mission delay was completed. Agency officials will make a decision on next steps based on this review in the coming months, Lori Glaze, head of NASA’s planetary science division, said at last month’s press conference. . But WIRED has been talking with other experts about options for sending a probe deep into the solar system, even if you can’t get it past Mars.

Parker, for example, thinks it might be possible for Psyche to reach her asteroid by relying more on the spacecraft’s solar-electric propulsion system. This system has solar panels that will deploy to the size of a tennis court, and they will convert sunlight into electricity to power Psyche’s Hall thrusters, efficient and long-lasting devices that emit a blue glow.

Parker says using the Falcon Heavy for launch is another benefit, as it will give the spacecraft more kinetic energy to start than a smaller rocket, which means it has to produce less solar power. along the way. Focusing on the power of liftoff and the onboard propulsion system would give mission planners some flexibility over launch times, he thinks, potentially allowing them to make the trip without relying on an alignment with Mars.

Another option for a spacecraft that needs a speed boost is to launch beyond Earth. This is the option chosen for the European Space Agency’s Rosetta spacecraft, which was launched in 2004 for a mission linked to a comet, explains Andrea Accomazzo, head of the Solar System and Exploration Missions Division of the ‘Agency. During the probe’s 10-year journey, it picked up speed through three flybys of Earth, then swung to Mars before heading for comet Churyumov-Gerasimenko and deploying the Philae lander there.

The Rosetta team faced two additional challenges: The comet had an elliptical orbit rather than a more circular orbit like most asteroids, which made it difficult to match its speed and velocity. And the researchers wanted to plan the trek so that Rosetta and its lander sidekick would meet up with the comet when it wasn’t very close to the sun, where it would be most active, ejecting chunks of ice and dust and complicating a landing that already would be difficult to remove.

Engineers design spacecraft with launch and trajectory options in mind, and in this case, a few trips around Earth was the best route. “You start from the target and then work backwards,” Accomazzo explains. “You have three sources of energy: the muzzle energy of the rocket, the energy in the spacecraft’s propellant tanks, and the energy you can get from planetary rotations. It’s a bit like the artisanal work of my colleagues who have tried to find the optimal solution.

Parker points out that the usefulness of planetary jumps depends on the geometry of the spacecraft’s trajectory, so they’re not always an option. But he agrees that they can be beneficial, especially when the destination is remote. “These main-belt asteroid missions are difficult and fuel-intensive,” he says. “Psyche could have launched directly to its target with a bigger launch vehicle or a smaller spacecraft or a different engine”, but that could have increased costs or reduced the scientific exploration that could be accomplished once the spacecraft arrived. . NASA expects the probe to have orbited the asteroid for at least 21 months while it images it and uses a magnetometer to look for remnants of a magnetic field, which could indicate it was origin of a planet’s core.

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