NASA and the Psyche team declined interview requests until an independent review of the mission delay is complete. Agency officials will make a decision on next steps based on that review in the coming months, Lori Glaze, chief of NASA’s planetary science division, said at a news conference last month. But WIRED talked to other experts about the 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 feasible for Psyche to reach its asteroid by relying more on the spacecraft’s solar-electric propulsion system. This system has solar arrays that will be deployed the size of a tennis court and convert sunlight into electricity to power Psyche’s Hall’s thrusters, efficient, long-lasting devices that emit a blue glow.
Parker says that using the Falcon Heavy for launch is another advantage, because it will give the spacecraft more kinetic energy to begin with than a smaller rocket, which means it has to generate less solar power along the way. Focusing on liftoff power and on-board propulsion would give mission planners some flexibility over launch times, he believes, allowing them to make the trip without counting on a Mars alignment.
Another option for a spacecraft that needs a speed boost is to launch beyond Earth. This was the option chosen for the European Space Agency’s Rosetta spacecraft, which launched in 2004 on a comet mission, says Andrea Accomazzo, head of the Solar System and Exploration Missions Division of the agency. During the probe’s 10-year journey, it gained speed through three flybys of Earth and then passed by Mars before heading to comet Churyumov-Gerasimenko and deploying the Philae lander there.
The Rosetta team faced two additional challenges: The comet had a steeply elliptical orbit rather than a more circular one like most asteroids, which hampered its speed and velocity. And the researchers wanted to plan the flyby so that Rosetta and its lander would encounter the comet when it wasn’t very close to the sun, where it would be most active, throwing up chunks of ice and dust and complicating an already tricky landing. ‘achieve.
Engineers design spacecraft with launch and trajectory options in mind, and in this case, a few trips around Earth were the best way to go. “Start at the goal and then work backwards,” says Accomazzo. “You have three sources of energy: the initial energy of the rocket, the energy of the propellant tanks of the spacecraft, and the energy you can get from planetary displacements. It’s a bit of handiwork by my colleagues who tried to find the optimal solution”.
Parker notes that the usefulness of planetary motions depends on the geometry of the spacecraft’s trajectory, so they are not always an option. But he agrees that they can be beneficial, especially when the destination is far away. “These main belt asteroid missions are tough and require a lot of fuel,” he says. “Psyche could have launched directly to its target with a larger 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 spatial NASA has been planning for the probe to orbit 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 that it was originally the core of a planet.