NASA has announced that its Psyche mission, which aims to explore a metal-rich asteroid of the same name, will be delayed by a year due to a problem with one of the spacecraft’s thrusters. The mission was originally scheduled to launch in August 2022, but now it is targeting a launch window that opens on October 5, 2023.
What is the NASA Psyche Mission?
The Psyche mission is a part of NASA’s Discovery Program, which supports low-cost and innovative exploration of the solar system. The mission’s goal is to study the asteroid Psyche, which is located in the main asteroid belt between Mars and Jupiter. Psyche is an unusual asteroid, as it is thought to be mostly made of iron and nickel, similar to the cores of terrestrial planets.
Scientists believe that Psyche could be the exposed core of a protoplanet that was stripped of its outer layers by violent collisions in the early history of the solar system. By studying Psyche, the mission hopes to gain insights into the formation and evolution of planetary cores, as well as the origin and diversity of asteroids.
The Psyche spacecraft will use solar electric propulsion to reach the asteroid, which will take about six years. The spacecraft will orbit Psyche for 21 months, using three scientific instruments to map and measure its surface features, composition, magnetic field, and gravity. The instruments are:
- A multispectral imager that will capture images of the asteroid’s surface in visible and infrared wavelengths.
- A magnetometer that will measure the strength and direction of the asteroid’s magnetic field.
- A gamma-ray and neutron spectrometer that will detect the elements present on the asteroid’s surface.
The mission will also carry a technology demonstration called Deep Space Optical Communications (DSOC), which will test the use of lasers to transmit data from deep space to Earth. This could potentially increase the data rate and efficiency of future missions.
What Caused the Delay?
According to NASA, the delay was caused by a problem with one of the four Hall thrusters that power the spacecraft’s solar electric propulsion system. Hall thrusters use electric and magnetic fields to accelerate and expel charged atoms of xenon gas, creating thrust. The problem was discovered during testing at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, where the spacecraft is being assembled and tested.
The issue was related to a misalignment between the thruster and its mount, which caused excessive wear on the thruster’s ceramic channel. The ceramic channel is a component that guides the flow of xenon gas inside the thruster. The wear could potentially reduce the thruster’s performance and lifespan.
The mission team decided to replace all four thrusters with new ones that have been modified to prevent the misalignment. The replacement process will take several months, pushing back the launch date by about a year.
What are the Implications of the Delay?
The delay will have some impacts on the mission’s cost, trajectory, and science objectives. NASA estimates that the delay will add about $117 million to the mission’s budget, which was originally capped at $450 million. The additional cost will be covered by NASA’s Planetary Science Division.
The delay will also affect the mission’s trajectory, or flight path, to Psyche. The original trajectory involved two gravity assist maneuvers from Mars and one from Earth, which would reduce the amount of propellant needed for the journey. The new trajectory will require three gravity assist maneuvers from Earth and none from Mars, which will increase the propellant consumption by about 10%. However, this will not affect the mission’s arrival date at Psyche, which is still expected to be in August 2029.
The delay will also have some minor impacts on the mission’s science objectives. The new trajectory will change the orientation of the spacecraft relative to the Sun and Psyche, which will affect how the instruments observe the asteroid’s surface and magnetic field. The mission team is working on adjusting the science plan to account for these changes and optimize the data collection.