NASA is days away from launching its Psyche mission, a venture that will send a spacecraft to a metal asteroid suspended in space between the orbits of Mars and Jupiter.
The mission’s launch window opens at 10:16 am on October 12 (US Eastern time) and is the first to study the asteroid 16 Psyche, which is believed to be the remains of an unformed planet core.
Psyche’s composition is unusual. As well as being mainly metallic – as opposed to rock or ice-based – the asteroid lacks many iron oxides found in the rocks of the solar system’s inner planets. Even so, scientists have hypothesised its metal body could be valued at $1 quintillion.
It’s believed that Psyche’s history is very different to that of rocky planets like our own. If it’s found to be the start of a planet-that-never-was, it will give a new perspective to the history of planet formation.
But it will take a while before NASA’s science team finds out.
After launching at the Kennedy Space Centre in Florida, the Psyche spacecraft will detach from its SpaceX Falcon Heavy launch rocket and begin its almost six-year journey towards the 226 km-wide object which is more than twice as far from the Sun than Earth is.
The spacecraft will run off a new propulsion system, which generates electric and magnetic fields using electricity generated from two large solar arrays.
The spacecraft’s thrusters will expel xenon atoms, enabling it to move forward. While it’s efficient, it’s not particularly powerful, so the acceleration is very different compared to fuelled space voyages to near-Earth destinations.
To help speed the journey, the spacecraft will first head towards Mars where it will ‘fly-by’ the red planet in May 2026 to achieve a gravity assist slingshot. With this momentum, it will arrive at Psyche in August 2029. That’s a little later than was originally intended after delays pushed its launch back a year.
Once it’s within sight of the asteroid, the spacecraft will begin transmitting information back to NASA from a multispectral imager which will photograph the asteroid using the visible and near-infrared spectra.
The elemental composition of the asteroid will be determined using a gamma-ray and neutron spectrometer – a tool that will measure these sources of radiation being emitted from 16 Psyche’s component metals.
Scientists believe Psyche’s unusual composition may be due to its past life as the core of an unformed planet. To determine this, a magnetometer be used to search for traces of an extinguished magnetic field – a hallmark of planets with a liquid metal core (like Earth).
NASA will also conduct a special test during the Psyche mission. Deep Space Optical Communications (DSOC) is a technology demonstration that will enable the space agency to try high-bandwidth optical communications beyond the Moon. DSOC will use a near-infrared laser to beam information back to Earth. If successful, DSOC will likely be used to transmit high-definition scientific data in future exploration missions.