Image Credit: NASA/Johns Hopkins/Princeton/Ed Whitman
By Hayley Dunning
Join our researchers as they install their instrument on NASA’s IMAP spacecraft, set to launch next year on a mission to study the A stream of charged particles, mostly protons and electrons, that escapes into the Sun's outer atmosphere at high speeds and streams out into the solar system..
The Interstellar Mapping and Acceleration Probe (IMAP) spacecraft will observe and map the Sun’s The region around the Sun where the solar wind dominates over the interstellar medium. – the volume of space filled with particles streaming out from the Sun, known as the solar wind – and study how it interacts with the local galactic neighborhood beyond, known as the All the gas and dust found between stars..
Imperial physicists have built a A device to measure the strength of a magnetic field. (MAG) instrument for the mission, which will measure the interplanetary A field of force that is generated by electric currents. The Sun's average large-scale magnetic field, like that of the Earth, exhibits a north and a south pole linked by lines of magnetic force. around the spacecraft. From these measurements, MAG will identify interplanetary shocks and measure the waves and turbulence that scatter particles in the solar wind.
The UK Space Agency has supported the UK development of the IMAP mission with £4.2 million, including funding for the MAG instrument.
IMAP is now being assembled at the Johns Hopkins University Applied Physics Lab (APL) in Maryland, USA, before launch in summer 2025. MAG’s Principal Investigator, Professor Tim Horbury, and Instrument Manager, Helen O’Brien, went out to APL in August to help MAG get installed on the spacecraft.
Here, Professor Horbury talks us through some of the photos and videos that captured the excitement of seeing their instrument get into its final position – ready for space.
“It feels very real when you’re in a room with it. The sensors were mounted on a boom – a long arm that will keep them away from the spacecraft when it’s in space, but for now is folded onto the main craft. So the sensors are mounted and we’ve plugged them in, along with the electronics box, so everything is in its ‘final flight configuration’. We won’t unplug it again.” - Professor Tim Horbury
Tim (left) and Helen (right) in the assembly clean room with the spacecraft.
Image Credit: NASA/Johns Hopkins/Princeton/Ed Whitman
“In our South Kensington lab, the sensors were always in special ‘cans’ when switched on, to shield them from the Earth’s magnetic field. Now, whenever they are switched on – which will be at various times in the next few months – they will measure the Earth’s and the spacecraft’s magnetic fields.”
The MAG instrument consists of two sensors, seen as the silver metallic cylinders on the black boom observed by Helen and Hunter McNamara of APL.
Image Credit: NASA/Johns Hopkins APL/Princeton/Ed Whitman
“Many of these times will be when the spacecraft goes through several rigorous tests to check everything will survive launch and the space environment, including thermal, vibration, electromagnetic and acoustic shocks.”
The A device to measure the strength of a magnetic field. (MAG) boom shown in the deployed position.
Image Credit: NASA/Johns Hopkins/Princeton/Ed Whitman
“We also tested the boom deployment. To simulate the lack of gravity, the spacecraft was turned on its side and the boom suspended by ropes. It was then ‘led’ out by an engineer. The moment the boom is released, there is a loud ‘pop’ that’s a little disconcerting, but everything worked as it should.”
[This video has no sound] Video Credit: NASA/Johns Hopkins/Princeton/Lee Hobson
“We also saw the spacecraft spin many times. In space, this is necessary to keep it stable and to ensure the particle sensors onboard get a full view of the sky. It also helps to calibrate the MAG sensors.”
[This video has no sound] Video Credit: NASA/Johns Hopkins/Princeton
“Before the boom is deployed, one of the MAG sensors will sit among the solar panels. As these will constantly face the Sun when out in space, the sensor could get extremely hot in its first few days.
“Ideally, we want to turn the sensors on to measure the magnetic field before and after the boom unfolds, to compare them, but if they’re too hot we can’t risk it. Once the spacecraft launches from Cape Canaveral in Florida, we’re going straight to an operations centre in Colorado to measure the temperatures and make that decision.”
John Schellhase performs a walk-out of the A device to measure the strength of a magnetic field. (MAG) boom on the Interstellar Mapping and Acceleration Probe (IMAP) at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.
Image Credit: NASA/Johns Hopkins/Princeton/Ed Whitman
“The team at APL have been outstanding. It’s an extraordinary operation, a complete juggling act, but they do it while allowing for setbacks that mean the overall project runs very smoothly.”
Helen and John Schellhase of APL inspect the A device to measure the strength of a magnetic field. sensors mounted on the MAG boom prior to a deployment test.
Image Credit: NASA/Johns Hopkins/Princeton/Ed Whitman
Princeton University professor David J. McComas leads the IMAP mission with an international team of 25 partner institutions. The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland builds the spacecraft and operates the mission. IMAP is the fifth mission in NASA’s Solar Terrestrial Probes (STP) program portfolio. The Explorers and Heliophysics Project Division at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the STP Program for the agency’s Heliophysics Division of NASA’s Science Mission Directorate.
Learn more on the Imperial website.