Author: Abbey Interrante

With the installation of a charged particle detector on Dec. 3, 2024, all 10 of NASA’s Interstellar Mapping and Acceleration Probe (IMAP) science instruments have been fully integrated on the spacecraft.

Slated to launch no earlier than September 2025, IMAP will map the boundaries of the heliosphere — the protective bubble surrounding the Sun and planets that is inflated by the constant stream of particles from the Sun called the solar wind. As a modern-day celestial cartographer, IMAP will also explore and chart the vast range of particles in interplanetary space, helping to investigate two of the most important overarching issues in heliophysics: the energization of charged particles from the Sun and the interaction of the solar wind with interstellar space. IMAP plans to provide near real-time information about the solar wind to provide advanced space weather warnings from its location at Lagrange point 1, one million miles from Earth toward the Sun.

To achieve these goals, IMAP will use 10 science instruments built by multiple organizations and integrated at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. The instruments, listed in order by when they were integrated, are:

• • Interstellar Dust Experiment (IDEX): a mass spectrometer studying interstellar dust and interplanetary dust particles, designed and built by the Laboratory for Atmospheric and Space Physics in Boulder, Colorado.
  • IMAP Magnetometer (MAG): a pair of identical magnetometers that measure the magnetic field near the spacecraft, designed and built by Imperial College London.
  • IMAP-Ultra: two high-energy-range energetic neutral atom (ENA) imagers designed and built at APL.
  • High-energy Ion Telescope (HIT): a high-energy ion imager designed and built by NASA’s Goddard Space Flight Center.
  • Solar Wind Electron (SWE) instrument: maps electrons from the solar wind in three dimensions, designed and built by the Los Alamos National Laboratory (LANL) in collaboration with the Southwest Research Institute (SwRI).
  • GLObal Solar Wind Structure (GLOWS) instrument: a Lyman-alpha photometer that measures the ultraviolet glow from interstellar hydrogen and helium to investigate the solar wind and studies its evolution over time, designed and built by the Space Research Center of the Polish Academy of Sciences in Warsaw, Poland.
  • Solar Wind and Pickup Ion (SWAPI) instrument: measures ions from the solar wind and particles from beyond the solar system, designed and built by Princeton University.
  • IMAP-Hi: two medium-energy-range ENA imagers to help advance our understanding of the evolution of the outer heliosphere, designed and built by LANL in collaboration with SwRI, the University of New Hampshire (UNH), and the University of Bern in Switzerland.
  • IMAP-Lo: a low-energy-range ENA imager mounted on a pivot platform to help advance our understanding of the evolution of the outer heliosphere, designed and built by UNH in collaboration with SwRI, APL, and the University of Bern.
  • Compact Dual Ion Composition Experiment (CoDICE): measures the distributions and composition of interstellar pickup ions (charged particles that make it through the boundary of the heliosphere), designed and built by SwRI.

    

The integrated spacecraft is now running through a series of operations simulating the launch and postlaunch environments to ensure the spacecraft can withstand the rigors of space. While at APL, IMAP will also undergo a vibration and separation shock test, which replicates the launch vehicle separating from the spacecraft after takeoff.

Princeton University professor and principal investigator David J. McComas leads the mission with an international team of more than 25 partner institutions. APL is managing the development phase and building the spacecraft, and it will operate the mission. IMAP is the fifth mission in NASA’s Solar Terrestrial Probes (STP) Program portfolio. The Explorers and Heliophysics Projects Division at Goddard Space Flight Center manages the STP Program for the agency’s Heliophysics Division of NASA’s Science Mission Directorate.

By Mara Johnson-Groh
NASA’s Goddard Space Flight Center, Greenbelt, Md.

NASA’s Interstellar Mapping and Acceleration Probe (IMAP) is embarking on its yearlong integration and testing campaign, during which all of the instruments and components will be added to the spacecraft structure, tested to ensure they will survive the harsh environments of launch and space, and made ready to execute its mission.

On Sept. 19, the spacecraft returned to the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, after a trip to Aerojet Rocketdyne, where the propulsion system was added. The spacecraft was then transported to NASA’s Goddard Space Flight Center in Greenbelt, Maryland, where it underwent thermal testing.

“We are thrilled to have the spacecraft back at APL and to embark on the main elements of the system build,” said John Scherrer, the program manager for IMAP at APL. “The next several months will be very exciting as we see the IMAP spacecraft come together.”

The IMAP mission, which will be ready to launch in 2025, will explore our solar neighborhood, decoding the messages in particles from the Sun and beyond our cosmic shield. The mission will map the boundaries of the heliosphere — the electromagnetic bubble surrounding the Sun and planets that is inflated by the solar wind. As a modern-day celestial cartographer, IMAP will also explore and chart the vast range of particles in interplanetary space, helping to investigate two of the most important overarching issues in heliophysics: the energization of charged particles from the Sun and the interaction of the solar wind at its boundary with interstellar space.

Princeton University professor and principal investigator, David J. McComas leads the mission with an international team of more than 20 partner institutions. APL is managing the development phase, building the spacecraft, and will operate the mission. IMAP is the fifth mission in NASA’s Solar Terrestrial Probes (STP) Program portfolio. The Explorers and Heliophysics Projects Division at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the STP for the agency’s Heliophysics Division of NASA’s Science Mission Directorate.

Dave McComas said, “I am very proud of our entire team, who have come together from 25 institutions around the world to find creative solutions, solve challenging problems, and get us to this point. That teamwork will continue to be needed in the coming months to ensure the components of the mission are integrated and tested successfully.”

The public can watch alongside APL and other team member experts working on IMAP. A YouTube livestream of the cleanroom, where the spacecraft will be built and tested over the next year, is now available to watch at any time on the IMAP mission website. Viewers can watch the continuous stream to see exactly how the IMAP team takes us from a bare-bones structure to the complex, fully operational IMAP spacecraft.

Over the next several months, IMAP’s 10 instruments will arrive at APL from all over the world and be integrated into the spacecraft structure one by one. Once all of the instruments and the spacecraft’s various other subsystems and components are integrated, the IMAP team will begin a rigorous testing campaign. Finally, the spacecraft will be shipped back to Goddard to finish testing before launch.

“In the near future, IMAP will help provide important insights into the Sun’s heliosphere,” said Patrick Koehn, IMAP program scientist at NASA Headquarters. “Now, however, we have a unique opportunity to see the work it takes to prepare the spacecraft to make those observations, advancing our understanding of the solar system we live in.”

NASA’s Interstellar Mapping and Acceleration Probe (IMAP) mission held a critical design review (CDR) last week with a NASA Standing Review Board (SRB). This mission-level review was the culmination of individual CDRs conducted for all the instruments and subsystems. While there are still challenges ahead to face as a team, the review board is confident that IMAP has a plan to succeed.

Although CDR is often a gate to spacecraft construction, IMAP has already begun building important components such as instrument engineering and flight models as well as parts of the structure. With 10 instruments designed and built globally, the complicated dance of testing, cross-calibrating, and integrating these pieces is carefully choreographed so that the completed observatory will be ready for launch in 2025.

IMAP will explore our solar neighborhood, known as the heliosphere, and decode the messages in particles from the Sun and beyond. Three of the instrument suites will work together to build detailed maps of the boundaries of the solar system using energetic neutral atoms, which travel from the edge to Lagrange point 1 (L1), the point between the Sun and Earth where gravitational forces balance. IMAP’s other instruments collect information from the Sun’s solar wind and provide timely updates about space weather conditions.

The SRB chair noted that IMAP was “good to go” and had a lot of work to do.

Princeton University professor and IMAP Principal Investigator David J. McComas expressed his gratitude to the board for the good questions and said, “New challenges will surely emerge between now and launch, but I have every confidence in the awesome, committed, and resilient team that we have assembled to carry out this challenging mission.”

“We’re finally starting to see the integration of all these efforts, which is absolutely remarkable for me,” said Deputy Principal Investigator Nathan Schwadron. “We started with an idea. We proposed the concept, and then there’s this shift of momentum into actually making the hardware, building the spacecraft, getting them to work together. It really is our commitment to discovery as a team that helps make the transition from concept to reality.”

McComas leads the mission with an international team of 24 partner institutions. The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, is building the spacecraft and will operate 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.

To learn more about the IMAP mission visit the website: https://imap.princeton.edu

By Lindsay Bartolone
IMAP Communications Lead for Princeton University