• Science

Interstellar Probe would be a first-of-its-kind voyage beyond the Kuiper Belt, through the boundary of the Sun's giant magnetic bubble in to galactic space. The groundbreaking science of an Interstellar Probe crosses-over disciplinary mission goals.

Artist rendition of Voyager 1 and Voyager 2 probes

Credit: NASA/JPL-Caltech

Approximate position of NASA's Voyager 1 and Voyager 2 probes, outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto. Voyager 1 exited the heliosphere in August 2012. Voyager 2 exited at a different location in November 2018.

The Heliosphere as a Habitable Astrosphere »

What is the global nature of the heliosphere?

How do the Sun and the galaxy affect the dynamics of the heliosphere?

What is the nature of the interstellar medium?

Plowing through interstellar space, the Sun's magnetic field carves a bubble – the heliosphere – shielding our habitable solar system from interstellar plasma and galactic cosmic rays. Its global structure and astrophysical plasma processes remain mysteries solvable only with comprehensive in-situ and remote observations; the same kind of observations that will also help us understand astrospheres around other stars.

Origin and Evolution of Planetary Systems »

How did matter in the solar system originate and evolve?

The creation of our solar system resulted not only in the major planets, but the Kuiper Belt, with over 130 worlds and a dust disk whose large-scale structure remains unknown to us. Flybys and dust measurements from an outbound Interstellar Probe would unlock the secrets of how our solar system evolved, and serve as the unique ground truth for the increasing diversity of other exoplanetary systems and dust disks.

The Universe Beyond the Circumsolar Dust Cloud »

How did galaxies form and evolve?

The diffuse infrared (IR) radiation from all stars and galaxies is an important window to understand their evolution. Because of the foreground IR radiation from our own dust disk (known as the zodiacal cloud), this spectral window has remained closed. IR observations beyond the zodiacal cloud would therefore provide the first clues to early galaxy formation.

  • Voyage

With a goal of reaching 1,000 astronomical units – about 1,000 times the distance between Earth and the Sun ¬ – Interstellar Probe would take humanity's first deliberate step on the path to the stars. Traveling farther and faster than even the legendary Voyager spacecraft, Interstellar Probe would begin its flyby phase of objects and dwarf planets in the Kuiper Belt in just about four years. Ten to 15 years after launch, the mission's outer heliosphere phase would commence – a mark the Voyager missions took more than 40 years to reach. Ultimately, after 50 years, the Interstellar Probe would reach the pristine interstellar medium and zoom deeper into the galaxy to explore as long as its power source would allow.

  • Team

  • From the dawn of the Space Age and the establishment of NASA, an Interstellar Probe mission has a topic of fascination and discussion. The remarkable science opportunities that arise from such a mission have fueled the space science community for almost six decades, and led to multiple international studies. A team led by the Johns Hopkins Applied Physics Laboratory (APL) is shaping the latest and most detailed of these concepts, a trade study of a realistic mission architecture that includes available (or soon-to-be available) launch vehicles, kick stages, operations concepts and reliability standards. The trade study would serve as a useful reference for science and technology definition team. APL's work has been aided by nearly 200 professional scientists and engineers worldwide, and supplemented by the creative efforts of authors, filmmakers and other visionaries – all in pursuit of interstellar space exploration.

  • Spacecraft

Only five spacecraft have escaped the Sun's gravity field to travel to the outer solar system toward interstellar space: Pioneer 10 and 11, Voyagers 1 and 2, and New Horizons. Any Interstellar Probe spacecraft must be autonomous, compact and lightweight, and lean on power –yet robust enough to gather data and communicate with operators on Earth. Relying on heritage, the team is using the New Horizons spacecraft as its baseline design, with incremental improvements as needed. As with the Pioneers, Voyagers and New Horizons, the baseline power source is a radioisotope thermoelectric generator, which provides reliable power over long mission lifetimes and great distances from the Sun.

Voyagers 1 and 2 were launched in 1977 and still operate in the edges of the heliosphere.

Credit: NASA/JPL-Caltech

New Horizons has explored the Pluto system and other Kuiper Belt objects.

Credit: NASA/Johns Hopkins APL/SwRI

Prospective Payload

All of the instrument technologies needed to achieve an interstellar mission's science goals exist today. Given the delicate balance between asymptotic speed and mass, the study leads are seeking solutions that combine certain instrumentation to save mass, power and data rates.

A payload that addresses all science goals notionally consists of:

  • A particle and fields suite for exploring the interstellar medium and its interaction with the heliosphere, with detectors such as:
    • energetic neutral atom (ENA) camera
    • energetic particles/cosmic rays
    • solar /interstellar plasma and neutral wind
    • vector helium magnetometer
    • plasma wave
  • Optical cameras for flyby imaging and astrometry
  • A suite to measure dust and its basic composition
  • Infrared cameras for obtaining the 3D distribution of dust beyond our planetary neighborhood
  • News and Resources

In the News




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