Since the dawn of the Space Age, Johns Hopkins APL has pushed the frontiers of space science, engineering, and exploration. APL captured the first picture of Earth from space, invented navigation by satellite, dispatched spacecraft across the solar system from our Sun to Pluto and beyond — and it continues to shape the future by providing our nation with innovative and low-cost solutions to its space challenges.
APL has become one of the few institutions in the country with proven capability to lead a space mission from design and build through operations and data delivery. Through the decades, the Lab has designed and built numerous groundbreaking projects, including more than 70 spacecraft and hundreds of specialized instruments. Hanging above you are six of the most notable of these projects.
Read below to learn more about each of these innovative and transformative missions.
Transit 1B
The Transit concept came just days after the launch of Sputnik on Oct. 4, 1957. Two APL scientists determined Sputnik’s orbit by analyzing the Doppler shift of its radio signals. If the satellite’s position was known and predictable, then Doppler shift could be used to locate a receiver on Earth. In other words, you could have navigation by satellite. Development of the Transit constellation began at APL in 1958. The first prototype satellite was launched in September 1959. The Transit system, the precursor to today’s GPS, entered naval service in 1984.
MESSENGER
Built by APL and launched Aug. 3, 2004, to study Mercury, the solar system's closest planet to the Sun, MESSENGER (or MEcury Surface, Space ENvironment, GEochemistry, and Ranging) entered orbit around the innermost planet on March 18, 2011, after a 6.5-year journey that covered 5 billion miles (8 billion kilometers). MESSENGER focused on Mercury's density, geologic history, magnetic field, core, key volatile molecules and unusual polar materials, which turned out to be water ice — on the closest planet to the Sun! The spacecraft’s global imaging of Mercury has also significantly improved our understanding of the terrestrial planets in our solar system. The spacecraft ended in April 2015 in a planned crash landing on Mercury.
New Horizons
New Horizons is a robust, lightweight observatory that withstood the long, difficult journey to the solar system's coldest, darkest frontiers. Launched in January 2006, New Horizons performed the first reconnaissance of Pluto and its moons in July 2015. It returned surprising new data about Pluto and its largest moon Charon, completing an initial exploration of the classical solar system before opening the door to a new realm of mysterious small planets and planetary building blocks in the Kuiper Belt. On Jan. 1, 2019, New Horizons broke its own record of farthest planetary exploration with its close flyby of the Kuiper Belt object called 2014 MU69 — officially named Arrokoth (Powhatan and Algonquian for “sky”). The spacecraft continues its journey out of the solar system even now.
Van Allen Probes
On Aug. 30, 2012, the twin Van Allen Probes were launched into nearly identical orbits to study and uncover details about Earth’s Van Allen Belts: invisible, donut-shaped rings of radiation that surround Earth. For seven years, the Van Allen Probes explored fundamental processes that operate throughout the solar system, particularly those that generate hazardous space weather effects near Earth and phenomena that could affect solar system exploration. The probes discovered processes that accelerate and transport electrons and charged atoms called ions within the radiation belts, and what conditions lead to that transport. They also provided a deeper understanding of how the radiation belts change during geomagnetic storms.
Parker Solar Probe
The Parker Solar Probe spacecraft will explore the Sun’s outer atmosphere and make critical observations to answer decades-old questions about the physics of stars. Launched on Aug. 12, 2018, the spacecraft will swoop within 4 million miles (6.4 million kilometers) of the Sun’s surface to face intense heat and radiation. The spacecraft and instruments are protected from the Sun’s heat by a 4.5-inch-thick carbon-composite shield, which withstands temperatures outside the spacecraft that reach nearly 2,500 degrees Fahrenheit. Parker Solar Probe will provide new data on solar activity and make critical contributions to our ability to forecast major space weather events that impact life on Earth.
DART
The Double Asteroid Redirection Test (DART) is the world’s first planetary defense test mission. Built at APL and launched Nov. 24, 2021, the DART spacecraft was designed to demonstrate the kinetic impact method of asteroid deflection. DART impacted the asteroid Dimorphos, the moonlet in the binary asteroid system Didymos, on Sept. 26, 2022. While neither asteroid posed a threat to Earth, DART showed a spacecraft can autonomously impact and change the course of a relatively small asteroid and deflect a genuinely dangerous asteroid if one were ever discovered.