Scientists loaded three missions worth nearly $1.6 billion on a SpaceX Falcon 9 rocket for launch Wednesday, toward an orbit nearly a million miles from Earth, to measure the supersonic stream of charged particles emanating from the Sun.
One of the missions, from the National Oceanic and Atmospheric Administration (NOAA), will beam back real-time observations of the solar wind to provide advance warning of geomagnetic storms that could affect power grids, radio communications, GPS navigation, air travel, and satellite operations.
The other two missions come from NASA, with research objectives that include studying the boundary between the Solar System and interstellar space and observing the rarely seen outermost layer of our own planet's atmosphere.
All three spacecraft were mounted to the top of a Falcon 9 rocket for liftoff at 7:30 am EDT (11:30 UTC) on Wednesday from NASA's Kennedy Space Center in Florida. The rocket arced on a trajectory heading east from Florida's Space Coast, shed its reusable first stage booster for a landing offshore, then fired its upper stage engine twice to propel the trio of missions into deep space.
A few minutes later, each of the spacecraft separated from the Falcon 9 to begin a multi-month journey toward their observing locations in halo orbits around the L1 Lagrange point, a gravitational balance point roughly 900,000 miles (1.5 million kilometers) from Earth toward the Sun. The combined pull from the Earth and Sun at this location provides a stable region for satellites to operate in, and a good location for instruments designed for solar science.
Liftoff of IMAP and its two co-passengers on a Falcon 9 rocket. Credit: SpaceX
Seeing the big picture
The primary mission launched on Wednesday is called the Interstellar Mapping and Acceleration Probe (IMAP). The spin-stabilized IMAP spacecraft is shaped like a donut, with a diameter of about 8 feet (2.4 meters) and 10 science instruments looking inward toward the Sun and outward toward the edge of the heliosphere, the teardrop-shaped magnetic bubble blown outward by the solar wind.