Kennedy Space Center

SpaceX confirms that fueling for the second stage of the Falcon Heavy rocket carrying the Europa Clipper spacecraft is underway at NASA’s Kennedy Space Center in Florida.Comprising three Falcon 9 nine-engine cores, the 27 Merlin engines of the Falcon Heavy combine to generate more than 5 million pounds of thrust at liftoff, equal to approximately 18,747 aircraft.

Merlin engines — originally designed for recovery and reuse — use RP-1 and liquid oxygen as rocket propellants in a gas-generator power cycle.

Falcon Heavy utilizes the same second stage and same payload fairings as flown on Falcon 9.

In about 10 minutes, engine chill will begin on the rocket in preparation for launch, followed by the rocket and spacecraft transitioning to internal power. This will be NASA’s Launch Services Program tenth mission using a SpaceX rocket.

As NASA’s largest planetary spacecraft heads to the solar system’s largest planet to study one of its moons, let’s take a closer look inside the numbers of NASA’s Europa Clipper mission.

• 9 — The spacecraft carries nine science instruments and a gravity experiment that uses the telecommunications system. All the science instruments will operate simultaneously on every flyby, and scientists will then layer the data together to paint a full picture of Europa.
• 24 — The Europa Clipper spacecraft has 24 engines.
• 90 — Europa’s diameter is about 90% that of Earth’s Moon, with an equatorial diameter of 1,940 miles (3,122 kilometers).
• 100 — The spacecraft extends 100 feet (30.5 meters) from one end to the other and about 58 feet (17.6 meters) across. That’s about the size of a basketball court, thanks in large part to the solar arrays, which need to be huge so they can collect enough sunlight while near Jupiter to power the instruments, electronics, and other subsystems.
• 105 — Europa Clipper is NASA’s Launch Services Program 105th end-to-end mission.
• 1610 — Galileo Galilei found Europa, along with Jovian moons Ganymede, Callisto, and Io, with his homemade telescope in January 1610.
• 2030 — Mission planners are sending Europa Clipper past Mars and then Earth, using the planets’ gravity as a slingshot to add speed to the spacecraft’s trek. After journeying about 1.8 billion miles (2.9 billion kilometers) over 5 1/2 years, the spacecraft will fire its engines to enter orbit around Jupiter in 2030.
• 4,000 — Since the mission was officially approved in 2015, more than 4,000 people have contributed to Europa Clipper, including teams who work for contractors and subcontractors. Currently, about a thousand people work on the mission, including more than 220 scientists from both the U.S. and Europe.
• 13,000 — At the time of launch, Europa Clipper will weigh approximately 13,000 pounds (6,000 kilograms) with nearly 6,000 pounds (2,750 kilograms) of propellant.
• 20,000 — Jupiter is surrounded by a gigantic magnetic field 20,000 times stronger than Earth’s. As the field spins, it captures and accelerates charged particles, creating radiation that can damage spacecraft. Mission engineers designed a spacecraft vault to shield sensitive electronics from radiation, and they plotted orbits that will limit the time Europa Clipper spends in most radiation-heavy areas around Jupiter.
• 2,600,000 — As part of a mission campaign called “Message in a Bottle,” the spacecraft is carrying a poem by U.S. Poet Laureate Ada Limón, cosigned by millions of people from nearly every country in the world. Their names have been stenciled onto a microchip attached to a tantalum metal plate that seals the spacecraft’s electronics vault. Along with the poem and microchip, the plate features waveforms of people saying the word “water” in over 100 spoken languages.
• 1,800,000,000 — NASA’s Europa Clipper spacecraft will travel 1.8 billion miles (2.9 billion kilometers) from the agency’s Kennedy Space Center in Florida to Europa.

Managed by Caltech in Pasadena, California, NASA’s Jet Propulsion Laboratory leads the development of the Europa Clipper mission in partnership with the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, for NASA’s Science Mission Directorate in Washington. The main spacecraft body was designed by APL in collaboration with NASA JPL and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, NASA’s Marshall Space Flight Center in Huntsville, Alabama, and NASA’s Langley Research Center in Hampton, Virginia. The Planetary Missions Program Office at Marshall executes program management of the Europa Clipper mission.

NASA’s Launch Services Program, based at Kennedy Space Center in Florida, manages the launch service for the Europa Clipper spacecraft, which will launch on a SpaceX Falcon Heavy rocket from Launch Complex 39A at NASA Kennedy in Florida in just under 40 minutes.

The nine science instruments on NASA’s Europa Clipper spacecraft are the most advanced and sensitive that have ever been sent the outer solar system:

• Europa Imaging System (EIS) is a wide-angle camera and a narrow-angle camera, each with an eight-megapixel sensor, that will produce high-resolution color and stereoscopic images of Europa. They will study geologic activity, measure surface elevations, and provide context for other instruments.
• Europa Thermal Emission Imaging System (E-THEMIS) is a thermal imager that uses infrared light to distinguish warmer regions on Europa where liquid water may be near the surface or might have erupted onto the surface. It will also measure surface texture to understand the small-scale properties of the surface.
• Europa Ultraviolet Spectrograph (Europa-UVS) will help determine the composition of Europa’s atmospheric gases and surface materials by collecting spectra and images with an ultraviolet telescope. It will also search near Europa for signs of plume activity.
• Mapping Imaging Spectrometer for Europa (MISE) is the mission’s infrared spectrometer that will map the composition and distribution of ices, salts, organics, and the warmest hotspots on Europa. The maps will help scientists understand the moon’s geologic history and determine if Europa’s suspected ocean is suitable for life.
• Europa Clipper Magnetometer (ECM) will study Europa’s magnetic field and aims to confirm that Europa’s ocean exists, measure its depth and salinity, and measure the moon’s ice-shell thickness. It will also study Europa’s ionized atmosphere and how it interacts with Jupiter and its magnetic field.
• Plasma Instrument for Magnetic Sounding (PIMS) will separate distortions due to charged particles from Europa’s induced magnetic field, which carries information about Europa’s ocean. Europa’s ionosphere and plasma trapped in Jupiter’s magnetic field distort magnetic fields near Europa.
• Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is an ice-penetrating radar that will probe Europa’s icy shell for reflections from the moon’s suspected ocean and study the ice’s structure and thickness. It will also study the moon’s surface topography, composition, and roughness.
• Mass Spectrometer for Planetary Exploration/Europa (MASPEX) will analyze gases — both in Europa’s faint atmosphere and in possible plumes. It will study the chemistry of the moon’s suspected subsurface ocean, how ocean and surface exchange material, and how radiation alters compounds on the moon’s surface.
• Surface Dust Analyzer (SUDA) will identify the chemistry of material emitted from Europa’s surface by tiny meteorite impacts. A subsurface ocean or reservoirs might also vent material into space as plumes and offer clues to Europa’s ocean salinity.
• Gravity/Radio Science equipment will measure how Europa’s shape and its gravity field change as the moon’s non-circular orbit carries it closer, then farther, from Jupiter. These measurements at various points in the moon’s orbit will show how Europa flexes and help reveal its internal structure.

Some of the instrument sensors are installed on the nadir deck, which enables simultaneous observations of Europa’s surface during flybys, while the two instruments designed to capture gas and dust face in the direction of spacecraft motion. Radar antennas are mounted directly onto the spacecraft’s solar arrays. The spacecraft’s magnetometer is on a boom that extends from the spacecraft, reducing obstructions and magnetic interference from the spacecraft. PIMS has four detectors, two placed on the upper part of the spacecraft and two on the lower part. The instruments’ electronics are installed in a vault to protect them from radiation.

We’re a little under two hours away from today’s launch of NASA’s Europa Clipper mission from Launch Complex 39A at NASA’s Kennedy Space Center in Florida.

Here’s a closer look at some of today’s important countdown and ascent milestones (all times are approximate):

Time                 Events
– 00:53:00      Launch Director verifies go for propellant load
– 00:50:00      1st stage RP-1 (rocket grade kerosene) loading begins
– 00:45:00      1st stage LOX (liquid oxygen) loading begins
– 00:35:00      2nd stage RP-1 (rocket grade kerosene) loading begins
– 00:18:30      2nd stage LOX loading begins
– 00:07:00      Falcon Heavy begins engine chill
– 00:00:59      Flight computer commanded to begin final prelaunch checks
– 00:00:45      Launch Director verifies go for launch
– 00:00:20      Propellant tanks pressurize for flight
– 00:00:06      Engine controller commands engine ignition sequence to start
00:00:00         Falcon Heavy liftoff
00:01:07          Max Q (moment of peak mechanical stress on the rocket)
00:03:03          Side boosters engine cutoff (BECO)
00:03:07          Side boosters separate
00:04:02         1st stage main engine cutoff (MECO)
00:04:06         1st and 2nd stages separate
00:04:13          2nd stage engine starts (SES)
00:04:31          Fairing deployment
00:07:53          2nd stage engine cutoff (SECO-1)
00:47:40         2nd stage engine starts (SES-2)
00:50:56         2nd stage engine cutoff (SECO-2)
01:02:12           Europa Clipper deploys

Though NASA’s Europa Clipper mission sounds like something out of science fiction — investigating an icy alien world to see if it has the ingredients for life — the main science goal of determining if there are places below the surface of Jupiter’s icy moon Europa that could support life is based in science fact.

While Europa’s chilliness is certainly a defining characteristic, with surface temperatures at Europa ranging from about minus 208 degrees Fahrenheit to minus 370 F (minus 133 degrees Celsius to minus 223 C), scientists describe Europa as an “ocean world” because decades of evidence strongly suggests that an ocean of liquid water is hidden beneath the moon’s surface of ice, which is one of the only explanations for some of the moon’s characteristics. Scientists estimate it could be around 40 to 100 miles (60 to 150 kilometers) deep — large enough to contain more than twice as much water as all Earth’s oceans combined.

The best evidence that there’s an ocean at Europa was gathered by NASA’s Galileo spacecraft, which orbited Jupiter from 1995 to 2003. While Europa has no magnetic field of its own, when the Galileo spacecraft made 12 close flybys of Europa, its magnetometer detected a magnetic field within Europa as Jupiter’s powerful magnetic field swept past the moon. Scientists think the most likely cause of this magnetic signature is a global subsurface ocean of salty water.

Europa’s surface also has signs there may be an ocean beneath it. Images of Europa’s surface show patterns of cracks and ridges that suggest a global ocean underneath. The largest two impact structures on Europa show concentric patterns, which suggests impacts that may have penetrated through Europa’s ice shell into liquid water. In addition, Europa’s surface geology suggests that warm ice has risen upward through the ice shell, perhaps from near an ice-ocean interface.

Models also suggest that Europa’s ocean and icy shell get stretched and released by the tug of tidal forces from Jupiter’s gravity as Europa orbits the giant planet. This intermittent squeezing is called tidal flexing, and it creates heat inside Europa. In fact, the tidal flexing is likely creating enough heat inside Europa to maintain the liquid ocean beneath the surface.

Scientists believe two of Saturn’s moons also contain oceans — with tiny Enceladus having a global saltwater ocean that sprays out into space as a plume of icy particles that fly hundreds of miles above its surface, and the large moon Titan, thought to have a subsurface ocean as well. However, NASA’s in-depth exploration of an ocean world in search of ingredients for life begins with Europa and the Europa Clipper mission.

Liftoff is targeted for 12:06 p.m. EDT on a SpaceX Falcon Heavy rocket from historic Launch Complex 39A at the Kennedy Space Center in Florida.