Concerns about the health of the Juno spacecraft’s main engine have compelled NASA managers to keep the research probe in its current arcing, high-altitude orbit around Jupiter, a decision that will delay the full science return from the $1.1 billion mission but should still allow it to meet all predetermined objectives.
Updated at 3:30 p.m. EST with additional comments from Scott Bolton. NASA’s Juno spacecraft made a high-speed pass less than 3,000 miles over Jupiter’s turbulent clouds Thursday, taking dozens of pictures, measuring radiation and plasma waves, and peering deep inside the planet’s atmosphere, but officials still have not cleared the orbiter’s main engine for a planned maneuver to position the probe for improved science observations. As Juno prepared for Thursday’s encounter, managers weighed whether to cancel an engine burn originally scheduled for October to reshape the craft’s orbit. The solar-powered spacecraft made its closest approach about 2,670 miles (4,300 kilometres) over Jupiter’s cloud tops at 1257 GMT (7:57 a.m. EST) Thursday. NASA said all of Juno’s science instruments and its JunoCam color camera were operating during the flyby, and the data is being returned to Earth. Juno zipped by Jupiter at a relative velocity of about 129,000 mph (57.8 kilometres per second), approaching the planet over its north pole and departing over the south pole, according to NASA. For the first time, the Juno team solicited votes from the public to select all the pictures the JunoCam camera would take during the flyby. Participants on the mission’s web site will
On course to collect specimens from asteroid Bennu after its launch last year, NASA’s OSIRIS-REx spacecraft will search this month for objects sharing an orbit with Earth, a bonus science opportunity to locate possible fragments of the primordial building blocks that formed our home planet. The long-range observations begin Feb. 9 and run through Feb. 20, using one of the probe’s cameras to look for asteroids embedded in swarms scientists believe lurk ahead of and behind Earth in its orbit around the Sun. Named Earth-Trojans, the objects likely group in clouds at Sun-Earth Lagrange points, where the combined pull of gravity from the bodies would allow asteroids to orbit in lock-step with Earth. The so-called L4 and L5 Lagrange points lead and follow Earth by 60 degrees in its path around the Sun. The same positions in front of and behind Jupiter harbour thousands of Trojan asteroids, and smaller Trojan swarms have been discovered near Venus, Mars, Uranus and Neptune. It turns out OSIRIS-REx is about to pass through the Sun-Earth L4 Lagrange point, and managers decided to scan the region where Earth-Trojans might be located to see what the spacecraft can find. Now located nearly 74 million miles (119
Scientists planning the the next phase of NASA’s New Horizons mission, a robotic craft that completed the first exploration of Pluto in 2015, are going into the flyby of a frozen, faraway city-sized clump of rock on New Year’s Day 2019 armed with little knowledge of the target lurking around 4 billion miles from Earth.
NASA has selected two robotic missions to visit asteroids in the early 2020s from a field of proposed interplanetary probes, approving projects to explore a metallic relic from the early solar system and a half-dozen so-called Trojan objects left over from the formation of the outer planets. The Lucy and Psyche spacecraft will join NASA’s line of cost-capped Discovery missions, a program under which the agency’s Mars Pathfinder rover, the Messenger mission to orbit Mercury, and the Dawn probe currently orbiting the dwarf planet Ceres were developed, built and launched. Picked from a slate of 28 proposals submitted to NASA in 2015, Lucy and Psyche will visit worlds never before seen close-up as scientists seek to sort out the violent early history of the solar system, in which proto-planets coalesced from mergers and collisions between rocks and boulders in a disk around the sun. Lucy will launch in October 2021 on a preliminary trajectory to escape the bonds of Earth’s gravity, then return for flybys to use the planet’s gravity to slingshot toward the mission’s targets in the asteroid belt and beyond. The probe’s first destination in April 2025 will be the asteroid DonaldJohanson, named for the paleoanthropologist who discovered