The January issue of Scientific American has a cover story about the search for "Planet Nine" (which all right-thinking people know is Pluto!), and another article about Europa Clipper. It includes a nice graphic.
Quote from: Blackstar on 12/21/2024 12:13 amThe January issue of Scientific American has a cover story about the search for "Planet Nine" (which all right-thinking people know is Pluto!), and another article about Europa Clipper. It includes a nice graphic.If Pluto gets to be a planet, its #10, cause then Ceres gets to be one too!
Mars Flyby on March 1, 2025: • End-to-end test of REASON, the ice-penetrating radar • Calibration of E-THEMIS, the thermal mapper • Main purpose is a gravity assist • Perseverance will try and get an image of the spacecraft flying over
The largest crater of Mars as a bullseye for 'Clipper's flyby feels like a big, but intriguing, coincidence.
Quote from: redliox on 01/18/2025 11:14 pmThe largest crater of Mars as a bullseye for 'Clipper's flyby feels like a big, but intriguing, coincidence.It’s usually possible to time your gravity assist within a few days so picking a target of interest is just good planning.
Nice What specifically allowed them to keep the Earth flyby and arrival dates the same?
The spacecraft’s star trackers help engineers orient the orbiter throughout its long journey to Jupiter’s icy moon Europa.Three months after its launch from NASA’s Kennedy Space Center in Florida, the agency’s Europa Clipper has another 1.6 billion miles (2.6 billion kilometers) to go before it reaches Jupiter’s orbit in 2030 to take close-up images of the icy moon Europa with science cameras.Meanwhile, a set of cameras serving a different purpose is snapping photos in the space between Earth and Jupiter. Called star trackers, the two imagers look for stars and use them like a compass to help mission controllers know the exact orientation of the spacecraft — information critical for pointing telecommunications antennas toward Earth and sending data back and forth smoothly.In early December, the pair of star trackers (formally known as the stellar reference units) captured and transmitted Europa Clipper’s first imagery of space. The picture, composed of three shots, shows tiny pinpricks of light from stars 150 to 300 light-years away. The starfield represents only about 0.1% of the full sky around the spacecraft, but by mapping the stars in just that small slice of sky, the orbiter is able to determine where it is pointed and orient itself correctly.The starfield includes the four brightest stars — Gienah, Algorab, Kraz, and Alchiba — of the constellation Corvus, which is Latin for “crow,” a bird in Greek mythology that was associated with Apollo.Hardware CheckoutBesides being interesting to stargazers, the photos signal the successful checkout of the star trackers. The spacecraft checkout phase has been going on since Europa Clipper launched on a SpaceX Falcon Heavy rocket on Oct. 14, 2024.“The star trackers are engineering hardware and are always taking images, which are processed on board,” said Joanie Noonan of NASA’s Jet Propulsion Laboratory in Southern California, who leads the mission’s guidance, navigation and control operations. “We usually don’t downlink photos from the trackers, but we did in this case because it’s a really good way to make sure the hardware — including the cameras and their lenses — made it safely through launch.”Pointing the spacecraft correctly is not about navigation, which is a separate operation. But orientation using the star trackers is critical for telecommunications as well as for the science operations of the mission. Engineers need to know where the science instruments are pointed. That includes the sophisticated Europa Imaging System (EIS), which will collect images that will help scientists map and examine the moon’s mysterious fractures, ridges, and valleys. For at least the next three years, EIS has its protective covers closed.Europa Clipper carries nine science instruments, plus the telecommunications equipment that will be used for a gravity science investigation. During the mission’s 49 flybys of Europa, the suite will gather data that will tell scientists if the icy moon and its internal ocean have the conditions to harbor life.The spacecraft already is 53 million miles (85 million kilometers) from Earth, zipping along at 17 miles per second (27 kilometers per second) relative to the Sun, and soon will fly by Mars. On March 1, engineers will steer the craft in a loop around the Red Planet, using its gravity to gain speed.
This paper will outline the driving requirements for the overall spacecraft as well as describe the resulting spacecraft design and its key characteristics, including an overview of flight system-level integration and testing.
We describe the interplanetary and Jovian orbit design, Mission Plan, and Navigation Plan, and forecast performance against mission requirements to date.
On March 1, NASA’s Europa Clipper will streak just 550 miles (884 kilometers) above the surface of Mars for what’s known as a gravity assist — a maneuver to bend the spacecraft’s trajectory and position it for a critical leg of its long voyage to the Jupiter system. The close flyby offers a bonus opportunity for mission scientists, who will test their radar instrument and thermal imager.Europa Clipper will be closest to the Red Planet at 12:57 p.m. EST, approaching it at about 15.2 miles per second (24.5 kilometers per second) relative to the Sun. For about 12 hours prior and 12 hours after that time, the spacecraft will use the gravitational pull of Mars to pump the brakes and reshape its orbit around the Sun. As the orbiter leaves Mars behind, it will be traveling at a speed of about 14 miles per second (22.5 kilometers per second).The flyby sets up Europa Clipper for its second gravity assist — a close encounter with Earth in December 2026 that will act as a slingshot and give the spacecraft a velocity boost. After that, it’s a straightforward trek to the outer solar system; the probe is set to arrive at Jupiter’s orbit in April 2030.“We come in very fast, and the gravity from Mars acts on the spacecraft to bend its path,” said Brett Smith, a mission systems engineer at NASA’s Jet Propulsion Laboratory in Southern California. “Meanwhile, we’re exchanging a small amount of energy with the planet, so we leave on a path that will bring us back past Earth.”Harnessing GravityEuropa Clipper launched from Kennedy Space Center in Florida on Oct. 14, 2024, via a SpaceX Falcon Heavy, embarking on a 1.8-billion-mile (2.9-billion-kilometer) trip to Jupiter, which is five times farther from the Sun than Earth is. Without the assists from Mars in 2025 and from Earth in 2026, the 12,750-pound (6,000-kilogram) spacecraft would require additional propellant, which adds weight and cost, or it would take much longer to get to Jupiter.Gravity assists are baked into NASA’s mission planning, as engineers figure out early on how to make the most of the momentum in our solar system. Famously, the Voyager 1 and Voyager 2 spacecraft, which launched in 1977, took advantage of a once-in-a-lifetime planetary lineup to fly by the gas giants, harnessing their gravity and capturing data about them.While navigators at JPL, which manages Europa Clipper and Voyager, have been designing flight paths and using gravity assists for decades, the process of calculating a spacecraft’s trajectory in relation to planets that are constantly on the move is never simple.“It’s like a game of billiards around the solar system, flying by a couple of planets at just the right angle and timing to build up the energy we need to get to Jupiter and Europa,” said JPL’s Ben Bradley, Europa Clipper mission planner. “Everything has to line up — the geometry of the solar system has to be just right to pull it off.”Refining the PathNavigators sent the spacecraft on an initial trajectory that left some buffer around Mars so that if anything were to go wrong in the weeks after launch, Europa Clipper wouldn’t risk impacting the planet. Then the team used the spacecraft’s engines to veer closer to Mars’ orbit in what are called trajectory correction maneuvers, or TCMs.Mission controllers have performed three TCMs to set the stage for the Mars gravity assist — in early November, late January, and on Feb. 14. They will conduct another TCM about 15 days after the Mars flyby to ensure the spacecraft is on track and are likely to conduct additional ones — upwards of 200 — throughout the mission, which is set to last until 2034.Opportunity for ScienceWhile navigators are relying on the gravity assist for fuel efficiency and to keep the spacecraft on their planned path, scientists are looking forward to the event to take advantage of the close proximity to the Red Planet and test two of the mission’s science instruments.About a day prior to the closest approach, the mission will calibrate the thermal imager, resulting in a multicolored image of Mars in the months following as the data is returned and scientists process the data. And near closest approach, they’ll have the radar instrument perform a test of its operations — the first time all its components will be tested together. The radar antennas are so massive, and the wavelengths they produce so long that it wasn’t possible for engineers to test them on Earth before launch.
Mars ahoy! Europa Clipper is now about 458,000 miles (738,000 kilometers) from the Red Planet & closing. If you were riding along with the spacecraft, you could now see Mars as a small sphere instead of a reddish star.
NASA’s Europa Clipper, now en route to Jupiter, departed with less-than-satisfactory and vulnerable devices that are susceptible to Jupiter’s intense radiation.The spacecraft’s liftoff on October 14, 2024, in many ways, was arguably a fingers-crossed undertaking.But the coincidental way that the Europa Clipper team learned about the spacecraft’s vulnerabilities and devised solutions about problems has resulted in new lessons learned for future civilian missions bound for harsh high-radiation space destinations. Those lessons learned include the degree of testing necessary, beyond simply counting on “military specification” (Mil-Spec) standards to assure hardware is radiation-resilient enough for flight.
It seems odd to me that JPL/NASA won’t name the supplier that sold them junk and didn’t inform them of it. It’s public money, the public should have that information available. It was only happenstance that the defects came to light, do we really want to rely on lightning bolt levels of luck in the future?
Quote from: matthewkantar on 03/03/2025 07:37 pmIt seems odd to me that JPL/NASA won’t name the supplier that sold them junk and didn’t inform them of it. It’s public money, the public should have that information available. It was only happenstance that the defects came to light, do we really want to rely on lightning bolt levels of luck in the future?It was Infineon and that was public pretty much as soon as the news about the problems became public.
