OrbitalHub

NASA dixit:

“Dwarf planet Ceres is shown in these false-color renderings, which highlight differences in surface materials. Images from NASA’s Dawn spacecraft were used to create a movie of Ceres rotating, followed by a flyover view of Occator Crater, home of Ceres’ brightest area.”

Wikipedia dixit:

“Ceres (minor-planet designation: 1 Ceres) is the largest object in the asteroid belt, which lies between the orbits of Mars and Jupiter. Its diameter is approximately 945 kilometers (587 miles), making it the largest of the minor planets within the orbit of Neptune. The thirty-third-largest known body in the Solar System, it is the only one identified orbiting entirely within the orbit of Neptune that is a dwarf planet. Composed of rock and ice, Ceres is estimated to comprise approximately one third of the mass of the entire asteroid belt. Ceres is the only object in the asteroid belt known to be rounded by its own gravity. From Earth, the apparent magnitude of Ceres ranges from 6.7 to 9.3, and hence even at its brightest, it is too dim to be seen with the naked eye, except under extremely dark skies.

Ceres was the first asteroid discovered, by Giuseppe Piazzi at Palermo on 1 January 1801. It was originally considered a planet, but was reclassified as an asteroid in the 1850s when many other objects in similar orbits were discovered.

Ceres appears to be differentiated into a rocky core and icy mantle, and may have a remnant internal ocean of liquid water under the layer of ice. The surface is probably a mixture of water ice and various hydrated minerals such as carbonates and clay. In January 2014, emissions of water vapor were detected from several regions of Ceres. This was unexpected, because large bodies in the asteroid belt do not typically emit vapor, a hallmark of comets.

The robotic NASA spacecraft Dawn entered orbit around Ceres on 6 March 2015. Pictures with a resolution previously unattained were taken during imaging sessions starting in January 2015 as Dawn approached Ceres, showing a cratered surface. Two distinct bright spots (or high-albedo features) inside a crater (different from the bright spots observed in earlier Hubble images) were seen in a 19 February 2015 image, leading to speculation about a possible cryovolcanic origin or outgassing. On 3 March 2015, a NASA spokesperson said the spots are consistent with highly reflective materials containing ice or salts, but that cryovolcanism is unlikely. On 11 May 2015, NASA released a higher-resolution image showing that, instead of one or two spots, there are actually several. On 9 December 2015, NASA scientists reported that the bright spots on Ceres may be related to a type of salt, particularly a form of brine containing magnesium sulfate hexahydrite (MgSO4·6H2O); the spots were also found to be associated with ammonia-rich clays.”

Video credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

ESA dixit:

“Liftoff of Vega VV06 carrying LISA Pathfinder from Europe’s Spaceport, French Guiana, at 04:04 GMT/05:04 CET on 3 December 2015. Vega will place LISA Pathfinder into an elliptical orbit around our planet. Then, the spacecraft will use its own propulsion module to raise the highest point of the orbit in six stages. The last burn will propel the spacecraft towards its operational orbit, around a stable point called L1, some 1.5 million km from Earth towards the Sun.

Once on its final orbit, LISA Pathfinder will test key technologies for space-based observation of gravitational waves. These ripples in the fabric of spacetime are predicted by Albert Einstein’s general theory of relativity but have not yet been directly detected.

To demonstrate the fundamental approach that could be used by future missions to observe these elusive cosmic fluctuations, LISA Pathfinder will realize the best free-fall ever achieved in space. It will do so by reducing all the non-gravitational forces acting on two cubes and monitoring their motion and attitude to unprecedented accuracy.”

Video credit: ESA/Arianespace

ESA dixit:

“The AIM spacecraft will be launched in October 2020 on board a Soyuz-Fregat launch vehicle from Kourou. After launch and one or more deep-space manoeuvres, AIM will arrive at Didymos in June 2022, some months before DART’s impact.After arrival, the AIM spacecraft will transition into a heliocentric co-flying orbit, from which it will observe the binary system to derive a high-resolution 3D model of the asteroid, determine its mass and dynamical state, and characterise its surface and shallow sub-surface properties by means of a thermal infrared imager and high-frequency radar. This first characterisation phase would last for a couple of months and be conducted from a distance of between 35 to 10 km from the asteroid. Following this, the AIM spacecraft will release a number of CubeSats and a lander which is based on DLR’s MASCOT lander used for the JAXA Hayabusa-2 mission. The lander will carry out a detailed characterization of the deep-interior structure of the asteroid by means of a low-frequency bistatic radar. Approximately two weeks before DART impact, the AIM spacecraft would be moved to an orbit about 100 km from the asteroid to safely conduct impact observations. After the impact, a second characterisation phase would conclude the mission.

The AIM spacecraft is based on a very simple design with fixed solar arrays and a fixed high-gain antenna. The baseline propulsion system uses a bi-propellant (MMH/MON) fuel with 24 thrusters each capable of producing 10 N of thrust. A separate Helium tank would keep the four 60 l propellant tanks pressurized. Power is generated by two deployable, fixed solar arrays with an output of 165 W each at a distance of 2.2 AU from the Sun, and a total panel surface of 5.6 m². The total spacecraft dry mass would be about 420 kg and the propellant mass about 292 kg.

The target of the AIM mission is asteroid 65803 Didymos (1996 GT), an Apollo-type near-Earth orbit (NEO) with a perihelion that is just below the aphelion radius of Earth orbit. Didymos is a binary body; the primary body has a diameter of around 750 m and a rotation period of 2.3 hours, while the secondary body had a diameter of around 170 m and rotates around the primary at a distance of 1.2 km in 12 hours. Study of the Didymos moon should offer valuable insights into the origins of our Solar System, and help scientists develop planetary defence strategies against any incoming asteroids in the future. Informally called ‘Didymoon’, the asteroid is nearly three times larger than the body thought to have caused the 1908 Tunguska impact in Siberia, the largest impact in recorded history. An equivalent asteroid striking Earth would be well into the ‘city-killer’ class, leaving a crater of at least 2.5 km diameter and causing serious regional and climate damage. The 2013 Chelyabinsk airburst, whose shockwave struck six cities across Russia, is thought to have been caused by an asteroid just 20 m in diameter.”

Video credit: ESA

NASA dixit:

“Researchers at NASA’s Jet Propulsion Laboratory are developing the Buoyant Rover for Under-Ice Exploration, a technology that could one day explore oceans under the ice layers of planetary bodies. The prototype was tested in arctic lakes near Barrow, Alaska.”

Video credit: NASA JPL

Wikipedia dixit:

“Ceres is the largest object in the asteroid belt, which lies between the orbits of Mars and Jupiter. Its diameter is approximately 945 kilometers (587 miles), making it the largest of the minor planets within the orbit of Neptune. The thirty-third largest known body in the Solar System, it is the only one within the orbit of Neptune that is designated a dwarf planet by the International Astronomical Union (IAU). Composed of rock and ice, Ceres is estimated to comprise approximately one third of the mass of the entire asteroid belt. Ceres is the only object in the asteroid belt known to be unambiguously rounded by its own gravity. From Earth, the apparent magnitude of Ceres ranges from 6.7 to 9.3, and hence even at its brightest, it is too dim to be seen with the naked eye, except under extremely dark skies.

Ceres was the first asteroid discovered, by Giuseppe Piazzi at Palermo on 1 January 1801. It was originally considered a planet, but was reclassified as an asteroid in the 1850s when many other objects in similar orbits were discovered.

Ceres appears to be differentiated into a rocky core and icy mantle, and may harbor a remnant internal ocean of liquid water under the layer of ice. The surface is probably a mixture of water ice and various hydrated minerals such as carbonates and clay. In January 2014, emissions of water vapor were detected from several regions of Ceres. This was unexpected, because large bodies in the asteroid belt do not typically emit vapor, a hallmark of comets.

The robotic NASA spacecraft Dawn entered orbit around Ceres on 6 March 2015. Pictures with a resolution previously unattained were taken during imaging sessions starting in January 2015 as Dawn approached Ceres, showing a cratered surface. Two distinct bright spots (or high-albedo features) inside a crater, incorrectly reported as observed in earlier Hubble images, were seen in a 19 February 2015 image, leading to speculation about a possible cryovolcanic origin or outgassing. On 3 March 2015, a NASA spokesperson said the spots are consistent with highly reflective materials containing ice or salts, but that cryovolcanism is unlikely. On 11 May 2015, NASA released a higher resolution image showing that, instead of one or two spots, there are actually several.”

Video credit: NASA JPL

Credits: NASA/JPL

Juno is a NASA spacecraft scheduled to start its journey to Jupiter in a few days. Juno will help scientists understand the origin and evolution of Jupiter. While the dense cover of clouds helps Jupiter keep its secrets away from Earth observers, Juno will get close enough to Jupiter so that fundamental processes and conditions characteristic to the early solar system will be revealed.

First, Juno will try to determine if Jupiter has a solid planetary core. While this is an important piece of the puzzle, it might also help determine how Jupiter’s magnetic field is generated (by the way, scientists are still unclear how Earth’s magnetic field is generated, and there are several theories trying to explain it). Juno will also map Jupiter’s magnetic field, study the auroras, and determine the amount of water and ammonia in the atmosphere.

The launch vehicle to lift off with Juno is the most powerful Atlas rocket ever built, the United Launch Alliance Atlas V 551. In this configuration, an Atlas V launch vehicle can lift 18,810 kg to Low Earth Orbit (LEO) and 8,900 kg to Geosynchronous Transfer Orbit (GTO). However, the Atlas V 551 is not powerful enough to put Juno on a direct trajectory to Jupiter. In order to get as far as Jupiter’s orbit, Juno has to perform a gravity assist maneuver.

Juno will orbit Jupiter in a polar orbit and get as close as 5,000 km above the planet’s top clouds. This will allow the spacecraft to do science below the radiation belt of the planet and allow for a complete coverage of the planet. The low altitude will allow for a detailed analysis of the planet’s atmosphere. The orbit will also allow Juno to take a very close look at the auroras that are forming at the north and south Jovian poles.

The scientific payload carried by Juno includes a gravity/radio science system, a microwave radiometer, a vector magnetometer, particle detectors, ultraviolet and infrared spectrometers, and a color camera to capture images of the Jovian poles.

One interesting feature of the spacecraft is the electronics vault. Even if Juno’s highly elliptical orbit avoids the deadly radiation belts by approaching the planet at the north pole, skimming the clouds below the radiation belts, and exiting over the south pole, as an additional protection measure the onboard electronics are protected by a radiation shielded vault. This will ensure that the computers will not malfunction due to single events, and that the electronics will meet the requirements for the mission lifespan.

While the previous missions to the Jovian system have been powered by Radio Thermal Generators (RTGs), Juno will benefit from advances in solar power cell design. The cells used for Juno’s solar panels are far more efficient and radiation tolerant than the cells available to space systems engineers decades ago. Three solar panels that extend more than 10 meters from the hexagonal body of the spacecraft will provide the power required by the scientific instruments.

The mission is scheduled for launch on August 5, 2011. After coasting for more than two years, in October 2013, Juno will swing by Earth. The gravity assist maneuver will provide the delta V necessary for the spacecraft to reach Jupiter’s orbit. Juno will arrive at Jupiter in July 2016. After performing the Jupiter Orbital Insertion (JOI) maneuver, the spacecraft will start to collect and send back home scientific data.

Juno will send back science and telemetry data through the Deep Space Network (DSN), a network of powerful antennas located in Madrid, Spain; Barstow, California; and Canberra, Australia.

At the end of the mission, planned for October 2017, and after 33 complete revolutions around Jupiter, Juno will fire up its thrusters and decrease its velocity, enter the upper atmosphere of Jupiter, and get incinerated. Why such a tragic end to the Juno mission? Remember the Prime Directive? While the Prime Directive is known only to Star Trek fans… and it might get serious consideration only from Star Fleet officers, the possibility of having Juno crashing on one of the Jovian satellites (especially Europa) has to be eliminated. NASA scientists take contamination of other worlds very seriously.

You can find out more about the Juno mission on NASA’s dedicated web site. The Juno mission is managed by NASA’s Jet Propulsion Laboratory in Pasadena, California. The Principal Investigator for the Juno mission is Dr. Scott Bolton of Southwest Research Institute in San Antonio, Texas. The spacecraft was designed and built by Lockheed Martin of Denver, Colorado.