OrbitalHub

NASA dixit:

“Parker Solar Probe mission will revolutionize our understanding of the Sun, where changing conditions can propagate out into the solar system, affecting Earth and other worlds. Parker Solar Probe will travel through the Sun’s atmosphere, closer to the surface than any spacecraft before it, facing brutal heat and radiation conditions — and ultimately providing humanity with the closest-ever observations of a star.

In order to unlock the mysteries of the Sun’s atmosphere, Parker Solar Probe will use Venus’ gravity during seven flybys over nearly seven years to gradually bring its orbit closer to the Sun. The spacecraft will fly through the Sun’s atmosphere as close as 3.8 million miles to our star’s surface, well within the orbit of Mercury and more than seven times closer than any spacecraft has come before. (Earth’s average distance to the Sun is 93 million miles.)

Flying into the outermost part of the Sun’s atmosphere, known as the corona, for the first time, Parker Solar Probe will employ a combination of in situ measurements and imaging to revolutionize our understanding of the corona and expand our knowledge of the origin and evolution of the solar wind. It will also make critical contributions to our ability to forecast changes in Earth’s space environment that affect life and technology on Earth.

Parker Solar Probe will perform its scientific investigations in a hazardous region of intense heat and solar radiation. The spacecraft will fly close enough to the Sun to watch the solar wind speed up from subsonic to supersonic, and it will fly though the birthplace of the highest-energy solar particles.

To perform these unprecedented investigations, the spacecraft and instruments will be protected from the Sun’s heat by a 4.5-inch-thick (11.43 cm) carbon-composite shield, which will need to withstand temperatures outside the spacecraft that reach nearly 2,500 F (1,377 C).”

Credits Video: NASA Goddard

Blue Origin dixit:

“New Shepard flew for the ninth time on July 18, 2018. During this mission, known as Mission 9 (M9), the escape motor was fired shortly after booster separation. The Crew Capsule was pushed hard by the escape test and we stressed the rocket to test that astronauts can get away from an anomaly at any time during flight. The mission was a success for both the booster and capsule. Most importantly, astronauts would have had an exhilarating ride and safe landing. This isn’t the first time we’ve done this type of extreme testing on New Shepard. In October of 2012, we simulated a booster failure on the launch pad and had a successful escape. Then in October of 2016, we simulated a booster failure in-flight at Max Q, which is the most physically strenuous point in the flight for the rocket, and had a completely successful escape of the capsule. This test on M9 allowed us to finally characterize escape motor performance in the near-vacuum of space and guarantee that we can safely return our astronauts in any phase of flight. Also on M9, New Shepard carried science and research payloads from commercial companies, universities and space agencies.”

Credits Video: Blue Origin

ESA dixit:

“One of the deepest ‘swimming pools’ in Europe, for three years has been helping preparations for a human return to the Moon. ESA’s Neutral Buoyancy Facility at the European Astronaut Centre has been the site of the ‘Moondive’ study, using specially weighted spacesuits to simulate lunar gravity, which is just one sixth that of Earth.

The three-year study took place in the Centre’s 10-m deep Neutral Buoyancy Facility (NBF) near Cologne in Germany. This is one of four such immersion tanks worldwide – the others are in the United States, China and Russia – and is used to train astronauts for ‘extra vehicular activity’ (EVA), also known as spacewalks.

With International Space Station operations moving towards an international lunar return in the late 2020s, ESA’s NBF has been used to investigate moonwalk procedures for the lunar surface.

Moondive was run by a consortium led by the French company, COMEX, which specialises in human and robotic exploration of extreme environments. Footage is also seen from precursor project Moonwalk, including simulated EVAs off the coast of Marseilles, funded by the European Commission’s Seventh Framework Programme.”

Credits Video: ESA/COMEX/EC FP7 Moonwalk project

ESA dixit:

“This is an animated 3D view of the sky as observed by ESA’s Gaia satellite using information from the mission’s second data release. The bright band in the left half of the image is the Milky Way, where most of the stars in our Galaxy reside. The animation starts with the Orion constellation at the centre; we then move towards the neighbouring Taurus constellation and to the Hyades star cluster, which is part of this constellation. Hyades is the closest open cluster to the Solar System, some 150 light-years away.

The animation first shows the 3D structure of the cluster, based on accurate position and distance information from Gaia. Then an animated view of the future motions of stars is shown – both in Hyades and beyond. This is based on Gaia’s measurements of the velocity of stars across the sky, also known as proper motion.”

Credits Video: ESA/Gaia/DPAC, CC BY SA 3.0 IGO/Gaia Data Processing and Analysis Consortium (DPAC); Gaia Sky; S. Jordan / T. Sagristà, Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Germany

NASA dixit:

“A new study using data from NASA’s NuSTAR space telescope suggests that the most luminous and massive stellar system within 10,000 light-years, Eta Carinae, is accelerating particles to high energies — some of which may reach Earth as cosmic rays. Cosmic rays with energies greater than 1 billion electron volts (eV) come to us from beyond our solar system. But because these particles — electrons, protons and atomic nuclei — all carry an electrical charge, they veer off course whenever they encounter magnetic fields. This scrambles their paths and masks their origins. Eta Carinae, located about 7,500 light-years away in the southern constellation of Carina, contains a pair of massive stars whose eccentric orbits bring them unusually close every 5.5 years. The stars contain 90 and 30 times the mass of our Sun.

Both stars drive powerful outflows called stellar winds, which emit low-energy X-rays where they collide. NASA’s Fermi Gamma-ray Space Telescope observes gamma rays — light packing far more energy than X-rays — from a source in the direction of Eta Carinae. But Fermi’s vision isn’t as sharp as X-ray telescopes, so astronomers couldn’t confirm the connection. To bridge this gap, astronomers turned to NASA’s NuSTAR observatory. Launched in 2012, NuSTAR can focus X-rays of much greater energy than any previous telescope.

The team examined NuSTAR observations acquired between March 2014 and June 2016, along with lower-energy X-ray observations from the European Space Agency’s XMM-Newton satellite over the same period. NuSTAR detects a source emitting X-rays above 30,000 eV, some three times higher than can be explained by shock waves in the colliding winds. For comparison, the energy of visible light ranges from about 2 to 3 eV.

The researchers say both the X-ray emission seen by NuSTAR and the gamma-ray emission seen by Fermi is best explained by electrons accelerated in shock waves where the winds collide. The X-rays detected by NuSTAR and the gamma rays detected by Fermi arise from starlight given a huge energy boost by interactions with these electrons. Some of the superfast electrons, as well as other accelerated particles, must escape the system and perhaps some eventually wander to Earth, where they may be detected as cosmic rays. Zoom into Eta Carinae, where the outflows of two massive stars collide and shoot accelerated particles cosmic rays into space.”

Credits Music: “Expectant Aspect” from Killer Tracks

Credits Video: NASA’s Goddard Space Flight Center

Wikipedia dixit:

“Near-Earth asteroids are objects in a near-Earth orbit without the tail or coma of a comet. NEAs survive in their orbits for just a few million years. They are eventually eliminated by planetary perturbations, causing ejection from the Solar System or a collision with the Sun or a planet. With orbital lifetimes short compared to the age of the Solar System, new asteroids must be constantly moved into near-Earth orbits to explain the observed asteroids. The accepted origin of these asteroids is that main-belt asteroids are moved into the inner Solar System through orbital resonances with Jupiter. The interaction with Jupiter through the resonance perturbs the asteroid’s orbit and it comes into the inner Solar System. The asteroid belt has gaps, known as Kirkwood gaps, where these resonances occur as the asteroids in these resonances have been moved onto other orbits. New asteroids migrate into these resonances, due to the Yarkovsky effect that provides a continuing supply of near-Earth asteroids. Compared to the entire mass of the asteroid belt, the mass loss necessary to sustain the NEA population is relatively small; totalling less than 6% over the past 3.5 billion years. The composition of near-Earth asteroids is comparable to that of asteroids from the asteroid belt, reflecting a variety of asteroid spectral types.

A small number of NEAs are extinct comets that have lost their volatile surface materials, although having a faint or intermittent comet-like tail does not necessarily result in a classification as a near-Earth comet, making the boundaries somewhat fuzzy. The rest of the near-Earth asteroids are driven out of the asteroid belt by gravitational interactions with Jupiter.

Many asteroids have natural satellites (minor-planet moons). As of March 15, 2017, 66 NEAs were known to have at least one moon, including three known to have two moons. The asteroid 3122 Florence, one of the largest PHAs with a diameter of 4.5 km (2.8 mi), has two moons measuring 100–300 m (330–980 ft) across, which were discovered by radar imaging during the asteroid’s 2017 approach to Earth.”

Credits Video: ESA