OrbitalHub

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

Wikipedia dixit:

“The James Webb Space Telescope (JWST) is a space telescope developed in collaboration between NASA, the European Space Agency, and the Canadian Space Agency that will be the scientific successor to the Hubble Space Telescope. The JWST will offer unprecedented resolution and sensitivity, and will enable a broad range of investigations across the fields of astronomy and cosmology. One of its major goals is observing some of the most distant events and objects in the universe, such as the formation of the first galaxies. These types of targets are beyond the reach of current ground and space-based instruments. Other goals include understanding the formation of stars and planets, and direct imaging of exoplanets and novas.

The JWST’s primary mirror is composed of 18 hexagonal mirror segments made of gold-coated beryllium that combine to create a mirror with a diameter of 6.5 meters (21 ft 4 in) – a large increase over the Hubble’s 2.4-meter (7.9 ft) mirror. The telescope will be deployed in space near the Earth–Sun L2 Lagrangian point, and a large sunshield made of five sheets of silicon- and aluminum-coated Kapton will keep JWST’s mirror and four science instruments below 50 K (−220 °C; −370 °F). Unlike the Hubble—which observes in the near ultraviolet, visible, and near infrared spectra—the JWST will observe in the long-wavelength (orange to red) visible light through the mid-infrared (0.6 to 27 μm) range. This will allow the JWST to observe high redshift objects that are too old and too distant for the Hubble and other earlier instruments to observe.

In development since 1996, the telescope is named after James E. Webb, the American government official who was the administrator of NASA from 1961 to 1968 and played an integral role in the Apollo program. The project has had numerous delays and cost overruns, and underwent a major redesign during 2005. In December 2016, NASA announced that construction of the JWST was complete and that its extensive testing phase would begin. In March 2018, NASA delayed the JWST’s launch an additional year after the telescope’s sunshield ripped during a practice deployment and the sunshield’s cables did not sufficiently tighten. It was further delayed on June 27, 2018 based on recommendations by an Independent Review Board. The JWST is scheduled to launch on March 30, 2021.”

Credits Video: NASA/Northrop Grumman

Wikipedia dixit:

“The James Webb Space Telescope (JWST) is a space telescope developed in collaboration between NASA, the European Space Agency, and the Canadian Space Agency that will be the scientific successor to the Hubble Space Telescope. The JWST will offer unprecedented resolution and sensitivity, and will enable a broad range of investigations across the fields of astronomy and cosmology. One of its major goals is observing some of the most distant events and objects in the universe, such as the formation of the first galaxies. These types of targets are beyond the reach of current ground and space-based instruments. Other goals include understanding the formation of stars and planets, and direct imaging of exoplanets and novas.

The JWST’s primary mirror is composed of 18 hexagonal mirror segments made of gold-coated beryllium that combine to create a mirror with a diameter of 6.5 meters (21 ft 4 in) – a large increase over the Hubble’s 2.4-meter (7.9 ft) mirror. The telescope will be deployed in space near the Earth–Sun L2 Lagrangian point, and a large sunshield made of five sheets of silicon- and aluminum-coated Kapton will keep JWST’s mirror and four science instruments below 50 K (−220 °C; −370 °F). Unlike the Hubble—which observes in the near ultraviolet, visible, and near infrared spectra—the JWST will observe in the long-wavelength (orange to red) visible light through the mid-infrared (0.6 to 27 μm) range. This will allow the JWST to observe high redshift objects that are too old and too distant for the Hubble and other earlier instruments to observe.

In development since 1996, the telescope is named after James E. Webb, the American government official who was the administrator of NASA from 1961 to 1968 and played an integral role in the Apollo program. The project has had numerous delays and cost overruns, and underwent a major redesign during 2005. In December 2016, NASA announced that construction of the JWST was complete and that its extensive testing phase would begin. In March 2018, NASA delayed the JWST’s launch an additional year after the telescope’s sunshield ripped during a practice deployment and the sunshield’s cables did not sufficiently tighten. It was further delayed on June 27, 2018 based on recommendations by an Independent Review Board. The JWST is scheduled to launch on March 30, 2021.”

Credits Music: Expanding Time and Space by Daniel jay Nielsen

Credits Video: NASA’s Goddard Space Flight Center/Sophia Roberts

ESA dixit:

“BepiColombo, the joint ESA-JAXA mission, comprises the European Mercury Planetary Orbiter and Japan’s Mercury Magnetospheric Orbiter, which will be transported to the innermost planet by the Mercury Transfer Module. The animation highlights several key milestones, including the solar array and antenna deployments once in space, through to the arrival at Mercury seven years later. When approaching Mercury, the transfer module will separate and the two science orbiters, still together, will be captured into orbit around the planet. Their altitude will be adjusted until the Magnetospheric Orbiter’s desired orbit is reached. Then the Planetary Orbiter will separate and descend to its lower orbit, and the two craft will begin their scientific exploration of Mercury and its environment.”

Credits Video: ESA

ESA dixit:

“Hera is the European contribution to an ESA-NASA double-spacecraft mission intended to test whether a kinetic deflection technique can be used to shift the orbit of an asteroid. The target of the mission is a double asteroid system, called Didymos, which will come a comparatively close 11 million km to Earth in 2022. The 800-m diameter main body is orbited by a 170-m moon, informally called ‘Didymoon’.

In 2022 NASA’s DART spacecraft will first perform a kinetic impact on the smaller of the two bodies, then Hera will follow-up with a detailed post-impact survey that will turn this grand-scale experiment into a well-understood and repeatable planetary defense technique.

Hera will also gather crucial scientific data on asteroids as a whole by carefully studying the exterior and interior properties of both bodies in the system. The spacecraft will also host two 6-unit cubesats that will be deployed near Didymos to perform, for the first time ever, multi-point measurements in a “mother-daughter” configuration. A novel intersatellite link will be used to establish a flexible communications network supporting the close-proximity operations in very low-gravity conditions, a crucial step for future exploration activities around small bodies.”

Credits Video: ESA

SpaceX CRS-15 lifted off on 29 June 2018 at 5:42 a.m. EDT. The Falcon 9 rocket cleared the tower at Space Launch Complex 40 at Cape Canaveral Air Force Station, sending a Dragon spacecraft on the company’s 15th commercial resupply services mission to the International Space Station.

NASA has contracted for the CRS-15 mission from SpaceX and therefore determines the primary payload, date/time of launch, and orbital parameters for the Dragon space capsule. CRS-15 hauled 1,712 kg (3,774 lb) of pressurized mass and 985 kg (2,172 lb) of unpressurized cargo. The external payloads manifested for this flight are ECOSTRESS and a Latching End Effector for Canadarm2.

The breakdown of cargo bound for the ISS: science investigations – 1,233 kg (2,718 lb), crew supplies – 205 kg (452 lb), vehicle hardware – 178 kg (392 lb), spacewalk equipment – 63 kg (139 lb), computer resources – 21 kg (46 lb), russian hardware – 12 kg (26 lb), external payloads – 985 kg (2,172 lb).

Credits Video: NASA