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Ulysses Encounter With Jupiter 1991 NASA; Solar Astronomy Spacecraft
🕑 Added 2019-12-08 07:11:27 +0000 UTCmore at http://quickfound.net/
Originally a public domain film from NASA, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
https://en.wikipedia.org/wiki/Ulysses_(spacecraft)
Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/
Ulysses (US: /juːˈlɪsiːz/, UK: /ˈjuːlɪ-/) is a decommissioned robotic space probe whose primary mission was to orbit the Sun and study it at all latitudes. It was launched in 1990 and made three "fast latitude scans" of the Sun in 1994/1995, 2000/2001, and 2007/2008. In addition, the probe studied several comets. Ulysses was a joint venture of NASA and the European Space Agency (ESA) with participation from Canada's National Research Council. The last day for mission operations on Ulysses was June 30, 2009.
To study the Sun at all latitudes, the probe needed to change its orbital inclination and leave the plane of the Solar System. To change the orbital inclination of a spacecraft to about 80° requires a large change in heliocentric velocity, the energy to achieve which far exceeded the capabilities of any launch vehicle. To reach the desired orbit around the Sun, the mission's planners chose a gravity assist maneuver around Jupiter...
The spacecraft was originally named Odysseus, because of its lengthy and indirect trajectory to study the solar poles. It was renamed Ulysses, the Latin translation of "Odysseus", at ESA's request in honor not only of Homer's mythological hero but also of Dante's character in the Inferno... the launch of Ulysses was delayed until October 6, 1990 aboard Discovery (mission STS-41)...
Until Ulysses, the Sun was only observed from low solar latitudes. The Earth's orbit defines the ecliptic plane, which differs from the Sun's equatorial plane by only 7.25 degrees. Even spacecraft directly orbiting the Sun do so in planes close to the ecliptic because a direct launch into a high-inclination solar orbit would require a prohibitively large launch vehicle.
Several spacecraft (Mariner 10, Pioneer 11, and Voyagers 1 and 2) had performed gravity assist manoeuvres in the 1970s. Those manoeuvres were to reach other planets also orbiting close to the ecliptic, so they were mostly in-plane changes. However, gravity assists are not limited to in-plane maneuvers; a suitable flyby of Jupiter could produce a significant plane change. An Out-Of-The-Ecliptic mission (OOE) was thereby proposed. See article Pioneer H.
Originally, two spacecraft were to be built by NASA and ESA, as the International Solar Polar Mission. One would be sent over Jupiter, then under the Sun. The other would fly under Jupiter, then over the Sun. This would provide simultaneous coverage. Due to cutbacks, the US spacecraft was canceled in 1981...
...changes delayed launch from February 1983 to May 1986 where it was to be deployed by the Space Shuttle Challenger, however, the Challenger disaster pushed the date to October 1990...
Ulysses was deployed into low-Earth orbit from the Space Shuttle Discovery. From there, it was propelled on a trajectory to Jupiter by a combination of solid rocket motors...
It arrived at Jupiter on 8 February 1992 for a swing-by maneuver that increased its inclination to the ecliptic by 80.2 degrees. The giant planet's gravity bent the spacecraft's flight path southward and away from the ecliptic plane. This put it into a final orbit around the Sun that would take it past the Sun's north and south poles. The size and shape of the orbit were adjusted to a much smaller degree so that aphelion remained at approximately 5 AU, Jupiter's distance from the Sun, and perihelion was somewhat greater than 1 AU, the Earth's distance from the Sun. The orbital period is approximately six years.
Polar regions of the Sun
Between 1994 and 1995 it explored both the southern and northern polar regions of the Sun, respectively.
Comet C/1996 B2 (Hyakutake)
On May 1, 1996, the spacecraft unexpectedly crossed the ion tail of Comet Hyakutake (C/1996 B2), revealing the tail to be at least 3.8 AU in length.
Comet C/1999 T1 (McNaught–Hartley)
An encounter with a comet tail happened again in 1999 when Ulysses flew through the ion tailings of C/1999 T1 (McNaught-Hartley). A coronal mass ejection carried the cometary material to Ulysses...
On June 30, 2009, ground controllers sent commands to switch to the low gain antennas. This stopped communications with the spacecraft, in combination with previous commands to shut down its transmitter entirely...
