Delta II is an American expendable launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and entered service in 1989, Delta II vehicles included the Delta 6000, and two Delta 7000 variants. In the early 1980s, all United States expendable launch vehicles were planned to be phased out in favor of the Space Shuttle, production of Delta, Atlas-Centaur, and Titan 34D had ended. McDonnell Douglas, at time the manufacturer of the Delta family. These were intended to launch a series of GPS Block II satellites, the Air Force exercised additional contract options in 1988, expanding this order to 20 vehicles, and NASA purchased its first Delta IIs in 1990 for the launch of three Earth-observing satellites. The first Delta II launch occurred in 1989, with a Delta 6925 boosting the first GPS Block II satellite into a 20,000 km high orbit, the first Delta II 7000-series flew in 1990, replacing the RS-27 engine of the 6000-series with the more powerful RS-27A.
Additionally, the steel-cased Castor 4A solid boosters of the 6000 series were replaced with the composite-cased GEM40, all further Delta II launches except three were of this upgraded configuration, and the 6000-series was retired in 1992. McDonnell Douglas began Delta III development in the mid-90s as increasing satellite mass required more powerful launch vehicles, the upgraded boosters would still find use on the Delta II, leading to the Delta II Heavy. In total, the Delta II family has launched 153 times, no one was injured, and the launch pad itself was not seriously impacted, though several cars were destroyed and a few buildings were damaged. In 2007, Delta II completed its 75th consecutive successful launch, with the launch of SMAP in 2015, the Delta II has enjoyed 98 consecutive successful launches, with two more scheduled in 2017 and 2018. Should these launches be successful, the Delta II would achieve an unprecedented 100 consecutive launch successes, the first stage of the Delta II is propelled by a Rocketdyne RS-27 main engine burning RP-1 and liquid oxygen.
This stage is referred to as the Extra-Extended Long Tank Thor. The RS-27 used on the 6000-series Delta II produced 915 kN, the stage is 26 meters long and 2.4 meters wide, weighs over 100 t when fueled, and burns for 260 seconds. In addition, two LR101-NA-11 vernier engines provide guidance for the first stage, for additional thrust during launch, the Delta II uses solid boosters. For the 6000-series, Delta II used Castor 4A boosters, while the 7000-series uses Graphite-Epoxy Motors manufactured by ATK, the vehicle can be flown with three, four, or, most commonly, nine boosters. The second stage of Delta II is the Delta-K, powered by a restartable Aerojet AJ10-118K engine burning hypergolic Aerozine-50 and these propellants are highly toxic and corrosive, and once loaded the launch must occur within approximately 37 days or the stage will have to be refurbished or replaced. This stage contains a combined platform and guidance system that controls all flight events. The Delta-K stage is 6 meters long and 2.4 meters wide, contains up to 6 t of propellant, for low Earth orbit, Delta II is not equipped with a third stage
Roald Engelbregt Gravning Amundsen was a Norwegian explorer of polar regions. He led the Antarctic expedition of 1910–12 which was the first to reach the South Pole, in 1926, he was the first expedition leader for the air expedition to the North Pole. Amundsen is recognized as the first person, without dispute, as having reached both poles and he is known as having the first expedition to traverse the Northwest Passage in the Arctic. In June 1928, while taking part in a mission for the airship Italia. Amundsen was a key leader during the Heroic Age of Antarctic Exploration, in the class of Douglas Mawson, Robert Falcon Scott. Amundsen was born to a family of Norwegian shipowners and captains in Borge and his parents were Jens Amundsen and Hanna Sahlqvist. Roald was the son in the family. His mother wanted him to avoid the family trade and encouraged him to become a doctor. He promptly quit university for a life at sea, Amundsen had hidden a lifelong desire inspired by Fridtjof Nansens crossing of Greenland in 1888 and Franklins lost expedition.
He decided on a life of exploration of wilderness places. Amundsen joined the Belgian Antarctic Expedition as first mate and this expedition, led by Adrien de Gerlache using the ship the RV Belgica, became the first expedition to winter in Antarctica. The Belgica, whether by mistake or design, became locked in the sea ice at 70°30′S off Alexander Island, the crew endured a winter for which they were poorly prepared. By Amundsens own estimation, the doctor for the expedition, the American Frederick Cook, probably saved the crew from scurvy by hunting for animals and feeding the crew fresh meat. In cases where citrus fruits are lacking, fresh meat from animals that make their own vitamin C contains enough of the vitamin to prevent scurvy and this was an important lesson for Amundsens future expeditions. In 1903, Amundsen led the first expedition to successfully traverse Canadas Northwest Passage between the Atlantic and Pacific oceans and he planned a small expedition of six men in a 45-ton fishing vessel, Gjøa, in order to have flexibility.
His ship had relatively shallow draft and his technique was to use a small ship and hug the coast. Amundsen had the ship outfitted with a gasoline engine. They traveled via Baffin Bay, the Parry Channel and south through Peel Sound, James Ross Strait, Simpson Strait and they spent two winters at King William Island in the harbor of what is today Gjoa Haven, Canada
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, after Mercury. Named after the Roman god of war, it is referred to as the Red Planet because the iron oxide prevalent on its surface gives it a reddish appearance. Mars is a planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys and polar ice caps of Earth. The rotational period and seasonal cycles of Mars are likewise similar to those of Earth, Mars is the site of Olympus Mons, the largest volcano and second-highest known mountain in the Solar System, and of Valles Marineris, one of the largest canyons in the Solar System. The smooth Borealis basin in the northern hemisphere covers 40% of the planet, Mars has two moons and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan, there are ongoing investigations assessing the past habitability potential of Mars, as well as the possibility of extant life.
Future astrobiology missions are planned, including the Mars 2020 and ExoMars rovers, liquid water cannot exist on the surface of Mars due to low atmospheric pressure, which is about 6⁄1000 that of the Earths, except at the lowest elevations for short periods. The two polar ice caps appear to be largely of water. The volume of ice in the south polar ice cap, if melted. On November 22,2016, NASA reported finding a large amount of ice in the Utopia Planitia region of Mars. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior, Mars can easily be seen from Earth with the naked eye, as can its reddish coloring. Its apparent magnitude reaches −2.91, which is surpassed only by Jupiter, the Moon, optical ground-based telescopes are typically limited to resolving features about 300 kilometers across when Earth and Mars are closest because of Earths atmosphere. Mars is approximately half the diameter of Earth with an area only slightly less than the total area of Earths dry land.
Mars is less dense than Earth, having about 15% of Earths volume and 11% of Earths mass, the red-orange appearance of the Martian surface is caused by iron oxide, or rust. It can look like butterscotch, other common colors include golden, tan. Like Earth, Mars has differentiated into a metallic core overlaid by less dense materials. Current models of its interior imply a core with a radius of about 1,794 ±65 kilometers, consisting primarily of iron and this iron sulfide core is thought to be twice as rich in lighter elements than Earths. The core is surrounded by a mantle that formed many of the tectonic and volcanic features on the planet
Alba Mons is an immense, low-lying volcano located in the northern Tharsis region of the planet Mars. It is the largest volcano on Mars in terms of area, although the volcano has a span comparable to that of the United States, it reaches an elevation of only 6.8 km at its highest point. This is about one-third the height of Olympus Mons, the tallest volcano on the planet, the flanks of Alba Mons have very gentle slopes. The average slope along the northern flank is 0. 5°. In broad profile, Alba Mons resembles a vast but barely raised welt on the planets surface and it is a unique volcanic structure with no counterpart on Earth or elsewhere on Mars. In addition to its size and low relief, Alba Mons has a number of other distinguishing features. The central portion of the volcano is surrounded by a ring of faults and fractures, called Alba Fossae on the volcanos western flank. The volcano has long, well preserved lava flows that form a radiating pattern from the volcanos central region. The enormous lengths of individual flows implies that the lavas were very fluid.
Many of the flows have distinctive morphologies, consisting of long, the low areas between the ridges show a branching pattern of shallow gullies and channels that likely formed by water runoff. Alba Mons has some of the oldest, extensively exposed volcanic deposits in the Tharsis region, geologic evidence indicates that significant volcanic activity ended much earlier at Alba Mons than at Olympus Mons and the Tharsis Montes volcanoes. Volcanic deposits from Alba Mons range in age from Hesperian to early Amazonian, for years the volcanos formal name was Alba Patera. Patera is Latin for a drinking bowl or saucer. The term was applied to certain ill-defined, scalloped-edged craters that appeared in early spacecraft images to be volcanic in origin, in September 2007, the International Astronomical Union renamed the volcano Alba Mons, reserving the term Alba Patera for the volcanos two central depressions. Nevertheless, the volcano is still commonly called Alba Patera in the planetary science literature.
The term Alba is from the Latin word for white and refers to the frequently seen over the region from Earth-based telescopes. The volcano was discovered by the Mariner 9 spacecraft in 1972 and was known as the Alba volcanic feature or the Arcadia Ring. The IAU named the volcano Alba Patera in 1973, the volcano is often simply called Alba when the context is understood
Tempe Terra is a heavily cratered highland region in the northern hemisphere of the planet Mars. Located at the edge of the Tharsis volcanic province, Tempe Terra is notable for its high degree of crustal fracturing. The region contains a number of small shield volcanoes, lava flows. The region is named after the albedo feature Tempe, first used by astronomer E. M. Antoniadi in 1930 to describe a bright patch of terrain centered near 40°N, 70°W. The name comes from the Vale of Tempe, a valley located south of Mount Olympus, the International Astronomical Union formally designated the region Tempe Terra in 1979. Terra is a Latin descriptor term used in geology for continent-like highland regions on other planets. Tempe Terra is located in the half of the Arcadia quadrangle. It is centered at 39. 7°N 289°E /39.7,289, the region extends from about 30° to 54°N and from 265° to 310°E, covering approximately 2.1 million km2, or an area roughly equivalent to that of Saudi Arabia. Tempe Terra occupies a zone between the old, heavily cratered highlands of the Martian south and the geologically younger, lowland terrain of the north.
Tempe Terra contains the northernmost exposures of ancient highland crust on the planet, the region is transected by large numbers of linear to curvilinear normal faults and grabens with ages that span much of Mars geologic history. Research on extension, or rifts in the crust, has suggested Tempa Terra may be the most highly strained geologic region on Mars with a lot of low shield volcanoes, there is evidence of valleys in Tempe Terra, including stream meanders, as in the image below. Martian gullies are small, incised networks of channels and their associated downslope sediment deposits. They are named for their resemblance to terrestrial gullies, first discovered on images from Mars Global Surveyor, they occur on steep slopes, especially on the walls of craters. Usually, each gully has an alcove at its head, a fan-shaped apron at its base. They are believed to be relatively young because they have few, a subclass of gullies is found cut into the faces of sand dunes which themselves considered to be quite young.
However, this remains a topic of active research, the pictures below show a variety of gullies and gully features. Linear ridge networks are found in places on Mars in. These features have been called polygonal ridge networks, boxwork ridges, ridges often appear as mostly straight segments that intersect in a lattice-like manner
Hellas Planitia is a plain located within the huge, roughly circular impact basin Hellas located in the southern hemisphere of the planet Mars. Hellas is the third or fourth largest impact crater and the largest visible impact crater known in the Solar System. The basin floor is about 7,152 m deep,3,000 m deeper than the Moons South Pole-Aitken basin and it is centered at 42. 4°S70. 5°E / -42.4,70.5. Hellas Planitia is in the Hellas quadrangle and the Noachis quadrangle, with a diameter of about 2,300 km, it is the largest unambiguous impact structure on the planet, the obscured Utopia Planitia is slightly larger. Hellas Planitia is thought to have formed during the Late Heavy Bombardment period of the Solar System, approximately 4.1 to 3.8 billion years ago. The altitude difference between the rim and the bottom is 9,000 m, the depth of the crater explains the atmospheric pressure at the bottom,12.4 mbar during the northern summer. It has been theorized that a combination of action and explosive boiling may be responsible for gully features in the crater.
These gullies are low enough for water to be transient around Martian noon. Hellas Planitia is antipodal to Alba Patera, whether the shield volcanoes were caused by antipodal impacts like that which produced Hellas, or if it is mere coincidence, is unknown. Due to its size and its coloring, which contrasts with the rest of the planet. The buried ice in these craters as measured by SHARAD is about 250 m thick on the crater and about 300 m and 450 m on the middle. Scientists believe that snow and ice accumulated on higher topography, flowed downhill and ridges on the surface were caused by deforming ice. Also, the shapes of many features in Hellas Planitia and other parts of Mars are strongly suggestive of glaciers, the Hourglass Sea on Mars, July 1,1897, pp. 169–172. Observations on the Planet Mars, Monthly Notices of the Royal Astronomical Society, Vol.23, p
It is the third biggest obvious impact structure on the planet after the Hellas and Argyre basins – it is about 1,500 km in diameter. Isidis was likely the last major basin to be formed on Mars, due to dust coverage, it typically appears bright in telescopic views, and was mapped as a classical albedo feature, Isidis Regio, visible by telescope in the pre-spacecraft era. A study reported in Icarus, described the complex history of parts of Isidis. This contact is the edge of a vast Martian ocean. The researchers found evidence of a Late Hesperian/Early Amazonian Sea in the area, the sea would have quickly froze over. Just to the west of Isidis is Syrtis Major Planum, a shield volcano that is a prominent dark albedo feature of Mars. Around the Isidis basin magnesium carbonate was found by MRO and this mineral indicates that water was present and that it was not acidic, pH conditions more favorable for the evolution of life. The name Isidis Planitia follows the earlier name Isidis Regio, isis is the Egyptian goddess of heaven and fertility.
The Beagle 2 lander was about to land in the part of Isidis Planitia in December 2003. In January 2015, NASA reported the Beagle 2 had been found on the surface in Isidis Planitia, high-resolution images captured by the Mars Reconnaissance Orbiter identified the lost probe, which appears to be intact. Google Mars zoomable map centered on Isidis Planitia
Noachis Terra is an extensive southern landmass of the planet Mars. It lies west of the giant Hellas impact basin, roughly between the latitudes −20° and −80° and longitudes 30° west and 30° east, centered on 45°S 350°E and it is in the Noachis quadrangle. The term Noachian epoch is derived from this region, the Planetary Report,34,1, 8-14 Lorenz, R. J. Zimbelman. Dune Worlds, How Windblown Sand Shapes Planetary Landscapes, springer Praxis Books / Geophysical Sciences. ESA Science and Technology, Noachis Terra
An aeroshell is a rigid heat-shielded shell that helps decelerate and protects a spacecraft vehicle from pressure and possible debris created by drag during atmospheric entry. Its main components consist of a shield and a back shell. The heat shield absorbs heat caused by air compression in front of the spacecraft during its atmospheric entry and its purpose is used during the EDL process of a spacecrafts mission, or the Entry and Landing process. First, the aeroshell decelerates the spacecraft as it penetrates the planet’s atmosphere, the heat shield absorbs the resulting friction. During descent, the parachute is deployed and the shield is detached. Rockets located at the shell are initiated to assist in the decrease of the spacecrafts descent. Airbags are inflated to cushion the impact, the spacecraft bounces on the planet’s surface directly after the first impact. The spacecrafts lander petals are deployed after the airbags are deflated and retracted, communication throughout this entire process is relayed back and forth from mission control and the actual spacecraft through low-gain antennas that are attached to the back shell and on itself.
Throughout the entry and landing stages, tones are sent back to earth in order to communicate the success or failure of each of these critical steps. Aeroshells are a key component of space probes that must land intact on the surface of any object with an atmosphere and they have been used on all missions returning payloads to the Earth. They are used for all landing missions to Mars, Venus and the Galileo probe to Jupiter. The aeroshell consists of two components, the heat shield, or forebody, which is located at the front of the aeroshell, and the back shell. The heat shield of the aeroshell faces flow during a spacecrafts atmospheric penetration, the backshell acts as a finalizer for the encapsulation of the payload. The parachute is located at the apex of the shell and slows the spacecraft during entry, descent. The pyrotechnic control system releases such as nuts, rockets. The Inertial Measurement Unit reports the orientation of the shell while it is swaying underneath the parachute. Rocket Assisted Descent rockets provide approximately one ton of force within 2 seconds, the Transverse Impulse Rocket System provides horizontal force to the back shell which helps orient it to a more vertical position during the main Rocket Assisted Descent rocket burn. A spacecrafts mission objective determines what flight requirements are needed to ensure mission success and these flight requirements are deceleration and impact and landing accuracy
A lander is a spacecraft which descends toward and comes to rest on the surface of an astronomical body. For bodies with atmospheres, the landing occurs after atmospheric entry, in these cases, landers may employ parachutes to slow down and to maintain a low terminal velocity. Sometimes small landing rockets are fired just before impact to reduce the impact velocity, landing may be accomplished by controlled descent and setdown on landing gear, with the possible addition of a post-landing attachment mechanism for celestial bodies with low gravity. Some missions used inflatable airbags to cushion the landers impact rather than a traditional landing gear. When a high velocity impact is planned not for just achieving the surface but for study of consequences of impact, the spacecraft is called an impactor. Several terrestrial bodies have been subject of lander and/or impactor exploration, among them Earths Moon, the planets Venus and Mercury, the Saturn moon Titan, the asteroids and comets. A number of Moon probes, such as members of the Soviet Luna program.
In 1959 the first impact on Moon intended to be by Luna 1 probe but occurred by Luna 2 probe, the Soviet Luna 9 was in 1966 the first spacecraft to achieve a lunar soft landing and to transmit photographic data to Earth. The Altair spacecraft, previously known as the Lunar Surface Access Module or LSAM, was the lander for Project Constellation. As of August 2012 NASA is developing vehicles that use a rocket descent engine permitting them land on the Moon and these vehicles include the Mighty Eagle lander and the Morpheus lander. The Project Morpheus lander may have sufficient thrust to propel a manned ascent stage, a first Boomerang-class lunar sample return mission plans under open source OpenLuna program. Russia has plans for Luna-Grunt mission to return samples from the Moon by 2021, the Chinese Change 3 mission and its Jade Rabbit rover landed on 14 December 2013. Then China plans to repeat lander with rover in Change 4 mission after 2015 that will followed by Change 5 and Change 6 sample return missions in 2017 and before 2020.
The Soviet Venera program included a number of Venus landers, some of which were crushed during descent much as Galileos Jupiter lander, Venera 3 in 1966 and Venera 7 in 1970 became the first impact and soft landing on Venus. The Soviet Vega program placed in 1985 two balloons in the Venusian atmosphere, they were the first aerial tools on other planets, the Soviet Unions Mars 1962B was the first Earth based mission intended to reach the surface as impact on Mars in 1962. Three other landers, Mars 2 in 1971 and Mars 5, Mars 6 in 1973, all four landers used an aeroshell-like heat shield during atmospheric entry. Mars 2 and Mars 3 landers carried the first small skis-walking Martian rovers that did not work on the planet. The Soviet Union planned the heavy Marsokhod Mars 4NM mission Mars sample return Mars 5NM mission, a double-launching Soviet Mars 5M sample return mission was planned for 1979 but cancelled due to complexity and technical problems
Deep Space 1
Deep Space 1 was a NASA technology demonstration spacecraft which flew by an asteroid and a comet. It was part of the New Millennium Program, dedicated to testing advanced technologies, launched on 24 October 1998, the Deep Space 1 spacecraft carried out a flyby of asteroid 9969 Braille, which was its primary science target. The mission was extended twice to include an encounter with comet 19P/Borrelly, problems during its initial stages and with its star tracker led to repeated changes in mission configuration. While the flyby of the asteroid was a success, the encounter with the comet retrieved valuable information. Three of twelve technologies on board had to work within a few minutes of separation from the rocket for the mission to continue. The Deep Space series was continued by the Deep Space 2 probes, Deep Space 1 was the first NASA spacecraft to use ion propulsion rather than the traditional chemical-powered rockets. The asteroids in the inner Solar System move in relation to other bodies at a noticeable, predictable speed, thus a spacecraft can determine its relative position by tracking such asteroids across the star background, which appears fixed over such timescales.
Two or more asteroids let the spacecraft triangulate its position, two or more positions in time let the spacecraft determine its trajectory, existing spacecraft are tracked by their interactions with the transmitters of the NASA Deep Space Network, in effect an inverse GPS. However, DSN tracking requires many skilled operators, and the DSN is overburdened by its use as a communications network, the use of Autonav reduces mission cost and DSN demands. The Autonav system can be used in reverse, tracking the position of relative to the spacecraft. This is used to acquire targets for the scientific instruments, the spacecraft is programmed with the targets coarse location. After initial acquisition, Autonav keeps the subject in frame, even commandeering the spacecrafts attitude control, the next spacecraft to use Autonav was Deep Impact. ABLE Engineering developed the technology and built the solar array for DS1, with Entech Inc, who supplied the Fresnel optics. The activity was sponsored by the Ballistic Missile Defense Organization, the SCARLET arrays generated 2.5 kilowatts at 1 AU, with less size and weight than conventional arrays.
This lack of a history in space meant that despite the potential savings in propellant mass. Furthermore, unforeseen side effects of ion propulsion might in some way interfere with scientific experiments, such as fields. Therefore, it was a mission of the Deep Space 1 demonstration to show long-duration use of an ion thruster on a scientific mission. The NASA Solar Technology Application Readiness electrostatic ion thruster, developed at NASA Glenn and this is an order of magnitude higher than traditional space propulsion methods, resulting in a mass savings of approximately half
Valles Marineris is a system of canyons that runs along the Martian surface east of the Tharsis region. At more than 4,000 km long,200 km wide and up to 7 km deep, Valles Marineris is one of the largest canyons of the Solar System, surpassed in length only by the rift valleys of Earth. Valles Marineris is located along the equator of Mars, on the east side of the Tharsis Bulge and it has been recently suggested that Valles Marineris is a large tectonic crack in the Martian crust. Most researchers agree that this formed as the crust thickened in the Tharsis region to the west, near the eastern flanks of the rift, there appear to be channels that may have been formed by water or carbon dioxide. It has proposed that Valles Marineris is a large channel formed by the erosion of lava flowing from the flank of Pavonis Mons. There have been many different theories about the formation of Valles Marineris that have changed over the years, ideas in the 1970s were erosion by water or thermokarst activity, which is the melting of permafrost in glacial climes.
Many scientists agree that there was liquid water flowing on the Martian surface in the past, Valles Marineris may have been enlarged by flowing water at this time. Another hypothesis by McCauley in 1972 was that the canyons formed by withdrawal of subsurface magma, around 1989 Tanaka and Golombek proposed a theory of formation by tensional fracturing. The most agreed upon theory today is that Valles Marineris was formed by rift faults like the East African Rift, made bigger by erosion and it has been proposed that Valles Marineris was formed by flowing lava. The formation of Valles Marineris is thought to be tied with the formation of the Tharsis Bulge. The Tharsis Bulge was formed from the Noachian to Late Hesperian period of Mars, stage two consisted of more volcanism and a loss of isostatic equilibrium, the source regions of the volcanism no longer resided underneath Tharsis, creating a very large load. Finally, the crust failed to hold up Tharsis and radial fractures formed, stage three mainly consisted of more volcanism and asteroid impacts.
The crust, having reached its failure point, just stayed in place. Landslides have left numerous deposits on the floor of Valles Marineris, possible triggers of landslides are quakes caused by tectonic activity or impact events. Both types of events release seismic waves that accelerate the ground at, Mars is much less tectonically active than Earth, and Mars-quakes are unlikely to have provided seismic waves of the required magnitude. Most sizable craters on Mars date to the Late Heavy Bombardment,4.1 to 3.8 billion years ago, and are older than the landslide deposits in Valles Marineris. However, three craters have been identified, on the basis of their proximity and dates, as ones whose formation may have caused some of the landslides, it contains canyons that run in different directions surrounding large blocks of older terrain. Most of the parts of the blocks are composed of younger fractured material thought to be of volcanic origin associated with the Tharsis bulge