“The unpiloted Russian ISS Progress 67 cargo ship launched atop a Soyuz booster June 14 from the Baikonur Cosmodrome in Kazakhstan on a two-day journey to the International Space Station. The new Progress, which is carrying three tons of food, fuel and supplies for the residents of the orbital complex, is scheduled to automatically dock to the rear port of the station’s Zvezda Service Module on June 16. It will remain attached to the station through December.”
“EchoStar was originally formed in 1980 as a distributor of C band TV systems. In 1987, it applied for a direct broadcast satellite (DBS) license with the Federal Communications Commission and was granted access to orbital slot 119° west longitude in 1992. On December 28, 1995, the firm successfully launched its first satellite, EchoStar I. On March 4, 1996, it established the Dish Network brand name to market its home satellite TV system.
In 1998, EchoStar purchased the broadcasting assets of a satellite broadcasting joint venture of News Corporation’s ASkyB and MCI Worldcom. With this purchase the firm obtained 28 of the 32 transponder licenses in the 110° W orbital slot, more than doubling existing CONUS broadcasting capacity at a value of $682.5 million. The acquisition inspired the company to introduce a multi-satellite system called DISH 500, theoretically capable of receiving more than 500 channels on one dish.
“Legacy” represent the 950 to 1450 MHz frequencies used to deliver the signal throughout the home; the signal is broadcast to the home on the Ku band from satellite (12.2-12.7 GHz). Ku frequencies will not work on home wiring, the signal is downconverted to the intermediate frequency (IF) of 950-1450 MHz at the dish antenna. Newer technology (DishPro) also uses 1650-2150 MHz in addition to 950-1450.
Also in 1998, the firm, in association with Bell Canada, launched Bell TV. On September 25, 2007, the firm announced it had agreed to acquire Sling Media, Inc.
On January 2, 2008, the Dish Network business was demerged from the technology and infrastructure side of the business. A split in the shares created two companies, DISH Network Corporation which consists mainly of the DISH Network business, and EchoStar Corporation which retains ownership of the technology side including the satellites, Sling Media, and the set-top box development arm. DISH Network completed its distribution to Echostar of its digital set-top box business, certain infrastructure, and other assets and related liabilities, including certain of their satellites, uplink and satellite transmission assets, and real estate (the “Spin-off”). Since the Spin-off, EchoStar and DISH Network have operated as separate publicly-traded companies. However, as a result of the Satellite and Tracking Stock Transaction, DISH Network owns shares of EchoStar and their subsidiary’s preferred tracking stock representing an aggregate 80.0% economic interest in the residential retail satellite broadband business of their Hughes segment.
EchoStar 21 will provide mobile broadband services over Europe with an S-band payload for EchoStar Mobile Ltd (formerly known as TerreStar 2).”
“SpaceX CRS-11, also known as SpX-11, is a current cargo resupply mission to the International Space Station, launched successfully on 3 June 2017. The mission was contracted by NASA and is being flown by SpaceX. The mission utilized a Falcon 9 launch rocket and reuses a Dragon v1 cargo vessel that was previously flown on the CRS-4 mission. CRS-11 is the penultimate of the first twelve missions awarded to SpaceX under the CRS contract to resupply the International Space Station.
This was the first time that a Dragon spacecraft is reused, helping SpaceX to scale back its production line and shift focus to Dragon 2. CRS-11 launched aboard a Falcon 9 rocket on 3 June 2017 at 21:07 UTC from Kennedy Space Center’s Launch Complex 39A. The spacecraft rendezvoused with the station on 5 June and conducted a series of orbit adjustment burns to match speed, altitude, and orientation with the ISS. After arriving at the capture point at 13:37 UTC, the vehicle was snared at 13:52 UTC by Canadarm2, operated by Peggy Whitson and Jack Fischer. It was berthed to the Harmony module at 16:07 UTC, where it will reside until 2 July 2017.
The first stage landed successfully on Landing Zone 1, making it the fifth successful touch down on land and the 11th overall.”
“The SpaceX Falcon 9 rocket lifted off on June 3 from Launch Pad 39A at the Kennedy Space Center, Florida, carrying the uncrewed Dragon cargo ship to orbit for the start of a delivery run to the residents of the International Space Station. Loaded with about 6,000 pounds of supplies and science experiments, Dragon is scheduled to arrive at the station on June 5, where it will be captured by Expedition 52 Flight Engineer Jack Fischer of NASA using the station’s Canadian-built robotic arm. Dragon is scheduled to remain at the station for a month before it is unberthed and deorbited for a parachute-assisted splashdown in the Pacific Ocean.”
“In the summer of 2016, Copenhagen Suborbitals launched one of the most advanced liquid fueled rockets built by a team of volunteer amateurs. Follow the team close up during final preparations for the launch and during the launch of the Nexø I rocket. Enjoy.
Copenhagen Suborbitals is the world’s only manned, amateur space program, 100% crowdfunded and nonprofit. In the future, one of us will fly to space on a home built rocket.”
“Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft. The motion of these objects is usually calculated from Newton’s laws of motion and Newton’s law of universal gravitation. It is a core discipline within space mission design and control. Celestial mechanics treats more broadly the orbital dynamics of systems under the influence of gravity, including both spacecraft and natural astronomical bodies such as star systems, planets, moons and comets. Orbital mechanics focuses on spacecraft trajectories, including orbital maneuvers, orbit plane changes, and interplanetary transfers, and is used by mission planners to predict the results of propulsive maneuvers.
In orbital mechanics, the Hohmann transfer orbit is an elliptical orbit used to transfer between two circular orbits of different radii in the same plane. The orbital maneuver to perform the Hohmann transfer uses two engine impulses, one to move a spacecraft onto the transfer orbit and a second to move off it.
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a Hohmann transfer orbit used to reach geosynchronous or geostationary orbit using high thrust chemical engines. Geosynchronous orbits (GSO) are useful for various civilian and military purposes, but demand a great deal of Delta-v to attain. Since, for station-keeping, satellites intended for this orbit typically carry highly efficient but low thrust engines, total mass delivered to GSO is generally maximized if the launch vehicle provides only the Delta-v required to be at high thrust–i.e., to escape Earth’s atmosphere and overcome gravitational losses–and the satellite provides the Delta-v required to turn the resulting intermediate orbit, which is the GTO, into the useful GSO.
GTO is a highly elliptical Earth orbit with an apogee of 42,164 km (26,199 mi), or 35,786 km (22,236 mi) above sea level, which corresponds to the geostationary altitude. The period of a standard geosynchronous transfer orbit is about 10.5 hours. The argument of perigee is such that apogee occurs on or near the equator. Perigee can be anywhere above the atmosphere, but is usually restricted to a few hundred kilometers above the Earth’s surface to reduce launcher delta-V requirements and to limit the orbital lifetime of the spent booster so as to curtail space junk. If using low-thrust engines such as electrical propulsion to get from the transfer orbit to geostationary orbit, the transfer orbit can be supersynchronous (having an apogee above the final geosynchronous orbit). This method however takes much longer to achieve due to the low thrust injected into the orbit. The typical launch vehicle injects the satellite to a supersynchronous orbit having the apogee above 42,164 km. The satellite’s low thrust engines are thrusted continuously around the geostationary transfer orbits in an inertial direction. This inertial direction is set to be in the velocity vector at apogee but with an outer plane direction. The outer plane direction removes the initial inclination set by the initial transfer orbit while the inner plane direction raises simultaneously the perigee and lowers the apogee of the intermediate geostationary transfer orbit. In case of using the Hohmann transfer orbit, only a few days are required to reach the geosynchronous orbit. By using low thrust engines or electrical propulsion, months are required until the satellite reaches its final orbit.
The inclination of a GTO is the angle between the orbit plane and the Earth’s equatorial plane. It is determined by the latitude of the launch site and the launch azimuth (direction). The inclination and eccentricity must both be reduced to zero to obtain a geostationary orbit. If only the eccentricity of the orbit is reduced to zero, the result may be a geosynchronous orbit but will not be geostationary. Because the Delta V required for a plane change is proportional to the instantaneous velocity, the inclination and eccentricity are usually changed together in a single manoeuvre at apogee where velocity is lowest.”
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