OrbitalHub

Wikipedia dicit:

The Cygnus spacecraft is an expendable American cargo spacecraft developed by Orbital Sciences Corporation and now manufactured and launched by Northrop Grumman Space Systems as part of NASA’s Commercial Resupply Services (CRS) program. It is launched by Northrop Grumman’s Antares rocket or ULA’s Atlas V and is designed to transport supplies to the International Space Station (ISS) following the retirement of the American Space Shuttle.

Since August 2000, ISS resupply missions have been regularly flown by the Russian Progress spacecraft, as well as by the European Automated Transfer Vehicle, and the Japanese H-II Transfer Vehicle. With the Cygnus spacecraft and the SpaceX Dragon, NASA seeks to increase its partnerships with domestic commercial aviation and aeronautics industry.

The Cygnus spacecraft consists of two basic components: the Pressurized Cargo Module (PCM) and the Service Module (SM). The PCM is manufactured by Thales Alenia Space in Turin, (Italy). The initial PCMs have an empty mass of 1,500 kg and a volume of 18 m3·. The service module is built by Orbital ATK and is based on their GEOStar and LEOStar spacecraft buses as well as components from the development of the Dawn spacecraft. It has a gross mass of 1,800 kg with propulsion provided by thrusters using the hypergolic propellants hydrazine and nitrogen tetroxide (the propellant mass is 800 kg). The service module is capable of producing up to 4 kW of electrical power via two gallium arsenide solar arrays. On 12 November 2009, Dutch Space announced it will provide the solar arrays for the initial Cygnus spacecraft.

Video credit: NASA

Wikipedia dicit:

The Aerojet Rocketdyne RS-25, also known as the Space Shuttle Main Engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA’s Space Shuttle. NASA is planning to continue using the RS-25 on the Space Shuttle’s successor, the Space Launch System (SLS).

Designed and manufactured in the United States by Rocketdyne (later known as Pratt & Whitney Rocketdyne and Aerojet Rocketdyne), the RS-25 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,859 kN (418,000 lbf) of thrust at liftoff. Although the RS-25 can trace its heritage back to the 1960s, the concerted development of the engine began in the 1970s, with the first flight, STS-1, occurring on April 12, 1981. The RS-25 has undergone several upgrades over its operational history to improve the engine’s reliability, safety, and maintenance load.

The engine produces a specific impulse (Isp) of 452 seconds (4.43 km/s) in a vacuum, or 366 seconds (3.59 km/s) at sea level, has a mass of approximately 3.5 tonnes (7,700 pounds), and is capable of throttling between 67% and 109% of its rated power level in one-percent increments. Components of the RS-25 operate at temperatures ranging from −253 to 3,300 °C (−400 to 6,000 °F).

The Space Shuttle used a cluster of three RS-25 engines mounted in the stern structure of the orbiter, with fuel being drawn from the external tank. The engines were used for propulsion during the entirety of the spacecraft’s ascent, with additional thrust being provided by two solid rocket boosters and the orbiter’s two AJ10 orbital maneuvering system engines. Following each flight, the RS-25 engines were removed from the orbiter, inspected, and refurbished before being reused on another mission. On Space Launch System flights, the engines will be expendable. For the first four flights, engines left over from the Space Shuttle program will be refurbished and used before NASA switches to the simplified RS-25E variant.

Video credit: NASA’s Kennedy Space Center

They will always be remembered…

Apollo 1 (January 27, 1967)

Virgil “Gus” Grissom – Commander, Edward White – Command Pilot, Roger Chaffee – Pilot

STS-51 L (January 28, 1986)

Francis R. Scobee – Commander, Michael J. Smith – Pilot, Judith A. Resnik – Mission Specialist 1, Ellison Onizuka – Mission Specialist 2, Ronald E. McNair – Mission Specialist 3, Gregory B. Jarvis – Payload Specialist 1, Sharon Christa McAuliffe – Payload Specialist 2

STS-107 (February 1, 2003)

Rick D. Husband – Commander, William C. McCool – Pilot, Michael P. Anderson – Payload Commander, David M. Brown – Mission Specialist 1, Kalpana Chawla – Mission Specialist 2, Laurel Clark – Mission Specialist 3, Ilan Ramon – Payload Specialist 1

Video credit: NASA