Orbital Sciences launches first operational Cygnus to International Space Station
Orbital Sciences Corporation launched their first commercial resupply mission to the ISS last Thursday. A Cygnus resupply vehicle mounted on an Antares launch system lifted off at 1.07pm EST after being delayed from December by the failure of a cooling loop on the ISS and a further day due to solar weather.
Orbital’s Cygnus is one of two NASA commercial partner vehicles that can currently launch material to the International Space Station after successfully completing the COTS demonstration mission last year. Cygnus 1 is carrying 1,465kg of cargo to the ISS including spare parts, science experiments and student cubesats that are designed to be launched from the JAXA robotic arm.
The Cygnus gets a ride to space on the Antares rocket. Antares is a two stage rocket developed and operated by Orbital Sciences Corporation and launched from the Mid Atlantic Regional Spaceport in Virginia.
The two stage rocket can lift around 5,000kg to low earth orbit and uses both liquid propulsion for the first stage and a ATK Castor 30B, for the Antares 120 that launched Cygnus CRS-1, solid rocket upper stage.
The first stage of the Antares rocket is made up of two Aerojet AJ-26 engines. These staged combustion cycle RP-1/LOX engines original started life as the Russian NK-33 engine that was to be used on the N1 Moon Rocket back in the 1960’s. Aerojet purchased these engines and brought them to the USA. After upgrading the electronics, fuel management systems and creating a thrust vector control system for the NK-33 they then sold them to Orbital as the AJ-26. Due to the nature of the engine there are a limited supply of these engines as the production lines for the NK-33 have yet to restart, despite talk of doing so in Russia for the past few years.
The rest of the first stage is contracted out to the Ukrainian company Yuzhnoye SDO who designed of the Zenit series of rockets. The core provided includes propellant tanks, pressurization tanks, valves, sensors, feed lines, tubing, wiring and other associated hardware needed at a diameter of 3.9m, the same as the Zenit rockets.
The second stage for Antares is contracted out to ATK who provide the Castor 30, a smaller derivative of the Castor 120. The Castor 30B used on the Antares 120 produces on average 293.4 kN of thrust, peaking at 395.7 kN of thrust. The stage uses a electromechanical thrust vector control system for the nozzle and has a Reaction Control System for fine tuning attitude. The second stage and Cygnus are hidden inside a 3.9m diameter payload fairing that is jettisoned shortly before second stage ignition.
Antares drops Cygnus off in a 218km x 280km orbit inclined by 51.64 degrees were the propulsion systems on Cygnus take over and begin adding velocity to Cygnus allowing it to catch up with the ISS.
After a smooth two day trip playing catch up to the station Cygnus arrived early Sunday morning to begin final approach to the orbiting station. Cygnus proceeded to move up to station with no issues and came to a stop about 10 meters away from the ISS. At the final hold point the crew of Mike Hopkins and Koichi Wakata used the stations CanadaArm2 to grapple onto the Cygnus and lock on. This event took place at 11:08 UTC on Sunday.
Ahead of berthing procedures the Cygnus was then moved to the pre-berth location to await being berthed to the station.
As the morning moved on the crew performed the needed steps to install Cygnus to the ISS, moving through the steps quickly and without any issues arising. At 13:05 UTC the hard bolts were driven into Cygnus to install it as part of the ISS creating a hard mate. Hatch opening is due to take place on Monday but the crew is thinking about moving forward and getting some of the critical cargo out later Sunday if the leak checks go ahead without issue.
Some of the more noteworthy experiments involve observing an ant colony’s behavior in zero gravity, modelling fuel sloshing around in tanks and studying drug-resistant bacteria.
Inside the Cygnus are 33 cube sats to be deployed by the Japanese robotic arm from station from various sources. Flock-1 represents 28 three-unit CubeSats operated by Planet Labs to build an Earth-observation constellation based on CubeSats.
LituanicaSat-1 was developed at Kaunas University of Technology. It is a one-unit cubesat and one of Lithuania’s first satellites, together with LitSat-1. LitSat-1 is also a Lithuanian satellite. It is a one-unit cubesat developed by the Lithuanian Space Federation to use low-cost open-source hardware and software for its flight computers that will control the satellite payload.
The SkyCube satellite is a project of Southern Stars Group LLC. Crowd-funding was used for the mission and investors get a chance to transmit a message from space or take pictures of locations of their selection. SkyCube is a 2-Kilogram one-unit satellite that features deployable solar panels, four cameras and communication antennas that are used to receive messages from Earth that are then transmitted at pre-determined times.
UAPSat-1 is a one-unit CubeSat built in Peru by the Institute for Radio Astronomy of the Pontificia Universidad Católica del Perú.
ArduSat-2 is a two-unit CubeSat based on the one-unit ArduSat-1 that was deployed from ISS in November 2013. The satellite is built and operated by NanoSatisfi, USA. The small satellite will provide a platform which may be used by students or space enthusiasts to run their own space-based Arduino experiments.
SPHERES stands for Synchronized Position Hold, Engage, Reorient, Experimental Satellites and involves two satellites that are used inside the space station to provide a miniature test bed to study maneuvering capabilities and spacecraft measurement systems.
The Slosh experiment investigates how liquids move around inside containers in microgravity. The physics of liquid motion in space are not well understood. A good understanding of the processes at work would improve modeling of the behavior of rocket fuel inside the tanks of satellites and other spacecraft or rockets.
To conduct the experiment, the two SPHERES are attached to the assembled experiment hardware and the system is put through a series of maneuvers via the SPHERES satellites. The data collected from this experiment, performed inside the ISS, is then down linked to the ground for processing along with any visual observations made by the crew operating the experiment.
The National Laboratory Pathfinder Vaccine payloads have been flying to the Space Station for several years. The studies seek to understand measures that should be taken to reduce the risk of infection and contraction of disease while in space. Earth applications of the experiment series include knowledge for the development of vaccines against life-threatening organisms.
Vaccine 21 aims to use a spaceflight antibiotic effectiveness model to address drug-resistance issues on Earth by identifying what phenotypic and transcriptomic changes permit bacterial survival under various antibiotics concentrations.
The payload is operated via the Fluid Processing Apparatus (FPA) that requires the crew members to activate and terminate the experiment.
Cygnus also carries crew provisions such as food and clothing, along with fresh fruit and vegetables for the crew to enjoy.
At the end of the Cygnus’s mission it will be filled with trash and waste not needed on station anymore. It will then be un-berthed and moved away from ISS by CanadaArm2 and released. Cygnus will then perform departure burns with it’s RCS and later perform a deorbit burn with its main engine sending the Cygnus into the atmosphere to burn up.Photo Credit:
Feature Image: NASA
Castor 30 Test: ATK
Cygnus Approach: NASA
Flock-1 Cubesats: Planet Labs
Spheres: Florida Institute of Technology/Dr. Daniel Kirk
Vaccine 21: NASA