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Primary Atomic Reference Clock in Space

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The Primary Atomic Reference Clock in Space or PARCS was an atomic-clock mission scheduled to fly on the International Space Station (ISS) in 2008, but cancelled to make way for the Vision for Space Exploration . The mission, to have been funded by NASA , involved a laser-cooled caesium atomic clock, and a time-transfer system using Global Positioning System (GPS) satellites. PARCS was to fly concurrently with the Superconducting Microwave Oscillator (SUMO) a different type of clock that was to be compared against the PARCS clock to test certain theories. The objectives of the mission were to have been:

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22-794: The proposed ISS location for the experiment was on the External Facility of the Japanese Experimental Module (JEM). This location afforded good views of the GPS constellation of satellites , needed for comparing space and ground clocks. In addition, the volume, available power, and coolant system were well matched to the mission requirements. The microgravity environment of space allows slowing of atoms to speeds well below those used in terrestrial atomic clocks, providing for substantial improvement in clock accuracy. This very accurate space clock will be compared continuously to

44-529: A central grapple pin topped with a sphere which the snares in the end of the arms latch on to. They use three "ramps" that help guide the robotic arm correctly onto the grapple fixture. The North American grapple fixture was developed at Spar Aerospace in the 1970s. Its invention is credited to Frank Mee, who also invented the Canadarm end effector for the Space Shuttle. The Grapple Fixture design

66-662: A rack of communication module in the Pressurized Module (ICS-PM) and the antenna module to be attached on the Exposed Facility (ICS-EF). It was used to communicate with the ground station via JAXA's communication technology demonstration satellite DRTS "Kodama"  [ ja ] . After the decommissioning of DRTS in August 2017, Kibō relies on the ISS's Ku band communication through NASA's TDRSS . ICS-EF

88-856: A secure connection for a robotic arm . The fixtures allowed the Space Shuttle's Canadarm (also known as the Shuttle Remote Manipulator System, or SRMS) to safely grapple large objects (e.g. ISS components, or satellites e.g. HST ). They currently do the same for the International Space Station 's Space Station Remote Manipulator System (SSRMS) (also known as Canadarm2) and the Japanese Experiment Module Remote Manipulator System (JEMRMS). The grapple fixtures are flat in appearance, with

110-568: A similar grapple fixture, called Electro Mechanical Grapple Fixture (EMGF). The Power and Video Grapple Fixture (PVGF) allows for grappling and latching. It has electrical connectors for data, video, and power. The electrical connections are compatible with the Space Station Remote Manipulator System (also known as Canadarm2). The Power Data Grapple Fixture (PDGF) allows for grappling and latching. It has electrical connectors for data, video, and power; it

132-606: Is a 10 m (33 ft) robotic arm, mounted at the port cone of the PM. It is used for servicing the EF and for moving equipment to and from the ELM. The JEMRMS control console was launched while inside the ELM-PS, and the main arm was launched with the PM. The small fine arm, which is 2 m (6 ft 7 in) long and attaches to the end effector of the main arm, was launched aboard HTV-1 on

154-806: Is a cooperative effort between the following organizations: Bill Klipstein of JPL was the Project Scientist, and Dave Seidel of JPL was the Project Manager. The Co-Principal Investigators were Don Sullivan and Bill Phillips of NIST, and Neil Ashby of the University of Colorado. John Lipa of Stanford University was the Principal Investigator for SUMO and John Dick of JPL was the Project Scientist for that program. Japanese Experimental Module Kibō ( Japanese : きぼう , lit.   ' Hope ' ) , also known as

176-478: Is also the only North American grapple fixture that is replaceable on-orbit. The electrical connections are compatible with the Space Station Remote Manipulator System (also known as Canadarm2). It is used on the International Space Station (ISS). PDGFs can be "grappled" by the Canadarm2 robotic arm, in order to allow the arm to manipulate and power a grappled object, or be commanded by operators based inside

198-529: Is the core component connected to the port hatch of Harmony . It is cylindrical in shape and contains twenty-three International Standard Payload Racks (ISPRs), ten of which are dedicated to science experiments while the remaining thirteen are dedicated to Kibō ' s systems and storage. The racks are placed in a 6-6-6-5 format along the four walls of the module. The end of the PM has an airlock and two window hatches. The exposed facility, experiment logistics module, and remote manipulator system all connect to

220-606: The Japanese Experiment Module (JEM), is a Japanese science module for the International Space Station (ISS) developed by JAXA . It is the largest single ISS module, and is attached to the Harmony module. The first two pieces of the module were launched on Space Shuttle missions STS-123 and STS-124 . The third and final components were launched on STS-127 . In initial configuration, Kibō consisted of six major elements: The Pressurized Module (PM)

242-669: The Payload Orbital replacement unit Accommodation (POA) (greater than 3 weeks). It does not have any electrical connectors. The Electrical Flight Grapple Fixture (EFGF) allows for grappling. It has a single electrical connection for data, power, and video from cameras on the manipulators. The electrical connection is compatible with the Shuttle Remote Manipulator System (also known as Canadarm1). Kibo (ISS module) Remote Manipulator System (Japanese Experiment Module Remote Manipulator System) uses

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264-835: The STS-127 mission. The ELM-ES was brought back to Earth at the end of the mission. The assembly of the EF was completed during the fifth spacewalk of the mission. Kibō is the largest single ISS module: The module and all its integrated accessories were manufactured at the Tsukuba Space Center in Japan. It is made from stainless steel, titanium, and aluminum. Source: Deorbited with Kounotori 5 (HTV-5): Deorbited with SpaceX CRS-15: Deorbited with SpaceX CRS-17: Jettisoned into orbit by ISS robotic arm: Japanese: American: Grapple fixture Grapple fixtures are used on spacecraft or other objects to provide

286-686: The SpaceX Dragon, Orbital ATK Cygnus and Japanese H-II Transfer Vehicle include a standard FRGF which is used by the Canadarm2 to grapple the capsule on approach to the International Space Station for berthing. The fixture can have a maximum payload rating of 65,000 pounds or 30,000 kg. An orbital replacement unit may also have a grapple fixture. The Latchable Grapple Fixture (LGF) allows for grappling and latching, intended to be used for longer‐term stowage on

308-596: The ISS. PDGFs located around much of the station provide connections for the arm. They have four rectangular connectors to transfer data, video and electrical power. During the penultimate Space Shuttle flight a PDGF was installed on the Zarya module to support Canadarm2 operations based from the Russian segment. Although the European Robotic Arm uses grapples to relocate in a similar fashion to Canadarm2,

330-427: The PM. It is the location for many of the press conferences that take place on board the station. The Exposed Facility (EF), also known as "Terrace", is located outside the port cone of the PM (which is equipped with an airlock). The EF has twelve Exposed Facility Unit (EFU) ports which attach to Payload Interface Unit (PIU) connectors on EF-equipment exchange units (EF-EEUs). All experiment payloads are fully exposed to

352-480: The SUMO oscillator, and these two clocks (being fundamentally different) will provide a test of " local position invariance ." Comparisons between the space and earth clocks will yield a related, but important measurement of the gravitational frequency shift. Finally, the signals conveyed to the ground through the GPS time-transfer system will serve as a truly international time standard available to anyone on earth. PARCS

374-508: The maiden flight of the HTV spacecraft. Once HTV had docked, the small fine arm was assembled by the crew and deployed outside the airlock to test it. The JEMRMS grappled the arm and unfolded it to flex the joints before stowing it onto the EF. The free end of the JEMRMS is able to use the same type of grapple fixtures that the Canadarm2 uses. Inter-orbit Communication System (ICS) consists of

396-454: The space environment. For proper functioning of these experiments, the payload requires an orbital replacement unit (ORU), consisting of the electrical power system (EPS), communications and tracking (CT), and the thermal control system (TCS). Of the twelve ORUs, eight are replaceable by the JEMRMS while the other four are EVA -replaceable. The experiment logistics module (ELM) includes two sections: The JEM remote manipulator system (JEMRMS)

418-820: The station automatically. On 12 March 2007, the Experiment Logistics Module-Pressurized Section (ELM-PS), the main laboratory, arrived at the Kennedy Space Center (KSC) from Japan . It was stored in the Space Station Processing Facility (SSPF) until launched into orbit aboard Endeavour on 11 March 2008 as part of the STS-123 mission. On 30 May 2003, the Pressurized Module (PM) arrived at KSC from Japan. It

440-537: Was disposed by jettisoning into orbit in February 2020 and reentered on March 17, 2023 over Sacramento, California. NASA launched the JEM complex over three flights using the Space Shuttle . The shuttle had a large payload bay which carried the modules into orbit along with the crew. This is in contrast to the Russian modules, which are launched into orbit on multistage Proton rockets and then rendezvous and dock with

462-663: Was further refined by Barrie Teb. The Flight-Releasable Grapple Fixture (FRGF) is the simplest variation of the North American grapple fixture, it allows only for grappling and does not have any electrical connectors. Its use began early in the Space Shuttle program and was developed from the Flight Standard Grapple Fixture (FSGF) by allowing the Grapple Shaft to be installed during extravehicular activity (EVA). Unpiloted ships like

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484-741: Was stored at the SSPF until launched into orbit aboard Discovery on 31 May 2008 as part of the STS-124 mission. On 3 June 2008, the PM was attached to the Harmony module. At first the ELM-PS, the small cargo bay, was connected to a temporary location on Harmony and later, on 6 June 2008, was moved to its final berthing location on top (zenith) of the main laboratory. The Exposed Facility (EF) and Experiment Logistics Module-External Section (ELM-ES) arrived at KSC on 24 September 2008. The two elements were launched on Endeavour on 15 July 2009 as part of

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