X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to calculate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter. [1] [2] [3] Experimental demonstrations have been reported in 2018. [4]
The Advanced Concepts Team of ESA studied in 2003 the feasibility of x-ray pulsar navigation [5] in collaboration with the Universitat Politecnica de Catalunya in Spain. After the study, the interest in the XNAV technology within the European Space Agency was consolidated leading, in 2012, to two different and more detailed studies performed by GMV AEROSPACE AND DEFENCE (ES) and the National Physical Laboratory (UK). [6]
In 2014, a feasibility study was carried out by the National Aerospace Laboratory of Amsterdam, for use of pulsars in place of GPS in navigation. The advantage of pulsar navigation would be more available signals than from satnav constellations, being unjammable, with the broad range of frequencies available, and security of signal sources from destruction by anti-satellite weapons. [13]
Among pulsars, millisecond pulsars are good candidate to be space-time references. [14] In particular, extraterrestrial intelligence might encode rich information using millisecond pulsar signals, and the metadata about XNAV is likely to be encoded by reference to millisecond pulsars. [15] Finally, it has been suggested that advanced extraterrestrial intelligence might have tweaked or engineered millisecond pulsars for the goals of timing, navigation and communication. [16]
Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space or on the surface of the Earth without relying solely on estimated positional calculations, commonly known as "dead reckoning." Celestial navigation is performed without using satellite navigation or other similar modern electronic or digital positioning means.
The Automated Transfer Vehicle, originally Ariane Transfer Vehicle or ATV, was an expendable cargo spacecraft developed by the European Space Agency (ESA), used for space cargo transport in 2008–2015. The ATV design was launched to orbit five times, exclusively by the Ariane 5 heavy-lift launch vehicle. It effectively was a larger European counterpart to the Russian Progress cargo spacecraft for carrying upmass to a single destination—the International Space Station (ISS)—but with three times the capacity.
The Japan Aerospace Exploration Agency (JAXA) is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orbit, and is involved in many more advanced missions such as asteroid exploration and possible human exploration of the Moon. Its motto is One JAXA and its corporate slogan is Explore to Realize.
Orbital Sciences Corporation was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other government customers. In 2014, Orbital merged with Alliant Techsystems to create a new company called Orbital ATK, Inc., which in turn was purchased by Northrop Grumman in 2018. The remnants of the former Orbital Sciences Corporation became a subsidiary of Northrop Grumman, known as Northrop Grumman Space Systems.
A mission control center is a facility that manages space flights, usually from the point of launch until landing or the end of the mission. It is part of the ground segment of spacecraft operations. A staff of flight controllers and other support personnel monitor all aspects of the mission using telemetry, and send commands to the vehicle using ground stations. Personnel supporting the mission from an MCC can include representatives of the attitude control system, power, propulsion, thermal, attitude dynamics, orbital operations and other subsystem disciplines. The training for these missions usually falls under the responsibility of the flight controllers, typically including extensive rehearsals in the MCC.
Uncrewed spaceflights to the International Space Station (ISS) are made primarily to deliver cargo, however several Russian modules have also docked to the outpost following uncrewed launches. Resupply missions typically use the Russian Progress spacecraft, European Automated Transfer Vehicles, Japanese Kounotori vehicles, and the American Dragon and Cygnus spacecraft. The primary docking system for Progress spacecraft is the automated Kurs system, with the manual TORU system as a backup. ATVs also use Kurs, however they are not equipped with TORU. The other spacecraft — the Japanese HTV, the SpaceX Dragon and the Northrop Grumman Cygnus — rendezvous with the station before being grappled using Canadarm2 and berthed at the nadir port of the Harmony or Unity module for one to two months. Progress, Cygnus and ATV can remain docked for up to six months. Under CRS phase 2, Cargo Dragon docks autonomously at IDA-2 or 3 as the case may be. As of December 2022, Progress spacecraft have flown most of the uncrewed missions to the ISS.
Dream Chaser is an American reusable lifting-body spaceplane being developed by Sierra Space. Originally intended as a crewed vehicle, the Dream Chaser Space System is set to be produced after the cargo variant, Dream Chaser Cargo System, is operational. The crewed variant is planned to carry up to seven people and cargo to and from low Earth orbit.
A pulsar is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth, and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays.
The following outline is provided as an overview of and topical guide to space exploration.
Cygnus is an expendable American cargo spacecraft developed by Orbital Sciences Corporation but manufactured and launched by Northrop Grumman Space Systems as part of NASA's Commercial Resupply Services (CRS) program. It is usually launched by Northrop Grumman's Antares rocket, although three flights were on ULA's Atlas V and three are planned for SpaceX's Falcon 9. It transports 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.
Commercial Resupply Services (CRS) are a series of flights awarded by NASA for the delivery of cargo and supplies to the International Space Station (ISS) on commercially operated spacecraft. The first CRS contracts were signed in 2008 and awarded $1.6 billion to SpaceX for twelve cargo Dragon and $1.9 billion to Orbital Sciences for eight Cygnus flights, covering deliveries to 2016. The Falcon 9 and Antares rockets were also developed under the CRS program to deliver cargo spacecraft to the ISS.
SpaceX CRS-3, also known as SpX-3, was a Commercial Resupply Service mission to the International Space Station (ISS), contracted to NASA, which was launched on 18 April 2014. It was the fifth flight for SpaceX's uncrewed Dragon cargo spacecraft and the third SpaceX operational mission contracted to NASA under a Commercial Resupply Services (CRS-1) contract.
The Neutron Star Interior Composition ExploreR (NICER) is a NASA telescope on the International Space Station, designed and dedicated to the study of the extraordinary gravitational, electromagnetic, and nuclear physics environments embodied by neutron stars, exploring the exotic states of matter where density and pressure are higher than in atomic nuclei. As part of NASA's Explorer program, NICER enabled rotation-resolved spectroscopy of the thermal and non-thermal emissions of neutron stars in the soft X-ray band with unprecedented sensitivity, probing interior structure, the origins of dynamic phenomena, and the mechanisms that underlie the most powerful cosmic particle accelerators known. NICER achieved these goals by deploying, following the launch, and activation of X-ray timing and spectroscopy instruments. NICER was selected by NASA to proceed to formulation phase in April 2013.
SpaceX CRS-11, also known as SpX-11, was a Commercial Resupply Service mission to the International Space Station, launched successfully on 3 June 2017. The mission was contracted by NASA and was flown by SpaceX. The mission utilized a Falcon 9 launch vehicle and was the first reuse of C106, a CRS Dragon cargo vessel that was previously flown on the CRS-4 mission.
Progress MS-01, identified by NASA as Progress 62P was a Progress spaceflight operated by Roscosmos to resupply the International Space Station (ISS) in 2015. It was launched on 21 December 2015, to deliver cargo to the ISS. Progress MS-01 is the first vehicle in the Progress-MS series.
Dragon, also known as Dragon 1 or Cargo Dragon, was a class of fourteen partially reusable cargo spacecraft developed by SpaceX, an American private space transportation company. The spacecraft flew 23 missions between 2010 and 2020. Dragon was launched into orbit by the company's Falcon 9 launch vehicle to resupply the International Space Station (ISS).
SpaceX CRS-23, also known as SpX-23, was a Commercial Resupply Service mission to the International Space Station, successfully launched on 29 August 2021 and docking the following day. The mission was contracted by NASA and was flown by SpaceX using the Cargo Dragon C208. This was the third flight for SpaceX under NASA's CRS Phase 2 contract awarded in January 2016. It was the second mission for this reusable capsule.
SpaceX CRS-25, also known as SpX-25, was a Commercial Resupply Service mission (CRS) to the International Space Station (ISS) that was launched on 15 July 2022. The mission was contracted by NASA and was flown by SpaceX using their reusable spacecraft, the Cargo Dragon. The vehicle delivered supplies to the crew aboard the ISS along with multiple pieces of equipment that will be used to conduct multiple research investigations aboard the ISS.
SpaceX CRS-26, also known as SpX-26, was a Commercial Resupply Service mission to the International Space Station (ISS) launched on 26 November 2022. The mission was contracted by NASA and flown by SpaceX using a Cargo Dragon. This was the sixth flight for SpaceX under NASA's CRS Phase 2 contract awarded in January 2016.
SpaceX CRS-27, also known as SpX-27, was a Commercial Resupply Service mission to the International Space Station (ISS) launched on 15 March 2023. The mission was contracted by NASA and was flown by SpaceX using Cargo Dragon C209. This was the seventh flight for SpaceX under NASA's CRS Phase 2.
Previously scheduled for a December 2016 launch on SpaceX-12, NICER will now fly to the International Space Station with two other payloads on SpaceX Commercial Resupply Services (CRS)-11, in the Dragon vehicle's unpressurized Trunk.