- Interstellar probe
An interstellar probe is a
space probe which has left -- or is expected to leave -- thesolar system and enter interstellar space (typically defined as the region beyond theheliopause ). Alternatively, the term interstellar probe is used to refer to a space probe that is capable of reachingstar system s other than the solar system (a probe capable ofinterstellar travel ).Current interstellar probes
Five
spacecraft (three active spacecraft) are currently on interstellar trajectories:Functional spacecraft
; "
Voyager 1 "In May2005 a NASA press release expressed the consensus that "Voyager 1" was now in theheliosheath . [cite web | url = http://www.nasa.gov/vision/universe/solarsystem/voyager_agu.html | title = Voyager Enters Solar System's Final Frontier | publisher = NASA] As ofJuly 7 ,2008 , "Voyager 1" is at a distance of around 106.3 AU from theSun and traveling outward at roughly 3.6 AU per year. Scientists believe the craft will reach theheliopause in 2015.; "
Voyager 2 ""Voyager 2" passed the termination shock into theheliosheath onOctober 30 ,2007 . Unlike "Voyager 1", it has a working plasma science instrument, and is returning data on the temperature and pressure of this region. As ofJuly 7 ,2008 , "Voyager 2" is at a distance of around 85.49 AU from theSun and traveling outward at roughly 3.3 AU per year. "Voyager 2" is expected to keep transmitting into the 2020s.; "
New Horizons "Following its gravitational assist fromJupiter , "New Horizons" is on an interstellar trajectory viaPluto . As of2008 March 7 , "New Horizons" is 9.37 AU from the Sun and traveling outward at 3.9 AU per year; however, it will slow to an escape velocity of only 2.5 AU per year as it moves away from the Sun, so it will never catch up to either "Voyager".Non-functional spacecraft
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Pioneer 10 "The last successful reception of telemetry from "Pioneer 10" was onApril 27 ,2002 , when it was at a distance of 80.22 AU.; "
Pioneer 11 "Routine mission operations for "Pioneer 11" were stoppedSeptember 30 ,1995 , when it was 6.5 billion km (approx 43.4 AU) from Earth.Proposed probes capable of reaching the interstellar medium
;
Innovative Interstellar Explorer The "Innovative Interstellar Explorer" ("IIE") is a proposed NASA project to send a 35 kg science payload out to at least 200 AU. It would achieve a top speed of 7.8 AU per year using a combination of a heavy lift rocket, Jupiter gravitational assistance and anion engine powered by standardradioisotope thermal generator s. The probe could launch in2014 , reaching 200 AU around2044 . [http://interstellarexplorer.jhuapl.edu/index.php]; "Interstellar Probe""Interstellar Probe" was a proposed
solar sail propulsion spacecraft planned by NASA Jet Propulsion Laboratory. It was planned to reach as far as 200-400 AU at a speed of 14 AU/year. [http://interstellar.jpl.nasa.gov/interstellar/probe/index.html]; "Medusa""Medusa" was a proposed
nuclear pulse propulsion craft that used fission or fusion bombs to provide propulsion, with a structure similar to a light sail used to derive motive force from the bombs' blast waves. The design was studied during the 1990s by theBritish Interplanetary Society as a means of interplanetary travel. []; "
AIMStar ""AIMStar" was a proposedantimatter catalyzed nuclear pulse propulsion craft that used clouds ofantiproton s to initiate fission and fusion within fuel pellets. [cite web | title = AIMStar: Antimatter Initiated Microfusion For Pre-cursor Interstellar Missions | url = http://www.engr.psu.edu/antimatter/Papers/AIMStar_99.pdf | last = Lewis | first = Raymond A | coauthors = Meyer, Kirby; Smith, Gerald A; Howe, Steven D] A magnetic nozzle derived motive force from the resulting explosions. The design was studied during the 1990s byPenn State University . The craft was designed to reach a distance of 10,000 AU from theSun .Proposed probes capable of reaching other stars
; "Project Orion"Project Orion was a proposed
nuclear pulse propulsion craft that used fission or fusion bombs to apply motive force. The design was studied during the 1950s and 1960s in theUnited States of America , with one variant of the craft capable ofinterstellar travel .; "
Project Daedalus "Project Daedalus was a proposednuclear pulse propulsion craft that usedinertial confinement fusion of small pellets within a magnetic field nozzle to provide motive force. The design was studied during the 1970s by theBritish Interplanetary Society . The craft was designed to reach and studyBarnard's Star .; "
Project Longshot "Project Longshot was a proposednuclear pulse propulsion craft that usedinertial confinement fusion of small pellets within a magnetic field nozzle to provide motive force, in a manner similar to that of Project Daedalus. The design was studied during the 1990s byNASA and theUS Naval Academy . The craft was designed to reach and studyAlpha Centauri .; "
Starwisp "Starwisp is a hypothetical unmanned interstellar probe design proposed by Robert L. Forward. It is propelled by a microwave sail, similar to a solar sail in concept, but powered by microwaves from an artificial source.References
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