Innovative Interstellar Explorer interstellar space probe

Innovative Interstellar Explorer was a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

"Vision Mission" study funded by NASA following a proposal under NRA-03-OSS-01 on 11 September 2003. This study focused on measuring the

interstellar medium In astronomy, the interstellar medium is the matter and radiation that exist in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstella ...

, the region outside the influence of the nearest star, the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

. It proposes to use a

radioisotope thermal generator A radioisotope thermoelectric generator (RTG, RITEG), sometimes referred to as a radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioacti ...

to power

ion thruster An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity. An ion thruster ionizes a neutral gas by extracting some electrons out of a ...

s. The project is a study of a proposed interstellar precursor mission that would probe the nearby interstellar medium and measure the properties of magnetic fields and

cosmic ray Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...

s and their effects on a spacecraft leaving the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

. Mission launch plans analyzed direct, one planet, multi-planet, and upper-stage trades. As a concept study, a number of technologies, configurations, and mission goals were considered, leading to the choice of a spacecraft propelled with

ion engine An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity. An ion thruster ionizes a neutral gas by extracting some electrons out of a ...

s powered by a

radioisotope thermoelectric generator A radioisotope thermoelectric generator (RTG, RITEG), sometimes referred to as a radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioacti ...

(RTG).''Innovative Interstellar Explorer'' Feb 2006
slides The focus was getting a spacecraft launched by about 2014, achieving 200 AU by the year 2031. A variety of strategies were assessed, including using launch windows (not counting backups) for a Jupiter assist in 2014, 2026, 2038, and 2050about every 12 years. The launch opportunity for the 2014 window passed, but for example it could have resulted in a Jupiter flyby by early 2016 and then go on to reach 200

astronomical units The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...

(AU) by 2044. With an ion drive, a speed of about 7.9 AU per year could be attained by the time its

xenon Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...

propellant was depleted, enabling a travel distance of 200 AU by 2044 and perhaps 1000 AU after one hundred years from launch. Different launch times and configurations have various timelines and options. One configuration for launch saw the use of a

Delta IV Heavy The Delta IV Heavy (Delta 9250H) is an Evolved Expendable Launch Vehicle, expendable heavy-lift launch vehicle, the largest type of the Delta IV family. It is the world's third highest-capacity launch vehicle in operation, behind NASA's Space L ...

and for the upper stages a stack of Star 48 and

Star 37 The Star is a family of US solid-propellant rocket motors originally developed by Thiokol and used by many space propulsion and launch vehicle stages. They are used almost exclusively as an upper stage, often as an apogee kick motor. Three Star 3 ...

leading to various gravity assist options. Another launch stack that was considered was the

Atlas V 551 Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture between Lockheed Martin ...

with a Star 48. In 2011, the study's primary author gave an update to website

Centauri Dreams Centauri may refer to: * Any of the stars (or star systems), in the constellation Centaurus, including: ** Alpha Centauri, a binary star including the brightest star of Centaurus ** Beta Centauri, the second-brightest star of Centaurus, at a much ...

, giving a retrospective on the mission and its feasibility since its publication in 2003. By that time, some of earliest launch windows were no longer feasible without a ready spacecraft. Some retrospectives were the advantages and potential of

solar sail Solar sails (also known as light sails and photon sails) are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A number of spaceflight missions to test solar propulsion and navigation have been p ...

s, but the need for them to be more advanced for a mission, and also the utility of a radioisotope propulsion (REP) for such a mission. REP was the combination of using an RTG to power an ion drive.

References

External links

Interstellar Explorer – NASAPresentation on IIE
{{Jupiter spacecraft Hypothetical spacecraft Interstellar travel Proposed space probes

See also

References

External links