[Space] News

[Rand]

Prosegue lo sviluppo di VASIMR:

Ad Astra VX-200 Plasma Engine Demonstrates Superconducting First Stage at Full Power

Ad Astra Rocket Company has successfully demonstrated operation of its VX-200 plasma engine first stage at full power and under superconducting conditions in tests conducted today at the company's Houston laboratory. This achievement is a key milestone in the engine's development and the first time a superconducting plasma rocket has been operated at that power level. Today's tests build on the achievements of the VX-200i, the engine's non-superconducting predecessor, which last fall underwent similar tests but under a greatly reduced set of requirements. A major difference between the two is the superconducting magnet, featured in the present system, which provides a ten-fold increase in the magnetic field and enables operation of the engine under conditions consistent with actual space flight. Power trace (black) shows the RF coupled power to the VX-200 first stage.

The VX-200 superconducting magnet, the first of its kind, was delivered to Ad Astra's Houston facility on February 10, 2009 by its manufacturer, Scientific Magnetics of Oxford, U.K. After successful acceptance tests, the superconductor was installed in the engine module, replacing the conventional magnet that had been used in the interim. This interim magnet, although incapable of reaching the strong magnetic fields required

for full rocket performance, enabled the integrated testing of the remaining engine sub-systems while the company awaited delivery of the superconductor. First plasma in full superconducting mode was achieved on June 24, 2009.

The successful first stage tests conducted today are critically important and are prerequisites to operational testing of the second stage of the engine. This activity is expected to commence on July 14, 2009, after the team completes a full analysis of the new data. The second stage is designed to inject up to 170 kW of additional power into the plasma for a total of 200 kW, the engine's total rated power.



The present configuration achieves drastic increases in key rocket performance parameters over previous VX- 200i results, including a 5-fold increase in propellant flow rate and an equivalent increase in the rate of plasma production with a ten-fold increase in the magnetic field, all consistent with the conditions required for space flight.

The VX-200 engine is the first flight-like prototype of the VASIMR(R) propulsion system, a new high-power plasma-based rocket, initially studied by NASA and now being developed privately by Ad Astra. VASIMR(R) engines could enable space operations far more efficiently than today's chemical rockets and ultimately they could also greatly speed up robotic and human transit times for missions to Mars and beyond.

ABOUT AD ASTRA

Ad Astra Rocket Company is a privately-owned corporation established January 14, 2005 to commercialize the technology of the VASIMR(R) engine in support of an emerging in-space transportation market. The company has its main laboratory and corporate headquarters at 141 W. Bay Area Boulevard in Webster, Texas, USA. Ad Astra also owns and operates Ad Astra Rocket Company, Costa Rica, a supporting research and development subsidiary in Guanacaste, Costa Rica.

Notare chi è il CEO/fondatore di Ad Astra

[Rand]

Nuovi sviluppi anche per i pannelli solari:

Boeing Team to Develop Revolutionary Spacecraft Power System for DARPA

HUNTINGTON BEACH, Calif., July 1, 2009 -- An industry team led by The Boeing Company [NYSE: BA] has received a contract from the Defense Advanced Research Projects Agency (DARPA) for work on Phase 2 of the Fast Access Spacecraft Testbed (FAST) program. The $15.5 million cost-plus-fixed-fee contract is currently funded to $13.8 million.

DARPA's FAST program aims to develop a new, ultra-lightweight High Power Generation System (HPGS) that can generate up to 175 kilowatts -- more power than is currently available to the International Space Station. When combined with electric propulsion, FAST will form the foundation for future self-deployed, high-mobility spacecraft to perform ultra-high-power communications, space radar, satellite transfer and servicing missions.

Boeing Phantom Works of Huntington Beach is leading the effort with support from Boeing Network and Space Systems, El Segundo, Calif. The Phase 2 work will include designing, fabricating and integrating test articles, performing a series of component-level evaluations and running two full-scale system tests.

"Our team is pleased to partner with DARPA in developing this powerful new technology," said Tom Kessler, FAST program manager, Boeing Advanced Network and Space Systems. "FAST offers significant cost and performance benefits to our commercial, civil and national security customers, including new high-power applications to provide a cost-effective means for spacecraft to travel to the outer solar system."

During Phase 1 of the program, the Boeing-led team, which includes DR Technologies, Northrop Grumman Astro Aerospace, Texas A&M University, Emcore, Boeing subsidiary Spectrolab Inc., and other key suppliers, developed a preliminary design for an HPGS capable of providing more than 130 watts per kilogram on a system that is less than half the weight and one sixth the size of an existing on-orbit solar power system. The team also defined the test program being conducted in Phase 2, which will verify the performance and operation of the HPGS's solar concentration, power conversion, heat rejection, structure and deployment, and sun pointing and tracking subsystems.

The Boeing team's unique solar concentrator design offers higher performance and greater radiation tolerance than current on-orbit solar power generation systems. Boeing will also be using different approaches to solar cell technology to include capabilities from Emcore and Spectrolab.

The size efficiency of the HPGS enables a new class of compact spacecraft that can self-deploy from low-Earth orbit to reach their final orbit using electric propulsion. This permits the use of smaller, less expensive launch vehicles that can support high-value science missions to the outer solar system without the need for expensive radioisotope power systems.

A unit of The Boeing Company, Boeing Integrated Defense Systems is one of the world's largest space and defense businesses specializing in innovative and capabilities-driven customer solutions, and the world's largest and most versatile manufacturer of military aircraft. Headquartered in St. Louis, Boeing Integrated Defense Systems is a $32 billion business with 70,000 employees worldwide.

[Octane]

Il VASIMR finalmente funzionante!
avranno però i loro bei grattacapi a schermare tutte le apparecchiature di bordo dalle microonde emesse dal motore!


per chi volesse info:
http://en.wikipedia.org/wiki/VASIMR

[Octane]

novità anche dall' ESA:

Europe launches study into manned spacecraft scheme
by Staff Writers
Paris (AFP) July 8, 2009
The European Space Agency (ESA) said it had taken an important first step in a tentative project to build a manned spacecraft that would be launched atop its Ariane 5 rocket.



ESA officials signed a contract in the northern German city of Bremen on Tuesday with space company EADS Astrium to conduct a feasibility study into the idea, it said in a press release.

Europe does not have its own manned spaceflight capability, and instead depends on the US shuttle and Russia's Soyuz rocket to take its astronauts to the International Space Station (ISS).

Ministers of ESA countries agreed last November to explore ways of developing an "advanced re-entry vehicle" (ARV) that would be based on an unmanned freighter that made a successful maiden flight to the ISS last year.

Under its present design, the freighter is jettisoned and destroyed by friction with the atmosphere after its mission.

The ARV project would need to modify the vehicle so that it becomes a cargo ship that can return to Earth. In a second phase, the craft would be transformed into a crewship.

The contract is "a clear sign of Europe's commitment to play an even greater role in the global human spaceflight and exploration undertakings," said Simonetta Di Pippo, ESA's director of human spaceflight.

"We are building on our technological basis and achievements to position Europe in a more important role in this strategic field, leveraging on our industrial base and nurturing its highly skilled workforce. Today's signature is the first step of a journey that will be very rewarding for Europe."

If the political green light is given, and all goes well technically, the first return-to-Earth cargo ship could make its first flight around the middle of the next decade, and a manned version possibly a decade later, say experts.

Observers caution that the feasibility report will be scrutinised closely, given the high costs of developing a manned spacecraft and concerns that the project could drain funds away from scientific research and Earth observation, which are ESA's mainstays.

http://www.space-travel.com/reports/...cheme_999.html

[Rand]

Originariamente inviato da Xile

Beh visto i tempi mi sembra normale come decisione, giusto qualche giorno fa su Discovery Channel hanno tirato fuori il Mars Sample Return programma mandato avanti proprio da NASA e ESa.

Spero che Mars Sample Return prima o poi si concretizzi: le prime proposte sono degli anni 70

Riguardo alle missioni in collaborazione mi auguro che si segua la consuetudine del JPL (dati disponibili "subito") e non quella dell'ESA (3 foto in croce e il resto dopo x mesi).

[Xile]

Anche se ormai non c'é più da sperare metto a conoscenza del progetto: Terrestrial Planet Finder

The Terrestrial Planet Finder (TPF) is a proposed project by the National Aeronautics and Space Administration of the United States for a telescope system which is intended to detect extrasolar terrestrial planets.

In May 2002, NASA chose two TPF mission architecture concepts for further study and technology development. Each would use a different means to achieve the same goal—to block the light from a parent star in order to see its much smaller, dimmer planets. That technology challenge has been likened to finding a firefly near the beam of a distant searchlight. Additional goals of the mission would include characterizing the surfaces and atmospheres of newfound planets, and looking for the chemical signatures of life. In May 2004, both architectures were approved. Congressional spending limits under House Resolution 20 passed on January 31, 2007, by the United States House of Representatives and February 14 by the U.S. Senate have postponed the program indefinitely.

The two planned architectures were:

* Infrared astronomical interferometer (TPF-I): Multiple small telescopes on a fixed structure or on separated spacecraft floating in precision formation would simulate a much larger, very powerful telescope. The interferometer would use a technique called nulling to reduce the starlight by a factor of one million, thus enabling the detection of the very dim infrared emission from the planets.
* Visible Light Coronagraph (TPF-C): A large optical telescope, with a mirror three to four times bigger and at least 10 times more precise than the Hubble Space Telescope, would collect starlight and the very dim reflected light from the planets. The telescope would have special optics to reduce the starlight by a factor of one billion, thus enabling astronomers to detect the faint planets.

NASA and Jet Propulsion Laboratory (JPL) were to issue calls for proposals seeking input on the development and demonstration of technologies to implement the two architectures, and on scientific research relevant to planet finding. Launch of TPF-C had been anticipated to occur around 2014, and TPF-I possibly by 2020.

According to NASA's 2007 budget documentation, released on February 6, 2006, the project was deferred indefinitely. In June 2006, a House of Representatives subcommittee voted to provide funding for the TPF along with the long-sought mission to Europa, a moon of Jupiter that might harbor extraterrestrial life. However, as of June 2008, actual funding has not materialized, and TPF remains without a launch date.

The European Space Agency, ESA, is considering a similar mission, called Darwin.

Link

[Rand]

Per la serie sonde robuste :

Galileo's atmospheric entry probe

The 339 kilogram atmospheric probe, built by Hughes Aircraft Company at its El Segundo, California plant, measured about 1.3 meters across. Inside the heat shield, the scientific instruments were protected from ferocious heat during entry. The probe had to withstand extreme heat and pressure on its high speed journey at 47.8 km/s.

The probe was released from the main spacecraft in July 1995, five months before reaching Jupiter, and entered Jupiter's atmosphere with no braking beforehand. It was slowed from the probe's arrival speed of about 47 kilometers per second to subsonic speed in less than 2 minutes.

This was by far the most difficult atmospheric entry ever attempted; the probe had to withstand 230 g's [25] and the probe's 152 kg heat shield made up almost half of the probe's total mass, and lost 80 kg during the entry. [26] [27] NASA built a special laboratory, the Giant Planet Facility to simulate the heat load, which was similar to that of an ICBM-style straight-down reentry through a thermonuclear fireball.[28] [29] It then deployed its 2.5-meter (8 ft) parachute, and dropped its heat shield.

[Rand]

Parlando invece di sonde (molto) fredde l'High Frequency Instrument di Planck ha raggiunto la sua temperatura operativa di 0.1 K:

Cooling Planck

The extremely low operational temperature of just a tenth of a degree above absolute zero (0.1 K) has been reached on the detectors of Planck's High Frequency Instrument (HFI). This makes the HFI detectors the coldest known objects in outer space. The achievement, seven weeks after launch, marks a key milestone for the Planck mission. The spacecraft's active cooling system has now reached its final operational conditions and the two instruments onboard Planck (HFI and the Low Frequency Instrument, LFI) are now both at their cryogenic operational temperatures.

The design of the Planck spacecraft allows it to cool down passively to about 45 K (-228 °C) by radiating heat towards the cold space environment. However, to reach the required operational temperatures for the two instruments (20K for LFI and down to 0.1 K for HFI) Planck is equipped with a sophisticated active cooling system. This system comprises three different coolers that act on different stages of the two Planck instruments, respectively down to 20K, 4K and 0.1K above absolute zero.

The passive cool down of the spacecraft in the space environment started immediately after launch on 14 May. The two coldest coolers (0.1K dilution cooler and 4K Joules-Thompson cooler) were switched on very shortly after launch, but at a low level. This was done to allow the gas that these stages use for cooling to flow through the system's pipes, to prevent any potential clogging of these pipes that might be caused by the rapid passive cool-down.

Two days after launch the coldest of the spacecraft's three V-grooves - panels that isolate thermally the payload from the hot spacecraft and help to cool the spacecraft by passively radiating excess heat - was already at 75 K. However, the Focal Plane Units (FPUs) of the HFI and LFI as well as the telescope were actively kept at a higher temperature of about 170 K (-103 °C) for two weeks, using dedicated heaters. This was to prevent any contamination, from the spacecraft that is outgassing early in the mission, to freeze onto the surface of these elements.

On 1 June the anti-contamination heaters were switched off and the focal plane and telescope were allowed to resume the passive cool down. Three days later, on 4 June, when the LFI FPU had passively cooled to 100K, the sorption cooler (20 K stage) was switched on. The sorption cooler is responsible for actively cooling the LFI Focal Plane Unit to its operational temperature of 20K and pre-cools the HFI Focal Plane Unit to 18K. Its coldest operational level was reached after nine days, on 13 June, with a temperature of ~17.5K.

As the next steps in activating the cooling system, the remaining two coolers (4K and 0.1K coolers), which had been switched on at a low level shortly after launch, were set to full power one after the other on 28 June. With all coolers of the active cooling chain in operation, the detectors in the HFI Focal Plane Unit finally reached the 0.1K level on 3 July.

Key dates of cooling system commissioning

14 May 2009 - Launch; start of passive cooling 4K and 0.1 K coolers ON at low level
16 May 2009 - FPUs and telescope kept at 170 K using heaters V-groove at 75 K
01 June 2009 - Heaters switched OFF: FPUs and telescope allowed to cool further
04 June 2009 - LFI FPU below 100 K 20K cooler is turned ON
13 June 2009 - LFI FPU at 20K, HFI FPU at ~17.5 K V-groove at 46 K
28 June 2009 - 4 K stage ON at full power 0.1 K stage ON at full power
03 July 2009 - HFI FPU at 0.1 K

For the two instruments HFI and LFI, the next and last phase of their commissioning before the start of nominal science operations is the Calibration and Performance Verification (CPV) phase. This phase will now last until mid August, during which they will carry out specific activities targeted to calibrate both the HFI and LFI. Upon completion of the CPV phase, Planck will start its scientific mission, surveying the whole sky twice over within about one year.

Editor's notes: The active coolers form part of the two sophisticated instruments onboard Planck, which have been built and delivered to ESA by two large consortia of scientific institutes: the LFI Consortium and the HFI Consortium. See the corresponding links in the right-hand menu for the lists of consortia member institutes and organizations.

The three state-of-the-art coolers of Planck's active cooling system were provided by: the Jet Propulsion Laboratory (Pasadena, California, US), a member of the LFI and HFI Consortia, built the 20 K cooler; the Rutherford Appleton Laboratory (Didcot, UK), a member of the HFI Consortium, & Astrium UK, built the 4K cooler; and the 0.1K cooler was built in collaboration by the Institut Néel (Grenoble), the Institut d'Astrophysique Spatiale (Orsay, FR), both members of the HFI Consortium, and DTA Air Liquide (Grenoble).

[Rand]

Il Corriere spaccia Amstrong e Collins come morti quando invece sono vivissimi:

Corriere: Neil Armstrong e Michael Collins dell'Apollo 11 sono morti

(ma da che fonti partono per scrivere queste notizie?)

[Octane]

Originariamente inviato da Rand

Il Corriere spaccia Amstrong e Collins come morti quando invece sono vivissimi:

Corriere: Neil Armstrong e Michael Collins dell'Apollo 11 sono morti

(ma da che fonti partono per scrivere queste notizie?)

per fortuna c'è sempre Paolo Attivissimo nella costante caccia a castronerie varie (e alla dimostrazione del fatto che son bufale)

[jumpjack]

Il "grande fratello marziano", dopo 105 giorni, è terminato:

http://www.wired.it/news/archivio/20...4/mars500.aspx

http://www.esa.int/esaCP/SEMIS47CTWF_index_0.html


Vi è mai passato per la testa che forse DAVVERO anche il GF "terrestre" è seguito con interesse da psicologi di NASA e ESA per capire i meccanismi che si innescano in un gruppo di giovani costretti a convivere per 3 mesi in uno spazio chiuso comune?

[Rand]

Il nuovo guardiano assunto da SpaceX mi sembra di conoscerlo :

[Rand]

Il giornale: Allunaggio: 1969-2009 Un’impresa spettacolare che sembra quasi finta...

Riporto il commento di Attivissimo che risponde alle solite domande poste nell'articolo:

"Prove? Più che altro dubbi, a partire dal fatto che risulta davvero difficile credere che la tecnologia dell’epoca - senza computer o quasi, e con tute da astronauti che sembrano uscite da un B-movie degli anni ’50 - potesse depositarci delicatamente sulla superficie lunare (e riportarci a casa indenni, soprattutto)" scrive il buon Mascheroni. Che forse non si rende conto che la tecnologia dell'epoca ci diede il Concorde, un aereo di linea supersonico. Sarà stato fatto in studio anche quello?

"Domande di rito: perché nelle foto e nei filmati della missione Apollo 11 non si vedono le stelle che, in mancanza di atmosfera, dovrebbero essere luminosissime?"

Perché è così che dev'essere. La Luna è illuminata a giorno dal Sole. Se regolo la fotocamera per esporre correttamente la superficie della Luna, le stelle sono troppo fioche. Tant'è vero che le stelle mancano anche nello foto fatte nello spazio dal nostro Umberto Guidoni. False anche quelle, oppure sarebbe il caso di studiare le basi della fotografia prima di ripetere a pappagallo certe fregnacce?


"Perché non ci sono crateri sotto il Lem nonostante il getto del motore a propulsione?"

Perché il LM si è posato su una distesa di roccia. Dura quasi quanto la zucca dei lunacomplottisti.


"Perché in molte immagini gli astronauti proiettano ombre e sono illuminati in un modo inspiegabile rispetto alla sola fonte di luce possibile sulla luna, cioè il sole?"

Perché sulla Luna c'è un'altra fonte di luce: la Luna stessa, che riflette la luce del Sole, illumina gli astronauti e schiarisce le ombre. C'è un corso CEPU di fotografia da regalare a chi scrive certe idiozie?


"Perché Armstrong è fotografato da Aldrin che si vede riflesso nel suo casco senza però avere in mano la macchina fotografica?"

Non diciamo scemenze, per favore. Innanzi tutto, la foto non ritrae Armstrong, ma Aldrin. C'è pure scritto il nome sulla tuta, caro Mascheroni. E il suo compagno ha eccome in mano la macchina fotografica. Basta guardare gli originali ad alta risoluzione invece delle cacchine sbiadite pubblicate dai lunacomplottisti.


"A conferma dei dubbi dei cospiratori, la Nasa due anni fa ha dichiarato di aver perso i filmati originali dello sbarco. Che forse però salteranno fuori per questo anniversario."

Per l'ennesima volta, no. La NASA non ha perso i "filmati originali". Ha perso una copia di alta qualità della diretta TV, ma ha quella in qualità normale. E le riprese filmate su pellicola 16mm a colori dello sbarco sono pubblicamente disponibili. Ne ho una copia persino io, grazie anche alla colletta dei lettori, e l'ho mostrata qui.


"Alla fine, tanti dubbi e una sola certezza. Che la celebre frase «un piccolo passo per me, un grande balzo per l’umanità» - al netto di qualsiasi prova scientifica così come di qualsiasi teoria complottista - non può che essere uscita dalla penna di un mediocre sceneggiatore. Hollywoodiano."

Alla fine, pochi dubbi e una sola certezza. Che un articolo del genere non può che essere uscito dalla penna di un... va be', la frase la lascio completare a voi.

[Rand]

Bolden and Garver Confirmed by Senate

Keith's note: Sources report that the Senate just confirmed Charles Bolden and Lori Garver by unanimous consent. The request was made on the Senate floor by Sen. Nelson.

@SenBillNelson "Charlie Bolden just confirmed by Senate as nation’s new space czar. He’s perfect to keep America leading in space, science and technology ... I’ve known Charlie Bolden the better part of a quarter century, since he was my pilot on the space shuttle in 1986 ... Naval academy grad, Marine test pilot, astronaut, general – Charlie will bring back the magic from a time when we rode rockets to the moon"

Senate confirms Bolden as NASA chief, Orlando Sentinel

"The U.S. Senate unanimously agreed Wednesday that ex-astronaut Charlie Bolden should become the next chief of NASA, clearing the way for Bolden to take control during what could be one of the toughest tenures in the agency’s half-century history."

Sen. Hutchison Statement on Senate Confirmation of NASA Nominees

"Senator Kay Bailey Hutchison (R-Texas), Ranking Member on the Senate Commerce, Science, and Transportation Committee, today said she was pleased the Senate approved Charles Bolden to be the next NASA Administrator."

Challenger Center congratulates Charles Bolden as NASA Administrator, Lori Garver as Deputy Administrator - an Ideally Qualified Team

"Bolden and Garver are exceptional role models, and extremely talented and accomplished space professionals. They are ideally qualified, both individually and as a team, to lead NASA at this critical time in the agency's history," said William Readdy, Chair of the Board, Challenger Center."

Commercial Spaceflight Federation Congratulates Incoming NASA Leaders Charles Bolden and Lori Garver

Bolden and Garver Confirmed by U.S. Senate, NASA

National Space Society Applauds the U.S. Senate Confirmation of Charles Bolden and Lori Garver to lead NASA

4chr

[Rand]

USA: ASTRONAUTA AFRO-AMERICANO BOLDEN GUIDERA' LA NASA

Il Senato degli Stati Uniti ha confermato l'ex astronauta Charles Bolden come nuovo direttore della Nasa. Bolden, 62 anni, e' il primo afro-americano alla guida dell'agenzia spaziale statunitense. Il voto che lo ha eletto all'unanimita' e' arrivato poco dopo il decollo dello shuttle Endeavour che aggancera' la stazione spaziale internazionale, dopo cinque tentativi di lancio falliti durante le ultime settimane. La sua nomina coincide anche con il quarantesimo anniversario dell'allunaggio dell'Apollo 11, avvenuto il 20 luglio 1969. Bolden, dodicesimo direttore della Nasa dalla sua creazione nel 1958, succede all'ingegnere e scienziato Michael Griffin. Lori Garver, 48 anni, consulente per la politica spaziale del presidente Obama, e' stata nominata vicedirettore dell'agenzia spaziale. E' al secondo incarico alla Nasa, dopo essere stata socia dal 1998 al 2001. Bolden si e' laureato nel 1979 alla Us Naval Test Pilot School e l'anno successivo e' stato selezionato come astronauta dalla Nasa. E' stato il comandante di due delle quattro missioni spaziali a cui ha partecipato ed e' stato membro dell'ufficio astronauti della Nasa per 14 anni. Come pilota da caccia nei marines, Bolden ha partecipato anche alla guerra del Vietnam. E' stato chiamato dall'agenzia spaziale per "fare spazio a nuove conquiste della scienza, continuare la ricerca aeronautica all'avanguardia, sostenere l'innovazione e stimolare i giovani a crearsi una carriera nel campo dell'aeronautica". La sua nomina e' arrivata proprio mentre la Casa Bianca sta esaminando il controverso programma spaziale Constellation, lanciato da George W. Bush nel 2004, che prevedeva il ritorno dell'uomo sulla Luna e l'atterraggio su Marte entro il 2020.

4chr

[jumpjack]

http://www.nasa.gov/mission_pages/LR...ollosites.html


LARGE--> http://www.nasa.gov/images/content/3...ollo11_lrg.jpg



NOTA:
l'orbita non è ancora stabile, quindi ha quota variabile, percio' foto di siti diversi hanno risoluzioni diverse.

[cangia]

Originariamente inviato da Octane

Il VASIMR finalmente funzionante!
avranno però i loro bei grattacapi a schermare tutte le apparecchiature di bordo dalle microonde emesse dal motore!


per chi volesse info:
http://en.wikipedia.org/wiki/VASIMR

sarebbe praticamente un motore elettromagnetico a flusso di plasma ? una cosa tipo Starblazer ?

[Rand]

Possible New Impact on Jupiter

[Octane]

Originariamente inviato da cangia

sarebbe praticamente un motore elettromagnetico a flusso di plasma ? una cosa tipo Starblazer ?

E' in pratica un innovativo motore a ioni.
Utilizza le microonde per ionizzare il gas e accelerarlo con un campo magnetico generato con un magnete a superconduzione.

dalla pagina di wikipedia:

The Variable Specific Impulse Magnetoplasma Rocket, sometimes referred to as Electro-thermal Plasma Thruster, uses radio waves to ionize and to heat propellant and magnetic fields to accelerate the resulting plasma to generate thrust

I vantaggi di questo tipo di motore a ioni sono la potenza massima e la capacità di funzionare sia ad alto sia a basso impulso

dalla pagina di wikipedia:

Current VASIMR designs should be capable of producing specific impulses ranging from 3,000 to 30,000 seconds (jet velocities 30 to 300 km/s). The low end of this range is comparable to some existing ion thruster designs. By adjusting the manner of plasma production and plasma heating, a VASIMR can control the specific impulse and thrust. VASIMR is also capable of processing much higher power levels (megawatts) than existing ion thruster electric propulsion designs. Therefore, it can provide orders of magnitude higher thrust, provided a suitable power source.

Ora il problema diventa trovare abbastanza energia elettrica (anche nell'ordine dei MW). Finchè si è vicini al sole (fino all'orbita di Marte diciamo) si possono usare pannelli solari, ma oltre? RTG?

[Rand]

Originariamente inviato da Octane

Ora il problema diventa trovare abbastanza energia elettrica (anche nell'ordine dei MW). Finchè si è vicini al sole (fino all'orbita di Marte diciamo) si possono usare pannelli solari, ma oltre? RTG?

Gli RTG sono troppo poco efficienti. L'unica soluzione realistica in quei casi è un qualche tipo di reattore nucleare.