MatteF88 ha scritto:Ma la fiammata dell'Atlas si espande così tanto per via della diminuzione di pressione con la quota? Appena partito ha una lingua di fuoco bella dritta e lunga....poi circa quando passa mach 1 si vede la fiamma che si espande sempre di più in larghezza....o sono dei razzi ausiliari per il controllo della direzione che fanno quell'effetto?
Direi si tratti proprio dell'espansione dei gas di scarico dei motori causata dal progressivo aumento della quota e dal conseguente calo della pressione atmosferica ..... anche perché non credo che lo "Atlas V" sia munito di razzi "vernieri" come lo era il suo antenato ICBM .....
Viene intanto annunciato che il motore "sotto inchiesta" ha fatto, in questo caso, il suo dovere .....
RL10 Engine Performs As Expected In X-37B Launch .....
The powered portion of flight for an Atlas V boosting the third U.S. Air Force X-37B Orbital Transfer Vehicle (OTV) has successfully completed, according to Pratt & Whitney Rocketdyne officials.
Ampiamente superati i 500 giorni in orbita (ormai dovrebbero essere 520) ..... e la missione continua .....
As of today (April 24), the vehicle has been aloft for 500 days — far longer than its officially stated maximum orbital lifetime of 270 days.
"Clearly, and understandably, the Air Force initially set the expected parameters [of the X-37B] conservatively, not really knowing what it could do until it was tested — which is what they are doing now," said Joan Johnson-Freese, professor of national security affairs at the Naval War College in Newport, R.I.
"Personally, I think it's commendable that they are pushing it to the extent that they appear to be," Johnson-Freese told Space.com via email.
"That's the only way to really know what it can do."
Mentre, come recita il titolo di questa discussione, la missione del misterioso X-37B continua ..... d'oltreoceano arriva la notizia del progetto di un nuovo spazio-plano militare sperimentale a basso costo e di più semplice utilizzo .....
The Air Force launched the miniature space shuttle into orbit on Dec. 11, 2012 using an expendable Atlas 5 rocket.
By the end of Friday (Aug. 29), the space plane had spent 627 days in orbit.
That's one year, eight months, 19 days and counting, to be exact.
robygun82 ha scritto:Praticamente un satellite ....
Bé ..... dal momento che è in orbita .....
Potrebbe essere interessante la lettura dei primi due articoli presenti in questo sito ..... ove si fa cenno dei parametri orbitali del misterioso veicolo spaziale .....
robygun82 ha scritto:Ma si sa qualcosa della missione???
Cioè .. se è su a far giri su giri e basta lo fanno dai tempi dello sputnik, non mi pare una grande conquista ...
Nell'articolo linkato poco fa da 'MatteF88' c'è questa frasetta ..... che spiega tutto .....
The Air Force has two X-37B space planes in its fleet and has been flying them on secret missions since 2010. But the exact purpose of those flights have been shrouded in secrecy.
La 'grande conquista' potrebbe consistere proprio in quello che sta combinando lassù ..... cosa che, come puoi ben vedere, a noi miseri mortali non è ancora dato sapere ..... dal momento che si tratta di una missione con scopi prettamente militari ..... e ai militari, spesso e volentieri, piace tener segrete le loro cose .....
richelieu ha scritto: noi miseri mortali (...) ...
Uh, dai, non mettiamo limiti alla Provvidenza...
"The curve is flattening: we can start lifting restrictions now" = "The parachute has slowed our rate of descent: we can take it off now!" Chesley Burnett "Sully" Sullenberger
Dal 'Daily Report' dell' AFA di questa mattina .....
Back Home, More to Come .....
Autumn A. Arnett (10/21/2014)
An Air Force X-37B orbital test vehicle returned to Earth after a 674-day classified mission in space.
The reusable, unmanned spaceplane touched down at Vandenberg AFB, Calif., on Oct. 17, announced the Air Force.
The mission, dubbed OTV-3, was the third and longest space trip to date for the two-vehicle, Boeing-built X-37B fleet.
OTV-3 began on Dec. 11, 2012, with the vehicle's launch into orbit from Cape Canaveral AFS, Fla.
Air Force officials were tight-lipped about the X-37's activities on orbit—as they have been about the previous two X-37 missions—other than to say the vehicle served as a test platform to validate new space technology and concepts of operation. More X-37 flights are to come.
Air Force Spokesman Capt. Chris Hoyler told Air Force Magazine on Monday that the next X-37 mission would take place in 2015 from Cape Canaveral.
He provided no additional details "on the current or future operating status of the OTVs" due to the classified nature of the spaceplanes' activities.
Earlier this month, NASA announced that the Air Force would begin using bays at the nearby Kennedy Space Center that formerly supported space shuttles for processing X-37 vehicles for launch from Cape Canaveral ..... http://www.nasa.gov/press/2014/october/ ... e-hangars/
See also Boeing release ..... http://boeing.mediaroom.com/2014-10-17- ... 3rd-Flight
On Oct. 17, one of two Boeing X-37B robotic spaceplanes in existence landed at Vandenberg Air Force Base in California after spending a record 675 days in orbit.
The U.S. Air Force has remained quite tight lipped about just what the small unmanned spaceplane was doing up there. In all likelihood, the payload and mission were both experimental, but what those experiments might have been remains the topic of speculation.
But strictly speaking, the X-37B is not the first design of its type.
Boeing’s X-20 Dyna Soar proposal, now more than 50 years old, offers some clues as to what today’s X-37B could do.
Fonte ..... "Wondering What the U.S. Air Force’s Secretive Spaceplane Can Do? History Offers Clues" .....
Un lungo commento appena apparso su 'The Space Review' .....
Of all the space activities over the past four years, none has generated more conjecture and controversy than the United States Air Force and its operation of the X-37B mini-shuttle.
The X-37B program began as a NASA program in 1999 before the program was transferred to the US Department of Defense in 2004.
The first flight of the first of the two vehicles, designated OTV-1, was launched on April 22, 2010, and ended on December 3, 2010.
The second flight, OTV-2, flown by the program’s second vehicle, launched on March 5, 2011, and returned over a year later on June 16, 2012.
The third flight (OTV-3), performed by the refurbished first vehicle, is so far the most impressive: it launched on December 11, 2012, and landed almost two years later on October 17, 2014.
The date of the fourth flight has yet to be announced, but at least one release points to a launch sometime in May of 2015.
X-37B ..... se ne riparla e, dalle parole di un generale, si potrebbe intendere si tratti di un mezzo atto al recupero o alla manutenzione dei satelliti in orbita ..... o, quanto meno, alla sperimentazione di tali tecniche ..... in vista della futura realizzazione di un veicolo spaziale più adatto a porle in opera .....
The X-37B and the Satellite Throwaway Paradigm .....
Michael C. Sirak (2/13/2015)
The X-37B reusable spaceplane has “great utility” and the Air Force intends to keep using it “for a while” because it is helping service officials understand the “re-usability aspect of space” for satellites, said Gen. John Hyten, Air Force Space Command boss, on Thursday at AFA’s Air Warfare Symposium in Orlando, Fla.
“That is the fundamental thing that X-37 is really getting at,” he said during a meeting with reporters.
Pretty much everything the Air Force does in space is “a throwaway,” said Hyten.
The Air Force launches a satellite and ”it is gone forever; you never can get it back,” he said.
The same holds true for launch vehicles, he said.
While companies like SpaceX are working to change that paradigm on the booster side, the X-37 is similarly “a way to change the equation on the satellite side,” said Hyten.
“I can say we are learning a ton about the utility to do that … so we are going to continue” to use the X-37, he said.
The Air Force has two X-37 vehicles in its fleet.
One of them has been in space two times, while the other has been on orbit once thus far.
The Air Force concluded the third X-37 mission in October after 674 days on orbit.
Service officials have been mum on the details of each mission, other than to say they are using the spaceplanes as testbeds to validate technologies and mature concepts of operation.
Hyten declined to say when the next X-37 mission is scheduled.
Pronto a ripartire .....
L' USAF si appresta dunque a rispedire nello spazio il più segreto dei suoi 'giocattoli in una altrettanto segretissima missione .....
Liftoff is targeted some time between 9am and 1pm EDT (between 11pm May 6 and 3am May 7 AEST).
The US Air Force hasn’t confirmed which of the Boeing-built spaceplanes will be making the voyage.
The first craft spent 224 days in space, followed by OTV-2 (orbital test vehicle) spending 469 days in space over 2011-12.
OTV-3 launched in December 2012 and returned from its 675-day mission in October, 2014.
The experiment - a collaboration between the Air Force Research Laboratory, Space and Missile Systems Center, and the Rapid Capabilities Office - will “enable in-space characterization of Hall thruster design modifications,” which will be used to improve similar units onboard Advance Extremely High Frequency communication satellites, states the release.
“Space is so vitally important to everything we do. Secure comms, ISR, missile warning, weather prediction, precision navigation, and timing all rely on it, and the domain is increasingly contested,” said Maj. Gen. Tom Masiello, AFRL commander .....
“A more efficient on-orbit thruster capability is huge. Less fuel burn lowers the cost to get up there, plus it enhances spacecraft operational flexibility, survivability, and longevity.”
The Air Force has two X-37 vehicles in its fleet and Air Force Space Command boss Gen. John Hyten said USAF would continue to use the planes “for awhile” as the service attempts to figure out “the re-usability aspect of space.”
The third mission concluded in October 2014 after 674 days on orbit.
It’s not clear when the fourth mission will launch.
Fonte ..... il 'Daily Report' dell' AFA .....
Il lancio dovrebbe avvenire intorno al 20 Maggio prossimo .....
All systems are now “go” for launch of the Air Force’s X-37B mystery spaceplane on May 20 from Cape Canaveral aboard an Atlas 5 rocket.
Officials had delayed the X-37B launch by two weeks - from May 6 to no earlier than May 20 - due to an undisclosed payload issue.
Officials on Monday removed their tentative caveat from the May 20 target and firmed it up.
A United Launch Alliance Atlas V rocket blasted off from Cape Canaveral AFS, Fla., at 11:05 a.m. on May 20, carrying the X-37B Orbital Test Vehicle, according to a May 20 release .....
The launch marked the fourth time the unmanned space plane has deployed into low earth orbit, with all four missions launched aboard an Atlas V rocket.
The current X-37B mission carries important new USAF experiments on board, such as the Hall thruster, which will be used to improve similar units onboard Advanced Extremely High Frequency communication satellites.
Service officials have said USAF plans to continue using the spacecraft to test reusability concepts in space.
The launch also marked the 83rd successful launch of the Evolved Expendable Launch Vehicle, noted Space and Missile Systems Center Commander Lt. Gen. Samuel Greaves in a statement .....
The AFSPC-5 mission also included 10 CubeSats on the rocket’s Centaur upper stage, a collaboration between SMC and the National Reconnaissance Office .....
Col. Thomas Falzarano, the 45th Operations Group commander, who served as the launch decision authority for the mission, thanked the Patrick AFB and Cape Canaveral teams for the launch success of the “very important mission”.
Video ..... ..... immagini veramente suggestive ..... il 'Capo' che, ripreso dalla telecamera a bordo del vettore, a mano a mano si allontana ..... la separazione degli stadi ..... .
Un articolo pubblicato da Scientific American .....
Most details about the space plane are classified, but the launch vehicle also carried 10 miniscule "cubesats," including the LightSail solar sail, developed by the Planetary Society .....
Mentre, a poco più di quattro mesi e mezzo dal lancio, prosegue, nel silenzio ufficiale, la quarta missione dello X-37B ..... ecco presentarsi alla ribalta un potenziale concorrente .....
Sierra Nevada Corporation (SNC) believes its Dream Chaser could be a viable alternative to the Boeing X-37B Orbital Test Vehicle for long-duration, recoverable experimentation in space.
The company says its vehicle, which is still in development, could be called upon to support the kinds of missions the US Air Force is currently conducting with the X-37B.
Sono ormai trascorsi otto mesi dall' inizio della quarta missione del misterioso veicolo spaziale militare X-37B senza che siano state rilasciate nuove informazioni in merito .....
L'unica cosa certa è che l' USAF sembra bene intenzionata a mantenere il segreto ..... come risulta da questo articolo risalente addirittura al Settembre scorso .....
Asked whether he would open up about the Air Force’s X-37B space plane, Gen. John Hyten gave an unequivocal answer:
t’s been five years since the first launch of the Air Force’s X-37B mini-shuttle, and outside observers - meaning those who lack the proper security clearances - still know little more about this mysterious unmanned vehicle than they did in 2010.
But after three completed flights and a fourth launch last May (the spaceplane was still in orbit as of mid-December), they’re at least able to make educated guesses.
