Pages

Wednesday 9 March 2011

F-15 Eagle

Mission
The F-15 Eagle is an all-weather, extremely maneuverable, tactical fighter designed to permit the Air Force to gain and maintain air supremacy over the battlefield.

Features
The Eagle's air superiority is achieved through a mixture of unprecedented maneuverability and acceleration, range, weapons and avionics. It can penetrate enemy defense and outperform and outfight any current enemy aircraft. The F-15 has electronic systems and weaponry to detect, acquire, track and attack enemy aircraft while operating in friendly or enemy-controlled airspace. The weapons and flight control systems are designed so one person can safely and effectively perform air-to-air combat.

The F-15's superior maneuverability and acceleration are achieved through high engine thrust-to-weight ratio and low wing loading. Low wing-loading (the ratio of aircraft weight to its wing area) is a vital factor in maneuverability and, combined with the high thrust-to-weight ratio, enables the aircraft to turn tightly without losing airspeed.

A multimission avionics system sets the F-15 apart from other fighter aircraft. It includes a head-up display, advanced radar, inertial navigation system, flight instruments, ultrahigh frequency communications, tactical navigation system and instrument landing system. It also has an internally mounted, tactical electronic-warfare system, "identification friend or foe" system, electronic countermeasures set and a central digital computer.

The pilot's head-up display projects on the windscreen all essential flight information gathered by the integrated avionics system. This display, visible in any light condition, provides information necessary to track and destroy an enemy aircraft without having to look down at cockpit instruments.

The F-15's versatile pulse-Doppler radar system can look up at high-flying targets and down at low-flying targets without being confused by ground clutter. It can detect and track aircraft and small high-speed targets at distances beyond visual range down to close range, and at altitudes down to treetop level. The radar feeds target information into the central computer for effective weapons delivery. For close-in dogfights, the radar automatically acquires enemy aircraft, and this information is projected on the head-up display. The F-15's electronic warfare system provides both threat warning and automatic countermeasures against selected threats.

A variety of air-to-air weaponry can be carried by the F-15. An automated weapon system enables the pilot to perform aerial combat safely and effectively, using the head-up display and the avionics and weapons controls located on the engine throttles or control stick. When the pilot changes from one weapon system to another, visual guidance for the required weapon automatically appears on the head-up display.

The Eagle can be armed with combinations of different air-to-air weapons:  AIM-120 advanced medium range air-to-air missiles on its lower fuselage corners, AIM-9L/M Sidewinder or AIM-120 missiles on two pylons under the wings, and an internal 20mm Gatling gun in the right wing root.

The F-15E is a two-seat, dual-role, totally integrated fighter for all-weather, air-to-air and deep interdiction missions. The rear cockpit is upgraded to include four multi-purpose CRT displays for aircraft systems and weapons management. The digital, triple-redundant Lear Siegler flight control system permits coupled automatic terrain following, enhanced by a ring-laser gyro inertial navigation system.

For low-altitude, high-speed penetration and precision attack on tactical targets at night or in adverse weather, the F-15E carries a high-resolution APG-70 radar and low-altitude navigation and targeting infrared for night pods

Background
The first F-15A flight was made in July 1972, and the first flight of the two-seat F-15B (formerly TF-15A) trainer was made in July 1973. The first Eagle (F-15B) was delivered in November 1974. In January 1976, the first Eagle destined for a combat squadron was delivered.

The single-seat F-15C and two-seat F-15D models entered the Air Force inventory beginning in 1979. These new models have Production Eagle Package (PEP 2000) improvements, including 2,000 pounds (900 kilograms) of additional internal fuel, provision for carrying exterior conformal fuel tanks and increased maximum takeoff weight of up to 68,000 pounds (30,600 kilograms).

The F-15 Multistage Improvement Program was initiated in February 1983, with the first production MSIP F-15C produced in 1985. Improvements included an upgraded central computer; a Programmable Armament Control Set, allowing for advanced versions of the AIM-7, AIM-9, and AIM-120A missiles; and an expanded Tactical Electronic Warfare System that provides improvements to the ALR-56C radar warning receiver and ALQ-135 countermeasure set. The final 43 included a Hughes APG-70 radar.

F-15C, D and E models were deployed to the Persian Gulf in 1991 in support of Operation Desert Storm where they proved their superior combat capability. F-15C fighters accounted for 34 of the 37 Air Force air-to-air victories. F-15E's were operated mainly at night, hunting SCUD missile launchers and artillery sites using the LANTIRN system.

They have since been deployed for air expeditionary force deployments and operations Southern Watch (no-fly zone in Southern Iraq), Provide Comfort in Turkey, Allied Force in Bosnia, Enduring Freedom in Afghanistan and Iraqi Freedom in Iraq.

General Characteristics
Primary function: Tactical fighter
Contractor: McDonnell Douglas Corp.
Power plant: Two Pratt & Whitney F100-PW-100, 220 or 229 turbofan engines with afterburners
Thrust: (C/D models) 23,450 pounds each engine
Wingspan: 42.8 feet (13 meters)
Length: 63.8 feet (19.44 meters)
Height: 18.5 feet (5.6 meters)
Weight: 31,700 pounds
Maximum takeoff weight: (C/D models) 68,000 pounds (30,844 kilograms)
Fuel  Capacity: 36,200 pounds (three external plus conformal fuel tanks)
Payload: depends on mission
Speed: 1,875 mph (Mach 2 class)
Ceiling: 65,000 feet (19,812 meters)
Range: 3,450 miles (3,000 nautical miles) ferry range with conformal fuel tanks and three external fuel tanks
Crew: F-15A/C: one. F-15B/D/E: two
Armament: One internally mounted M-61A1 20mm 20-mm, six-barrel cannon with 940 rounds of ammunition; four AIM-9 Sidewinder and four AIM-120 AMRAAMs or eight AIM-120 AMRAAMs, carried externally.
Unit Cost: A/B models - $27.9 million (fiscal 98 constant dollars);C/D models - $29.9 million (fiscal 98 constant dollars)
Initial operating capability: September 1975
Inventory: Total force, 522

F-15 Eagle Video

Airbus A319 - A Leading Aircraft Manufacture

The A319 provides a new standard of service to markets where only the smallest jets have operated.

Flexibility and comfort
As a slightly smaller version of Airbus’ A320 cornerstone single-aisle jetliner, the A319 continues to prove its versatility – enabling carriers around the world to benefit from the aircraft’s range options and seat layout flexibility.  In addition to the standard 124-seat configuration with a range of up to 3,740 nautical miles, Airbus offers an option with a seating capacity of up to 156 passengers – a version that is being ordered by an increasing number of low-cost airlines.

The A319 has the same optimised cabin cross-section as the other A320 Family members – which is the widest single-aisle fuselage on the market and sets the standards for passenger cabin adaptability in this segment.  This allows for top-of-the-range comfort with generous seat width, or an extra-wide aisle for fast turn arounds.

Cabin Excellence
The A319 is a slightly smaller version of Airbus’ A320 cornerstone single-aisle jetliner.
A new cabin interior introduced by Airbus for the A320 Family ensures the A319 meets the needs of airline travellers today and tomorrow, bringing passenger comfort to a new level for its category.  It provides a fresh new look, significant increase in overhead stowage, a noticeable reduction in noise, and options for ambience lighting – all with lower weight.

Facilitating the A319’s onboard operational effectiveness is its digital cabin management system, which controls cabin-related tasks ranging from interior lighting, pre-recorded messages and emergency evacuation signalling to potable water management.  It also can perform the checkout of all service units from a single point.

Below the main deck, an unmatched cargo capability results from the A320 Family’s wider fuselage – enhanced by its containerised cargo loading system that is unique in its aircraft category and is compatible with the airline industry’s freight system for widebody jetliners.

Precision And Commonality
Advanced navigation technology developed for the A320 Family is available on the A319.  The use of RNP-AR (Required Navigation Precision – Authorisation Required) procedures combined with RTA (Required Time of Arrival) operations eliminates the need for holds during a flight, and enables a continuous descent approach.  The net benefits are lower noise and reduced fuel burn, as less engine thrust is required.
The A319 shares the same fly-by-wire flight controls and state-of-the-art cockpit as the other A320 Family members, profiting from the unique benefits of Airbus operational commonality.  All of these aircraft – the A318, A319, A320 and A321 – share the same pilot type rating.  With only minimal additional training, A320 Family-rated pilots can quickly transition to Airbus’ widebody jetliners.

Performance Improvements
Airbus invests more than 100 million euros annually in A320 Family improvements that result in enhanced payload and range capabilities, better performance, easier maintenance and more efficient operations.  A significant enhancement will be the 2012 introduction of large wingtip devices called “Sharklets” which are to provide more than 3.5 per cent savings in overall fuel consumption on long route sectors.
In addition, Airbus’ A319 will be even more fuel-efficient and eco-friendly with the A320neo new engine option now being offered to customers. This option is to deliver significant fuel savings of up to 15 per cent, along with double-digit reductions in CO2 and NOx emissions, additional range and lower operating costs.

World’s 10 Fastest Aircraft – Sky’s No Limit For Them

They are the emperors of the sky – watching over us with some of the deadliest arsenal tucked right under their bellies. Their awesome power never fails to make us wonder if they weren’t unreal. They can soar up there much faster than the roars of their engines. They are some of the ultimate man-made machines, and heck, they sure can fly !!!
Lets have a look at some of mankind’s most incredible innovations – The 10 fastest aircrafts that grace the sky!!

10. General Dynamics F-111 “Aardvark”

F111-AircraftDeveloped in the 1960’s, this all American tactical strike aircraft was built with one thing in mind; incredible speed with an agility to match. It was designed for multiple roles, but mainly as a naval fighter-bomber for aircraft carriers. Now discontinued by the US Air Force, the latest Aardvark, the F-111C is still part of the Royal Australian Air Force fleet. The F-111 pioneered many technologies like variable sweep wings, after burning turbofan engines and automated terrain tracking radar for low-level, high-speed flight. The wing sweep has a range of 16 to 75 degrees to allow more maneuverability at slow flight speeds (Thanks to Dugg – see comments). The fighter is powered by two Pratt & Whitney TF30-P-100 turbofans which generate 17,900 lbf of dry thrust each! The afterburner increases this figure by a nifty 7000 lbf which brings us to the most interesting part, its speed. The Aardvark flies at a maximum speed of 2.5 Mach or 2.5 times the speed of sound. This amounts to a whopping velocity of 1,650 mph and makes it the tenth fastest aircraft of all time.

09. Mig 31 FoxHound

MiG-31 AircraftThe Mikoyan MiG-31 FoxHound is a supersonic interceptor aircraft developed by Russia. It was designed to replace the MiG-25 FoxBat which though an outstanding performer, lacked the maneuverability at interception speeds. The Foxhound breathes through a large twin-engine, which provides an aspect ratio of 2.94 with a shoulder-mounted wing, side-mounted air intakes and twin vertical tail-fins. These specs render it one agile flying machine. The passive array radar for terrain ranging and the four R-33 air-to-air missiles under its belly make it a deadly fighting machine. The twin Soloviev D-30F6 afterburning turbofans produce a thrust of 34,172 lbf which propels the aircraft to a top flying speed of 1,860 mph! That’s 2.83 times the speed of sound.

08. F-15 Eagle

F-15 Eagle AircraftThe McDonnell Douglas F-15 Eagle is a twin-engine, all-weather tactical fighter designed to acquire and maintain air superiority in aerial combat. This American designed true blue fighter plane packs quite a punch. The F-15 has a “look-down/shoot-down” radar that can detect low-flying moving targets from ground clutter and engage them. Most of the functions of the aircraft are computer controlled, thus requiring only a single pilot under a single clear frame canopy. Newer developments include increased capacity to carry payload and extra fuel, a new radar and a redesigned central computer; all directed towards aerial superiority and stamina.The F-15 is built on a solid semi-monocoque fuselage with shoulder-mounted wings. The Eagle uses a versatile APG-63/70 pulse-Doppler radar system which can range and contour moving objects below differentiating them from immobile objects. It can also track flying objects well beyond the visual range and at altitudes down to tree level. The heart of the jet are the twin two Pratt & amp; Whitney F100 axial-flow turbofan engines with afterburners mounted side-by-side in the fuselage. They produce a massive 29000 lbf of thrust enough to propel this machine to speed up to 1,660 mph and beyond! The jet flies at Mach 1.2 at low altitudes and a mind numbing Mach 1.5 plus at high altitudes.

07. XB-70 Valkyrie

XB 70A ValkyrieThe XB-70A was built by Los Angeles division of North American Aviation for the U.S Air Force. It was an experimental aircraft sketched out to test supersonic speeds devised with a delta-wing. The XB-70 primarily served the USAF as a strategic bomber which surfaced into the U.S fleet in the early 60’s. Though the aircraft suffered an early retirement from the service, it definitely grabbed the attention of the aviation world in its short span. The Valkyrie was able to achieve Mach 3 speed with a service ceiling of 70,000 ft. The Valkyrie was able to achieve these figures with 6 General Electric YJ93-GE-3 afterburning turbojet engines with a top speed of 2,056 mph (3.1 Mach). The XB-70 had changes in its structure compared to a conventional aircraft, the air-intake control system was specifically designed to adjust and reduce the force of supersonic at the air-intake duct. During a single stop while landing a XB-70 Valkyrie, it absorbs kinetic energy equivalent to that used to stop 800 vehicles speeding at 100 miles an hour.

06. Bell X-2 “Starbuster”

Bell X-2Bell X-2 was a research aircraft built by  United States to investigate flight characteristics in the Mach 2-3 range. Stability and control were top concerns for aviation researchers as aircraft were crossing the supersonic speed zone by leaps and bounds rapidly. A major issue was the “thermal barrier” encountered when nearing Mach 3 which caused severe heating effects due to aerodynamic friction. Constructed of a copper-nickel alloy and stainless steel, and powered by a two-chamber XLR25 sea level thrust throttleable engine, the swept-wing Bell X-2 was contrived to probe this section. The maiden test flight was undertaken by Lt. Col. Frank K. “Pete” Everest in November 1955. He reported severe instability as the aircraft neared Mach 3. The boundaries were pushed when Captain Iven C. Kincheloe took the same X-2 to a peak altitude of 126,200 ft and became the first man to fly beyond Mach 3 when he clocked a peak air speed of 2094 mph. Tragedy struck when the captain tried to take a banking turn while he was still above Mach-3, and the jet tumbled out of control due to inertia coupling and eventually crashed. The X-2 delivered valuable information on aerodynamic friction and built-up heat, but after this tragedy, the services of the aircraft perpetually put on hold until the arrival of the North American X-15. The 15000 lbf thrust powered Starbuster clocked a peak speed of 2094 mph or 3.196 Mach.

05. MiG-25 “Foxbat”

MiG 25fNext in line is none other than MiG-25 “foxbat”. In the late 60’s Americans were on the verge of developing a bomber far more advanced than any before, the B-70 bomber. The B-70 had the capability to deliver nuclear weapons while traveling at Mach3 at an altitude above 70000 ft. The Soviets wasted no time and started designing a high altitude, super-fast interceptor; the first prototype of this combat aircraft was called Ye-155R-1. In 1969 it went into production MiG-25R, which was given the codename “Foxbat-B” by the NATO. The MiG-25 is carved only for high-altitude flights and consequently performs terrible on low altitude flights and “dog-fights”, as it is not swift and nimble in its maneuvers. The MiG-25 is a classic interceptor aircraft which has a service ceiling of 80,000 ft, tearing a maximum of 3.2 Mach (2170 mph). The MiG-25 gets this phenomenal performance from 2 Tumansky R-15B-300 afterburning turbojets producing a thrust of 100.1 kN with the afterburner. With 2170 mph, this Soviet masterpiece holds the 5th in the countdown.

04. SR-71 Blackbird

SR-71 BlackbirdThe SR-71 Blackbird is a strategic reconnaissance aircraft developed by Lockheed Skunk Works from the Lockheed A-12 and YF-12A. The Blackbird was a huge improvement over its predecessor the U-2 reconnaissance aircraft. The SR-71 could cruise at 3.5 Mach, which is about 3 times faster than the speed of sound, at an altitude above 100,000 feet and has a range of about 4000 miles. The power plant of SR-71 Blackbird is the two Pratt & amp; Whitney J58-1 continuous-bleed afterburning turbojets, 32,500 lbf (145 kN) each, the fuel for the SR-71 is JP-7 giving the aircraft enough thrust to touch 2,500 mph. It had its ups and downs during the 4 decades of serving in the United States Air Force, after being introduced in 1966 and later retiring from service in the late 80’s. The SR-71 Blackbird was revoked into the USAF in the early 90’s due to its reconnaissance abilities and because no better replacement was available. The aircraft took a second and final retirement in 1998.

03. X-15

X-15 AircraftThe X-15 was part of the X-series of rocket-powered experimental aircraft development. It was probably the most ambitious effort made to push the limits of flight and explore the prospects of space travel. During this experimental program the X-15 recorded a ground-breaking altitude of 354,330 ft attaining a maximum speed of 4,520 mph (6.72 Mach), the fastest set by any manned aircraft till date. It could be said that X-15 proved to be the test bed for a variety of experiments concerning the space. The X-15 used a Thiokol XLR99-RM-2 liquid-fuel rocket engine to deliver the thrust that it packed; it was fueled by liquid oxygen and ammonia. The aircraft also consumed hydrogen peroxide to drive the high-speed pump that pumped the fuel in to the engine. The aircraft essentially had no landing gear, just a pair of skies and a long run-way as the aircraft skidded to a stop after a 200 mph landing. Much of the data collected during the X15 program proved to be valuable in the space shuttle development.

02. X-43A

X 43 AircraftThe X-43A scram-jet is an unmanned experimental hypersonic aircraft meant to assess capabilities of a hypersonic flight; it was recognized for the worlds fastest flight set by a jet-powered aircraft. The speed clocked by the X-43 scram-jet was beyond comparison to any aircraft ever. On Nov. 16, 2004 it touched 9.8 Mach (7,546 mph), which is more than 3 times faster than the SR-71 Blackbird. The craft was designed to encapsulate a new breed of engine called the supersonic-combustion-ramjet, or the “scramjet”. In this engine the external combustion takes place occurs within the air that is flowing in at supersonic speed. The form design of the X-43 was markedly affected by this; the fore-body of the craft was part of the intake airflow, and the aft section was to function like a nozzle. The X-43 engine was primarily fueled by Hydrogen and unlike other engines the scram-jet does not require oxygen to fuel the engine thus the need to carry oxygen on board, thus considerably reducing the size and weight of the aircraft.

01. Space Shuttle

Space ShuttleEditors Note: The inclusion of this has been a source of considerable debate and disappointment. We apologize if this choice doesn’t satisfy your criteria to be on this list.
The Space Shuttle is part of the STS or the Space Transport System developed by NASA for human space-flight missions. Each space shuttle is a RLS or Reusable Launch System which is comprised of 3 assemblies, the reusable Orbiter Vehicle (OV), the External Tank (ET) and two reusable Solid Rocket Boosters or SRB. The three Rocketdyne Block IIA Space Shuttle Main Engine or SSME are mounted on the Orbiter‘s aft. The 3 assemblies of the shuttle use up different fuel, the External Tank, is fueled by LOX/LX2 and the Orbiter uses MMH/N2O4. The space shuttle reaches a maximum speed of 17,320 mph making it the cream of this countdown.What future holds for us is still safe under the blue prints and secure, encrypted files of some of the top-priority projects launched by some of the big-guns in the aviation business.

Top 10 Fastest Aircraft in The World

Wondered which aircraft/airplane is the fastest? this article gives you information about those aircrafts.

1.Space Shuttle:- you might know what it is ! yes, they are used as rockets for gaining useful information about outer space . it was first invented by the NASA in 1981.okay coming to the speeds they can gain during flight, they can travel at a speed of 20,000 miles per hour but the average speed is 17,500 miles per hour.



2.X-43A :-this aircraft was built by NASA ,it is used for a single time and later it is crashed in the ocean beyond recovery. their time of flying is 20 seconds only.it came under lime light when it broke a world record by setting up a high speed flight back in November 2004. it travels at a speed of 7,500 miles per hour.

( the x43 a being dropped from a plane).


3. X-15:-this is also an aircraft designed by the NASA and the “X” denotes experimental plane. it was discovered back in 1959.this was excluded from services a decade after it’s launch.not much to discuss about it.it travels at an average speed of 4510 miles per hour.



4.SR-71 Blackbird:- it was invented by Clarence Kelly Johnson in 1966.it was developed in the united states under NASA.it can travel at speeds of 2200 miles per hour.



5.MiG-25R Fox bat-B:-known as Mikoyan-Gurevich , was founded in 1960 in the Russian army!. this is one of their greatest inventions.it has also served the Algerian,Syrian armies .this was intentionally created as a answer to USA mack 3.it can travel speeds up to 2000 miles an hour.



6.X-2:- well the X-2 known as the “star buster” , was also an experimental plane invented in 1955 manufactured by the united states army.it was good at speed but ineffective in other aspects ,as a result it was excluded the next year.it can travel an average speed up to 1,900 miles an hour.



7.XB-70 Valkyrie :-this was a strategic bomber plane first invented in the USA and later travelled to almost all parts of the world.it was invented in 1964.it can travel an average speed of 1890 miles an hour.



8.F-15 Eagle:- originally built by the US , it travelled to far places like japan,Saudi Arabia and Israel.it was invented in 1972. it can travel an average speed of 1875 miles an hour.



9.MiG-31 Foxhound :- the MiG 31 was a newer release to the MiG 25 . interestingly the first MiG could travel faster than this one. it can travel to speeds up to 1,750 miles an hour .



10.F-111 Aardvark :- it is a fighter-bomber plane invented by the Australian air force .the 0primary reason for it’s invention is to take part in wars. it’s average speed of flight is 1,650 miles an hour.

Filaments in the Orgueil meteorite, seen under a scanning electron microscope, could be evidence of extraterrestrial bacteria, claims NASA scientist Richard Hoover.
CREDIT: Hoover/Journal of Cosmology.
 The recent announcement by a NASA scientist of evidence for alien life in meteorites from outer space has created a firestorm of controversy that researchers say is unlikely to die down anytime soon.
The claim, announced Friday (March 4), called "startling, paradigm busting research," by the Journal of Cosmology, which published the findings, has been derided by critics, one of which referred to it "garbage." [5 Bold Claims of Alien Life ]

The Finding
Astrobiologist Richard Hoover of NASA's Marshall Space Flight Center in Huntsville, Ala., used scanning electron microscopes to analyze slices of carbonaceous meteorites that fell to Earth from space.
Based on the appearance of "filaments" and other features that resemble microbes, Hoover argues that the meteorites contain fossilized life in the form of cyanobacteria – single-celled organisms also known as blue-green algae. He supports this claim by presenting evidence of chemical compounds present in the meteorites that are consistent with a biological origin.

These features in the Orgueil meteorite, seen under heavy magnification, could be evidence for life, or just random mineral formations.
CREDIT: Hoover/Journal of Cosmology
View full size imageHoover writes that the "the size, structure, detailed morphological characteristics and chemical compositions of the meteorite filaments are not consistent with known species of minerals," and that they must be evidence of single-celled life in the rocks.
If true, the discovery would mean life in the universe is not unique to planet Earth – that it may have sprouted up multiple times in other locations, or even that Earth's life originated in space and was deposited on the planet by meteorites.
"Because this would be a very important result if true, scientists are going to do what they should do: be skeptical," said astronomer Seth Shostak of the Search for Extraterrestrial Intelligence (SETI) Institute in Mountain View, Calif.

The Reaction
Shostak called the paper "an extensive and thorough review" of Hoover's findings, but said they did not amount to convincing evidence.
"If you look at the microscope photos, they are certainly suggestive – looking like photos made of various terrestrial bacteria. But then again, while intriguing, that's hardly proof. If similarity in appearance were all it took to prove similarity in kind, then it would be pretty easy for me to demonstrate that there are big animals living in the sky, because I see clouds that look like them."
The same goes for the chemical evidence Hoover presents, Shostak said. While these compounds could have been produced by microbial life, they also could have been made by non-biological, mundane processes.
The type of microbe Hoover claims to have discovered has also provoked some scientists' skepticism.
Cyanobacteria live in liquid water and are photosynthetic, meaning they convert carbon dioxide into organic compounds using energy from sunlight. That implies that the meteorites would have had to contain liquid water exposed to sunlight, and also that high concentrations of oxygen would be present, said astrobiologist Chris McKay of NASA's Ames Research Center in Moffett Field, Calif.
Such a scenario is unlikely based on researchers' current understanding of meteorites, McKay said. If they contain liquid water at all, it is likely in their interior, not on the surface, where it would be in contact with sunlight.
McKay said Hoover's findings suggest that either the filaments in the microscopic images are chance shapes, or that the environments on meteorites were much different than scientists expect.
He expressed respect for the overall methods of the study, and said Hoover had presented enough evidence that the structures present do come from the meteorites and weren't introduced as contamination after the rocks landed on Earth.
"Richard Hoover is a careful and accomplished microscopist, so there is every reason to believe that the structures he sees are present and are not due to contamination.

Questioning The Journal
As soon as word of the paper was announced, some scientists were reluctant to give it credence based on the Journal of Cosmology's reputation.
"It isn't a real science journal at all, but is the ginned-up website of a small group of crank academics obsessed with the idea of [Fred] Hoyle and [Chandra] Wickramasinghe that life originated in outer space and simply rained down on Earth," P.Z. Myers, a biologist at the University of Minnesota, Morris,  wrote on his popular science blog Pharyngula. "It doesn't exist in print, consists entirely of a crude and ugly website that looks like it was sucked through a wormhole from the 1990s, and publishes lots of empty noise with no substantial editorial restraint."
Myers also referred to the paper as "garbage."
Rosie Redfield, a microbiologist at the University of British Columbia, questioned whether the journal's papers are really peer-reviewed, as it claims.
"The journal proudly announces that it is obtaining and will publish 100 post-publication reviews," she wrote on her blog, RRResearch. "But did it bother getting any pre-publication reviews?  It will be shutting down in a few months, after only two years of online publication (the 13 'volumes' are really just 13 issues). Its presentation standards are pretty bad – there doesn't seem to have been any effort at copy-editing or formatting the text for publication (not even any page numbers)."
NASA confirmed that the paper had not been peer-reviewed.
"NASA cannot stand behind or support a scientific claim unless it has been peer-reviewed or thoroughly examined by other qualified experts," Paul Hertz, chief scientist of NASA’s Science Mission Directorate in Washington, D.C., said in a statement. "This paper was submitted in 2007 to the International Journal of Astrobiology. However, the peer review process was not completed for that submission."
Some scientists approached about the paper asked not to comment officially but said the research didn't merit attention.
The editors of the Journal of Cosmology dismissed such attacks as "tantamount to school-yard taunts by jealous children," in a follow-up press release after the paper's announcement.
In response to some critics questioning why the research wasn't published in the more prestigious journals Science or Nature, the Journal of Cosmology responded with a statement that "both Science and Nature have a nasty history of rejecting extremely important papers, some of which later earned the authors a Nobel Prize."
"Science and Nature are in the business of making money," the journal charged. "The Journal of Cosmology, is free, open access, and is in the business of promoting science."

We've seen this before
This is not the first time that a debate has raged over possible evidence for life in meteorites.
In 1996, researchers made a splash when they announced evidence for fossilized microbial life in a meteorite from Mars called Allan Hills 84001 (ALH 84001). The lead author of the paper announcing these findings in the journal Science was David McKay, a researcher at NASA's Johnson Space Center (not to be confused with NASA Ames' Chris McKay).The claim prompted giant headlines in papers around the world at the time, and even a statement from President Bill Clinton.
But in the years since, scientists have questioned those findings — and most remain unconvinced that the meteorite offers conclusive evidence.
"Prior claims for evidence of microfossils in ALH 84001 remain controversial at best, despite more than a decade of dedicated research by many groups and dozens of scientific papers on the subject," said planetary geologist Victoria Hamilton of the Southwest Research Institute in Boulder, Colo. "I'm skeptical that these new claims will be any less controversial or any more easily proven or falsified."
Shostak said wariness after the Allan Hills controversy could be carrying over to this announcement.
"The ALH 84001 result was based on photos and chemical evidence, much as the current story," Shostak said. "And I think that's a major part of the reason why many experts in this field are skeptical of Hoover's claim to have found life that cooked up in comets."
Ultimately, this find, like the Allan Hills report, isn't enough to settle the score one way or the other.
"Sometimes scientific results are ambiguous, and are greeted with the common (and rather uninspiring) refrain that 'more research is needed,'" Shostak said. "That's the case here. We need evidence from other approaches and from other researchers."