reaction control system


     Take the fastest and highest flying jet of the day, then strap a rocket engine to it. Most trainer aircraft are meant to be docile and forgiving. The NF-104A surely was not. It was a space trainer, meant to zoom climb to the edge of the atmosphere using mixed power, simultaneously burning its jet and rocket engines. Once at an altitude of more than 120,000 ft, it gave future Air Force astronauts an opportunity to emulate a spacecraft, using reaction control system thrusters in a near-vacuum environment.

     Even today, it remains a simple fact: it’s easy to get yourself in trouble in a rocket plane. The first NF’s rocket engine exploded in flight. Chuck Yeager nearly met his end during the loss of NF ship three. NF-104A 56-0760 was the second of three ever built (pictured above). She remains the only surviving example from the program, mounted proudly in front of the USAF Test Pilot School at Edwards Air Force Base. Her reaction control system was loaned to Darryl Greenamyer and installed on his F-104 which was lost on a civilian altitude record setting attempt. Thus, even the surviving NF had some of her parts destroyed in a crash. Thankfully, in all said incidences, no human being was lost.

     The aircraft stands as a reminder to all who walk through the doors of the USAF Test Pilot School of the glorious trials, tribulations and sacrifices of all who have trod before them. These adventures epitomize the golden age of flight test and the pioneering spirit that flies over the High Desert of California.

I just realized there was a Salmonid field guide yesterday and am still surprised by the little bits of cultural(?) info about ‘em

•They inhabit a restricted ocean zone, and any unauthorized contact with them is expressly forbidden by law.

•New recruits usually start as Snatchers and are allowed to join the front lines when they’ve shown aptitude at snatchin golden eggs

•Steelheads are the company commanders of a troop. Its scales are ink resistant due to “arduous conditioning”. It’s filling up that bomb with its own spit btw.

•Steel Eel drivers wear those masks because of the spray from the machine.

•The little car thing Scrappers drive around is “a much-desired item for many salmonids”.

•The Stinger boils ink in the pots it’s on to generate pressure for its attacks. Also it wears shock absorbing equipment.

•The Maw is perpetually hunting for prey because of how big it is so hey that’s terrifying.

•This one is good; “The ranks of the Drizzlers are made up by renegade Salmonids who prefer to go it alone and fight on their own terms.”

•The Flyfish are intense - it was designed by leading Salmonid engineers, has space-grade reaction control systems, and it’s piloted only by “the most elite” Smallfry who went through special training. Wtf.

Also Nintendo’s gotta be planning something bigger with this because they’re building this world history of Salmonid swarms destroying cities in ancient times and like paintings of them and such in both the field guide and the sunken scrolls. I love it I love these li'l guys


Thrust Vectoring Overview

Thrust vectoring is a method of aeronautical control that works by modifying the jet stream from an aircraft’s engine to produce yaw, pitch and/or roll. In general, there are 5 types of thrust vectoring mechanisms which I will touch on. I will also discuss one method that is in development for use on 6th gen fighters. In general, thrust vectoring occurs on jet engines, so assume that I am referring to some sort of jet engine unless I specify otherwise.

Gimbaled Engines

Gimbaling an engine is when the engine or at least the exhaust portion of the engine is set on a sort of ball joint so that it can pivot around in all directions to a certain degree. In very short and simple language, a gimbaled engine is an engine set in a ball joint. Now what this does for us is, it allows us to move the angle of thrust about so as to generate torque on the body in flight. Imagine balancing a rod on your palm. If you move your palm to the right, the rod will tend to fall to the left because of torque. A picture can help explain this.

So basically, gimabling an engine, allows us to vector its thrust and thereby control its pitch and yaw. Gimbaled engines do not allow for roll control so rockets will generally rely on fins or some sort of Reaction Control Systems (RCS) to control roll. Gimballing can be (read “is”) mechanically complex which results in higher failure rate and increased weight. Gimbaled engines have been used on the Saturn V and the Space Shuttle.

Reactive Liquid Injection

Reactive Liquid Injection or RLI as I will refer to it, (not because this is an accepted acronym but because I don’t want to type it out) is a system by which liquid is injected into the thrust plum of a jet engine in order to modify its thrust profile. RLI works in the same way as a gimbaling but rather than moving the entire thrust profile, the injected liquid simply weakens the thrust on one side of the plume producing an asymmetric thrust which, again, results in torque which pitches or yaws the missile. This mechanism was used on early Submarine Launched Ballistics Missiles of the US Navy.

Actuated Nozzles

Actuated nozzles are the method that most people think of when they think of thrust vectoring. Commonly used on fighter aircraft, actuated nozzles are nozzles whose position and shape can be modified to produce differentiated thrust.

This, again, works in the same way as gimbaling, adjusting the stream of the engine to produce torque. Thrust vectoring on fighter aircraft allows for maneuverability at high angle of attack and extremely low airspeed. It also allows improved maneuverability at high altitude where aerodynamic control surfaces tend to be far less effective. The reason that the most advanced fighters of the day use thrust vectoring is that vectored engines allow for vastly improved maneuverability in all situations. Thrust vectoring can allow fighters to enter a controlled flat spin at extremely low speeds which can allow them to achieve missile lock in hairy situations. Additionally, I mentioned earlier that thrust vectoring cannot produce roll, only pitch and yaw. Consider the PAK FA.

Note that this fighter features two side-by-side thrust vectored engines. If one engine was vectored down while the other was vectored up, this would produce a roll effect.

Thrust vectoring can also be used to achieve VTOL/STOL. Examples of this include the F-35 and the Harrier. This typically requires more than one type of thrust vectoring and at least on auxiliary engine adding *considerable* weight, mechanical complexity and fuel usage. Below is the Yak-38′s VTOL/STOL setup. It is incredibly complex and extremely typical of STOL/VTOL systems.

As much as it pains me to mention this meme maneuver, thrust vectoring can allow fighters to execute a “Pugachev’s Cobra.” I hate this shit so much that I am not going to explain it. You can google this yourself. I will say that *IN MY OPINION* it has little to no combat application and it is a matter of fact that it produces “unacceptable stress” on the air frame of any aircraft performing it.

Fighter aircraft to feature engine nozzle thrust vectoring include the PAK FA, some F-15 models, famously the F-22 and the McDonnell Douglas X-36.

Exhaust Vanes

Exhaust vanes are simply post nozzle vanes that vector the thrust in different directions. I know this sounds the same as the actuated nozzle that we just discussed, but its not. Thrust vanes are slightly different as they allow for more options but, generally, less power. A picture.

As you can see on this picture of a crashed V-2 rocket, the famous Nazi missile, there are a series of four fins around the exhaust nozzle of the rocket. Note that the V-2 also has simple aerodynamic control surfaces on the outer corners of its fins. What the thrust vanes do is they vector the thrust in a fairly logical fashion, producing differential thrust. The way in which vanes are special is that they can also control roll. by setting all of the vanes so the face in clockwise or counter clockwise, an opposite direction roll can be produced. The vanes on the V-2 were made of graphite, a heat resistant substance.

Tilt-rotor Thrust Vectoring

Tilt-rotor thrust vectoring uses actuated rotors to produces vectored thrust. The best example of this is the V-22 Osprey.

This aircraft can rotate its rotors to go from efficient lifting to efficient forward flight.

Fluidic Thrust Vectoring

The final type of thrust vectoring that I will mention is the experimental Fluidic Thrust Vectoring or FTV, an actual accepted acronym. FTV is different than the aforementioned RLI as it uses air rather than some liquid. Experiments have found that injecting air into the thrust of a jet engine can produce up to a 15 degree deflection. FTV has the advantage of being simpler, lighter, cheaper and stealthier and will likely be employed on 6th gen fighters.

Hit me up with some ideas for future stuff.



The manual-winding Omega Speedmaster Professional was not originally designed for space exploration.  It was introduced in 1957 as a sports and racing chronograph, to complement Omega’s position as the official Olympic timekeeper.  High performance Chronographs became indispensable to pilots, race car drivers and Submariners, who relied heavily on precision timing to clock and calibrate fuel consumption, trajectory and other variables, for what was essentially blind travel.    On October 3 1962, astronaut Wally Schirra (above) took his personal Speedmaster aboard Mercury-Atlas 8. Later that same year, as the story goes, a number of different chronograph mechanical hand-wind wristwatches were purchased by NASA agents from Corrigan’s, a Houston jeweller, to evaluate their use for the space Program.  The watches were all subjected to tests under extreme conditions: prolonged cycles of high and low temperature, high and low pressure, humidity, shock, acceleration, vibration and acoustic noise.  The evaluation concluded in March 1965 with the selection of the Speedmaster, which survived the tests while remaining largely within 5 seconds per day rate. To accommodate the bulky space suit the watch used a long nylon strap secured with Velcro. On June 3 1965 Ed White (above) became the first American to spacewalk, effectively setting himself adrift in the zero gravity of space, whilst wearing his Omega Speedmaster during Gemini 4.   July 20, 1969, at 20:18 UTC the Apollo Lunar module put the first humans on the moon. Although Apollo 11 commander Neil Armstrong was first to set foot on the surface, he left his Speedmaster inside the Lunar Module as a backup because the LM’s electronic timer had malfunctioned. So Buzz Aldrin's Speedmaster became the first watch to be worn on the moon.  Incredibly, having travelled over half a million miles in space safely, Aldrin’s Speedmaster was lost during shipping when he sent it to the Smithsonian Institute. In 1970, after Apollo 13 was crippled by the rupture of a Service Module oxygen tank, Jack Swigert's Speedmaster (above) was famously used to accurately time the critical 14-second Mid-Course Correction 7 burn using the Lunar Module's Reaction Control System, which allowed for the crew’s safe return to Earth.

New Shepard makes third trip into sub-orbit testing improved systems.

The third sucessful flight of Blue Origin’s New Shepard rocket occurred Saturday, April 2, from the company’s test site in west Texas. New Shepard reached an altitude of 64.2 miles, the highest yet it has flown.

Liftoff occurred at 10:18am CDT and followed a flight plan nearly identical to the vehicle’s first two test flights in March and November 2015. The only significant change in this flight was relighting the single BE-3 engine for the landing burn. 

Reignition occurred 1.1 kilometers above the ground, opposed to the 1.5 kilometers of previous flights. This tested out more efficient landing methods to conserve fuel.

Additionally, tweaks to the Reaction Control System on the Crew Capsule were made in order to increase performance.

New Shepard is the first vehicle in history to launch from Earth, reach the van Karman line defining the boundary of space, and land successfully. It is also the world’s first reusable sub-orbit rocket.

Check out New Shepard’s other flights by checking our our archive here.


     Every great advance in history is initially seen as lunacy until it works. In 1947, the Ryan Aeronautical Company began to solve the preposterously difficult task of vertically landing a jet aircraft backward using the thrust from its engine. The idea began when the US Navy wanted to launch and land fighter jets from submarines. This was never fully realized, but the X-13 Vertijet would prove that a “tailsitting” jet was possible, paving the way for future vertical takeoff and landing technology.

     X-13 54-1619 was the first of two prototypes, originally flying with temporary landing gear, making its first horizontal runway takeoff on December 10, 1955. Later, the aircraft would be fitted with a tail stand, allowing it to take off and land vertically. Finally, the aircraft was launched using the vertical trailer (shown above).

     Many interesting problems had to be overcome to effectively operate the X-13. During takeoff and landing, there was not enough airflow over the conventional control surfaces to maneuver, so the aircraft was fitted with a reaction control system, giving the pilot control authority at any airspeed. The pilot’s seat was tilted forward during takeoff and landing, allowing them good visibility of the area even while the aircraft was pointed straight up at the sky.

     A beautifully preserved Vertijet stands on display at the San Diego Air & Space Museum’s Gillespie Field Annex in El Cajon, California. This remains as one of only two ever built.


On July 13, the Progress MS03 booster underwent final integration at Baikonur Cosmodrome in Kazakhstan. The spacecraft was encapsulated on July 12 and rolled out to the launch pad July15.

Progress will bring more than 2.5 tons of supplies and experiments to the members of Expedition 48 currently onboard the International Space Station.

Progress MS03 is the third flight of the MS series of spacecraft developed for both the Progress and Soyuz vehicles. It is the latest upgrade of the spacecraft, including additional Reaction Control Systems, rendezvous systems, and communications systems, among other changes.

Launch is scheduled for 5:41pm EDT July 16, and will arrive at the station Monday, July 18. Another station cargo flight is scheduled to launch July 18, with the SpaceX CRS-9 mission slated for a 12:45am EDT launch from Cape Canaveral.


T-17 hours, 5 minutes (2:00 PM EST, 3 December)

The long road to launch: A timeline of Exploration Flight Test-1 

Orion’s journey to launch tomorrow has been long and complex. Many different components from dozen of different contractors had to come together on schedule in order to make the flight a reality.

The initial welds on the vehicle’s pressurized hull began in September, 2011 at NASA’s Michoud Assembly Facility in New Orleans. After a nine and a half months of construction, the pressure vessel arrived at Kennedy Space Center’s Operations and Checkout Building in June, 2012. It was here, #3 on the above chart of Florida pad flow operations, that the capsule underwent final assembly. Click here for my post on the completion of Orion’s assembly.

In the O&C, Orion’s numerous subsystems were tested and installed, including avionics, thermal protection system, reaction control system, and heat shield. The inert Launch Abort System arrived in February, 2013 and the heat shield on December 4, 2013. 

The capsule remained here undergoing final assembly for over two years until September 11, 2014, when it was rolled over to the Payload Hazardous Servicing Facility for fueling. Click here for my post on Orion’s rollover from the O&C to the PHSF.

While Orion was still in the Operations and Checkout building, its Delta IV Heavy launch vehicle arrived at Cape Canaveral. The starboard and core booster arrived in early March 2014 while the port booster and Delta Cryogenic Second Stage (DCSS) arrived on May 6. The next day they were transported from Port Canveral to the Horizontal Integration Facility at Cape Canaveral Air Force Station  - #2 on the chart - for inspection and testing ahead of integration. Instead of directly going to the HIF, the DCSS was sent to the Delta Operations Center - #1 on the chart - for checkout and testing. It remained here until August 29, when it joined the rest of the vehicle at the HIF. It was mated with the Delta Common Core Booster on September 12.

At the PHSF - #4 on the chart - where the capsule arrived on September 11, Orion’s toxic propellants were loaded, including thruster propellant for the Reaction Control System and fluids for the Environmental Control and Life Support System. The Orion shortstack, as the capsule and service module combination were called, was moved to the Launch Abort System Facility - #5 on the chart - after 16 days. Click here for my post on the vehicle’s transfer from the PHSF to the LASF.

Arriving here on September 28, the spacecraft was encapsulated under five ogive panels on October 3. These make the vehicle’s aerodynamics smoother during its climb uphill through Earth’s atmosphere. Additionally, the Launch Abort System was installed atop the capsule. While the LAS on EFT-1 will be inert, all future flights of Orion will carry live systems installed here. Click here for my posts covering Orion’s Launch Abort System installation.

While Orion was preparing to get covered in protective paneling, the Delta IV Heavy was rolled out to LC-37. The rocket left the HIF in the early morning hours of October 1, arriving shortly after sunrise. Erection was completed a few hours later. Click here for my post covering the booster’s rollout and erection at LC-37.

The spacecraft now complete, the Orion vehicle was moved to Launch Complex 37 overnight November 11-12. Integration atop the Delta IV Heavy was completed by the afternoon of the 12th. Click here for my post on the capsule’s move to the pad, and here for integration with the Delta IV.

Various tests, dress rehearsals, and inspections have been made in the past few weeks. The next major milestone for Orion’s voyage into space will occur later tonight when the Mobile Service Structure at LC-37 - #6 on the chart - begins rolling away from the launch mount towards its retracted position. First motion is expected at 11:05 PM EST tonight. Launch is projected for 7:05 AM EST tomorrow, December 4, 2014.

Through this entire 27 month process, EFT-1’s launch date has slipped only once - and then not due to manufacturing or testing schedules, but political factors. A Delta IV medium rocket’s December flight of a classified spy satellite was bumped up to Orion’s original launch window in September, with the latter taking their slot in December.


SpaceX has released specifics regarding yesterday’s crew Dragon pad abort test. During the 1 minute, 39 second flight, the capsule experienced 6 times the pull of Earth’s gravity, or 6G.

The vehicle flew 3,894 feet in altitude and 3,943 feet downrange. Initial expectations saw the capsule fly 6,000 feet downrange, but winds from a nearby storm blew the capsule back towards shore under parachute.

A top speed of 345 miles per hour and 155 meters per second was reached by the capsule, which was propelled from a test rig on SLC-40 by eight SuperDraco engines. Dragon’s main parachutes deployed at an altitude of 3,182 feet. 

The pad abort test validated Dragon’s ability to pull itself - and its human crew - away from danger in the event of a catastrophic disaster prior to liftoff. The launch escape system is revolutionary in many ways, not just because it is the first abort systems to be available during all aspects of a flight, but also because its fuels can be channeled into the reaction control system on orbit. This way, extra fuel does not have to be carried - and subsequently wasted - once the capsule reaches orbit.

The specific information came directly from CEO Elon Musk in tweets sent out later in the day Wednesday.

Click here for our coverage of the Pad Abort test.

February 26 - inaugural Saturn 1B lofts AS-201

February 26, 2015, marks the 50th anniversary of AS-201, the inaugural flight the intermediate rocket in the Saturn family, the Saturn 1B.

The Saturn 1B was used for Earth-orbital Apollo Command/Service module missions, which included Apollo 7, Skylabs 2-4, and the Apollo Soyuz Test Project. Additionally, unmanned flights of the booster tested out Apollo spacecraft systems as well as rocket capabilities.

AS-201 launched on February 26, 1966, from SLC-34 at Cape Canaveral. The 37-minute flight tested out vehicle performance, Apollo spacecraft Reaction Control Systems, heat shield capabilities form low Earth Orbit, and other mechanical tests. The capsule reached an altitude of 310 miles before beginning its descent to Earth.

The flight was a partial failure, with faulty wiring in the CSM causing steering control and data recording to be lost. Additionally, the Service Propulsion System engine on the Apollo Service Module did not properly burn for its intended full duration. Helium was accidentally introduced into the combustion chamber.

Splashdown of the AS-201 capsule occurred in the Atlantic ocean, where it was subsequently recovered and used for various parachute drop tests.

Currently, the capsule, which is serial number 009, is restored and on display at the Strategic Air and Space Museum in Ashland, Nebraska. Photograph above taken in August, 2014, when I visited the museum and the spacecraft.


Earlier this morning, 11 September 2014, NASA’s Orion Multi-Purpose Crew Vehicle made its first voyage on the road to the launch pad. The capsule had been in final assembly at Kennedy Space Center’s Apollo-era Operations and Checkout Building since mid-2012. Now that the spacecraft has been assembled, the next step is to fuel the spacecraft’s Reaction Control System. This will take place in the Payload Hazardous Processing Facility, roughly a mile away from the O&C.

Orion will spend 16 days in the PHPF, where it will then be transferred to another building for installation of its Launch Abort System.

Although designed for the Space Launch System, the first flight-worthy Orion capsule will fly on a Delta IV Heavy rocket for the Exploration Flight Test 1 mission, slated for a December, 2014 liftoff.

This will be NASA’s first spacecraft flight in over three and a half years, and their first capsule design to see flight since 1975. 

To see a time lapse video of today’s move, click here.

SpaceX gears up for crew Dragon pad abort test

SpaceX is preparing to take a giant step towards sending American astronauts into space. The company will perform a pad abort test of its crew-capable Dragon V2 spacecraft tomorrow morning, Wednesday, May 6, 2015. The prototype capsule used for the test is seen above at Space Launch Complex 40 earlier today.

The pad abort test will see Dragon fire its eight SuperDraco engines to pull the capsule and service module away from a test rig set up at SLC-40 at Cape Canaveral. It will simulate an abort scenario that Dragon may face in the future, a necessary step towards getting the capsule ready for its first human flight.

Four key systems will be tested during the pad abort test. Since numerous, complicated subsystems must be executed in a short period of time, Dragon’s ability to sequence the pad abort time line is essential to a successful test. The eight SuperDraco engines - which have previously only been test fired, never as a group - will have to respond to real-time data to ensure the capsule stays on course. Additionally, accurate avionics data, and data on internal and external conditions will be collected.

Dragon will fly 6,000 feet downrange during the one and a half minute test. The SuperDracos will fire for six seconds, shooting the service trunk and capsule to an altitude of around 5,000 feet. One second after ignition, Dragon will already be traveling over 100 miles per hour, and after two seconds, will already be clearing the lightning towers surrounding the pad.

The service trunk will separate 21 seconds after launch and Dragon will deploy its parachute systems for recovery, splashing down just 3,000 feet from the Cape Canaveral shoreline.

SpaceX will position a recovery barge just off shore to retrieve the capsule, where it will be taken to the company’s McGregor facility for deservicing and inspection. No destruct mechanisms will be in place due to the short downrange distance the vehicle will be traveling. However, a 2.2 mile safety perimeter is in place.

At 21,000 pounds, the capsule itself weighs the same it would with a compliment of five crew members. Inside the capsule for this test is a partially outfitted interior with a crew mass simulator dummy strapped in.

There is a 7.5 hour test window on both planned test days, stretching from 7 AM EDT to 2:30 EDT. For spectators around the Cape, the test should be visible for only a few seconds near the capsule’s apogee.

Following the pad abort test, Dragon will perform an in-flight abort test from Vandenberg Air Force Base later this year. This will certify the capsule’s abort systems during flight at the most hazardous portion of the ascent profile - Max Q. Max Q, or maximum aerodynamic pressure, is where the stresses on a vehicle are the greatest, posing the highest threat to an aborting spacecraft.

Dragon’s launch abort system is revolutionary. Unlike previous systems, Dragon’s will be available all the way into orbit, providing the crew with a safe return option at all times. Previous abort methods used a “pull” system of rocket motors mounted on a tower above the capsule. This would only be available during the first minutes of launch, jettionsing away at a certain altitude. There would be no option for aborts after this time. Additionally, fuel from Dragon’s abort system transfers to the capsule’s reaction control system, saving separate fuel systems. 

NASA TV coverage of the test starts at 6:30 AM EDT, and will continue through to the test’s conclusion.