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Written by Subject: Space Travel and Exploration

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Thursday, May 6, 2010

As we continue to progress towards the first Falcon 9 launch from Cape Canaveral, certification of the flight termination system (FTS) and subsequent range availability remain the two primary schedule drivers.

Air Force Range safety requires the FTS system, which allows them to safely end the launch should the vehicle stray from its designated flight corridor. The system consists of a command receiver and an ordnance system designed to split the vehicle's fuel and liquid oxygen tanks in the event of an errant flight.

Static test firing of the Falcon 9 first stage, conducted at SpaceX's launch site, Cape Canaveral, Florida on March 13, 2010. Credit: SpaceX / Chris Thompson.

SpaceX is working closely with Ensign Bickford to complete testing of the explosive elements of the FTS system, but there are other components, such as the FTS radios, antennas and the transponder that come from other suppliers as well. All of these components must be qualified specifically for our flight environments, so unfortunately, it is not simply a case of buying "off the shelf".

FTS testing is an iterative process where the number of remaining tests depends on the results of previous tests, making it very difficult to predict a completion date. Once testing is complete, final data is submitted to SpaceX and Air Force Range safety officials for review and acceptance. Much of the range calendar for May is already reserved for other activities, so range availability will be a key factor in identifying a launch date. Fortunately the FTS is the last remaining significant milestone--the vehicle is otherwise ready for flight, so once we complete certification, we will be "all systems go" for launch.

Wet Dress Rehearsal

During our successful wet dress rehearsal (WDR) conducted in March, we experienced some problems with the thermal protective cork layer that covers the first stage. In some areas subjected to the extreme cold of liquid oxygen (LOX), the cork's bonding adhesive failed and several panels separated from the vehicle. It is important to emphasize that the cork is not needed for ascent and there is no risk to flight even if it all came off. This is for thermal protection on reentry to allow for the possibility of recovery and reuse. While stage recovery is not a primary mission objective on this inaugural launch, it is part of our long-term plans, and we will attempt to recover the first stage on this initial Falcon 9 flight.

After applying a new layer of cork thermal protection using a new adhesive system, we opted to perform a second wet dress rehearsal in April, as well as an electromagnetic interference (EMI) test. Everything performed well and the new adhesive remained properly bonded. A word of thanks to NASA and our resin supplier for helping our structures team find these effective solutions.

As we ramp up our flight rate, Florida will continue to be SpaceX's fastest growing region. We are entering continuous launch operations mode, meaning we will have over 100 people in Florida on average. That count may go as high as 200 later this year when we start preparing and launching Dragon. We expect our direct employment at the Cape to eventually reach thousands of people; using standard multipliers for indirect regional employment, this could mean in excess of several thousand jobs long term.

Presidential Visit

President Obama honored us with a visit to the SpaceX Falcon 9 launch site at Cape Canaveral on April 15, 2010, just prior to his national speech at Kennedy Space Center describing the administration's new space initiatives.

President Barack Obama and SpaceX CEO and CTO Elon Musk at the SpaceX Falcon 9 launch pad, Cape Canaveral, Florida on April 15, 2010. SpaceX's Leslie Woods Jr. and NASA Administrator Charles Bolden in background. Credit: Associated Press.

Credit: Associated Press.

Meeting the President at the Falcon 9 launch site, from left: Neil G. Hicks, Florence Li, Brian Mosdell, President Obama, Leslie Woods Jr., and Elon Musk. Credit: Getty Images.

Several members of our SpaceX team were able to meet the President during his tour of the Falcon 9 launch pad including:

Neil G. Hicks, SpaceX Lead Fluid System Engineer

Neil received his BS in Mechanical Engineering from the University of Florida and is a Florida Licensed Professional Engineer with 31 years experience. Neil spent 17 years as a NASA shuttle technician on the main engines, 13 years as a launch propulsion engineer involved in design and development of the Delta IV RS-68 rocket engine, and a year designing the Ares I launch pad pneumatic system for NASA. In the two and a half years since joining SpaceX, Neil has lead the team designing, building, and activating the launch pad fluid systems for Falcon 9.

Florence Li, SpaceX Structures Manager

Florence received her BS in Mechanical Engineering from the University of Delaware, and her MS in Aeronautics and Astronautics from Stanford University. Florence has been with SpaceX almost seven years. She started with structural analysis, testing and launch integration on the first four Falcon 1 rocket launch campaigns, and currently works on Falcon 9 vehicle integration at Cape Canaveral.

Brian Mosdell, SpaceX Director, Florida Launch Operations

Brian received his BS in Aeronautical Engineering from Embry Riddle Aeronautical University and brings over 20 years of launch operations experience, including work on the Titan, Delta, and Atlas programs. Brian was the Chief Launch Conductor for ULA prior to joining SpaceX two years ago.

Leslie Woods Jr., SpaceX Compensation and Human Resources Information Systems Manager

Leslie received his BS in Mechanical Engineering from Stanford University and has been with SpaceX for nearly five years. His diverse background in engineering, technical sales and recruiting has helped lead SpaceX's growth from 200 employees in 2006 to nearly 1,000 in 2010.

The President impressed us all with his level of understanding, and the nature of his questions. He clearly perceives both the challenges we face, as well as the opportunities for these new initiatives to become powerful economic engines.

Next: Falcon 9 Flight 2 -- The First NASA COTS Launch

Our second Falcon 9 flight, which will be the first launch under the NASA COTS program, will carry our first operational Dragon spacecraft to orbit. If all goes as planned, liftoff should occur a few months after the inaugural Falcon 9 flight.

This "COTS 1" Dragon will perform several orbits of the Earth, followed by reentry and splashdown off the coast of Southern California. We will gather performance data and retire significant amounts of risk on key spacecraft systems, including Draco thrusters, the Dragon communication systems, PICA-X high performance heat shield material, and other critical navigation, reentry, landing and recovery systems.

This first COTS mission will pave the way for the following COTS and CRS flights to demonstrate, and then actually provide, commercial cargo transport to and from the International Space Station in support of its continued growth and operation.

Falcon 9 Flight 2 -- Primary Structures

The largest sections of flight hardware for the second Falcon 9 flight--the 6.5 meter (89 foot) long first stage tank structure, and the shorter second stage tank--left our Hawthorne, California headquarters some weeks ago and have completed acceptance testing at our Texas Test Facility.

Installing the Falcon 9 Flight 2 second stage tank structure (white cylinder, top) and test interstage black cylinder, center) into the structural test stand at our Texas Test Facility. Subsequently, we filled the stage with cryogenic nitrogen, then pressurized and tested it under a variety of load conditions, qualifying it for flight. Credit: SpaceX.

We have completed primary fabrication of the carbon-composite interstage structure that join the two stages and houses the second stage's Merlin Vacuum engine during first stage flight. It has already passed structural acceptance testing, and after fitting it out with pneumatic collets, pushers, and other supporting hardware, it will ship to the Cape.

Looking upwards through the interstage for Falcon 9 Flight 2, shown undergoing final assembly in California. The four black containers will house the parachutes that will help return the first stage to Earth after stage separation. Credit: SpaceX.

Falcon 9 Flight 2 -- Propulsion

The nine Merlin 1C first stage engines are undergoing final integration into the thrust structure assembly in Hawthorne, and will be shipped to Texas for mating with the first stage tank.

After integrating the nine Merlin 1C engines into the thrust structure assembly it will be ready for shipment to Texas. Credit: SpaceX.

Each engine has already passed an individual acceptance test firing in Texas. After mating the nine-engine assembly to the first stage tank structure, it will be fired as a complete stage.

Second stage Merlin Vacuum engine for Falcon 9 Flight 2, preparing to leave the Hawthorne factory for Texas. Credit: SpaceX.

Similarly, the Merlin Vacuum engine for the second stage has shipped to Texas for testing at the engine level, to be followed by mating to the second stage tank and test firing as a complete stage.

The Merlin Vacuum engine's large radiatively cooled expansion nozzle for Falcon 9 Flight 2, ready for final processing. It does not participate in the static test firing, and will ship directly to the Cape. Credit: SpaceX.

Falcon 9 Flight 2 -- Dragon Spacecraft

Most significantly, the second flight of Falcon 9 will launch the first operational Dragon spacecraft into Earth orbit. After several trips around the Earth to verify its performance, it will reenter and splashdown off the coast of Southern California, to be met by our recovery team.

Mounted to the top of the Falcon's second stage, the Dragon spacecraft consists of a trunk section, a separate pressurized capsule section with integral service section around its base, and at the top, an aerodynamic nose cap that the vehicle jettisons after leaving the atmosphere.

Overview of Dragon spacecraft showing (from top) the nose cap, the cargo or crew carrying pressure vessel surrounded by a service ring which holds propellant tanks, Draco thrusters, parachutes, etc, and trunk section which can carry unpressurized cargo to orbit.

Draco Thruster Module Testing

Depending on its mission, each Dragon spacecraft will carry as many as 18 Draco thrusters for orbital maneuvering and attitude control. The SpaceX-developed Draco thrusters can generate up to 400 Newtons (90 pounds) of force. They can fire in bursts as short as a few milliseconds for precision maneuvering, or up to many minutes for changing orbital parameters and initiating the return to Earth.

Technicians produce Draco thrusters in the SpaceX Hawthorne propulsion clean room. With up to 18 Dracos per Dragon, and with 17 Dragon missions currently on our launch manifest, we are manufacturing many thrusters per month. Credit: SpaceX.

Like the Merlin engines, each completed Draco undergoes an acceptance test firing before integration into the Dragon spacecraft. On Dragon, we mount the thrusters in groups of four and five, positioned to provide complete control of the spacecraft's direction of motion (X, Y and Z axis), as well as orientation (roll, pitch and yaw).

The video below shows a test of five Draco thrusters firing in various combinations and durations.

Testing a set of five Draco thrusters, conducted at our Texas Test Facility. Click to play video.

Four Draco thrusters fire to pull the Dragon spacecraft away from its expended trunk section in preparation for reentry. Credit: SpaceX.

Inspecting the first 18 flight Draco thrusters prior to their installation into the COTS 1 Dragon spacecraft, scheduled to fly on Falcon 9 Flight 2. Credit: SpaceX.

Dragon Propellant Tank Fabrication

The Dragon spacecraft carries a total of eight spherical titanium propellant tanks--four each for monomethyl hydrazine (MMH) fuel, and nitrogen tetroxide (NTO) oxidizer--the same as used for orbital maneuvering by the Space Shuttle. These propellants have long on-orbit lifetimes, permitting future Dragon flights to remain in space for a year or more. A system of valves provides redundant cross-connection between the propellant tanks for maximum reliability.

Like many other critical components, we found that the optimum path to maximum quality and lowest cost was to bring their production in-house. We take a flat circle of sheet titanium, mount it to a steel mandrel, then slowly rotate it while heating it to glowing, and then form it on to a hemispherical steel tool.

Spin-forming titanium sheet material into hemispheres. With a melting point of 1725 °C (3135 °F), we heat the metal to its plastic deformation point. Then a large metal wheel presses the softened metal around a steel hemisphere. Credit: SpaceX / Roger Gilbertson.

When cool, we remove the titanium hemisphere from the tool and finish it into final form. We then install the interior components, and weld a second hemisphere into place to make the finished spherical tank.

Technicians prepare a titanium hemisphere for installation of the interior components and welding of a second half to make a complete propellant tank. Credit: SpaceX.

Dragon Trunk Separation Testing

At the end a Dragon mission's orbital phase, the spacecraft's thrusters fire to slow the craft and begin the return to Earth. Then, a set of dual-redundant electrically activated frangible nuts fire to release the trunk and expose the heat shield for reentry.

The trunk and pressurized sections of the Dragon spacecraft join together at six load-bearing mounts. The video below shows a full-scale test of the trunk separation system, using a qualification trunk, and with a steel structure suspended above simulating the Dragon's pressurized section.

Testing a set of pyrotechnic frangible nuts that release the trunk section from the Dragon spacecraft prior to start of reentry. Click to play high-speed video.

Following separation, Draco thrusters fire to move the Dragon capsule away from the trunk, and reorient it into reentry position.

High Performance PICA-X Heat Shield

On a typical return, Dragon will enter into the Earth's atmosphere at around 7 kilometers per second (15,660 miles per hour), heating the exterior of the spacecraft as high as 2000 degrees Celsius (3632 degrees F).

However, just a few inches of SpaceX's PICA-X (Phenolic Impregnated Carbon Ablator) heat shield material will protect the spacecraft and keep its interior to a comfortable temperature.

Protected by a PICA-X heat shield, the Dragon spacecraft reenters the Earth's atmosphere at around 7 kilometers per second (15,660 miles per hour), heating the exterior of the spacecraft as high as 2000 degrees Celsius (3620 degrees F). Credit: SpaceX.

Developed with the assistance of NASA, the originator of PICA, the "X" stands for the SpaceX-developed variants of the rigid, lightweight material, which have some improved properties and a greater ease of manufacture. Read more about PICA-X here.

We produce the PICA-X material in-house in large billets, then cut and machine them into separate tiles, each as large as a cafeteria tray, but over 8 cm (3 inches) thick, and weighing only about a kilogram (2.2 pounds) each. During reentry, less than 1 cm (1/2 inch) chars away from the surface of the PICA-X tiles, providing plenty of safety margin.

Inspecting a PICA-X tile prior to attachment to the heat shield assembly. We fabricate each strong, lightweight tile to an exact shape for a precision fit to the carrier structure and its neighboring tiles. Credit: SpaceX.

Inspecting the carbon-composite carrier structure for the first Dragon spacecraft heat shield, fresh from its mold. At nearly 4 meters (13 feet) in diameter, the structure supports the PICA-X tiles that protect the spacecraft during reentry. Credit: SpaceX.

Test placement of the flight PICA-X tiles on the first flight Dragon heat shield carrier structure. During reentry the lightweight tiles withstand temperatures as high as 2000 degrees Celsius (3620 degrees F). Credit: SpaceX / Roger Gilbertson.

We have started final assembly of the first flight heat shield that will protect the Dragon spacecraft on its return. After fabrication and inspection, we attach the PICA-X tiles to the lens-shaped carbon-composite carrier structure, and fill the thermal expansion joints between tiles with a high-performance silicon compound.

>From its inception, SpaceX designed the Falcon 9 and Dragon spacecraft to transport and return both cargo and astronauts. With 17 unmanned Dragon missions presently on our launch manifest, the Falcon 9 and Dragon spacecraft will have plenty of flight heritage by the time we carry our first crewmembers to orbit.

Now In Production -- Falcon 9 Flight 3

In addition, we have started production on Falcon 9 Flight 3 hardware and its Dragon spacecraft. We've completed fabrication of all six domes (three for first stage, three for second stage) and have started production of the tank barrel sections. We have the next ten Merlin engines in-process, components for the Dragon spacecraft pressure vessel formed, and many other elements under way.

Hardware for the third Falcon 9 flight in process in our Hawthorne factory, including first and second stage domes, barrel segments, and Dragon capsule pressure vessel walls. Credit: SpaceX.

Our SpaceX team is nearing 1,000 members, and we're continuing to hire the most sought-after and enterprising engineers and production technicians seeking to make access to space regular, cost-effective and reliable. If you'd like to join our efforts in California, Texas, or Florida, please visit our Careers page.

Stay tuned for more updates as we progress towards the first flight of Falcon 9 and beyond.

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