Keeping it Cool: CEV Heat Shield MDU Arrives

Tanya Nguyen, Staff Writer
NASA's John F. Kennedy Space Center

NASA is teaming up technology developed for the space shuttle and designs used for the Apollo Program to produce elements of the next spacecraft destined to deliver astronauts to the moon.

An early sign of that combination has made its way to NASA's Kennedy Space Center in the form of a prototype heat shield, which is the same size and dimensions of the one planned to protect the Orion spacecraft as it enters Earth's atmosphere on the way back from the International Space Station or the moon.

The arrival of the heat shield stirred up excitement from workers on the Constellation Program as they were able to see for the first time one of the first pieces of Orion's full-scale test hardware.

"When (it) got here at the end of November, it was very exciting because it is the first piece of hardware," said Joy Huff, a NASA shuttle orbiter thermal protection system engineer who is spearheading Kennedy's work on the Orion heat shield. "Not flight hardware, but it is flight-type material. And just to see the full size, it really gives you a scale of the size of it."

At five meters in diameter, the heat shield is the largest one of its kind ever built. The prototype was built largely just to prove it could be done, Huff said.

Also known as a manufacturing demonstration unit, or MDU, the prototype was also created by the need to develop heat shield evaluation, inspection and handling procedures, said Jim Reuther, project manager of the Crew Exploration Vehicle thermal protection system at NASA's Ames Research Center.

Although parts of Orion's thermal protection system, which serves as a barrier against the heat upon re-entry into Earth, will use shuttle tile materials, the base of the heat shield endures the most heat and will burn away or "ablate" as it descends through the atmosphere at more than 25,000 mph.

The use of ablative materials mirrors that of the Apollo Program's approach, in which the entire entry capsule was covered with an ablator, Reuther said. The Orion heat shield also uses techniques perfected for the shuttle's thermal protection system, particularly the bonding method used to attach the segments of ablative material to the base heat shield. But since the area to be protected is much smaller than that of the shuttle, and because the base of Orion's heat shield will not be reused, its design is simpler in respect to the number of parts and reusability.

The prototype heat shield is made of the leading candidate material called PICA, which stands for phenolic impregnated carbon ablator material. The PICA material was previously used for the base heat shield of Stardust, a small robotic spacecraft that successfully completed its mission of obtaining comet samples and returned to Earth in January 2006.

Because Stardust was less than 3 feet in diameter, it was possible to cast its heat shield in a single piece as opposed to the many pieces needed to make Orion's heat shield. At 16.5 feet in diameter, Orion's heat shield will require up to 200 pieces of PICA blocks.

"The actual final number of PICA blocks will be determined by both manufacturing and thermal-mechanical design constraints,"Reuther said. "However, when compared to the roughly 24,000 tiles used on the shuttle, the final number of blocks will be very manageable."


The blocks on the heat shield share the same delicate characteristics as the shuttle's tiles. Designers also plan to include gap fillers between blocks, just as with the shuttle.

NASA chose an ablative heat shield that slowly burns off because it can handle higher temperatures than the shuttle's reusable tiles. A spacecraft returning from a lunar mission is expected to encounter temperatures as high as 5,000 degrees Fahrenheit during re-entry into Earth’s atmosphere, compared to about 2,300 degrees for a space shuttle re-entry.

Because of this, the Orion heat shield can only be used once, Huff said. The prototype heat shield rests in Hangar N at Cape Canaveral Air Force Station where will it undergo several months of nondestructive evaluation testing, or NDE, that mainly includes laser scans and X-rays. The tests will be used to reveal flaws purposely built into the heat shield.

"We want to get it into the X-ray facility to use X-rays to look for these known flaws," Huff said. "That's part of the NDE task to come up with standards, so when you get a flight unit, you know what you're flying."

But before any NDE testing can be performed, the team at Kennedy has to learn the best way to move and handle the heat shield. Because of the size of the prototype, they also will have to test and develop new handling standards that will be applied to the actual flight heat shields.

Backup procedures call for using a crane to handle the prototype, but Huff said she hopes to see an adaptor made that will allow a forklift to be used instead. The forklift would make it easier to handle the prototype inside buildings and as it undergoes testing procedures.

"The materials (for the adaptor) have been ordered, (so we) should be fabricating (it) within the next few weeks, get that built and then we'll put the MDU on the adaptor and start NDE testing," Huff said.

She's looking forward to a special milestone to take place by late summer: turning all handling and NDE testing results over to Lockheed Martin.

And when that happens, the Constellation Program's mission of putting man on the moon and beyond will be one big step closer.

BACK TO THE MOON

BACK TO THE MOON:

Paul Grayson of Control Engineering, a cutting edge pub touching on the often overlooked and essential field of Robotics has tipped his hat to Team FredNet. The latter are heavily involved with the Google Lunar X Prize and may be among the first teams announced next month. Reading his column turned out to be one of those "Manifest Deja'vu" experiences, as when you discuss Elvis with someone, hang up your cellphone, and "Are You Lonely Tonight?" is the next very next song you hear when you turn up the radio.

East Carolina University with it's exceptional pioneering use of robotics in surgery is eliminating a lot of grossly traumatic open thorastic proceedures and replacing them with sometimes hands-free bilateral rib operations, an obviously far less invasive snip snip than "the old Black and Decker," as Jerry Lewis once described it.

This is happening at East Carolina University's Biomechanics and Robotics Exploration for Information Technology Literacy and Skills Project, an outreach to the engineers who will likely one day be replacing your liver over the Internet. Right in the operating room, my daughter Valerie tells me, is the Uncle of a friend who contracted Hepititis C while ever-learning to become one of the most skilled chest men on Earth. Rather than allow that set-back, which banned him from the operating room, stop him, he instead became devoted to remote procedures, which is akin to watching real surgery online, except he is actually performing this surgery online. He might yet be in the next room, but some procedures he's partnered with already over the web, and at great distances. As much as we are talking about the future of health care in politics these days, whether to socialize or about "single-payer" insurance, etc., few are talking about the advancements, which are astounding.

The grand debate over Internal Improvements in the early United States, whether Charleston Teriffs collected as federal revenue should pay for the Chesapeake and Ohio Canal, for example, is long over. Whether governments should facilitate commerce, by building roads rather than concentrating on agenda-driven regulation, is not discussed any longer. That's why we need Libertarians and Liberals, particularly to remind us of what matter and what doesn't.

In lunching as I do weekly with Lobbyist X, always rotating the location to some great and some common locations, I discussed these things with him in the context of my own experience with getting completely off pain medications to treat symptoms related to facet arthrothopy, which I have written about elsewhere. He reminded me about ECU, with that wink that is not a wink that indicates he is giving me yet another clue about what his secretive clients are up to. That it involves Space Exploration, Earth's relatively large natural satellite the Moon, and North Carolina obviously means it involves robotics.

Their interest in eastern North Carolina makes more sense yet agan. As my former employer and good friend Patrick Ballantine once said, the "economic engine that drives" the feeble "economy" of my home region "is the" boom city "of Greenville, home of ECU" and as excellent a hospital in Pitt County Memorial Hospital as can be found on the planet.

I'm assured by Lobbyist X that none of those he is working for are "officially" (he repeated that twice) involved with the Google X Prize, always insisting "they're going for a different magilla."

The weekly meetings are becoming more interesting, and the latest venue was also telling. We ate lunch yesterday surrounded by virtual dinosaurs and other state government administrative types at the rooftop cafeteria in the North Carolina Museum of Natural Sciences. You can't miss it. It's firectly in front of North Carolina's General Assembly, where, in the interests of full disclosure, I work for House Republican Leader Paul Stam.

Once again, I should point out because of the Post-Speaker Black ethics legislation that Lobbyist X and I always split the tab. He never pays for my lunch or gasoline nor anything else when we meet. We also have yet to discuss passed, pending, or possible legislation, directly or indirectly, outside the formal settings of the General Assembly's proper facilities. Although I've known LX since 1999, we talk only about the future, and he feeds me information which I share here about his employers activities. While he's said his clients are talking with NC's Department of Commerce, I have no idea what that might be about or why. I can guess, sure. But I don't.

We share an interest, LX and I, in amateur astronomy and the history of space exploration. And being too stupid to know how, I haven't profited and probably never will from our conversations except in life experiences.

And yet, it's very much like when you're driving down the road and a street light blinks off as you drive under it when talk turns to robotics at ECU and within a few minutes you are Emailed an article from a friend hundreds of miles away and in another state and who wouldn't know LX from "Adam's housecat" where Paul Grayson, an expert in the subject, is talking about Team FredNet and Destination Moon.

"Quite a world," said David Ossman, wrapping it all up and tying the package with a red ribbon.

SpaceX conducts first multi-engine firing of Falcon 9 rocket

Roger G. Gilbertson

media@SpaceX.com

(310) 363.6446

McGregor TX – January 18, 2008 – Space Exploration Technologies Corp. (SpaceX) conducted the first multi-engine firing of its Falcon 9 medium to heavy lift rocket at its Texas Test Facility outside McGregor. The engines operated at full power, generating over 180,000 pounds of force, equivalent to a Boeing 777 at full power, and consuming 700 lbs per second of fuel and liquid oxygen during the run.

“This is a major hardware milestone for our company," said Elon Musk, CEO and CTO of SpaceX. "It marks the first time that we have simultaneously fired two engines on the same stage. No significant problems were encountered transitioning from single engine testing in November, which suggests that we will be able to ramp up rapidly to a full complement of nine Merlin engines. Our propulsion and test team has done a remarkable job.”

This two engine test was the largest to date on the BFTS (Big Falcon Test Stand). The next run, scheduled for February, will use three engines operating for a full first stage mission duty cycle of three minutes. When operating in flight, the first stage will accelerate the 180 ft long Falcon 9 vehicle to more than ten times the speed of sound in that short period of time. Following stage separation, the Falcon 9 second stage continues accelerating the payload to a final change in velocity that may be in excess of Mach 30 for missions beyond low Earth orbit.

The test series will continue with five, seven and finally the full compliment of nine engines. With all engines firing, the Falcon 9 can generate over one million pounds of thrust in vacuum or four times the maximum thrust of a 747 aircraft. SpaceX has designed its Merlin engine for rapid mounting and change-out. A new engine can be installed in a period of hours, a feature that will provide significant operational efficiency and responsiveness on the launch pad.

The Merlin 1C next generation liquid fueled rocket booster engine is among the highest performing gas generator cycle kerosene engines ever built, exceeding the Boeing Delta II main engine, the Lockheed Atlas II main engine, and on par with the Saturn V F-1 engine. It is the first new American booster engine in a decade and only the second American booster engine since the Space Shuttle Main Engine was developed thirty years ago.

Merlin 1C will power SpaceX’s next Falcon 1 mission, scheduled to lift off in Spring 2008 from the Central Pacific. The first Falcon 9 is scheduled for delivery to the SpaceX launch site at Cape Canaveral (Complex 40) by the end of 2008.

SpaceDev to Develop Payload for International Lunar Observatory

Design to include astrophysics and communications capability for private Moon mission

Poway, CA – SpaceDev, Inc. announced today that it has been awarded a contract by the International Lunar Observatory Association (ILOA) of Hawaii to conduct requirements definition and preliminary design of the ILO spacecraft’s astrophysics and communications payload. ILO will perform various astronomical observations from the South Pole of the Moon, and will also engage in commercial communications activities.

“We see this as a critical phase of work for ILO, as it will solidify the mission’s goals and priorities,” said Mark N. Sirangelo, SpaceDev’s Chairman and Chief Executive Officer. “We will determine how to deliver the most valuable and desirable astrophysics data from the surface of the Moon to scientists around the world, while pursuing a design to allow the rapid, low-cost mission development that will be a hallmark of ILO.”

About SpaceDev
SpaceDev, Inc. is a space technology/aerospace company that creates and sells affordable and innovative space products and mission solutions. For more information, please visit www.spacedev.com.

About ILOA
The International Lunar Observatory Association is a Hawaii-based non-profit organization dedicated to expanding human knowledge of the Cosmos through observation from the Moon, via its ILO and ILO Human Service missions. For more information, please visit www.iloa.org.