Sunday, December 21, 2008

130p 12/21 Update: Amid uncertainty, NASA plans for Ares 1-X test flight

=================================

CBS NEWS Coverage of Space News
Posted: 01:30 PM, 12/21/08

By William Harwood
CBS News Space Consultant

Changes and additions:

11/13/08 (03:20 PM): Griffin says he expects Obama administration to replace him as head of NASA
11/14/08 (03:30 PM): Griffin interview with CBS News
12/04/08 (02:30 PM): NASA delays Mars Science Laboratory launch to 2011
12/04/08 (05:30 PM): STS-125/HST SM-04 retargeted for May 12 launch
12/21/08 (01:30 PM): Amid uncertainty, NASA prepares for Ares 1-X test flight

=================================

01:30 PM, 12/21/08, Update: Awaiting guidance from Obama, NASA prepares for Ares 1-X test flight

As the incoming Obama administration considers whether to accelerate development of the Ares 1 rocket that will replace the space shuttle - or possibly change course and switch to a different system or even extend shuttle operations - NASA is pressing ahead with plans to launch a critical sub-orbital test flight next year to show off the new rocket and collect valuable engineering data.

The goals of the unmanned Ares 1-X mission are to help engineers resolve questions about launch vibration, roll control, aerodynamic forces and thermal effects, as well as test stage separation systems and recovery of the spent first stage using new 150-foot-wide parachutes.

The flight also will serve as a pathfinder for Kennedy Space Center engineers and technicians modifying facilities and developing new processing procedures after nearly four decades of shuttle operations.

Equally important, perhaps, the test flight will give American taxpayers their first real glimpse of the new Constellation program and the towering, slender rocket intended to replace the space shuttle after it is retired in 2010.

"One test is worth a thousand expert opinions," said Jon Cowart, a ground systems manager at the Kennedy Space Center. "It's brand new, it's a long, thin rocket. We want to make sure we can guide this thing. Balance a broomstick on the end of  your finger, you'll get some idea of what we're dealing with here."

Because the unmanned test rocket features a dummy upper stage and a less-powerful version of the shuttle-heritage solid-fuel first stage intended for the eventual manned rocket, some space insiders say the $330 million test flight is little more than an expensive show.

But don't try telling that to the managers, engineers and technicians busy building the rocket and modifying the Kennedy Space Center's launch processing infrastructure to support it.

"It's showing ... the next rocket's coming, we're real serious about putting something together and being able to get back to the moon and to Mars," said Carol Scott, deputy mission manager for the Ares 1-X project at Kennedy. "While everybody says 'this is a show,' it is not a show.

"We have gone through PDRs, preliminary design reviews, for a new vehicle. We are telling the long-term vehicle, hey, here are the lessons we've learned, this is the stuff you've got to have solved. What all the other folks don't realize is, this rocket here, the first test objective is flying the rocket, you know, are we going to be able to control it?

"The other one is validating those models, making sure we actually fly what we predicted we can fly," Scott said. "Ares needs to know when they put their models together and they make their predictions that this rocket is going to fly the way they want it to fly. That gives you huge confidence when you're putting this rocket together. So it's a big deal to get that piece of data."

Jeff Hanley, Constellation program manager at the Johnson Space Center in Houston, said critics "grousing about (the test flight) are misinformed."

"I would remind folks about how many flight tests did Apollo do, and all the launches that preceded the first crewed Mercury, Gemini and Apollo flights," Hanley said in an interview. "There was a considerable amount of unmanned testing. And the very first Apollo didn't look anything like the Saturn 5.

"In this case, we're trying to fly something that is dynamically similar. We have the power of the computer today to do a lot of the testing and simulation under various conditions that the Apollo team didn't have. And so, that's to our benefit, that means we don't have to have as robust a flight test program, we can actually do some of that, at least, in the computer. But we need to anchor it in reality and that's what 1-X is all about."

The ground-shaking test flight, currently scheduled for launch in mid July, will only last a few minutes. But engineers are counting on it to generate the data they need to make sure they understand the flight environment and the forces that will be acting on the real rocket before the design is locked down in a critical design review scheduled for early 2010.

"It's a flight whose purpose is to validate the computer models, it doesn't have to be exactly like Ares 1," said NASA Administrator Mike Griffin. "It has to be close, but what it has to do is show that the analysis we're doing, the predictions we make, match what's going on in the real world. And it will do that."

The Constellation program was born in the wake of the 2003 Columbia disaster. The accident review board recommended that if NASA chose to fly the shuttle past 2010, the agency should re-certify the spacecraft. Re-certification would have required re-examining the engineering rationale that went into every aspect of the shuttle's design to identify areas that needed improvements to boost safety.

Instead, the Bush administration decided in January 2004 to finish the international space station and to retire the shuttle in 2010. At the same time, NASA was told to begin development of a replacement system that could ferry astronauts to and from the space station and eventually, on to the moon, a system that would be safer and less expensive to operate than the shuttle. The long-range goal is establishment of Antarctica-type lunar research stations where astronauts can live and work for months at a time.

The Constellation program is a radical departure from the world of shuttle operations. Instead of one rocket designed to carry astronauts and heavy payloads, two rockets are now envisioned: the manned Ares 1, designed to boost Apollo-like Orion crew capsules to low-Earth orbit; and the unmanned Ares 5, a huge heavy lift rocket that will carry a four-person lunar lander into space.

NASA will modify its two shuttle launch pads and the cavernous Vehicle Assembly Building at the Kennedy Space Center to assemble and launch the new rockets. For a moon shot, the Ares 5 will be launched from one pad, followed a few hours later by launch of the crew in an Orion capsule atop an Ares 1.

After linking up in low-Earth orbit, the Ares 5 upper stage will propel the Altair lunar lander and astronauts in the attached Orion capsule to the moon. The entire crew will descend to the lunar surface in the lander and, when its mission is complete, blast off, rendezvous with the orbiting Orion capsule and return to Earth for an ocean splashdown reminiscent of the Apollo program.

The Bush administration did not give NASA much in the way of additional funding to pay for initial Constellation development and the agency has been forced to cut back in other areas to kick start the new program. After station assembly is complete and the shuttle is retired in 2010, NASA plans to divert more than $4 billion a year into Constellation that currently goes into shuttle and station operations.

But given the lack of funding up front, NASA will not be ready to begin initial operations with Ares 1 until late 2014 or early 2015 at best. During the five-year gap between the end of shuttle operations and the debut of Ares 1/Orion, NASA will be forced to buy seats on Russian Soyuz spacecraft to ferry U.S. and international astronauts to and from the space station.

During the presidential campaign, President-elect Barack Obama promised to look into adding one or more shuttle flights and spending additional money to reduce the gap between shuttle and Ares operations. Anticipating questions from the new administration, NASA has conducted studies to find out what would be required to fly additional shuttle flights or stretch out the current schedule to ease reliance on the Russians for space station crew rotation flights.

NASA also has conducted an analysis of options for accelerating Ares/Orion development, but the agency has not yet revealed what could be done or how much it might cost. An Obama transition team currently is reviewing shuttle operations, the Constellation architecture and alternatives.

"The role of the agency review teams is not to make recommendations on any of the issues they are reviewing," said Nick Shapiro, a transition team spokesman. "They are fact finding and preparing the full range of options for consideration by the incoming appointees."

Almost from the beginning, critics have railed against the Constellation architecture. Some believe NASA should look into modifying heavy lift Atlas or Delta rockets - evolved expendable launch vehicles, or EELVs - for manned flights. Others believe it makes more sense to eliminate the Ares 1, which requires development of a new five-segment solid-fuel booster, and instead rely on different versions of a single large rocket, using current four-segment shuttle boosters, to launch crew and cargo.

Griffin, brought in by the Bush administration to oversee the shuttle retirement and the new moon program, has made no secret of his belief that a switch away from the current Ares 1/Ares 5 architecture would drive up costs, increase the current five-year gap between the end of the shuttle and the debut of its replacement and reduce the scope of planned lunar exploration.

That argument doesn't sit well with critics who point to development problems with the Ares 1 rocket, fueling an on-going internet debate that "has been surprising, amusing and irritating at different times to me," Griffin told CBS News in a recent interview.

"I don't get it. The development project is going very well. Anyone who has been part of any aerospace development project can cite comparable examples at the same stage where things were in much more difficulty than we are with Ares 1. There's actually no significant difficulty with the program at all. The little nits that come up, we've got work-arounds for. It's very solid from a technical point of view. I have taken pains to examine those issues myself, I think that's where I do add value as an administrator, I am knowledgeable of these issues. Politics may be difficult for me, but rocketry's not. And the vehicle and the plan and the program are in solid shape. So I don't get it.

"I think it may be due to the fact that everybody likes to play space architect," he said. "We get an enormous amount of input from people who think that NASA would be better if we would use this technical approach rather than that technical approach. And the truth is, some of them would work. But just because they would work, doesn't mean the approach we've chosen won't. At some point, you have to make a selection and go. And our selection was based first and foremost on crew safety and second on economics. And that's what drove us in the direction we are in and we're still happy with it."

A certain amount of friction apparently has developed between Griffin, a straight-talking rocket scientist who flies his own plane, holds five master's degrees and a doctorate in aerospace engineering, and Obama transition team members who served in the Clinton era and whose academic backgrounds are less technical.

Sources say the transition team has asked about EELVs as a Constellation alternative and expressed concern about Griffin allegedly telling NASA civil servants and contractors not to freely discuss Constellation issues and alternatives with the Obama team.

Reliable NASA sources said no such directions were ever issued and checks with NASA's major contractors found no evidence to the contrary; company representatives adamantly denied any such guidance from Griffin or any of his representatives.

"That's ludicrous," one company official told CBS News.

Griffin insists that any switch to EELVs would be a major mistake. Boeing's Delta 4, for example, could be pressed into service launching a smaller Orion-type capsule to low-Earth orbit, but he said that would require major modifications and development of a new abort system. In addition, the booster would have to be "man-rated," a costly process designed to maximize safety margins.

Even if the Obama administration ordered a change of course, United Launch Alliance, the new Boeing-Lockheed Martin partnership that builds and launches Delta and Atlas rockets, might have problems supporting a major new initiative.

"DOD (Department of Defense) faces numerous uncertainties in the EELV program and ULA transition related to the reliability of the launch vehicles, the amount of work remaining in the ULA transition, and program budget decisions based on preliminary data," the Government Accountability Office study said in a September report.

"I'm not knocking the EELVs," Griffin said in a recent interview. "I've flown payloads that I personally was close to on both vehicles. I'm not knocking EELVs at all, they're great vehicles. What I have tried to say is that if we're designing an architecture capable of taking people back to the moon, and that's what our enabling legislation requires us to do, then the EELVs don't serve well in that role.

"Either we would have to downgrade our requirements enormously, and I don't know how to do that, or we would have to upgrade the EELVs, In which case, they would no longer be existing EELVs, we've got a new vehicle family. So that path doesn't work for us in terms of meeting the requirements for a human lunar return."

Regardless of how the transition team's fact finding plays out, presidential-level decisions will be needed in the next few months to avoid additional costs and delays. Among the space-related issues requiring immediate attention:

-- A decision on whether to extend shuttle operations with one or more additional flights. A decision is needed within the next few months, managers say, to keep hardware deliveries stay on track.

-- Obtaining long-term funding to pay the Russians for seats on Soyuz spacecraft during the gap when a U.S. launch vehicle is unavailable. As it now stands, U.S., European and Japanese astronauts only have confirmed seats on Soyuz ferry craft through the spring of 2013.

-- Deciding how long to support space station operations in general. NASA's current budget projections include no money for station operations past 2015, an issue that concerns the space agency and its international partners.

-- Deciding whether to provide additional money to accelerate development of the Ares 1, whether to stick with current plans or whether to switch to a different architecture.

"A decision that must be made soon whether to retire the space shuttle in 2010, as currently planned, or to extend its life in view of limited options for supporting the international space station," the GAO wrote in a report listing "urgent issues" facing the incoming administration. "However, extending the shuttle could also have significant consequences on the future direction of human spaceflight for the United States. Specifically, NASA is counting on the retirement of the shuttle to free up resources to pursue a new generation of space flight vehicles that is anticipated to come online in 2015."

"According to NASA, reversing current plans and keeping the shuttle flying past 2010 would cost $2.5 billion to $4 billion per year," the GAO wrote. "On the other hand, the new administration may well decide to extend the shuttle and defer development of new transportation vehicles in light of budgetary constraints."

Obama has expressed support for NASA on several occasions and the space agency has been invited to participate in the inauguration parade. But as of this writing, Obama has not indicated whether he will ask Griffin to stay on or whether a replacement will be brought in, perhaps to chart a different course. In the meantime, NASA is pressing ahead with Constellation and plans for a dramatic first test flight next year.

"We will have a new administration in place and together with Congress, they will set our path for the coming years," Doug Cooke, deputy associate administrator of NASA's Exploration Systems Mission Directorate, told reporters during an end-of-year teleconference. "We don't know yet exactly what that will be or if there are changes to what we're doing. But of course, we'll adapt and support (their) direction."


TEST FLIGHT CRITICAL TO NEW ROCKET DESIGN

The Constellation program represents the first new American manned rocket since development of the space shuttle began in the early 1970s.

As currently envisioned, the 33-story Ares 1 rocket will be made up of a five-segment solid-fuel shuttle booster and a new second stage powered by a hydrogen-fueled Apollo-era J-2X engine. The Orion capsule will sit atop the second stage, equipped with a solid-fuel abort rocket designed to pull a crew to safety at any point during the climb to space.

The slender rocket, its second stage wider than the first, stands twice as tall as a space shuttle "stack." Its pencil-thin appearance quickly led to a somewhat derisive nickname: the "stick."

NASA currently is modifying launch complex 39B at the Kennedy Space Center to support Ares 1 rockets. Three huge lightning rod towers are being built around the pad and the current fixed and rotating service structures in place for the space shuttle eventually will be removed. Pad 39A will be modified to support the Ares 5 heavy lift rocket after the shuttle is retired.

Using a "clean pad" concept, the Ares 1 rocket will be hauled to the pad atop a modified shuttle launch platform equipped with its own support gantry. Engineers envision rolling the rocket to the pad about four days prior to launch for final preparations.

The Ares 1 development program currently calls for four large-scale test flights: Ares 1-X in 2009; Ares 1-Y in 2012; and then two Ares/Orion test flights in 2013. If all goes well, the new rocket will be operational starting in late 2014 or shortly thereafter.

For the first test flight - Ares 1-X - NASA will use a standard four-segment shuttle booster with an empty fifth segment and new 150-foot-diameter parachutes to lower the spent rocket to the ocean for recovery. A dummy second stage loaded with ballast and topped off with a make-believe Orion capsule and abort rocket will be bolted to the top of the first stage.

Engineers are in the process of building the dummy second stage in the Vehicle Assembly Building, stacking "tuna can" segments and bolting them together from the inside. The second stage will be attached to the first stage motor after it is assembled, or "stacked," in the VAB next spring.

The Ares 1-X first stage will be mounted on a modified shuttle launch platform, held in place by four explosive bolts just like shuttle boosters. Until just few hours before launch, the towering rocket will be stabilized by two swing arms mounted on the shuttle's fixed service structure.

Of the $330 million budgeted for the Ares 1-X test flight, about $50 million is going to pay for facilities and processing modifications at the Kennedy Space Center.

"A couple of years ago, when we all started looking at having a test flight, and a test flight program, we came up with a concept ... that would be minimal modifications to the existing facilities here, because we wanted to be low cost," Scott said. "You don't want to go do a lot of modifications for a one-time use.

"These guys came up with a very clever concept for the upper stage, which has all the access for stacking and doing the work putting these tuna cans together, all the access is on the inside. So (when stacking is going on) his folks are going to be inside this vehicle and they're going to do it all from the inside."

The test rocket is rigged with more than 800 sensors - 377 on the first stage and 446 on the second - to record an enormous amount of engineering data on all phases of flight, from launch through motor burn out two minutes later, through stage separation, parachute deployment and ocean impact. At least four video cameras will be mounted on the rocket, two on the first stage looking up and two on the second stage looking down.

"The big issue with a big, tall, skinny rocket on the dynamics and the controllability of it, we're using existing hardware but it's a different environment," said Billy Stover, a ground systems manager for Ares 1-X. "There are a lot of unknowns. We have a lot of models, but we don't have a lot of data to verify the models. So we've got to go get some data, is it really going to go fly the way you think it is and the only way to do it is (fly it)."

At launch, Ares 1-X will stand 327.2 feet tall and weigh 1.8 million pounds, generating some 2.6 million pounds of thrust. Unlike the space shuttle, which operates under fairly restrictive weather constraints, the Ares system is being designed to launch in less-than-ideal weather.

One area of concern is worst-case winds from the south, which could push the rocket close to its launch gantry as it climbs away. Decades of weather records indicate worst-case conditions would only be expected less than 1 percent of the time and in any case, engineers say the rocket's guidance system can easily steer the vehicle away from any close encounters with its gantry. Alternatively, NASA could simply impose shuttle wind constraints and not launch on days when worst-case winds are expected.

For Ares 1-X, a modified Atlas countdown will be used, along with Atlas-heritage avionics software and hardware. Because it's a maiden voyage of sorts, NASA managers have decided launch will only occur when there is not a space shuttle on nearby pad 39A.

One wild card in NASA's planning is what to do about shuttle flight STS-125, a delayed mission to service and upgrade the Hubble Space Telescope. Launch from pad 39A currently is targeted for May 12. Because the Hubble crew cannot reach safe haven aboard the international space station in case of an emergency, NASA will process a second shuttle in parallel to serve as a rescue vehicle.

For the Hubble crew's first launch campaign earlier this Fall, the rescue shuttle was processed on pad 39B. Agency planners are considering a plan that would free up pad 39B for Ares 1-X by processing the rescue shuttle in the Vehicle Assembly Building.

If single-pad processing is approved for the Hubble mission, Ares 1-X could fly as early as July 11 or 12, although engineers say the timeline is tight. If the agency sticks with dual-pad operations for Hubble, launch would slip to next Fall.

As of this writing, it appears more likely NASA will stick with dual-pad operations because of problems with payload bay door moisture-absorption that might occur if the rescue shuttle is kept inside the Vehicle Assembly Building for an extended period. Mission managers plan to make a decision one way or the other after a Jan. 23 meeting to review shuttle processing options and Ares X-1 hardware deliveries.

While the Constellation program would like to get the flight off as soon as possible, a launch anytime next year would still let the team meet its goal of collecting flight data from Ares 1-X well ahead of the Ares 1 critical design review in early 2010.

Whenever it goes, the rocket should put on quite a show.

Accelerating to a peak velocity of nearly five times the speed of sound, the first stage will burn for about two minutes, reaching an altitude of around 130,000 feet, or 25 miles. When the rocket's thrust falls to less than 40,000 pounds of push, the first and second stages will separate. The ballistic trajectory will carry the dummy second stage to a maximum altitude of about 150,000 feet before it begins arcing over and plunges back to Earth.

The first stage will make a controlled descent to the Atlantic Ocean under three huge parachutes. The spent booster will be towed back to Cape Canaveral for detailed inspections, but there are no plans to recover the dummy upper stage.

Among the areas of special interest are thrust oscillations, roll control, stage separation and the performance of the new parachutes, designed to help slow and stabilize the larger five-segment booster when it falls back to Earth from a higher altitude.

For roll control, Ares 1-X will be equipped with two thrusters on each side of the rocket near the base of second stage. To keep costs down, the system was borrowed from the Peacekeeper ICBM program.

"There's a flow circulation as the flow comes out through the nozzle," said Charles Precourt, a former shuttle commander who serves as vice president of space launch systems for ATK, builder of the shuttle/Ares solid-fuel boosters. "I'm going to use a real crude analogy, but when water goes down the drain you know how it circulates? Well, in a similar fashion, you get a torque force generated by the flow coming out the motor. We understand what it is, we've measured it and we've sized that for this roll control system on 1-X."

The magnitude of the roll force varies a bit from rocket to rocket, but it begins with motor ignition and continues through burnout.

"There's a torque that will vary a little bit in magnitude, but it is essentially there during the flow of the exhaust out through the nozzle," Precourt said. "The roll control system will have to pulse to counter that. We understand, to the degree the analysis allows, we've been able to understand how much will be required, but this will be validation of that. It's not going to be spinning the vehicle at a high rate, it's just going to cause it to want to turn. And so we're going to control how much it turns."

Like the space shuttle, Ares 1-X will execute a "roll program" to put it in the proper orientation as it arcs to the East and climbs toward space. The roll torque phenomenon can either help or hinder the roll program.

"Let's say it causes you to roll in the direction you want to go in, then you may need less of a pulse from your RCS (reaction control system thrusters) to get the roll you have asked for," Precourt said. "If it's against you, you may need more of a pulse to go the other way."

Data collected during the Ares 1-X flight will help engineers better understand the roll torque phenomenon and design a suitable roll control system for the Ares 1 rocket.

Another major question mark is thrust oscillation and vibration, the result of vortices forming inside the booster as part of the complex supersonic exhaust flow. Engineers are designing dampers to "de-tune" the first stage booster and the upper stage/Orion components to minimize amplification effects that might otherwise occur toward the end of the first stage burn.

No such dampers will be in place on the Ares 1-X rocket. Instead, sensors will characterize the thrust oscillation present in a four-segment motor to help engineers properly model the sort of acoustic environment present in a five-segment booster.

"This is a four segment motor, but it's got a fifth segment simulator and the mass and size of the vehicle is representative," Precourt said. "So the data will be instructive.  We really won't have real flight data of what the crew will ride, for vibration purposes, until Ares 1-Y. That'll be the first time we see everything that is essentially identical to what the crew will see. (But) we will collect a great amount of data to help us further understand what we're dealing with."

Solid-fuel rocket motors are hollow and, like a bottle rocket, burn from the inside out. Moving from a four-segment booster to one with five segments changes the frequency of the vibrations produced by the burning propellant.

"If you've got a longer pipe, the frequency drops, just like when you whistle over a Coke bottle, the more full it is the higher the pitch and the more empty it is, the lower the pitch," Precourt said. "Well, that's what's happening here. As the motor gets longer, the frequency changes and when the frequency changes relative to what we've had in the past, we just need to understand where it ends up relative to the natural resonance of the structure that's sitting on top of it. We want to separate the resonance frequency of the structure on top as far as we can from the frequency this motor is creating."

The problem is not just the vibrations of the first stage motor. It's how those vibrations are amplified by the rest of the structure, much like a tuning fork sounds louder when its base is pressed to a solid surface.

"The motor as it burns hasn't got a continuous amount of vibration," Precourt said. "This oscillation that we get is a little more random in that it comes and goes. Part of that is due to the fact that as we burn the propellant off, the flow is causing some vortices to form as it's coming out of the motor and those vortices will attach and unattach inside, it's all this complex flow inside, it's not a turning piece of hardware machinery, it's propellant burning and coming out the back at a very high rate. But it's got some random oscillations in it that tend to be the most noticeable from a thrust oscillation standpoint in the last few seconds of the motor's burn."

Precourt said the sort of up-and-down jarring shuttle crews experience at launch illustrates the sort of forces that get transmitted through the vehicle from the boosters and "we certainly wouldn't want it to get a lot worse than that."

"When the frequency of the motor changes and you happen to build a structure that's sitting on top of it that is at that same resonant frequency, in other words, its size and shape and mass and stiffness all say that if it is introduced to the same frequency as the motor, it will resonate and it will amplify that frequency," he said.

"In the case of the shuttle, it doesn't do much amplification because the structures aren't that close to the frequency of the motor. But in the case of Ares 1, there's a potential that when you add the crew vehicle on top, the upper stage and our motor, the frequencies could be close enough that you get more amplification. And that amplification is an upward and downward movement of the structure that can be translated into a G force. And if that G force gets too high, then of course, the crew is in a bad environment. So that's what we're trying to do, to make sure that G level stays down to about a quarter of one G."

Based on data collected during launch of the shuttle Endeavour in November, engineers no longer think they will need to add active dampers to move the frequencies away from each other or dampen the amplitude of the effect. Instead, passive spring-mounted weights are envisioned to counteract the effects of thrust oscillation. Additional data will be collected during upcoming shuttle flights.

"There's also a structural thing we can do just above our motor that is a what we call a C-clamp isolator," Precourt said. "That will tend to move the frequencies of the structure above and the motor below apart, away from each other a little bit. So we're looking at all of those things. The latest data suggest that the amount of amplification we're going to get may not be as severe as we initially were looking at. So we'll just continue to work it. It's well within our ability to mitigate so we hit the target structural result."

The coupling of vibration frequencies is not linear and a slight separation in frequencies will result in a significant reduction in vibration. Precourt said engineers won't know exactly how the resonance phenomenon works until NASA launches Ares 1-Y with a five-segment motor. But the Ares 1-X flight will pave the way to better modeling.

"What you won't have on this, obviously, is the fifth segment and the upper stage J-2," he said. "Rather than waiting and doing it all at once, we've taken an incremental approach that retires risks that can be retired as quickly as possible.

"We don't need to do any of this if you want to take the approach that the outsiders are suggesting, just wait until the very end, build it all at once and go fly it. But (that approach ignores) the mantra and principle of many, many years of flight test, both in rockets and in other flight vehicles and aircraft, that you do a build-up approach and you depart from a known and you move towards an unknown in incremental fashion. And this is a really good first incremental test."

Hanley agreed, saying he sees two primary benefits for the Constellation program.

"The first, of course, is the engineering value we'll get out of it," he said. "We've had issues like thrust oscillation that have come up over the last year, which is the kind of thing we can be interrogating with real hardware under real flight conditions. That kind of data is like gold to engineers. We test to be able to better improve our understanding of the flight hardware behavior and the way that we model. ... The computer models are only as good as the real life data you have to base them on. And so Ares 1-X, we expect it to be a dynamically similar system to Ares 1.

"The other half of it is really being a pathfinder to help us both train our team and understand and appreciate what it takes to process a system like this at this scale, using new, more modern techniques and systems. We started with the way shuttle does business. But we are going to, to a great extent, lean that out. Because what we want to do is end up with a system that is as low cost and efficient as we've ever achieved in human spaceflight."

=================================

Quick-Launch Web Links:

CBS News STS-119 Status Reports:
http://www.cbsnews.com/network/news/space/current.html

CBS News STS-119 Quick-Look Page:
http://www.cbsnews.com/network/news/space/currentglance.html

NASA ISS Expeditions Page:
http://www.nasa.gov/mission_pages/station/expeditions/index.html

NASA Shuttle Web: http://spaceflight.nasa.gov/shuttle/index.html
NASA Station Web: http://spaceflight.nasa.gov/station/index.html
Spaceflight Now: http://spaceflightnow.com/index.html
GoogleSatTrack: http://www.lizard-tail.com/isana/tracking/

=================================




Post a Comment
Related Posts Plugin for WordPress, Blogger...

Popular Posts