Battle of the Titans (part 1)
by Wayne Eleazer
|While the shuttle had many enthusiastic supporters in the Air Force, not everyone in the Air Force thought that relying on one vehicle exclusively was a good idea.|
These concerns found a receptive audience in the Reagan Administration and, as a result, a new Air Force acquisition program was begun in fiscal year 1984. It came to be known as the Complementary Expendable Launch Vehicle (CELV) program, because it was designed to “complement” the Space Shuttle rather than replace it. A total of only ten missions would be procured, all using Centaur upper stages in order to handle the associated large performance requirements, and all were limited to one launch pad at the Eastern Test Range. And while the idea was to be able to replace the shuttle in the event of a problem, there was no way the Air Force was going to buy such expensive boosters, estimated at $250 million each, and not fly them. So, the chosen payloads were effectively being transferred from the shuttle, although that did not mean that the future launches for those same programs might not fly on the shuttle as had been planned originally.
The Titan 34D production that ended in 1983 originally was designed to be the last new expendable boosters bought by the Air Force and program plans included the theoretical capability for some payloads to fly on either the shuttle or the T34D, if the decision was made early enough. Much the same thing was envisioned for CELV, although the capabilities of the Centaur upper stage were a must for the selected missions, which were the huge highly sophisticated communications Milstar spacecraft, the Defense Support Program missile early warning spacecraft, and an unnamed classified program.
It was thought to be possible to replace the shuttle for the selected missions because the Centaur upper stage had flown not only on the Atlas booster for numerous missions but also on the Titan IIIE booster, where it was used primarily for scientific payloads, including most notably the Viking Mars landers, for a total of seven launches.
But despite the Titan IIIE experience serving as a basis for CELV, the Air Force wanted a competitive procurement. In addition to Martin Marietta, the Air Force prevailed on General Dynamics Space Systems Division, builder of the Centaur upper stage, to submit a bid.
Martin Marietta proposed a further development of the Titan 34D, with the full seven segment strap-on solid motors originally developed for the Titan IIIM and a much larger fairing than even the “hammerhead” configuration of the Titan IIIE. The Space Shuttle cargo bay was 15 feet (4.57 meters) in diameter and the CELV payload fairing would have to be at least that large to accommodate large payloads originally designed to fly on the shuttle. The Centaur upper stage would be based on the version to be used by the shuttle, using two Pratt and Whitney RL10 engines.
Unlike the Titan IIIE, the CELV vehicle would have two separate guidance systems, one for the Titan and one for the Centaur. Since at the time the Centaur was supposed to also serve as an upper stage for shuttle payloads, no doubt the decision was not to perturb the Centaur program by adding Titan guidance to the requirements. Whatever the reason, this was to prove to be a very fortunate design decision.
The General Dynamics proposal brought forth the ultimate development of the original Atlas concept. A one-and-a-half-stage pressure stabilized stainless steel “balloon” tank 15 feet in diameter, 50% larger in diameter than the Atlas, would be powered by five Rocketdyne RS-27 engines, the same ones used on the Delta booster. The “half-stage” would drop off, during ascent, jettisoning four of the RS-27’s, leaving the remaining RS-27 as a sustainer. Of course, it would also feature the virtually mandatory Centaur upper stage and a 15-foot-diameter payload fairing.
It was obvious that the Martian Marietta design, which came to be known as Titan IV, was the easiest design to adopt and the least risky. But as things would turn out, the design proved to be a great deal more challenging than anyone had envisioned.
A key feature included in both proposals is that a completely new procurement approach would be used for CELV—or, at least, one new to the space launch industry. All previous launch procurements had the Air Force signing contracts with not only with the company that designed the booster but also the individual private firms—associate contractors—that built the rocket engines, any strap-on rocket boosters, the upper stages, and at least some of the electronics and telemetry systems. The required hardware needed to flesh out the entire vehicle was procured by the Air Force and delivered to the booster company. NASA used the same approach. In addition, the procurement of a new design was accompanied by defined phases that allowed the Air Force to review how well the effort was going. This approach was much the same as the one used for aircraft procurement, but for launch vehicles there usually was also a separate contract covering launch operations manpower.
|As things would turn out, the design for what became the Titan IV proved to be a great deal more challenging than anyone had envisioned.|
But CELV would be quite different. The Air Force contract would be with the prime contractor and that was it. The Air Force would pay the prime and all the others would not be associate contractors to the Air Force but instead subcontractors to the prime. Furthermore, the entire launch was purchased: not design, parts, assembly, and a separate launch operations contract. The older way gave the Air Force a lot more control over all aspects but was far more manpower intensive. No doubt a related factor was that the Air Force System Program Office for expendable boosters had been consolidated a few years before, and additional manpower would be hard to obtain for what had been postured as an area that was about to go out of business.
Key to the new approach was assigning to the prime contractor Total System Performance Responsibility (TSPR). The prime contractor was responsible for getting everything to work, not the Air Force.
One reason for the new approach was the need for US private industry to become commercially competitive, especially internationally. Previously all US commercial satellite launches were done through NASA. The Commercial Space Launch Act of 1984 permanently eliminated that arrangement and US launch companies were going to have to figure out how to operate on their own rather than selling their services through the government.
And few people indeed realized that the procurement approach, which involved buying the whole ten launches before all the design details were even worked out or proven correct, was a re-creation of something called Total Package Procurement (TPP). TPP was a 1960s concept based on the idea that programs would run better if the government was less involved. TPP was tried on a few programs, most notably the C-5A cargo aircraft, and was roundly criticized as being responsible for huge cost overruns that led to far fewer aircraft being procured than had been planned.
Needless to say, NASA was not exactly overjoyed with the CELV program, which was a clear threat to the Space Shuttle’s formerly exclusive domain. But, while by 1984 the shuttle clearly was flying and the fears of the shuttle concept proving to be unworkable seemingly had been laid to rest, the claim of 50 flights per year at a cost of $14 million each was being found to be an utter fantasy. Even if everything worked, the shuttle was not going to have the capability to meet the launch demand in all cases. McDonnell Douglas had abandoned the Delta booster but both Martin Marietta and General Dynamics saw commercial opportunities and were seriously considering offering launches using their already developed vehicles.
NASA issued its own assessment of the two designs offered for CELV. The personnel working in the CELV source selection team were told not to read it. And then NASA did something that was so unprecedented that no one knew how to handle the situation. The agency submitted its own proposal for CELV.
This was simply unheard of. “In-House Solutions” are a common option for government work, but the idea of a government agency competing against private firms for a procurement being conducted by another government agency was unprecedented. Clearly, NASA was very concerned that the Air Force action endangered the real objective of the shuttle program, to make the agency’s human space efforts bulletproof by making them mandatory.
|And then NASA did something that was so unprecedented that no one knew how to handle the situation. The agency submitted its own proposal for CELV.|
NASA Administrator James M. Beggs explained the agency’s attitude toward CELV in an interview in June 1986. He said that he believed that the Air Force objective was to bail out of the shuttle, let the program collapse as a result, and then take the shuttle over and do as they wished with it, “just like they always do.” Beggs favored the NASA proposal for CELV, which he explained would be a “big dumb booster” to complement the shuttle for large payloads, such as the space station.
The NASA proposal for CELV featured three Space Shuttle solid rocket boosters mounted side by side and spaced by means of rather long struts so to fit on the Shuttle launch pads at LC-39A/B. The center solid booster was to be built slightly shorter than the standard ones and atop it was a Titan second stage. Atop the Titan second stage was a Centaur stage with a 15-foot-diameter fairing.
The Air Force decided to evaluate the Martin Marietta and General Dynamics proposals and then come back a few months later and evaluate the NASA proposal separately. Aside from the questionable legality of the NASA action, it was rather obvious that if the ultimate objective was to provide an alternative to the shuttle, then relying on major elements of the same system was not much of a real alternate approach.
The Air Force formally evaluated the NASA proposal after evaluating those from Martin Marietta and General Dynamics. It was not viewed as unworkable, although the long struts connecting the three solid booster sections generated some concern. Some analysts even pointed out that the NASA proposal made sense if you were going to develop heavy-lift boosters based on shuttle technology, a need that had never been identified. In the end, the basic need to have a system that was not dependent on the shuttle design eliminated the NASA proposal from consideration.
Some analysts viewed the General Dynamics “Super-Atlas” design with concern, specifically the structural aspects of the balloon tank. The original Atlas was a masterpiece of lightweight design, the basic booster structure of a space launch Atlas weighed around 1% of the total liftoff weight. But at around 15 feet in diameter, the hoop stresses in the balloon tank become so large as to almost eliminate the design’s advantages.
The Martin Marietta proposal won the CELV contract. It certainly appeared to be a lower risk proposal that met all the requirements. After all, the Titan 34D was a well developed and reliable vehicle and the Titan IIIE with the Centaur had already been flown. The propulsion systems would certainly give no problems and every other element was within the Air Force’s experience base. The Prime Contractor, Total Systems Performance Responsibility, and Total Package Procurement aspects were not very worrisome because the contract was for a known vehicle of proven reliability, with little or no unknown technical challenges and in a single configuration launched from a single pad and for only three types of payloads.
Every one of these seemingly unassailable assumptions would be found to be grossly wrong.
The 15-foot-diameter fairing of the vehicle that became known as the Titan IV was to be manufactured by McDonnell Douglas Astronautics Company (MDAC), using the basic Isogrid structure that had first been used with the SM-75 Thor IRBM in the 1950s. MDAC made the fairings for its own Delta series of boosters using the Isogrid design but was unable to roll the material to the 15-foot diameter required by Titan IV; they sent the Isogrid to Rockwell to accomplish the rolling process.
|A Titan 34D exploded shortly after launch at Vandenberg, doing extensive damage to the launch pad. This was another new one! The legendary Titan reliability seemingly had gone to hell for some reason.|
MDAC soon received a call from Rockwell, “We thought you could not roll this type Isogrid to a diameter this large.” MDAC asked where Rockwell got that information and Rockwell cited an MDAC report. “Your own report says it will buckle.” MDAC said to try it anyway; then the material buckled as predicted. A redesign was required.
Meanwhile, the Air Force ran some numbers on the sensitivity to winds of the big new Titan and found it could not withstand conditions that the earlier versions could punch through with ease. The extra length of the solids and that huge new fairing were the cause of the problem. The Air Force reminded Martin that, included in the proposal, was a launch availability specification. Martin replied that to meet that requirement it required faster and more accurate winds aloft data than the current range capabilities could provide. The Air Force responded that Martin would have to provide the required capabilities and Martin replied that meeting range support requirements was entirely an Air Force responsibility.
Then, in August 1985, a Titan 34D failed after launch from Vandenberg Air Force Base. This was a shock to the Air Force; they had never lost a big Titan from Vandenberg. Investigation pointed to a failure of the core vehicle liquid rocket engines to start properly, and that was really a new demonstrated failure mode for the vehicle. The investigation was hampered considerably by the fact that as the last few Titan 34D’s came off the production line, they saved weight and cut costs by deleting some instrumentation that normally would have been considered quite basic. The final determination was that both the fuel and oxidizer lines suffered significant leaks, although no one could quite explain exactly how that could occur.
What occurred next, in April 1986 was more than a shock. A Titan 34D exploded shortly after launch at Vandenberg, doing extensive damage to the launch pad. This was another new one! The legendary Titan reliability seemingly had gone to hell for some reason. Unable to explain why a solid motor segment could have been manufactured improperly, huge X-ray machines were installed at the launch sites to allow radiographic inspection of each segment prior to its being stacked.
But it was not a Titan failure that really shook the program to its core.
On January 28, 1986, the Space Shuttle Challenger exploded 70 seconds after launch from the Kennedy Space Center. The immediate impact was to take the shuttle out of the launch lineup for a significant period of time. Longer term, the policy of relying on the shuttle exclusively was finally, officially, recognized as very unwise; so was the policy of subjecting spaceflight crews to hazards that could be handled just as well by uncrewed vehicles.
Also, soon after the loss of the Challenger, NASA deemed the Centaur upper stage as too hazardous to fly on the shuttle. That meant everything requiring the power of a Centaur would have to fly on Titan IV, not just those ten missions originally identified. And it was not just Centaur missions either, and not just those that went from Cape Canaveral. All the larger shuttle payloads for the Defense Department would have to move to expendable boosters, as well as at least some NASA payloads.
Titan IV had to pick up all the heaviest Shuttle DoD payloads; there was nothing else to do the job. The Titan IV procurement had to be expanded into not only Centaur but also Inertial Upper Stage and No Upper Stage versions. The launch facilities used had to be expanded to two pads at Cape Canaveral and two at Vandenberg AFB, and the new Vandenberg pad had to be capable of handling Titan IV Centaur (but was cancelled after the Soviet Union went out of business.) The 10 missions for the original Titan IV contract were expanded into a total of 39; four of them were failures.
A Titan IV begins to break apart in a 1998 launch failure. (credit: US Air Force)
In order to provide improved performance a competitive procurement was held for a new strap-on rocket booster for the Titan IV. The contract was won by Alliant Techsystems, and featured new motors with composite cases rather than the steel cases of the earlier United Technologies Chemical Systems Division (CSD) solid motors. The first segment came off the production line and was found to be delaminating, a serious problem that had to be corrected and caused some delay. Then, when the first motor was being stacked for a ground test firing at Edwards Air Force Base on September 7, 1990, the crane collapsed and the segment fell and ignited on impact, resulting in more delay. When the first motor was finally stacked and fired, it exploded; redesign was required and that caused more delay. Additional CSD steel cased motors had to be procured. Then the motors for two launches that were already stacked on the pads at Cape Canaveral were found to have signs of corrosion and had to be de-stacked.
|Titan IV was born of the recognition that the shuttle-only policy was flawed and could have unacceptable impacts on US national security. But Titan IV was affected by other policy mistakes.|
In response to these difficulties, the stockholders of Alliant Technologies sued the company. Alliant then sued Martin on the basis that it should have told the company that this rocket stuff was so hard to do, or something like that. Martin sued Alliant on the basis that it had failed to deliver usable hardware per their contract. Finally, the companies got together and agreed to kiss and make up if the Air Force would cough up another $250 million. The New Jersey delegation responded by inserting direction in appropriations legislation that the Air Force should quit being so mean to Martin and Alliant and pay them the extra $250 million.
The first Titan IV failure occurred on the seventh mission flown, on August 2, 1993, at Vandenberg. An improperly repaired CSD solid rocket motor segment caused the vehicle to explode near the end of the solid booster burn. Investigation showed that key personnel who understood the repair procedure had left the company after CSD lost the competition for the new motors.
The 1993 Titan IV failure was followed by a long string of successful launches, with the first launch of the new Alliant solid motors not occurring until February 1997. Then, in August 1998, Titan IV launches from Cape Canaveral suffered an unprecedented three failures in a row. The entire management approach for the Titan IV was revisited and revised. There were no more failures, and the last Titan IV was launched on October 19, 2005, at Vandenberg Air Force Base.
All of the American expendable launch vehicle programs that were in existence in the 1970s were adversely affected by the decision to phase out all ELVs in favor of the shuttle. Each program suffered failures as a result of the neglect of ELVs due to the shuttle-only policy. For example, the Titan 34D suffered a failure rate of 20%.
Titan IV was born of the recognition that the shuttle-only policy was flawed and could have unacceptable impacts on US national security. But Titan IV was affected by other policy mistakes. It was assumed that the Titan launch vehicle was so well developed that the Air Force could reduce its engineering oversight role; this was not the case. It was assumed that private firms would still be responsible for due diligence even without the Air Force ensuring that they did so; that was not true. It was assumed that the space launch mission could transition to a more “operational” style; that proved to be disastrously wrong. Titan IV suffered a failure rate of 10.2%, only half that of the Titan 34D but about 50% more than the usual average. Titan 3 Commercial suffered a failure rate of 25%.
Titan IV proved to be a vitally important program and it came at a very important time. After the loss of the Space Shuttle Challenger, the US lacked adequate capability for placing large payloads into orbit. There were only six Titan 34Ds left in the inventory at that time and production had ended three years before. The Titan IV program gave the country a two-year head start on building new Titans to replace the shuttle. The first Titan IV did not fly until 1989 and it was not even in the configuration that the program originally was intended to produce; the first Titan IV Centaur did not fly until 1994, 10 years after the program began. It was 1994 before the US even started a program that eventually produced a Titan IV replacement. If the real purpose of the Titan IV program was not just to address the original 10 launches but for the Air Force to get its foot in the door to better handle a future Shuttle grounding, it succeeded brilliantly.
The Titan IV program faced enormous challenges that had not been anticipated when it was conceived, some of the most difficult of which were not self-generated. These challenges included an attempt by another government agency to destroy the program and efforts by some in the Air Force to impose changes that were nearly as damaging. In the end it has to be judged as a successful program because there was no feasible alternative. Rather, Titan IV was the alternative that worked.
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