The US space program is begin-fling to lose the snakebitten look it took on last year amid a shocking succession of accidents befalling Space Shuttle Challenger and three unmanned launch vehicles.
The program still has a long, long way to go in fully recovering from the impact of those accidents. They left the Air Force incapable of launching growing numbers of satellites vital to national security.
This sobering—even scary—state of affairs will persist into next year and will not be much alleviated for another year or so after that.
Shuttle Orbiters will not fly again until February 1988, at the earliest. The first of the big Titan IV Complementary Expendable Launch Vehicles (CELVs) now being developed to carry outsized payloads high into space will not be ready for launch until early 1989.
Less powerful boosters are available, but they are relatively few in number and cannot take most high-priority military payloads to where they need to go in space.
Even so, Air Force space officials are feeling a bit better about the space program's prognosis these days. They believe that the space-launch recovery plan now in place to correct launch-system weaknesses glaringly exposed by the Challenger accident in particular will result in launch capabilities far better—more vigorous, more versatile, and less vulnerable—than those of the pre-Challenger era.
Such robust, resilient launch capabilities are sorely needed.
National security has become heavily dependent on the increasingly sophisticated satellites that provide communications, weather information, surveillance, early warning of attack, and navigational support to US strategic and conventional forces. Better satellites of all such varieties are in hand or in the making. They are worth nothing, however, while on the ground.
Blueprint for Launch
The space-launch recovery program devised by Air Force Systems Command's Space Division in Los Angeles, Calif., is a blueprint for getting those satellites launched as efficiently and as expeditiously as possible well into the 1990s.
Col. Donald C. DePree, SD's Deputy for Space Transportation Systems, characterizes that program as "step one" in the space program's comeback and as "doable on the national level."
"Technical problems are the relatively easy ones," Colonel DePree declares. "They can always be fixed. The problems of decisions, strategies, and plans are the tough ones. In past months, those kinds of things have been thrashed out, and now it's over to us in the field to do the implementing."
The Challenger accident "made us come to grips with the need for a national-level strategy for space and made the nation realize that we do need assured access to space," Colonel DePree asserts.
Air Force officials take satisfaction in the American public's post-Challenger awareness of some other verities that USAF had always honored but was often stymied in getting across. These are that the US must:
¾ Exploit space for all it is worth as a military arena, which is plenty.
¾ Never get into the perilous position of depending too much on only one launch system, as it did with NASA's Shuttle-centered Space Transportation System (STS).
¾ Use man more judiciously in space and leave it to unmanned, expendable launch vehicles to truck satellites into orbit on all occasions not requiring human interaction with the hardware.
¾ Bear down in developing such spacecraft as modular unmanned launchers and manned aerospace planes.
¾ Acknowledge once and for all that space missions are inherently risky and should be populated, when necessary, by professional crews—period.
Space Division's space-launch recovery program addresses all this. It emphasizes USAF's future acquisition of Titan IVs to share heavy-lift duties with the Shuttles, of Medium Launch Vehicles (MLVs) to launch Navstar Global Positioning System (GPS) satellites, and of Space Launch Vehicles (SLVs)—modifications of Titan us that were deactivated as ICBM launchers—to boost medium-size military payloads into polar orbit from Vandenberg AFB, Calif.
The Air Force intends to launch military payloads on the Shuttles only when this is imperative or most convenient. In all other instances, it will launch such payloads on expendable boosters.
In keeping with this, USAF plans to design or to redesign several types of satellites to be capable of going either way. Among them are the Milstar Extremely High Frequency (EHF), tough-to-jam satellites that are expected to be the crowning glories of defense communications in the 1990s and beyond, the Defense Satellite Communications System (DSCS III) satellites, the Defense Support Program (DSP) early warning satellites, and the Navstar navigation satellites.
Prior to Challenger, the Defense Department's Strategic Defense Initiative Organization (SDIO) anticipated using the Shuttles for a great many tryouts of SDI technologies for space-oriented defense against ballistic missiles.
Now SDIO is considering moving a substantial number of such payloads off the Shuttles and onto unmanned launchers.
A few months ago, Vice Chairman of the Joint Chiefs of Staff Gen. Robert T. Herres, then Commander in Chief of US Space Command and of North American Aerospace Defense Command, reflected on the post-Challenger comeback now gathering momentum.
General Herres said that a crucial element in that comeback will need to be better teamwork among military and civilian space officials in cutting the soaring costs of doing business in space.
"Despite the discouraging setbacks of past months, I am more convinced than ever that our goals, objectives, and ambitions are on track," the General said. "We have become dependent on space, and this means that what we seek to do there must be undertaken out of absolute necessity—and what must be done out of necessity must be done right.
"We can't expect our forces to prevail in war without space systems."
The latest and best of satellites for such systems are going nowhere for lack of launchers.
For instance, this month was to have marked the start of something big for the US armed forces. The first Navstar satellite of an eighteen-satellite GPS operational constellation was scheduled to be launched aboard a Shuttle Orbiter.
US forces, spread thinly in the execution of their global responsibilities, are counting on that Navstar constellation to give air, sea, and land units ultraprecise position-fixing data, thus enabling them to make the most of their mobility and firepower.
They will have to wait a long time for it to happen. Given the launch situation, the Air Force will be lucky to get the first Navstar operational satellite into orbit by early 1989.
By now, too, the new-generation DSCS III communications satellites should have been proliferating in space as scheduled. Only two are in orbit. The Air Force is taking deliveries on some of the twelve additional DSCS III satellites that it will need to position in space as an operational constellation and as spares, but it must store them because it has no way of launching them.
Those satellites are virtually indispensable. In relaying the critical military messages that make it possible for the US to deter war and to wage it, they will be much more capable and survivable than the older satellites of the DSCS II constellation now doing that job in space.
Across the spectrum, satellites needed by the armed forces for a variety of force-enhancing purposes are languishing in storage. The Air Force must pay extra to store them or to put off their production in order to avoid having to store them. Either way, space program costs go up.
USAF's Space Launch Complex Six (SLC-6) at Vandenberg AFB has also been idled. The first Shuttle launch from SLC-6 was to have taken place last July. It will not take place until 1992, and SLC-6 will remain on "operational caretaker status" until then.
Meanwhile, a launchpad at Vandenberg is being modified for launching the Titan IVs that USAF had the foresight to begin developing prior to the Challenger disaster to shoulder Shuttle-sized payloads.
The Air Force will buy twenty-three Titan IVs instead of the ten originally planned.
Assessing the Setback
The only officials who know how badly the launching limbo affects classified satellites are those with the need to know. Clearly, however, some of those high-priority spacecraft are on hold and will be joined in that status by others until the Shuttles and other lifters capable of handling them are in business.
Shortly after Challenger blew up last January 28, Space Division was charged with assessing how severely the space program had been set back by the disaster and the subsequent grounding of the remaining three Shuttle Orbiters, only two of which—Discovery and Atlantis—are capable of boosting most military payloads into space.
SD was also assigned to devise a plan for a proper mix of new and improved unmanned launchers of various capacities and purposes and to enfold in it NASA's plans for resumption of Shuttle flights and for a replacement Orbiter.
The resultant SD space recovery program would have to meet with the approval of the Air Staff, the Secretary of Defense, the National Security Council, and the President.
SD's job was even more complicated than it had seemed at first, for the space-launch situation soon became even worse.
Less than three months after Challenger, an Air Force Titan 34D ELV with a classified military payload exploded nine seconds after liftoff at Vandenberg AFB, Calif. This mishap marked the second straight failure of a Titan 34D, the first having occurred nine months earlier at Kennedy Space Center, Fla.
Now there would be no more Titan 34D launches until the design and construction of the six such ELVs remaining in USAF's inventory were rigorously and painstakingly reexamined—and there went USAF's medium- to heavy-lift capability until further notice.
Then came yet another hitch for Space Division in formulating the space recovery program.
NASA had said that it expected Shuttle Orbiters to resume flying in early to mid-1987. But when it reflected on all that needed to be done to make the Shuttles safer, with emphasis on their solid rocket boosters (SRBs) and on crew-escape measures, it put off the first flight until February 1988.
Even that timetable may have to be slipped. Secretary of the Air Force Edward C. Aldridge, Jr., told an Air Force Association audience in Los Angeles last October that it could turn out to be "extremely tight."
Working through the plight of the Titan 34D and the change in the Shuttle schedule, Space Division had barely completed its space-launch recovery plan when Congress, acting with extraordinary alacrity, approved the acquisition of a new Shuttle Orbiter to replace Challenger, with its first flight now scheduled for 1991, and also provided funds for a start on everything that SD had programmed to be done.
Lt. Col. Barry Zilin, who headed the team that devised the space-launch recovery program and who now directs SD's MLV program, says that "as part of the congressional action, we were directed to go out and buy additional Titan IVs, to make high-priority satellites dual-compatible with the Shuttles and the Titan IVs, and to develop and buy the MLVs for launching GPS satellites."
There is a down side to altering the Shuttles for safety purposes and to designing and building satellites for dual compatibility. Structural changes to the Orbiters and to their SRBs will add weight and, thusly, will reduce payload capacity by thousands of pounds. Moreover, says Colonel DePree, "designing payloads for versatility of launch is bound to drive up their costs."
"I believe," he continues, "that payloads will be designed to be optimized for launching either on the Shuttle or on ELVs, with some built-in capability to go the other way. R&D birds requiring man's interaction will have to be designed exclusively for the Shuttle."
What it comes down to, says Colonel DePree, is that "if we want guaranteed access to space for certain payloads for which we may have emergency needs, within certain time windows, then making them dual-compatible is the only strategy we can follow. Where some satellites are concerned, it doesn't make much difference whether we get them up one year or the next. But there are others that, if the sky is falling, we've got to get up somehow—and it's on those that we'll put our [dual-compatibility] resources.
"It's all workable. We'll sort it out. But the decisions will have to be made at the national level in terms of strategy. They can't be made on the basis of individual bits and pieces of space systems. We'd get lost in that.
"The important thing in all this is that we've been allowed to reassess and to change the decision of ten years ago that we would eventually launch all our satellites on the Shuttle. In the end, we'll be much stronger in our ability to react if something like the Challenger accident happens again.
"Maybe that's our Challenger legacy."
The weight to be added to the Shuttles in their structural changes will force USAF to lower its requirement that they be capable of boosting 32,000 pounds of payload into polar orbits out of Vandenberg and of landing—in case it's necessary—with 24,000 pounds of payload still aboard.
Even prior to Challenger, the 32,000-pound polar-orbit payload goal was shaping up as difficult to attain without throttling up the engines well beyond their recommended thrust limitations.
Now it seems that the additional weight in store for the Shuttles will force USAF to compromise on a Vandenberg payload launch weight that is well below the 32,000 pounds that had once been deemed to be necessary.
It may have to lower the Shuttle payload landing-weight limit of 24,000 pounds as well.
Such compromises will likely mean the end of experiments of the sort that Shuttle crews had been conducting in the middeck locker areas of the Orbiters. There are several such areas, each capable of holding 100 pounds of research gear.
In the past, they were used, for example, to check out crew interactions with hardware to be applied to primary payloads in subsequent flights and to do biomedical, oceanographic, meteorological, and optical research.
On one Shuttle flight, a middeck locker contained equipment for an SDI-related test in which a laser was beamed at the Orbiter from the Hawaiian island of Maui to check out its aiming, tracking, and atmosphere-penetration propensities.
Forgoing such experimentation "is where we're going to hurt," Colonel DePree declares.
Mixing Shuttles and ELVs
Withal, the Shuttle will continue to be highly important to USAF's space-launch aspirations.
"It's an excellent vehicle," says Colonel DePree, "but why not use it only for those missions where there's a payoff to having man in the loop? Why use man just to accompany satellites into orbit, throw them out of the bay, and come back home?"
Military payloads will be carried on fewer than half of the Shuttle flights now scheduled over the next few years—on two of five flights in 1988, on four often in 1989, and on four of eleven in 1990.
There is some skepticism in the military space community about NASA's ability to build up its Shuttle flight rates so sharply.
When it comes to hurling especially heavy payloads high into space, the Shuttles will give way to the Titan IVs.
NASA has abandoned its plan to use the General Dynamics Centaur rocket as a Shuttle upper stage in order to boost 10,000-pound payloads into geosynchronous orbit 22,300 miles above the planet—orbits in which early-warning satellites, many communications satellites, and others operate.
This will leave the Shuttle capable of boosting a maximum 5,100 pounds of payload into geosynchronous orbit from low-earth orbit by means of its Inertial Upper Stage (IUS).
The Air Force's Titan IVs, on the other hand, will accommodate Centaur G-prime upper stages, and this will make them the mightiest of all US launch vehicles in their weight-to-altitude prowess. They will also be compatible with the IUS.
Martin Marietta is building the Titan IVs as variants—mainly by virtue of their extended solid rocket boosters—of the company's Titan 34Ds.
Each Titan IV will be nearly 113 feet long and ten feet in diameter. Its two SRBs will generate a total 2,725,000 pounds of thrust; its first stage, 546,000 pounds of thrust; and its second stage, 104,000 pounds.
Delivery of two Titan IVs to the Air Force is scheduled for late this year, and the first of them is earmarked to launch a satellite into equatorial orbit from Cape Canaveral, Fla., in April 1988.
Titan IV launches of satellites into transpolar orbits from Vandenberg AFB are scheduled to commence in early to mid-1989.
The first Titan IV-Centaur launch of an ultraheavy military payload into geosynchronous orbit from Canaveral is now scheduled for early 1990.
"We've progressed from a program for ten Titan IV launches at the Cape to one of twenty-three launches at the Cape and at Vandenberg," explains Col. Victor W. Whitehead, Space Division's Deputy for Expendable Launch Vehicles. "Before Challenger, we had three payloads signed up. Since Challenger, a large number of payloads have come over to us to fly on Titan IV. We're up to fifteen and counting."
The Titan IV design has breezed through its preliminary and critical design reviews and is "in good shape for us to make our initial launch date at the Cape," Colonel Whitehead says.
A Big Head Start
He joins the chorus in saluting Secretary Aldridge for having led the way in persuading the Administration and Congress to authorize the Titan IV (formerly the Titan 34D-7) CELV program in 1985.
NASA had objected to that program on grounds that the CELVs would compete with the Shuttles for payloads and hurt their chances of turning a profit with the commercial payloads that NASA saw in store for them.
Now, post-Challenger, the prospects of commercial payloads on the Shuttles are dim, and their profit-making potential is practically nil.
President Reagan ruled last year that the only commercial payloads to be qualified for Shuttle flights will be those already designed to be unique to the Shuttle or to be valuable to US national security or foreign policy.
Colonel Whitehead notes that Secretary (then Under Secretary) Aldridge "pushed for the CELVs when they weren't very popular in some circles—and thank goodness he did. We got a big head start on the Titan IV program as a result."
It now appears that USAF's Titan 34Ds will be ready to go to work sooner than might have been expected after two of them failed, one after the other, in August 1985 and in April 1986.
The first Titan 34D failure was probably caused by a leak of nitrogen tetroxide and the loss of a turbopump in a liquid engine. The second happened when rubber insulation debonded from the casing of a solid-rocket engine and let propellant burn through the casing.
With respect to the Titan 34D's basic design, this was actually good news. The disparity of causes indicated that the problems were isolated ones—not the result of any inherent or universal flaw in the boosters.
Space Division and the Titan 34D contractors have conducted an exhaustive review of the rocket's design and construction and have built up a considerable body of knowledge in testing all segments and components.
The upshot, says Colonel Whitehead, is that "we do not think we will have to do a redesign" of the Titan 34D.
The Testing Dividend
Aside from the eventual restoration of the rockets to service, a major benefit from Space Division's $160 million inspection and recovery program has been "the quantum leap forward we've been able to make in nondestructive testing," the Colonel says.
"We got together everybody we could find who knew anything at all about nondestructive testing—from the Department of Defense, the Department of Energy, from industry, from everywhere—and we put together a program to do all sorts of things that had never been done before.
"We used X-rays, thermography, ultrasonics, and lasers to inspect the innards, and we learned how to process all the data and put it together. Now we're giving the Cape and Vandenberg the capability to automate all this so that it will be repeatable from test to test."
This means that the innovations in nondestructive testing resulting from the Titan 34D recovery program will be applicable to such testing of all US launch vehicles. Confidence levels will consequently rise.
Given the fatal failure of a field joint on one of Challenger's solid rocket boosters, Space Division has taken special care in testing such joints on the Titan 34D SRBs.
It has found, says Colonel Whitehead, that those joints "are probably the toughest parts of the old beasts."
This finding has great meaning for all Titan launchers and for the design of the Titan IV CELVs too, perhaps. Had it turned out otherwise, there might have been much bigger trouble all across the space-launch program.
Space Division expected its reassessment of the Titan 34Ds to be completed by early this year. The rockets could be back in action by the end of the year.
The Titan 34D testing touches on Space Division's MLV development program as well.
One of the rockets in the running for the MLV production contract is a modification of the Martin Marietta Titan 34D. The others are variants of the General Dynamics Atlas and of the McDonnell Douglas Delta.
SD plans to pick a winner from among the three by February 6. It desperately needs the MLVs to launch Navstar satellites and has scheduled them to begin doing so in January 1989.
Even if the MLV production and operational schedules are strictly kept, however, the deployment of Navstar satellites will have slipped badly from the timetable for their launches exclusively on Shuttles that were to have begun this month.
After Challenger went down, Space Division faced the harsh prospect of an indefinite delay in depositing a fully operational GPS constellation plus spares and replenishment satellites in space.
"We had an emergency need to get twenty-eight satellites costing over a billion dollars into orbit—and the Shuttle obviously wasn't going to do it," recalls SD's Colonel Zilin. "It was painful."
It still is, although a little less so. The current schedule calls for the launching of twenty-two GPS satellites by October 1991. Twelve will go up on MLVs and ten on Shuttles.
This schedule, too, could slip, however. There is going to be a lot of jockeying among the various military satellite programs for space on the Shuttles in the years ahead. Many questions of which satellites ride on which launchers may have to be settled at the national level.
"It's been a tough year," says Col. Gaylord B. Green, SD's Deputy for Space Navigation Systems and director of the GPS program.
Frustration is especially keen in Colonel Green's shop because the seven engineering development GPS satellites now in space have performed so beautifully. This intensifies the itch to get on with launching the operational GPS satellites, many of which have already been produced.
All seven development satellites have exceeded the four years of life that the Air Force and Rockwell, its GPS prime contractor, believed they would average. Two are now weak as a result of their atomic clocks running down, but each has been in orbit for more than eight years.
Rubidium is the main element in those clocks. The newer Navstar engineering satellites have longer-lasting cesium clocks, as will the operational GPS satellites.
The satellites now in orbit can provide some useful navigation data. However, they are too few in number to provide the around-the-clock, three-dimensional time, distance, and position data that the fully operational Navstar constellation of eighteen satellites and at least three spares will be capable of providing.
"We won't have any real operational capability until we have worldwide coverage," explains Colonel Green. "What's up there now provides the Navy—only with roughly eleven hours a day of two-dimensional accuracy.
"But we've had remarkable results from those satellites. They've met or exceeded everything we ever expected of them. This makes us very optimistic about the production satellites—and once we're able to deploy them in the operational mode, they'll dazzle folks, I'm sure."
The only plus in the long wait to begin such deployment is the extra time available to Space Division and to the services to integrate GPS terminals into aircraft, tanks, ships, submarines, and other combat and combat-support platforms.
GPS capability is a major element, for example, in the Air Force's upgrading of the avionics of its F-16Cs, F-15Cs, and F-his. GPS is also a big player in the avionics integration of the F-15E dual-role fighter, of the Advanced Tactical Fighter (ATF), and presumably of the Advanced Technology Bomber (ATB).
There are no present plans to provide the B-1B bomber with GPS capability. The B-52 bomber, on the other hand, was on top of USAF's list of aircraft to incorporate GPS terminals.
Once the B-52s began using navigation data from the Navstar satellites now in space to help them in their bombing practice, "the results were spectacular," declares Col. Wayne Jones, SD's GPS deputy program manager.
In executing the GPS engineering development program, Space Division and Space Command have turned out to be quite a team.
When the two oldest Navstar development satellites went sour in space, SD decided to move one of them into a position nearer the other, thereby enabling the five satellites still functioning well to close ranks, as it were, and work better together.
The repositioning job fell to Space Command, which controls all US satellites in space. "They did the maneuver flawlessly," says Colonel Green. "They have supported us very well in operating our system."
DSCS II Holding Up
Fortunately, Space Division's DSCS II communications satellites, built by TRW, are also holding up in space much better than anticipated.
"We have a good constellation up there," says Col. Glenn D. Rogers, SD's Deputy for Defense Satellite Communications Systems. "The satellites are lasting longer than they were designed to last."
The newer and much heavier DSCS III satellites, being produced by General Electric, represent significant improvements in survivability, capacity, and ability to service many more users. Of the three in orbit, two are operational. Three more are in storage waiting to be launched.
In the future, DSCS III satellites will be built for Titan IV launch as well for Shuttle launch.
The complexity of the space-launch situation is exemplified by what has happened to DSCS III launch schedules in just the past seven months. They have been changed at least six times, and the dates of individual launches have been moved around by as much as two to three years.
"It's tough," Colonel Rogers says. "One thing that's comforting, though, is that the DSCS constellation should remain healthy until we again have a launch capability. Once we have it, we will have satellites available to upgrade and replenish the constellation."
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