Funding And Scheduling Issues May Delay Initial Air Launch Missile Intercept
BY RAY NELSON
The first intercept of an air launch target missile from a military cargo plane, currently scheduled for 2008, could slip another year due to funding and mission planning schedules, according to Air Force officials involved with the program.
The air launch missile system, known as Long Range Air Launched Target (LRALT), is designed to provide a realistic threat simulation for testing long-range ballistic missile defense systems.
LRALT is the result of a Missile Defense Agency (MDA) program to provide target missiles that can be used from any location. The target missile is dropped from a C-17 flying at about 25,000 feet altitude. It descends beneath a trio of parachutes to about 20,000 feet, then after the parachutes disconnect and the pallet separates, the target missile ignites and launches vertically at about 19,000 feet. It has already been tested in a 2004 launch over the Pacific Ocean northwest of Hawaii as a risk reduction flight. All of the risk reduction was completed during that flight. The LRALT system was developed and built by Coleman Aerospace in Orlando, Fla.
"Right now we’re still on a tentative schedule to do the first interceptor launch sometime in mid-2008," said Air Force Lt. Col. Randall Riddle, who is head of Space and Missile Systems Center, Detachment 12, Rocket Systems Launch Program (RSLP) at Kirtland Air Force Base, N.M.
He said MDA’s test schedule has considerable flexibility as different testing requirements arise or go away, and he would not be surprised to see that mission slip to 2009. Asked if funding might be the main factor in a delay, Riddle said, "Funding is a major factor. For that particular mission they haven’t decided which interceptor we’re going to go up against yet, so where that test ends up falling into the overall MDA scheme of things is probably just as big as the money factor."
Riddle said, "One of the factors that we were looking for is a rocket technology issue that’s called head-end erosion, where if you accelerate a rocket at really high Gs, which the LRALT does, there could be a problem with the rocket fuel being used up in the front of the rocket before it’s used up in the rest of it, so we kept an eye on that in the risk reduction flight and did not see that issue crop up, which was a little bit of a surprise to us."
In September 2005, an LRALT was launched 800 miles (1,287 kilometers) off the coast of Alaska in an exercise that successfully tested the Cobra Dane radar, located in the Aleutian Islands, and the fire control system for the Ground-based Midcourse Defense element of the Ballistic Missile Defense System. Riddle said Cobra Dane will certainly be engaged again with LRALT launches in future missile defense tests if the flights are in the right area of the Pacific Ocean.
"The director of MDA [Air Force Lt. Gen. Trey Obering] was highly complimentary on our ability to put that mission together and execute it in the timeline that we did, and to be able to pull off a really good realistic test for the Cobra Dane radar, and we got a lot of attention for that, which we were pretty happy about," he said. "The Ballistic Missile Defense System is a good customer in several ways for LRALT, both in terms of stimulating the sensors, which is what we were after this time, and providing a good, realistic target that can come at a fixed defense site from any given direction. We anticipate that as the Ballistic Missile Defense System gets more and more operational as the years go by there will be more and more need to test against targets of this kind that can be launched from any direction rather than a fixed site."
SMD Report asked Riddle how many LRALT target missile launches could be provided per year.
"Our primary constraint on providing LRALT launches is basically our launch contractor’s ability to build additional sets of equipment, and our ability to do the refurbishment on the motors. So about six times a year is probably our practical limit, and if you want to go beyond that it would require a significant investment in building some infrastructure so that we could have two launch campaigns going on at the same time," Riddle said. He added that two launches per year is all that the RSLP anticipates having to do.
The LRALT is a two-stage missile with a range of 2,000 km (1,243 miles). It is powered by two SR-19-AJ-1 rocket motors in tandem, and uses components from deactivated Minuteman I and II intercontinental ballistic missiles.
Riddle explained that for the planned 2008 intercept test there will probably be a significant modification of the LRALT.
"We’re probably going to put a larger front end on the rocket; we had a pretty small front section on the test item, both for the risk reduction flight and for the Cobra Dane flight, but some of the future customers that we’re looking at will probably want a little bit different front end, something larger, and so that would make the LRALT about three feet (0.9 meters) longer, as well as making the pallet that it comes out of the aircraft on about three feet longer." Asked if that change is easy to make, Riddle said, "It’s a fairly significant design issue, not for the rocket so much as for the booster extraction system because we’ll be having to increase that by about three feet as well to accommodate the longer rocket. It’s not an issue weight-wise or size-wise. We’ve got plenty of performance to carry a larger front end; it’s just a matter of having to go back and do a little bit of redesign on the carriage extraction system to make sure that when it comes out of the aircraft we haven’t changed the dynamics."
Riddle said that pretty much everything that is done with the LRALT system is driven by what the customers need, and changes are not made based on any other requirements. However, he said that RSLP would like to do space launches with an air launched system in the future.
"We always have an eye on the future for things we can do that leverage off the experience that we have had with LRALT, and one of the things that we hope to do in the future is to be able to do an air launch of an actual space launch system to put a satellite in orbit using some of the techniques that we’ve developed in putting together both the LRALT and the Short Range Air Launched Targets (SRALT, the predecessor of LRALT). We’re eager to be able to apply that to some sort of a space launch mission, but we don’t have anything on the books right now."