WASHINGTON -- An annual U.S. defense appropriations bill for fiscal 2012 has cut $25 million from a program aimed at developing a conventional capability to attack faraway targets on short notice (see GSN, Aug. 18).
Lawmakers said in a House-Senate conference report that new appropriations for non-nuclear “prompt global strike” systems would be reduced because of “program delays caused by two consecutive flight test failures of the Hypersonic Technology Vehicle 2.”
“Prompt global strike” refers to a capability sought by the Defense Department in which targets halfway around the world could be attacked within 60 minutes of a launch command. The HTV-2 technology -- a leading component in the effort to build a prompt global strike capacity -- produced two test-flight disappointments, first in April 2010 and again this past August.
For several years, it has appeared that the Air Force Conventional Strike Missile -- designed to feature a technology based on the Defense Advanced Research Project Agency’s HTV-2 experimental apparatus -- would be the first prompt global strike weapon system to be fielded. Whether that will continue to be the case is unclear.
Initial estimates were that the Conventional Strike Missile could initially be deployed before the end of 2012, but repeated program delays have slowed its development (see GSN, Sept. 3, 2008). Industry officials earlier this year said an initial missile might be ready for fielding around 2020 (see GSN, June 24).
When deployed, a Conventional Strike Missile would pair space boosters with a hypersonic "payload delivery vehicle" on the front end that dispenses a kinetic energy projectile. Upon nearing its target, the projectile would break up into dozens of lethal fragments.
Top U.S. strategic commanders have repeatedly insisted that this type of fast-flying conventional capability is needed as an alternative to launching a nuclear weapon against an imminent missile threat or other time-urgent target in instances where no other strike assets are within range (see GSN, May 28, 2008).
In total, the legislation offers $179.8 million for prompt global strike for this fiscal year, down from the Obama administration’s $204.8 million request. The conference report is part of an omnibus 2012 spending bill for several federal entities, including the Defense, Energy, Treasury, Homeland Security, Interior and Labor departments.
The appropriations conferees noted that another technology under development for the prompt global strike mission, the Army’s Advanced Hypersonic Weapon, had recently completed a successful flight demonstration (see GSN, Nov. 18). Pentagon officials have said the AHW technology could contribute to their understanding of hypersonic flight but probably would not lead to a deployable weapon in the near future.
Apparently seeking to build on the successful AHW test, the lawmakers directed that their $25 million reduction to defense-wide prompt global strike efforts “not be applied to the Advanced Hypersonic Weapon program.”
A Pentagon spokeswoman said on Thursday, though, that the new funding reduction could affect a number of projects related to conventional prompt global strike, beyond simply reflecting schedule alterations that resulted from the two HTV-2 flight test mishaps.
Fiscal 2012 “investments will exploit the DARPA and Army flight tests, as well as conduct and analyze ground tests, modeling and simulation, and systems engineering,” said the spokeswoman, who asked not to be named while substituting for a colleague who normally handles the issue area. “All are relevant to a range of [conventional prompt global strike] concepts.
“The $25 [million] reduction will limit the scope of these activities, which are spread across the Hypersonic Glide, Alternate Re-entry System, and [Office of the Secretary of Defense] Studies program codes,” the Pentagon representative said in an e-mailed response to written questions.
The appropriations conference bill for fiscal 2012, which began Oct. 1, passed the House on Dec. 16 and the Senate the following day. It remains to be signed by President Obama.
The legislation reflects a compromise between the earlier House-drafted version of the bill, which moved to reduce prompt global strike coffers by $100 million, and the Senate version, which fully funded the line item.
House appropriators did not reveal in their legislation why they slashed the funds, but a committee staffer said at the time the reduction was one among many bill payers for what the panel considered "more important, higher priority programs.”
In a prior action, legislation drafted by the House Armed Services Committee and passed in that chamber authorized a $25 million cut to prompt global strike, voicing concern that in the Air Force Conventional Strike Missile effort the Pentagon was “pursuing a weaponized missile system … before demonstrating that the technology is feasible" (see GSN, June 16).
As always, the legislative process gave the House and Senate appropriations processes the final word on the spending matter.
An “engineering review board,” or ERB, continues to study the August HTV-2 flight test in a bid to determine which functions succeeded or failed, and why, Pentagon officials said this week.
The defense research agency said in August that the latest test for the hypersonic vehicle was terminated as the craft was ascending. An unspecified system “anomaly” prompted the vehicle to initiate a controlled descent and splash down into the Pacific Ocean, the agency said after the test.
In response to questions, a DARPA spokesman, Eric Mazzacone, would not detail how the anomaly manifested itself.
Agency officials were confident at the time, though, that the type of problems determined to have caused the April 2010 flight test failure were not responsible for the latest mishap.
Engineers have cited a “higher than predicted yaw” -- the angle at which the vehicle flies -- as the culprit in causing the 2010 flight anomaly.
That finding “prompted engineers to adjust the vehicle’s center of gravity, decrease the angle of attack flown and use the onboard reaction control systems to augment vehicle flaps during the vehicle’s second flight test,” the defense research agency said in August. “Those changes appear to have been effective.”
“An initial assessment indicates,” the agency quoted HTV-2 program manager Maj. Chris Schulz as saying, “that the Flight 2 anomaly is unrelated to the Flight 1 anomaly.”
Despite the serious glitches, both tests offered significant advancements in understanding hypersonic flight, DARPA officials said.
“The second flight test, according to preliminary data, demonstrated stable aerodynamically controlled Mach 20 hypersonic flight for approximately three minutes,” Mazzacone told Global Security Newswire in August.
The test event also demonstrated a key transition point in aerodynamics, according to the DARPA director.
“We’ve been working for more than 50 years to identify how to predict when the transition from laminar to turbulent flow will occur,” said Regina Dugan, noting this would allow engineers “to assess when a vehicle is about to experience its highest drag and heat load.” Early data from the flight test “indicates that our preflight models successfully predicted transition to within 10 seconds of actual transition point,” she said in an Aug. 25 statement.
Dugan said the new information, if confirmed through further analysis, could help determine “how far [HTV-2] can fly with more accuracy.”
Additionally, the first flight test in 2010 “demonstrated advances in high lift-to-drag aerodynamics; high temperature materials; thermal protection systems; autonomous flight safety systems; and advanced guidance, navigation and control for long-duration hypersonic flight,” Mazzacone said.
The DARPA spokesman declined to release the names, titles or affiliations of members of the HTV-2’s second flight test engineering review board -- or even say how many individuals comprise the panel.
“DARPA, to protect the integrity of the review process, currently has no plans to release the names of those associated with the independent engineering review board,” Mazzacone said in August.
The “review of the HTV-2 flight test 2 anomaly is still under way,” the Pentagon spokeswoman said this week. “The ERB has not concluded its analysis nor recommendations.”
WASHINGTON -- An annual U.S. defense appropriations bill for fiscal 2012 has cut $25 million from a program aimed at developing a conventional capability to attack faraway targets on short notice.