U.S. mis­sile sys­tem found to have flaws But in­ter­cep­tors won’t be re­placed

Northwest Arkansas Democrat-Gazette - - NATIONAL - DAVID WILLMAN

WASH­ING­TON — The Pen­tagon is push­ing ahead with an ex­pan­sion of the na­tion’s home­land mis­sile-de­fense sys­tem in­stead of re­plac­ing rocket in­ter­cep­tors af­fected by a newly rec­og­nized de­fi­ciency.

The prob­lem threat­ens the per­for­mance of small thrusters at­tached to the in­ter­cep­tors. In the event of a nu­clear at­tack, the thrusters would be re­lied on to steer in­ter­cep­tors into the paths of en­emy war­heads, de­stroy­ing them.

If a thruster mal­func­tioned, an in­ter­cep­tor could fly off course and miss its tar­get, with po­ten­tially dis­as­trous con­se­quences. The in­ter­cep­tors are the spine of the Ground-based Mid­course De­fense sys­tem, the na­tion’s pri­mary pro­tec­tion against a mis­sile strike by North Ko­rea or Iran.

The prob­lem af­fect­ing the thrusters came to light as a re­sult of the sys­tem’s most re­cent flight test, on Jan. 28, 2016, when an in­ter­cep­tor was launched from Van­den­berg Air Force Base in Cal­i­for­nia.

It did not go as planned. One of the in­ter­cep­tor’s four thrusters shut down dur­ing the test, caus­ing the in­ter­cep­tor to veer far from its in­tended course.

The U.S. Mis­sile De­fense Agency and its lead sys­tem con­trac­tors nev­er­the­less touted the ex­er­cise as a suc­cess, mak­ing no men­tion of the mal­func­tion.

Now, the first pub­lic ex­pla­na­tion for the thruster mal­func­tion has emerged in Pen­tagon doc­u­ments and from in­ter­views with mis­sile-de­fense spe­cial­ists.

A re­view board formed by the mis­sile agency linked the fail­ure to a cir­cuit board that pow­ers the thrusters. The most likely ex­pla­na­tion, the panel said, was that a “for­eign ob­ject” in the in­ter­cep­tor’s in­ter­nal guid­ance mod­ule came loose, fell onto the board and caused a short cir­cuit.

The re­view board did not say what the for­eign ob­ject was, but govern­ment and in­de­pen­dent sci­en­tists say it could have been a wire frag­ment, a piece of sol­der­ing ma­te­rial or other de­bris.

Of the Ground-based Mid­course De­fense sys­tem’s 37 op­er­a­tional in­ter­cep­tors, 34 are equipped with older cir­cuit boards vul­ner­a­ble to the same kind of prob­lem, ac­cord­ing to mis­sile de­fense spe­cial­ists, in­clud­ing for­mer and cur­rent govern­ment of­fi­cials.

The mis­sile agency is in the midst of ex­pand­ing the sys­tem to a planned to­tal of 44 in­ter­cep­tors by the end of this year. The 10 new­est in­ter­cep­tors will have cir­cuit boards made with “im­proved man­u­fac­tur­ing pro­cesses,” an agency spokesman said.

But agency of­fi­cials do not plan to retro­fit or re­pair the older cir­cuit boards, which were man­u­fac­tured dif­fer­ently. Spokesman Christo­pher John­son, in writ­ten re­sponses to ques­tions from The Times, said that based on the re­view board’s anal­y­sis, “no cor­rec­tive ac­tions are needed.”

In­de­pen­dent mis­sile-de­fense ex­perts, how­ever, said the re­view board’s find­ings sig­nal a weak­ness in the 34 older in­ter­cep­tors, which now make up more than 90 per­cent of the fleet. When the ex­pan­sion is fin­ished, they will still ac­count for three­fourths.

For­mer As­sis­tant De­fense Sec­re­tary Philip Coyle III, who led the Pen­tagon’s of­fice of op­er­a­tional test­ing and eval­u­a­tion for six years, said the Jan­uary 2016 test fail­ure was cause for se­ri­ous con­cern about the Ground-based Mid­course De­fense sys­tem’s re­li­a­bil­ity.

“If the cir­cuitry caused a fail­ure, that’s a bad thing,” Coyle said. “One out of four [thrusters] failed, and that’s im­por­tant. I don’t think any­body should white­wash that.”

The na­tion’s de­fense against a nu­clear at­tack by China or Rus­sia re­lies on de­ter­rence: the Cold War doc­trine that none of the ma­jor nu­clear pow­ers would strike first out of fear of re­tal­i­a­tion.

The Ground-based Mid­course De­fense sys­tem, in con­trast, was de­signed to thwart a “lim­ited” strike by a non­super­power such as North Ko­rea by in­ter­cept­ing and de­stroy­ing in­com­ing war­heads.

Af­ter a Jan­uary 2010 test in which a thruster shut down, of­fi­cials blamed a miss­ing fas­tener in the thruster assem­bly. In De­cem­ber of that year, an in­ter­cep­tor again missed its tar­get, and the fail­ure was at­trib­uted to se­vere vi­bra­tions caused by the thrusters’ “rough com­bus­tion” of fuel.

In 2011, Lt. Gen. Pa­trick O’Reilly, then the mis­sile agency’s di­rec­tor, shut down pro­duc­tion of in­ter­cep­tors in an ef­fort to cor­rect tech­ni­cal short­com­ings ex­posed by the test fail­ures.

O’Reilly re­tired in late 2012, and pro­duc­tion re­sumed un­der his suc­ces­sor, Vice Adm. James Syring, as Pres­i­dent Barack Obama’s ad­min­is­tra­tion pre­pared to ex­pand the Ground-based Mid­course De­fense sys­tem fleet — a de­ci­sion sup­ported by bi­par­ti­san ma­jori­ties in Congress.

In the Jan­uary 2016 test, the in­ter­cep­tor launched from Van­den­berg was sup­posed to per­form ma­neu­vers be­fore mak­ing a close flyby of a mock war­head in space.

As the flight un­folded, one of the thrusters stopped fir­ing. Project en­gi­neers had planned for the in­ter­cep­tor to fly within a nar­row “miss dis­tance” of its tar­get. In fact, the clos­est it came was a dis­tance 20 times greater than ex­pected, ac­cord­ing to Pen­tagon sci­en­tists who spoke on con­di­tion of anonymity.

The find­ings of the Jan­uary 2016 ex­er­cise are sum­ma­rized in the most re­cent an­nual re­port of the Pen­tagon’s Of­fice of Op­er­a­tional Test and Eval­u­a­tion.

Re­gard­ing the ex­er­cise, the re­port said all four of the in­ter­cep­tor’s thrusters “turned on and off as com­manded” at the out­set. But one thruster could not be restarted af­ter the cir­cuit board that pow­ered it “ex­pe­ri­enced a short,” the re­port said.

The re­port cited the re­view board’s find­ing that “for­eign ob­ject dam­age” was the most likely cause.

Ten­sions arose over how the of­fice would char­ac­ter­ize the Jan­uary 2016 flight test.

The mis­sile agency in­sisted that the re­port say the re­designed thrusters — tech­ni­cally known as al­ter­nate di­vert thrusters — worked flaw­lessly, and that the fail­ure stemmed from an un­re­lated prob­lem with the in­ter­cep­tor’s elec­tron­ics.

“They made a big deal about, ‘The ADTs worked as de­signed.’ And in fact, when you look at it, no, they didn’t,” said a govern­ment of­fi­cial fa­mil­iar with the mat­ter. “Be­cause the one thruster didn’t fire. … If this was ac­tu­ally an in­ter­cept, it prob­a­bly would have missed.”

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