Editing Solid rocket booster (section)

==Disadvantages==
Solid propellant boosters are not controllable and must generally burn until exhaustion after ignition, unlike liquid propellant or [[Cold gas thruster|cold-gas]] propulsion systems. However, launch abort systems and [[range safety]] destruct systems can attempt to cut off propellant flow by using [[Shaped charge|shaped charges]].<ref>{{Cite journal|title = Shock Initiation Studies of the NASA Solid Rocket Booster Abort System|url = http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADP005341|date = 1986-08-01|language = en|first = Douglas G.|last = Tasker|journal = |access-date = 2016-02-08|archive-date = 2016-02-13|archive-url = https://web.archive.org/web/20160213215445/http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADP005341|url-status = dead}}</ref> {{as of |1986}} estimates for SRB failure rates have ranged from 1 in 1,000 to 1 in 100,000.<ref>{{Cite news|title = NASA Estimate of Rocket Risk Disputed|url = https://www.latimes.com/archives/la-xpm-1986-03-05-mn-15406-story.html|newspaper = Los Angeles Times|date = 1986-03-05|access-date = 2016-02-08|issn = 0458-3035|language = en-US|first = MICHAEL|last = WINES}}</ref> SRB assemblies have failed suddenly and catastrophically. Nozzle blocking or deformation can lead to overpressure or a reduction in thrust, while defects in the booster's casing or stage couplings can cause the assembly to break apart by increasing aerodynamic stresses. Additional failure modes include bore choking and combustion instability.<ref>{{Cite web|title = Solid Rocket Motor Failure Prediction - Introduction|url = http://ti.arc.nasa.gov/tech/dash/pcoe/solid-rocket-motor-failure-prediction/introduction/|website = ti.arc.nasa.gov|access-date = 2016-02-08|url-status = dead|archive-url = https://web.archive.org/web/20160814173318/http://ti.arc.nasa.gov/tech/dash/pcoe/solid-rocket-motor-failure-prediction/introduction/|archive-date = 2016-08-14}}</ref> Failure of an [[O-ring]] seal on the ''Challenger'' space shuttle's right solid rocket booster led to its [[Space Shuttle Challenger disaster|disintegration]] shortly after liftoff.

Solid rocket motors can present a handling risk on the ground, as a fully fueled booster carries a risk of accidental ignition. Such an accident occurred in the August 2003 [[Brazilian rocket explosion]] at the Brazilian [[Centro de Lançamento de Alcântara]] VLS rocket launch pad, killing 21 technicians.<ref>[http://www.astronautix.com/lvs/vls.htm VLS<!-- Bot generated title -->] {{webarchive|url=https://web.archive.org/web/20050812074304/http://www.astronautix.com/lvs/vls.htm |date=2005-08-12 }}</ref>