Editing Strategic Defense Initiative (section)

===Homing Overlay Experiment (HOE)===
[[File:ABM test vehicle (Homing Overlay Experiment).jpg|thumb|right|{{cvt|13|ft|m|0}} diameter web deployed by Homing Overlay Experiment]]
Given concerns about previous programs' nuclear-tipped interceptors, in the 1980s the US Army began studies about the feasibility of kinetic hit-to-kill vehicles, i.e. interceptors that would destroy incoming ballistic missiles by colliding with them.

The Homing Overlay Experiment (HOE) was the first such system tested by the Army, and the first successful hit-to-kill intercept of a mock ballistic missile warhead outside the Earth's atmosphere.<ref>{{cite web| url = https://www.lockheedmartin.com/en-us/news/features/history/hoe.html| title = Striking a Bullet with a Bullet: HOE|author= Lockheed Martin Corporation| date = March 28, 2022}}</ref>

HOE used a [[kinetic kill vehicle]] (KKV). The KKV was equipped with an infrared seeker, guidance electronics and a propulsion system. Once in space, the KKV could extend a folded structure similar to an umbrella skeleton of {{cvt|4|m|ft|order=flip}} diameter to enhance its effective cross section. This device was intended to destroy an ICBM reentry vehicle on collision.

Four test launches were conducted in 1983 and 1984 at [[Kwajalein Missile Range]] in the [[Marshall Islands]] using first two stages of [[Minuteman missile]], M55E1 and M56A1.<ref>{{Cite web |title=HOE |url=https://space.skyrocket.de/doc_lau/hoe.htm |access-date=2024-12-06 |website=Gunter's Space Page |language=en}}</ref> For each test a Minuteman missile was launched from [[Vandenberg Air Force Base]] in California carrying a single mock re-entry vehicle targeted for Kwajalein lagoon more than {{convert|4000|mi|km}} away.<ref>{{cite web| url = http://www.designation-systems.net/dusrm/app4/hoe.html| title = Directory of U.S. Military Rockets and Missiles * Appendix 4: Undesignated Vehicles * HOE; Andreas Parsch, 2003.}}</ref>

After test failures with the first three flight tests because of guidance and sensor problems, the DOD reported that the fourth and final test on June 10, 1984, was successful, intercepting the Minuteman RV with a closing speed of about {{cvt|6.1|km/s|mi/s|order=flip}} at an altitude of more than {{cvt|100|mi}}.<ref>{{cite encyclopedia|encyclopedia=Encyclopedia Astronautica   |title=Index: 1 |url=http://www.astronautix.com/4/404page.html |access-date=2024-07-05}}</ref>

Although the fourth test was described as a success, the ''New York Times'' in August 1993 reported that the HOE4 test was rigged to increase the likelihood of success.<ref>{{cite news|last1=Weiner|first1=Tim|title=Lies and Rigged 'Star Wars' Test Fooled the Kremlin, and Congress|url=https://www.nytimes.com/1993/08/18/us/lies-and-rigged-star-wars-test-fooled-the-kremlin-and-congress.html|access-date=December 22, 2015|newspaper=The New York Times|date=August 18, 1993}}</ref> At the urging of Senator [[David Pryor]], the [[General Accounting Office]] investigated the claims and concluded that though steps were taken to make it easier for the interceptor to find its target (including some of those alleged by the ''New York Times''), the available data indicated that the interceptor had been successfully guided by its onboard infrared sensors in the collision, and not by an onboard radar guidance system as alleged.<ref>{{cite web| url = http://archive.gao.gov/t2pbat2/152203.pdf| title = United States General Accounting Office, Ballistic Missile Defense: ''Records Indicate Deception Program Did Not Affect 1984 Test Results,'' GAO/NSIAD-94-219; Secretary of Defense Les Aspin, Press Briefing, September 9, 1993.}}</ref> Per the GAO report, the net effect of the DOD enhancements increased the infrared signature of the target vessel by 110% over the realistic missile signature initially proposed for the HOE program, but nonetheless the GAO concluded the enhancements to the target vessel were reasonable given the objectives of the program and the geopolitical consequences of its failure. Further, the report concluded that the DOD's subsequent statements before Congress about the HOE program "fairly characterize[d]" the success of HOE4, but confirmed that the DOD never disclosed to Congress the enhancements made to the target vessel.

HOE technology was later expanded into the Exoatmospheric Reentry-vehicle Interception System program.<ref>{{cite encyclopedia|encyclopedia=Encyclopedia Astronautica |url=http://www.astronautix.com/lvs/hoe.htm |title=SVC Lockheed HOE|archive-url=https://web.archive.org/web/20031026093929/http://astronautix.com/lvs/hoe.htm |archive-date=October 26, 2003 |access-date=March 10, 2006}}</ref>