:Lockheed X-17

{{Short description|Experimental solid-fuel research rocket}}

{{Redirect|X-17||X17 (disambiguation)}}

{{Infobox weapon

| is_missile = yes

| name = Lockheed X-17

| image = Lockheed X-17 horizontal.jpg

| image_size = 300

| caption =

| origin =

| type = Atmospheric reentry testing

| used_by =

| manufacturer = Lockheed Corporation

| unit_cost =

| propellant =

| production_date =

| service =

| engine = 1st stage:1× Thiokol XM20 Sergeant solid-fuel rocket, {{convert|48,000|lbf|kN|abbr=on}}
2nd stage: 3× Thiokol XM19 Recruit solid-fuel rocket, {{convert|33,900|lbf|kN|abbr=on}} (each)
3rd stage: 1× Thiokol XM19E1 Recruit solid-fuel rocket, {{convert|35,950|lbf|kN|abbr=on}}

| engine_power =

| weight =

| length = {{convert|40|ft|4|in|m|abbr=on}}

|height=

| diameter = 1st stage: {{convert|2|ft|7|in|m|abbr=on}}
2nd stage: {{convert|1|ft|5|in|m|abbr=on}}
3rd stage: {{convert|0|ft|9.7|in|m|abbr=on}}

| wingspan = {{convert|7|ft|7|in|m|abbr=on}}

| speed = Mach 14.5

| vehicle_range = {{convert|135|mi|km}}

| ceiling =

| altitude = {{convert|250|mi|km|abbr=on}}

|filling=

| guidance =

| detonation =

| launch_platform =

}}

The Lockheed X-17 was a three-stage solid-fuel research rocket to test the effects of high mach atmospheric reentry. The first stage of the X-17 carried the rocket to a height of {{convert|17|mi|km}} before burning out. The rocket would then coast on momentum to about {{convert|100|mi}} before nosing down for reentry. The second stage engine would then fire before jettisoning and igniting the third and final stage. On April 24, 1957, an X-17 reached a speed of {{convert|9000|mph}} at Patrick AFB.E. Emme, ed., Aeronautics and Astronautics, 1915–1960, p. 85. Ultimately the X-17 would be traveling towards Earth at up to Mach 14.5.

The X-17 was also used as the booster for the Operation Argus series of three high-altitude nuclear tests conducted in the South Atlantic in 1958.{{cite web|url=http://nuclearweaponarchive.org/Usa/Tests/Argus.html|title=Operation Argus tests|author=Carey Sublette|publisher=Nuclear Weapon Archive|date=20 September 1997|access-date=2008-01-11}}

The rocket engine used by the rocket is called 1.5KS35000, a solid propellant rocket engine designed by Thiokol. It was used in at least 23 launches.{{Cite web| last = McDowell| first = Jonathan| title = Stages| date = February 2007| url = http://www.planet4589.org/space/lvdb/sdb/Stages| access-date = 2010-03-02| archive-date = 2003-10-23| archive-url = https://web.archive.org/web/20031023221003/http://www.planet4589.org/space/lvdb/sdb/Stages| url-status = dead}}{{unreliable source?|date=August 2020}}[https://web.archive.org/web/20161228031022/http://astronautix.com/1/15ks35000.html 1.5KS35000]{{unreliable source?|date=August 2020}}