{"id":22654,"date":"2019-03-30T12:00:00","date_gmt":"2019-03-30T12:00:00","guid":{"rendered":"https:\/\/astronautix.com\/?astx_entry=polarbear"},"modified":"2026-10-22T18:43:54","modified_gmt":"2026-10-22T18:43:54","slug":"polarbear","status":"publish","type":"astx_entry","link":"https:\/\/astronautix.com\/p\/polarbear.html","title":{"rendered":"Polar Bear"},"content":{"rendered":"\n<p>American earth magnetosphere satellite built by JHU\/APL for USAF STP (Space Test Program), USA. Used Transit-Bus. One launch, 1986. Also known as STP P87-1, a military mission designed to study communications interference caused by solar flares and increased auroral activity.<\/p>\n<p>Polar Beacon and Research satellite. The data from the mission complemented data taken by its predecessor, HILAT. The core vehicle was a Transit navigational satellite that was retrieved from the Smithsonian's National Air &amp; Space Museum where it had been on display for 8 years. <em>Spacecraft:<\/em> Gravity gradient stabilized by deployable boom with tip mass.4 small deployable solar arrays. <em>Payload:<\/em> Auroral Imaging Remote Sensor imaged the aurora borealis; Beacon Experiment monitored ionospheric propagation over the poles.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>American earth magnetosphere satellite built by JHU\/APL for USAF STP (Space Test Program), USA. Used Transit-Bus. One launch, 1986. Also known as STP P87-1, a military mission designed to study communications interference caused by solar flares and increased auroral activity.<\/p>\n","protected":false},"template":"","meta":{"inline_featured_image":false,"bs_cache_bypass_cache":0},"astx_kind":[8],"astx_nation":[5],"astx_family":[78,98,76],"class_list":["post-22654","astx_entry","type-astx_entry","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/astronautix.com\/wp-json\/wp\/v2\/astx_entry\/22654","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/astronautix.com\/wp-json\/wp\/v2\/astx_entry"}],"about":[{"href":"https:\/\/astronautix.com\/wp-json\/wp\/v2\/types\/astx_entry"}],"wp:attachment":[{"href":"https:\/\/astronautix.com\/wp-json\/wp\/v2\/media?parent=22654"}],"wp:term":[{"taxonomy":"astx_kind","embeddable":true,"href":"https:\/\/astronautix.com\/wp-json\/wp\/v2\/astx_kind?post=22654"},{"taxonomy":"astx_nation","embeddable":true,"href":"https:\/\/astronautix.com\/wp-json\/wp\/v2\/astx_nation?post=22654"},{"taxonomy":"astx_family","embeddable":true,"href":"https:\/\/astronautix.com\/wp-json\/wp\/v2\/astx_family?post=22654"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}