OPS 3762

{{Short description|American reconnaissance satellite launched in 1964}}

{{Infobox spaceflight

| name = OPS 3762

| image =

| image_caption =

| mission_type = Radar imaging

| operator = US National Reconnaissance Office

| website =

| COSPAR_ID = 1964-087A

| SATCAT =

| mission_duration = 4 days

| spacecraft_bus = Agena-D

| spacecraft_type = Quill

| manufacturer = Boeing
Goodyear
ERIM
Lockheed (Agena)

| dry_mass =

| launch_mass = {{convert|1500|kg}}

| power =

| instruments = SLAR

| launch_date = {{start-date|21 December 1964, 19:08:56|timezone=yes}} UTC

| launch_rocket = TAT SLV-2A Agena-D 425

| launch_site = Vandenberg LC-75-1-1

| launch_contractor =

| deactivated = {{end-date|December 1964}}

| decay_date = 11 January 1965

| orbit_epoch = 21 December 1964, 14:12:00 UTC{{Cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1964-087A|title=NASA - NSSDCA - Spacecraft - Trajectory Details|website=nssdc.gsfc.nasa.gov|access-date=2018-05-02}}

| orbit_reference = Geocentric

| orbit_regime = Low Earth

| orbit_eccentricity = 0.00196

| orbit_periapsis = {{convert|238|km|mi|sp=us}}

| orbit_apoapsis = {{convert|264|km|mi|sp=us}}

| orbit_inclination = 70.1 degrees

| orbit_period = 89.4 minutes

| apsis = gee

}}

OPS 3762, also known as FTV-2355, was an American reconnaissance satellite which was launched in 1964.{{cite web|last=McDowell|first=Jonathan|author-link=Jonathan McDowell|title=Satellite Catalog|url=http://planet4589.org/space/log/satcat.txt

|publisher=Jonathan's Space Page|access-date=9 June 2010}} It was the first radar imaging satellite to be launched, and the only Quill spacecraft to fly. Its mission was to demonstrate radar imaging techniques for future missions. However, the programme was cancelled before any more satellites were launched.{{cite web|last=Day|first=Dwayne A.|title=Flight of a feather: the QUILL radar satellite|url=http://www.thespacereview.com/article/1631/1|publisher=The Space Review|access-date=9 June 2010|date=24 May 2010}}

OPS 3762 was successfully launched aboard a Thrust Augmented Thor SLV-2A Agena-D carrier rocket, flying from Launch Complex 75-1-1 at the Vandenberg Air Force Base. The launch, which was the last orbital launch of the year, occurred at 19:08:56 UTC on 21 December 1964, and successfully placed the spacecraft into the low Earth orbit in which it conducted its mission.{{cite web|last=McDowell|first=Jonathan|title=Launch Log|url=http://planet4589.org/space/log/launchlog.txt|publisher=Jonathan's Space Page|access-date=9 June 2010}} Owing to concerns that using radar over the Soviet Union may have been seen as provocative, OPS 3762 conducted imaging tests over the Northwestern United States instead.{{cite web|last=Richelson|first=Jeffrey T.|title=Ups and Downs of Space Radars|url=http://www.airforce-magazine.com/MagazineArchive/Pages/2009/January%202009/0109radars.aspx|archive-url=https://web.archive.org/web/20110712042706/http://www.airforce-magazine.com/MagazineArchive/Pages/2009/January%202009/0109radars.aspx|url-status=usurped|archive-date=July 12, 2011|publisher=airforce-magazine.com|access-date=9 June 2010|date=January 2009}}

OPS 3762 was a {{convert|1500|kg}} spacecraft, based on the Agena-D which also served as the upper stage of its carrier rocket.{{cite web|last=Krebs|first=Gunter|title=Quill|url=http://space.skyrocket.de/doc_sdat/quill.htm|publisher=Gunter's Space Page|access-date=9 June 2010}} It operated for four days. Its orbit had a perigee of {{convert|208|km}}, an apogee of {{convert|222|km}}, 70 degrees of inclination, and an orbital period of 88.8 minutes. Its side looking airborne radar produced images, which were returned in a KH-4 film capsule at the end of the mission.{{cite web|title=Space Radars|url=http://www.docstoc.com/docs/41903914/SPACE-RADARS|publisher=docstoc|access-date=9 June 2010}} OPS 3762 itself remained in orbit until 11 January 1965, when its orbit decayed and it reentered the atmosphere. OPS 3762 completed its mission successfully.{{cite web|last=Day|first=Dwayne A.|title=Radar love: the tortured history of American space radar programs|url=http://www.thespacereview.com/article/790/1|publisher=The Space Review|access-date=9 June 2010|date=22 January 2007}}