| 词条 | USA-224 |
| 释义 |
| name = USA-224 | image = | image_caption = | insignia = NROL49 patch.jpg | mission_type = Optical imaging | operator = US NRO | COSPAR_ID = 2011-002A | SATCAT = 37348 | mission_duration = | spacecraft = | spacecraft_type = KH-11 | spacecraft_bus = | manufacturer = Lockheed Martin | launch_mass = | launch_date = {{start-date|20 January 2011, 21:10:30|timezone=yes}} UTC | launch_rocket = Delta IV Heavy D352 | launch_site = Vandenberg SLC-6 | decay_date = | orbit_epoch = 5 August 2014, 00:12:52 UTC[1] | orbit_reference = Geocentric | orbit_regime = Low Earth | orbit_periapsis = {{convert|270|km|mi|sp=us}}[1] | orbit_apoapsis = {{convert|986|km|mi|sp=us}}[1] | orbit_inclination = 97.92 degrees[1] | orbit_period = 97.13 minutes[1] | apsis = gee }} USA-224, also known as NRO Launch 49 (NRO L-49), is an American reconnaissance satellite which was launched in 2011. It is a KH-11 optical imaging satellite, the fifteenth such spacecraft to be launched, and intended as a replacement of the USA-161 satellite launched in 2001. Project history and costAfter the failure of the Boeing led Future Imagery Architecture program in 2005, NRO ordered two additional legacy hardware KH-11s. Critics of the decision voiced concerns that each "exquisite-class" satellite would cost more than the latest Nimitz class aircraft carrier (CVN-77)[2] with its projected procurement cost of US$ 6.35 billion as of May 2005.[3] USA-224 - the first of these two - was completed by Lockheed US $ 2 billion under the initial budget estimate, and two years ahead of schedule.[4] USA-224 was launched atop a Delta IV Heavy rocket from Space Launch Complex 6 at the Vandenberg Air Force Base in California. The launch was conducted by United Launch Alliance, and was the first flight of a Delta IV Heavy from Vandenberg.[5] Liftoff occurred on January 20, 2011 at 21:10:30 UTC.[6] Upon reaching orbit, the satellite received the International Designator 2011-002A.[7] The early launch of USA-224, and operational changes to extend the lifetime of its predecessor USA-161, reduced the coverage gap caused by the end of the primary mission of USA-161 to just 33 days.[4] Of the fifteenth KH-11 satellite to be launched, USA-224 is a member of one of the later block configurations occasionally identified as being a separate system. Details of its mission and orbit are classified, however amateur observers have identified it as being in a Low Earth orbit and tracked it. Shortly after launch it was in an orbit with a perigee of {{convert|251|km}}, an apogee of {{convert|1023|km}} and 97.9 degrees of inclination, typical for an operational KH-11 satellite.[8] By April it was {{convert|260|by|987|km|mi}} at 97.93 degrees.[9] As of {{Orbit|epoch|5 August 2014}} it is in a {{convert|{{Orbit|perigee|270}}|by|{{Orbit|apogee|986}}|km|mi}} orbit with inclination of {{Orbit|inclination|97.92}} degrees and an orbital period of {{Orbit|period|97.13}} minutes See also{{Portal|Spaceflight}}
References1. ^1 2 3 4 {{cite web|url=http://www.heavens-above.com/orbit.aspx?satid=37348|title=USA 224 - Orbit|last=Peat|first=Chris|publisher=Heavens-Above|date=5 August 2014|accessdate=25 January 2015}} {{NRO Launches}}{{Orbital launches in 2011}}{{Keyhole}}2. ^{{cite web|url=http://www.defensenews.com/article/20090602/C4ISR02/906020302/Spy-sat-rescue|title=Spy- sat rescue: Obama's proposal to prevent a gap in coverage sparks debate, optimism|publisher=Defense News|first=Ben|last=Iannotta|date=2 June 2009}} 3. ^{{cite web|url=http://www.history.navy.mil/library/online/navycvn21.htm|title=Navy CVN-21 Aircraft Carrier Program: Background and Issues for Congress|publisher=Naval Historical Center|first=Ronald|last=O'Rourke|date=25 May 2005}} 4. ^1 {{cite web | title=10 Who Made a Difference in Space: Bruce Carlson, NRO Director|date=2011-09-07 |publisher= Space News / NRO | url=http://www.nro.gov/news/articles/2011/2011-01.pdf}} 5. ^{{cite web|url=http://www.spaceflightnow.com/delta/d352/padmods/|title=Delta 4-Heavy ready to serve nation from West Coast pad|date=19 January 2011|publisher=Spaceflight Now|first=Justin|last=Ray|accessdate=22 January 2011}} 6. ^{{cite web|url=http://www.spaceflightnow.com/delta/d352/status.html|title=Mission Status Center|work=Delta Launch Report|publisher=Spaceflight Now|first=Justin|last=Ray}} 7. ^{{cite web|url=http://www.zarya.info/Diaries/2011.php|title=Space events - 2011|first=Robert|last=Christy|work=Zarya|accessdate=22 January 2011|deadurl=yes|archiveurl=https://web.archive.org/web/20121019065644/http://www.zarya.info/Diaries/2011.php|archivedate=19 October 2012|df=}} 8. ^{{cite web|url=http://www.satobs.org/seesat/Jan-2011/0195.html|title=RE: NROL-49 search elements|publisher=SeeSat-L|first=Ted|last=Molczan|date=21 January 2011|accessdate=22 January 2011}} 9. ^{{cite web|url=http://www.satobs.org/seesat/Apr-2011/0337.html|title=NROL-34: NOSS 3-5 elements|publisher=Visual Satellite Observer|first=Ted|last=Molczan|date=2011-04-27}} 3 : Spacecraft launched in 2011|Spacecraft launched by Delta IV rockets|USA satellites |
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