Question: What country is Riverside, Grant County, in the state where the headquarters of White Knight Two's operator is located a part of?

full_context: Document 1: Israel: The Israeli Space Agency coordinates all Israeli space research programs with scientific and commercial goals. In 2012 Israel was ranked ninth in the world by the Futron's Space Competitiveness Index. Israel is one of only seven countries that both build their own satellites and launch their own launchers. The Shavit is a space launch vehicle produced by Israel to launch small satellites into low earth orbit. It was first launched in 1988, making Israel the eighth nation to have a space launch capability. Shavit rockets are launched from the spaceport at the Palmachim Airbase by the Israeli Space Agency. Since 1988 Israel Aerospace Industries have indigenously designed and built at least 13 commercial, research and spy satellites. Some of Israel's satellites are ranked among the world's most advanced space systems. In 2003, Ilan Ramon became Israel's first astronaut, serving as payload specialist of STS-107, the fatal mission of the Space Shuttle Columbia.
Document 2: Riverside, Umatilla County, Oregon: Riverside is a census-designated place (CDP) in Umatilla County, Oregon, United States. The population was 189 at the 2000 census. It is part of the Pendleton–Hermiston Micropolitan Statistical Area.
Document 3: Space Race: Von Braun and his team were sent to the United States Army's White Sands Proving Ground, located in New Mexico, in 1945. They set about assembling the captured V2s and began a program of launching them and instructing American engineers in their operation. These tests led to the first rocket to take photos from outer space, and the first two-stage rocket, the WAC Corporal-V2 combination, in 1949. The German rocket team was moved from Fort Bliss to the Army's new Redstone Arsenal, located in Huntsville, Alabama, in 1950. From here, von Braun and his team would develop the Army's first operational medium-range ballistic missile, the Redstone rocket, that would, in slightly modified versions, launch both America's first satellite, and the first piloted Mercury space missions. It became the basis for both the Jupiter and Saturn family of rockets.
Document 4: Riverside, Delaware: Riverside is an unincorporated community in New Castle County, Delaware, United States. Riverside is located at the intersection of U.S. Route 13 Business and Harvey Road southwest of Claymont.
Document 5: Airport: Most of the world's airports are owned by local, regional, or national government bodies who then lease the airport to private corporations who oversee the airport's operation. For example, in the United Kingdom the state-owned British Airports Authority originally operated eight of the nation's major commercial airports - it was subsequently privatized in the late 1980s, and following its takeover by the Spanish Ferrovial consortium in 2006, has been further divested and downsized to operating just five. Germany's Frankfurt Airport is managed by the quasi-private firm Fraport. While in India GMR Group operates, through joint ventures, Indira Gandhi International Airport and Rajiv Gandhi International Airport. Bengaluru International Airport and Chhatrapati Shivaji International Airport are controlled by GVK Group. The rest of India's airports are managed by the Airports Authority of India.
Document 6: Three Rivers Petroglyph Site: There are over 21,000 petroglyphs at the Three Rivers Petroglyph Site at Three Rivers, New Mexico, located midway between Tularosa and Carrizozo in Otero County on Highway 54. Many of the petroglyphs can be easily viewed from a trail open to the public which winds through the rocks for about one mile. The petroglyphs are thought to be the product of the Jornada Mogollon people between about 1000 and 1400 AD. The site is protected and maintained by the Bureau of Land Management.
Document 7: Virgin Galactic: Virgin Galactic is a British spaceflight company within the Virgin Group. It is developing commercial spacecraft and aims to provide suborbital spaceflights to space tourists and suborbital launches for space science missions. Virgin Galactic plans to provide orbital human spaceflights as well. SpaceShipTwo, Virgin Galactic's suborbital spacecraft, is air launched from beneath a carrier airplane known as White Knight Two.
Document 8: Entwicklungsring Nord: West Germany provided 53.3% of Spacelab's cost and fulfilled 52.6% of all Spacelab work contracts. ERNO VFW Fokker, in competition with MBB, submitted the winning design, and became the prime contractor for Spacelab. MBB in 1981 took over VFW Fokker. The ERNO plant in Bremen continued as the headquarters for Spacelab design, production management, component testing, and assembly. It became a part of EADS Astrium Space Transportation, then Airbus Defence and Space, then Airbus Safran Launchers, and now ArianeGroup.
Document 9: Riverside, Grant County, New Mexico: Riverside is an unincorporated community in Grant County, New Mexico, United States. It lies on the left (east) bank of the Gila River and on both sides of U.S. Route 180 in southwestern New Mexico, by road south of Cliff, New Mexico.
Document 10: Oceanic (unfinished ship): The RMMV "Oceanic" (Royal Mail Motor Vessel) was the planned name of an unfinished ocean liner that was partially built by Harland and Wolff for the White Star Line. The ship was to have been the first -long ocean liner. It was intended to be the largest ocean liner for the White Star Line, thus it would have been larger than the earlier White Star giants, "Olympic", "Titanic", "Britannic", and "Majestic."
Document 11: VMS Eve: VMS "Eve" is the first, and so far only, White Knight Two, built by Scaled Composites for Virgin Galactic. The "VMS" prefix stands for "Virgin Mothership".
Document 12: Lockheed Martin VH-71 Kestrel: The Lockheed Martin VH-71 Kestrel was a variant of the AgustaWestland AW101 (formerly the EH101) that was being manufactured to replace the United States Marine Corps' Marine One U.S. Presidential transport fleet. Originally marketed for various competitions as the "US101", it was developed and manufactured in the US by a consortium headed by Lockheed Martin, consisting of Lockheed Martin Systems Integration – Owego (LMSI), AgustaWestland and Bell Helicopter.
Document 13: New Mexico Spaceport Authority: The state of New Mexico has privatized the operations of Spaceport America; the spaceport will be operated by Virgin Galactic, a component of the Virgin Group of global companies operated by Sir Richard Branson. While the Spaceport Authority will exercise public-sector oversight, Virgin Galactic will be the "anchor tenant" of the spaceport.
Document 14: Virgin Games: Virgin Games is a company that provides online gambling services, predominantly in the United Kingdom, that licences the brand from Sir Richard Branson's Virgin Enterprises.
Document 15: Riverside, Nevada: Riverside is an unincorporated community in northeastern Clark County, Nevada, United States. It is located on the Virgin River near Bunkerville and Mesquite; the town is accessible via Nevada State Route 170, which connects all three towns. Riverside is the site of the highway bridge over the river.
ground_truth: U.S.
sub_queries: White Knight Two >> operator Answer: Virgin Galactic
Virgin Galactic >> headquarters location Answer: New Mexico
Riverside, Grant County, New Mexico >> country Answer: U.S.