Question: What date was the manufacturing company who developed the sounding rocket named Zenit-C renamed?

Context paragraphs:
Rheinmetall Air Defence: Rheinmetall Air Defence AG is a division of German armament manufacturer Rheinmetall, created when the company's Oerlikon Contraves unit was renamed on 1 January 2009 and integrated with Rheinmetall's other air-defence products.  Oerlikon Contraves was a Swiss anti-aircraft artillery manufacturer famous for its adaptation of the 1916 20 mm Becker as the Oerlikon 20 mm autocannon design, which was used in the Second World War and still in use today.  Copies and derivatives of these designs were made by German, French, British and Japanese weapon manufacturers.  Oerlikon Contraves was purchased by Rheinmetall, a German armament manufacturer, in 1999.

FalconLaunch: FalconLaunch is the name of a small sounding rocket development program at the United States Air Force Academy.  The program falls beneath the purview of the Academy Department of Astronautics.  The program has two basic purposes: first, to educate cadets in the practice of space systems engineering; and two, to produce a sounding rocket each year.  The original technological goal of the program was to develop a light (~100 lb) sounding rocket capable of delivering a small (~5 lb) payload to the edge of space (~100 km).  Senior-level cadets handle most aspects of the program.

RTV-G-4 Bumper: The RTV-G-4 Bumper was a sounding rocket built by the United States.  It was a combination of the German V-2 rocket and the WAC Corporal sounding rocket and was used to study problems pertaining to two-stage, high-speed rockets.

Mesquito: The Mesquito is a new sounding rocket vehicle developed for the NASA Sounding Rocket Program on Wallops Island, Virginia.  The "skeeter" (from similarity of name to mosquito) was developed to provide rocket-borne measurements of the mesospheric region of the upper atmosphere.  An area of great science interest is in the 82–95 km region, where the conventional understanding of atmospherics physics is being challenged.

M-100 (rocket): The M-100 was a two-stage Soviet sounding rocket.  As some 6640 of these rockets were built between 1957 and 1990, it was the most used sounding rocket model ever.  Payloads typically radioed science data to ground while descending by parachute.  Cross-calibrations with Western counterparts has allowed data's inclusion in global databases.  Unfortunately, production ceased on demise of Soviet Union.

Terrier Orion: The Terrier Orion sounding rocket is a combination of the Terrier booster rocket with the Orion rocket used as a second stage.  This spin stabilized configuration is most often used by the Goddard Space Flight Center, who operate out of the Wallops Flight Facility for sounding rocket operations.  The system supports payloads ranging from 200 to , and is capable of achieving altitudes as high as 200 km , but at least 80 km , depending on payload size.

Kartika I: Kartika I is an Indonesian sounding rocket built by LAPAN, AURI, Bandung Institute of Technology, and Pindad under PRIMA (Sounding and Military Rocket Development Project/"Indonesian: Proyek Pengembangan Roket Ilmiah dan Militer Awal") project.  This rocket was launched on August 14, 1964 in LAPAN Rocket Launching Station Pameungpeuk, West Java, becoming the first sounding rocket ever launched in Indonesia, and the second in Asia after Japan through Kappa Rocket.

Zenit-C: Zenit-C was a sounding rocket developed from Oerlikon Contraves (today Rheinmetall Air Defence in Switzerland.  The Zenit was a single-step rocket with a length of 5.6 meters, a diameter of 0.42 meter and a takeoff weight of 610 kilograms.  Propelled by a solid-propellant engine which supplied a thrust between 45 kN at launch and 22 kN in flight, the Zenit could carry a payload of 25 kilograms to a height of 210 km or a payload of 130 kilograms to a height of 115 km.  At its maiden flight on October 27, 1967 at Salto di Quirra the Zenit topped 145 km.  The Zenit was later launched only twice — once on July 30, 1971 at Salto di Quirra with a British Cuckoo rocket as a starting stage and once on December 13, 1973 at Andøya likewise with a "Cuckoo" starting stage.  Oerlikon used the knowledge from the Ground to Air Missile RSE Kriens for the Zenit.

VS-30: The VS-30 is a Brazilian sounding rocket, derived from the Sonda 3 sounding rocket's first stage.  It consists of a single, solid-fuelled stage, and has been launched from Alcântara, Maranhão, and Parnamirim, Rio Grande do Norte, in Brazil, and Andøya in Norway.

Nike-Cajun: The Nike-Cajun was a two-stage sounding rocket built by combining a Nike base stage with a Cajun upper stage.  It was launched 714 times between 1956 and 1976 and was the most frequently used sounding rocket of the western world.  The Nike Cajun had a launch weight of 698 kg (1538 lb), a payload of 23 kg (51 lb), a launch thrust of 246 kN (55,300 lbf) and a maximum altitude of 120 km (394,000 ft).  It had a diameter of 42 cm (1 ft 4½ in) and a length of 7.70 m (25 ft 3 in).  The maximum speed of the Nike-Cajun was 6760 km/h .

Supporting paragraphs: Zenit-C Rheinmetall Air Defence
Answer: 1 January 2009