Question: What year was Sergei Korolev arrested?
About the article "Space Race", section "Rocket teams assembled".

Candidate passages:
On 22 June 1938, during the Great Purge, Korolev was arrested by the NKVD after being denounced by Ivan Kleymenov, Georgy Langemak, and Valentin Glushko.
He was accused of deliberately slowing the work of the research institute, and following torture in the Lubyanka prison to extract a confession, was tried and sentenced to ten years in a Gulag work camp.
Korolev later learned that he had been denounced by Glushko, and this may have been the cause of the lifelong animosity between the two men.
Glushko and Korolev had reportedly been denounced by Andrei Kostikov, who became the head of RNII after its leadership was arrested (Kostikov was ousted a few years later over accusations of budget irregularities).
Believing that his arrest was a mistake, Korolev wrote many appeals to the authorities, including Stalin himself.
Following the fall of the NKVD head, Nikolai Yezhov, the new chief Lavrenti Beria chose to retry Korolev on reduced charges in 1939, but by that time Korolev was on his way from prison to a gulag camp in the far east of Siberia, where he spent several months in a gold mine in the Kolyma area before word reached him of his retrial.
In the work camp, conditions were extremely rough – inadequate food, shelter, clothing, work assignments, and thousands of prisoners dying each month.
Towards the end of 1939 he was sent back to Moscow, but he had already sustained injuries and had lost most of his teeth due to the labor camp's brutal conditions.
When he reached Moscow, Korolev's sentence was reduced to eight years, which he did not have to serve in a labor camp.
He rarely talked about his experience in the Gulag.
Other members of the RNII had also been arrested.
Kleymenov and Langemak were executed, leaving Korolev very fortunate to have even survived.
The rocket program was set back for years and fell far behind the rapid progress taking place in Germany.
Korolev was assigned to a "sharashka", a penitentiary for intellectuals and the educated.
These were effectively slave-labor camps where scientists and engineers worked on projects assigned by the Communist party leadership.
The "Central Design Bureau 29" (CKB-29, ЦКБ-29) of the NKVD, served as Tupolev's engineering facility, and Korolev was brought here to work for his old mentor.
During World War II, this sharashka designed both the Tupolev Tu-2 bomber and the Petlyakov Pe-2 dive bomber.
The group was moved several times during the war, the first time to avoid capture by advancing German forces.
In 1942 Korolev managed to be moved to the "sharashka" of Kazan under Valentin Glushko, which designed rocket-assisted take off boosters for aircraft.
Korolev was kept in the sharashka and isolated from his family until 1944.
He lived under constant fear of being executed for the military secrets he possessed, and was deeply affected by his time in the camp, becoming reserved and cautious.
On 27 June 1944, Korolev – along with Tupolev, Glushko and others – was finally discharged by special government decree, although the charges against him were not dropped until 1957.
The design bureau was handed over from NKVD control to the government's aviation industry commission.
Korolev continued working with the bureau for another year, serving as deputy designer under Glushko and studying various rocket designs.
In 1944, Korolev and Glushko designed the RD-1 KhZ auxiliary rocket motor tested in an unsuccessful fast-climb Lavochkin La-7R. 
Korolev continued his schooling at the Odessa Building Trades School (Stroyprofshkola No.
1) where he received vocational training in carpentry and in various academics.
However his primary interest was in aeronautical engineering, perhaps due to the influence of an air show he had enjoyed back in 1913.
Korolev began designing a glider plane during his free time while he studied for his graduation exams at the vocational school.
He made an independent study of flight theory, and also worked in the local glider club.
A detachment of military seaplanes had been stationed in Odessa, and Korolev took a keen interest in their operations.
In 1923 he joined the Society of Aviation and Aerial Navigation of Ukraine and the Crimea (OAVUK).
By joining the Odessa hydroplane squadron he had his first flying lesson, and also had many opportunities to fly as a passenger.
In 1924 he personally designed a glider called the K-5, which was accepted by the OAVUK as a construction project.
At about the same time he also trained to become accomplished as a gymnast, but his academic work began to suffer from his distractions with these other interests.
Korolev had hoped to go to Moscow and attend the Zhukovsky Academy.
However, his qualifications did not meet the academy’s standards.
To pursue his interests, he decided in 1924 to attend the Kiev Polytechnic Institute as they had an aviation branch.
In Kiev he lived with his uncle Yuri, and he earned money to pay for his courses by performing odd jobs.
His curriculum was technically oriented, and included various engineering, physics and mathematics classes.
He met and became attracted to a classmate, Xenia Vincentini, who would later become his first wife.
In 1925 he was accepted into a limited class on glider construction.
He was allowed to fly the training glider on which he worked, but ended up with two broken ribs.
He continued with his courses, completing his second year in 1926.
In July of that year he was accepted into the Bauman Moscow State Technical University (MVTU, BMSTU).
Until 1929, Korolev studied specialized topics in aviation at the school.
He lived with his family, who had moved to Moscow, in what were typical but crowded conditions.
In addition to his studies, Korolev had more opportunities to fly gliders and powered aircraft, and he revelled in the experience.
He also designed a glider in 1928, and flew it in a competition the next year.
During 1929 the Communist Party had decreed that the education of engineers be accelerated to meet the country's urgent need for their skills.
Korolev could obtain a diploma by producing a practical aircraft design, and had the design completed and approved by the end of the year.
His advisor was none other than Andrei Tupolev. 
Sergei Alexandrovich Korolev (1874-1932) was a Russian microbiologist and professor and the founder of industrial microbiology.
He was one of the founders of the Soviet dairy industry at the beginning of the 20th century.
Through the work of Korolev, his colleagues and students, the microbiology of milk and dairy products was developed considerably. 
Having graduated, Korolev began work at an aircraft design bureau designated OPO-4, or 4th Experimental Section.
It was headed by a Frenchman named who emigrated to USSR in the 1920s and included a number of the Soviet Union's best designers.
He did not stand out in this group, but while so employed he also worked privately on a pair of personal design projects.
One of these was a glider design that was capable of performing aerobatics.
By 1930 he became a lead engineer on the Tupolev TB-3 heavy bomber.
In 1930, Korolev finally earned his pilot's license.
The next year, on 6 August, he was wed to Xenia Vincentini, a woman he had been courting since 1924.
He had proposed marriage to her back then, but she declined as she wanted a higher education.
It was during 1930 that Korolev became interested in the possibilities of liquid-fueled rocket engines.
As his interest was primarily in aircraft, he saw the potential for use of these engines to propel airplanes.
It was one day, while he was flying around, that he looked up and wondered about what was beyond the point of where he could take his plane and how he could get there.
Many believe this was the start of his interest in space.
In 1931, together with Friedrich Zander, a space travel enthusiast, he participated in the creation of the Group for the Study of Reactive Motion (GIRD), one of the earliest state-sponsored centers for rocket development in the USSR.
In May 1932 Korolev was appointed chief of the group.
During the following years, GIRD developed three different propulsion systems, each more successful than the last.
In 1932, the military became interested in the efforts of this group, and began providing some funding.
In 1933, the group accomplished their first launch of a liquid-fueled rocket, which was called GIRD-X (not GIRD-09 as often cited; hybrid GIRD-09 used solid gasoline and liquid oxygen) .
This was just seventeen years after colonel Ivan Platonovich Grave's first launch in 1916 (patent in 1924).
In 1934, Korolev published the work "Rocket Flight in Stratosphere".
With growing military interest in this new technology, it was decided by the government in 1933 to merge GIRD with the Gas Dynamics Laboratory (GDL) in Leningrad.
The merger created the Jet Propulsion Research Institute (RNII), headed up by the military engineer Ivan Kleimenov and containing a number of enthusiastic proponents of space travel, including Valentin Glushko.
Korolev became the Deputy Chief of the institute.
He led the development of cruise missiles and a manned rocket-powered glider.
On 10 April 1935, Korolev's wife gave birth to their daughter, Natasha.
In 1936 they were able to move out of his parents' home and into their own apartment.
Both Korolev and his wife had careers, and Sergey always spent long hours at his design office.
By now he was chief engineer at RNII.
The RNII team continued their development work on rocketry, with particular focus on the area of stability and control.
They developed automated gyroscope stabilization systems that allowed stable flight along a programmed trajectory.
Korolev was a charismatic leader who served primarily as an engineering project manager.
He was a demanding, hard-working man, with a disciplinary style of management.
Korolev personally monitored all key stages of the programs and paid meticulous attention to detail. 
212 was a kind of soviet cruise missile developed in 1936 by Sergei Korolev.
It was tested twice before being cancelled in 1939.
The design was completed in August 2, 1936, and consisted of a rocket with wings which launched from a catapult.
The catapult was tested twice in November, 1936, using a mock-up of the missile; both tests failed.
It was then decided to use a Tupolev TB-3 aircraft as launch platform.
The first test was done in May 27, 1938.
Korolev was arrested one month later, but the project continued without him.
In January 10, 1938 it was decided to no longer use Valentin Glushko's ORM-65 rocket engine due to problems with the control system and some explosions.
At that time the name of the missile was changed to "803".
During 1939 there were two more tests, failing again due to the control system.
The project was finally abandoned.