NASA space shuttle Atlantis in Earth orbit is seen during a Rendezvous Pitch Maneuver, or back flip to enable space station crew members to take high resolution digital pictures of the shuttle's heat shield before docking for the last time with the International Space Station July 10, 2011 in space. Atlantis has embarked on a 12-day mission to the International Space Station where it will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts. This will be the final launch of the space shuttle program, which began on April 12, 1981 with the launch of Colombia. (Photo by NASA via Getty Images)

Space shuttle Atlantis launches from pad 39A on July 8, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Florida. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. (Photo by Bill Ingalls/NASA via Getty Images)

Police officers with a sniffer dog check a railway as the Soyuz MS spacecraft for the next International Space Station (ISS) crew of Kate Rubins of the U.S., Anatoly Ivanishin of Russia and Takuya Onishi of Japan is ready to be transported from an assembling hangar to the launchpad ahead of its launch scheduled on July 7, at the Baikonur cosmodrome in Kazakhstan July 4, 2016. (Photo by Shamil Zhumatov/Reuters)

Trainees of the Tianjiao Special Guard/Security Consultant bodyguard training camp watch their instructor use a scarf to cover a student's head during a demonstration of close-quarter combat skills at a special course on flight safety inside a scale model of a passenger jet at a flight attendant training centre on the outskirts of Beijing, March 18, 2014. Inspired by the missing Malaysia Airlines Flight MH370, the company wanted to emphasize the importance of aviation safety by teaching their trainees emergency evacuation procedures and close-quarter combat skills to handle situations such as natural disasters and plane hijacks, according to the company. (Photo by Jason Lee/Reuters)

Sikh devotee take part in Nagar Keertan procession on the occasion of Guru Gobind Singh birth anniversary in Allahabad, India on December 29, 2016. Guru Gobind Singh, born Gobind Rai (1666 – 1708), was the 10th Sikh Guru, a spiritual master, warrior, poet and philosopher. When his father, Guru Tegh Bahadur, was beheaded for refusing to convert to Islam, Guru Gobind Singh was formally installed as the leader of the Sikhs at age nine, becoming the last of the living Sikh Gurus. (Photo by Prabhat Kumar Verma/Pacific Press via ZUMA Wire/Rex Features/Shutterstock)

A young Sikh boy shouts religious slogans during a procession ahead of the birth anniversary of Guru Nanak in Jammu, India, Wednesday, November 21, 2018. The birth anniversary of Guru Nanak, founder of Sikhism and first Sikh guru, will be marked on Nov. 23. (Photo by Channi Anand/AP Photo)

A Sikh devotee carries on over-sized religious sword during a religious procession to celebrate the birth anniversary of the first Sikh Guru or master, Sri Guru Nanak Dev Ji, the founder of Sikhism in Amritsar, India, 05 November 2014. The birth anniversary of Guru Nanak Dev Ji will be observed on 06 November. (Photo by Raminder Pal Singh/EPA)

A child dressed in an imitation dress of army soldier enjoys a cold drink during a religious procession in Amritsar, India, 15 December 2015. The religious procession was taken out on the eve of the martyrdom day of the 9th Guru or Master of the Sikhs Sri Guru Tegh Bahadur Ji. Guru Tegh Bahadur was executed for not converting to Islam on the orders of Mughal Emperor Aurangzeb in Delhi in 1675 AD. The place of this occurrence is called Gurudwara Sis Ganj at Delhi. Guru Tegh Bahadur the youngest of the five sons of Guru Hargobind was born in Amritsar in 1621. (Photo by Raminder Pal Singh/EPA)