I hope you will never see this letter
Days before entering space, Yuri Gagarin writes a letter to be opened in the event of his death
The following letter can be found in Letters of Note: Space. Keep scrolling and you’ll find some other letters from that same book.

On this day in 1961, history was made when Yuri Gagarin, a humble man born to a carpenter and farmer in the Russian village of Klushino, bravely embarked on a journey that would forever change humanity's understanding of the cosmos. Leaving behind his loving wife, Valentina, and their two young daughters, Yelena and Galina, Gagarin boarded the Vostok 1 spacecraft at Baikonur Cosmodrome and became the first person to venture into space. Although he safely returned to Earth, Gagarin had prepared for a different outcome. Just two days prior to his historic flight, he penned a heartfelt letter to his family, to be read in the event of his untimely demise.
My dear beloved Valechka, Lenochka, and Galochka!
I decided to write you a few lines to share with you the joy and happiness that befell me today. Today the government commission decided to send me to the first spaceflight. I am so glad, dear Valiusha, and I want you to share this joy with me. An ordinary man, I have been trusted with an important national mission—to pave the first road into space!
I fully trust the technology. It should not fail. But it sometimes happens that a man falls and breaks his neck with no reason at all. Something may happen here too. I do not believe it will happen. But if it does, I ask all of you and especially you, Valiusha—do not be overcome with grief. Such is life. Please take care of our girls and love them just like I do. Please raise them as true human beings who are not afraid of the challenges of life. Raise them as people who will deserve to live a new communist society.
This letter is coming out a bit too gloomy. I do not believe in this bad outcome. I hope you will never see this letter, and I will feel ashamed for this momentary weakness. But if something happens, you must know the whole truth
When I was a child, I once read the words of Valerii Chkalov, “If you are to be, be the first.” So I try, and I will to the end. Valechka, I wish to dedicate this flight to the people of the new communist society, which we are already entering, to our great Motherland, and to our science
I hope in a few days we will be together again, and we will be happy. Valechka, please, do not forget my parents, and if you have an opportunity, help them somehow. Give them my warm greetings, and let them forgive me for not telling them about this, for they were not supposed to know. This is it, I think.
Good bye, my dears. I hug you tightly and kiss you.
Greetings
Your daddy and Yura
Also from the Letters of Note: Space book
“I am clearly suspect and not believable”
—Neil Armstrong responds to a conspiracy theorist“The proverbial ‘really good’ science-fiction movie”
—The birth of 2001: A Space Odyssey“I can be patient no longer”
—An aspiring astronaut pleads with JFK to be sent into space“Tears don’t flow the same in space”
—High above Earth on 12th September 2001, an astronaut writes home“E. T. has changed Tommy’s life”
—Various fans write to E. T. & Steven Spielberg
I hope you will never see this letter
“If you are to be, be the first.” Then I shall be the first to comment on this lovely letter! His bravery is inspiring. Thank you so much for sharing!
Very inspiring. From a time people looked at nation states in a positive enough way to sacrifice their lives for the benefit of all.
"We do things not because they are easy but because they are hard'. John Fitzgerald Kennedy