This week saw the 50th anniversary of one of mankind's most dazzling achievements.
On April 12, 1961, the Russian cosmonaut Yuri Gagarin became the first human being in space and the first to orbit the earth in Vostok 1.
And at Sotheby's this week, the first Soviet test capsule that made it all possible sold for an astronomical sum.
Vostok 3KA-2 is among the most unique pieces of space memorabilia to ever appear on the market, and certainly one of the most important. It's also now the world's most expensive.
It sold for $2.88m, but as strange as it sounds I think the buyer may have got a bargain.
It is the only Vostok capsule to remain in private hands, with all others displayed in permanent Russian museum collections and unlikely to appear on the market in the near future.
It's truly unique and certain to grow in both historical stature and value over the years. As investments go, it could be out of this world.
I've always had a fascination for space memorabilia, and one look at the test capsule sold at Sotheby's reminds me why the area is so remarkable.
Gagarin was sent hurtling around the Earth in a radio-controlled capsule just 2.3m wide. To put it into perspective, that's smaller than a Mini Cooper!
Describing the capsule, David Redden, the head of Sotheby's special projects department said:
"It's an extraordinary object that makes [the history of the flight] real and also totally terrifying."
The sheer level of bravery and determination involved in each mission is something few of us can imagine, and the few men and women who have made that remarkable journey are rightly celebrated.
Even better, for collectors and investors it means that the signatures of astronauts are some of the most sought after on the planet.
The number of space collectors grows every year, and major auction houses across the world now conduct regular sales in what was once a very niche area.
But here's the thing: while the demand has increased substantially, the number of items available remains the same.
The figures are clear for all to see. According to the industry's PFC40 Index, photos signed by all three members of the Apollo 11 crew were valued at £2,000 in 2000. Today, they are worth closer to £8,950.
That's an increase of 347.5% in a 10 year period, and it's all down to the simple law of supply and demand.
This rare photo signed by all three Apollo 11 crew
members is currently available for £9,950.
Anniversaries like Gagarin's are celebrated across the world as important landmark moments for the human race.
The good news is, the global publicity they receive only serves to strengthen the space memorabilia market and prices continue to rise as they have done in recent years.
As more and more people become fascinated by the personal stories of bravery behind each space mission, a new generation of collectors is born.
And this can only mean great things for any of you with an Armstrong or two in your collection.
To find out more about investing in space memorabilia, you can read our special investment report pages. Or check out our space collectibles for sale. Alternatively, you can benefit from our expert advice by contacting us here:
+44 (0) 117 933 9500
All the best, until next week