Space autographs is an area of collecting and investing that has long experienced solid growth due to its inherent scarcity, but recent results indicate that the market is really coming into its own.
The PFC40 Index has tracked impressive growth of the most valuable autographs from 2000-2013 - and signatures from many of the leading astronauts have achieved significant results.
Neil Armstrong's autograph has shown growth of 22.8% per annum since 2000, and is likely to see further increases in value in the run-up to the 50th anniversary of the first manned Moon landing in 2019.
The same is true of a complete set of the Apollo 11 crew, which was worth £2,000 in 2000 and is now worth £11,000 ($17,695) in 2013 - an increase of 14.0% pa.
If that's not impressive enough, a collection of the signatures of the 12 astronauts to walk on the Moon grew 17.6% pa over the same time period and is currently worth £16,000 ($25,739).
Across the board we are seeing impressive auction results for space autographs, as rising consumer demand drives growth.
Last week, an Apollo 11 space-flown signed flag achieved $71,875 at Heritage Auctions' Space Exploration Signature Auction in Dallas, making it one of the most valuable flown flags ever auctioned.
An Apollo 11 flown cover featured in the same sale, realising $46,875.
Neil Armstrong's death last year has certainly heightened interest in this sector. The recent price growth may also have something to do with NASA's retirement of its space shuttle fleet in 2011, which essentially capped the market for flown memorabilia.
We have a variety of space memorabilia for sale, including some of the finest autographs on the market.
Sign up to our free weekly newsletter for the latest on collectibles and collecting.