What technical challenges would be playing this LP in (actual) space?

Question

In the NYTimes article Third Man Records Sends a Vinyl Record Into Space an LP record player was designed and built to be flown in a balloon. It seems to have achieved only about 28.5 km which is definitely not "Space" proper. The Kármán line is generally considered to be 100km, and I can't find any example of a balloon even suggested to reach past 50 km.

Question: What would be the technical challenges that would have to be overcome to do it right - to play a vinyl record (of Carl Sagan "singing") in space?

The first two Sounds of Earth "gold records in space" were carried by Voyager 1 and Voyager 2 and Carl Sagan was a major proponent and influence there.

This current effort intends to put a record of Carl Sagan into space as a tribute to his tremendous positive influence on both the science of space exploration, and the public's understanding and appreciation of space exploration.

In the words of Professors Carl Sagan and Stephen Hawking:

Answer 1

If you want to do this in orbit, the main challenge is lack of gravity. A record player needs to apply a very specific amount of pressure onto the needle (about 1 gram), and just about every design uses an adjustable counterweight on the arm to achieve that. You'd have to add a spring that pulls or pushes the arm down. There were a few turntables designed to operate vertically, I don't know what mechanism they used to get the correct needle pressure, though. Might still be gravity.

Minor issues: you also need to push the record against the turntable to prevent it floating. And the torque from the turntable has to be handled by the spacecraft.

According to this article by the group that ran this mission, there was another issue: vinyl melts at the temperatures reached in space under full illumination by the sun:

As you rise higher and higher into the thinning atmosphere, temperature and increasing vacuum (lack of air) can cause issues. Vinyl has a rather low melting point (160°F), and without air to keep things cool, you could wind-up with a lump of melted plastic on your hands if a record is exposed to the sun for too long. Without air, things in direct sunlight can get very hot while things in shade can get very cold. This constant expansion and contraction can physically distort a vinyl record rendering it unplayable. so our turntable platter also served as a heat-sink in order to keep the vinyl cool in direct sunlight.” The gold plating on the record was another measure to keep the grooves from losing their shape.

The balloon didn't have a pressure capsule, so the record was played in the thin upper atmosphere. When you get high enough, the atmosphere becomes too thin to carry sound.

You also need a mechanism to keep the turntable and record safe during ascent and descent, you don't want the changing G-loading to damage the record or needle and pickup mechanism.

Answer 2

As hinted by @Hobbes there were turntables that operated vertically; in fact some of them were designed to work in any orientation and work under variable gravity conditions as they were portables designed to play EPs while moving. A veritable disc based Walkman pre-cassettes. I saw one in my younger days.

Here is a similar one on show from the 1970s:

They used a clutch to grip the disc (as is done with CDs and DVDs) and a spring loaded stylus to track the groove and apply the correct force. (It does, however, still have a tone arm but there is some built in compensation for lateral forces to enable it to resit the jolts and bumps of being used whilst carried and swung about. The only issue is the gyroscopic forces of the spinning disc to any space craft. Details of the operational mechanism is shown here:

This technology developed through the '80s with the Sharp RP-114:

or the Sony PS-F5 or PS-F9:

The other commercially available technology is the laser phonograph which also has a clutch grip and uses a non-contact laser. This therefore has no tone arm and is much more resistant to lateral forces:

I personally cannot see why Icarus went to trouble to re-invent what they could have bought on eBay to play the disc!

Something like these can then just be sent up as cargo in a Progress or SpaceX; perhaps it would amuse one of the sponsors to do so! :-)