Traditionally, access to space has been extremely expensive. However, prices continue to fall with each passing decade as new technologies are developed and the sector becomes more commercialised.

SpaceX, for example, has demonstrated the potential of reusable rockets. Other advances in the future may include lighter materials, the use of inflatable modules, new fuel types, space planes, and more efficient engines. More speculatively, it may eventually be possible to deliver payloads to orbit with more exotic delivery methods such as space elevators or other non-rocket space launch systems.

As of 2020, although the cost to launch a payload to LEO has dropped considerably in recent decades, spaceflight remains a fairly costly endeavour. For example, a flight to LEO on a Falcon 9 rocket with a reused first stage costs about $50 million for a 15,600kg maximum reusable payload; meaning the price per kilo to LEO is about $3,205.

However, there is optimism that a significant reduction in cost to LEO could be achieved in the near future. SpaceX CEO Elon Musk claims that the company's Starship and Super Heavy launch system, currently in development, could eventually achieve a cost per kilogram to LEO of as little as $10:

Starship + Super Heavy propellant mass is 4800 tons (78% O2 & 22% CH4). I think we can get propellant cost down to ~$100/ton in volume, so ~$500k/flight. With high flight rate, probably below $1.5M fully burdened cost for 150 tons to orbit or ~$10/kg.

Before 1 January 2025, what will be the lowest cost, in inflation-adjusted dollars, to deliver a kilogram of mass to low Earth orbit (or beyond; suborbital flights are excluded) using any system that has actually completed at least one successful delivery at the stated price?

Inflation adjustment should be completed using a consumer price index method, with January 2020 taken as the reference month.