Tesla CEO Elon Musk recently promised on social media that future Tesla vehicles will have the ability to fly while announcing the same day that Tesla will no longer be producing certain popular Model S vehicles.

In a recent series of tweets, Tesla CEO Elon Musk claimed that future Tesla vehicles will have the ability to fly. Replying to a tweet in which one Twitter user jokingly implied that Tesla vehicles in the year 2022 will look something like a flying DeLorean car from Back to the Future, Musk stated that “the new Roadster will actually do something like this.”

The new Roadster will actually do something like this https://t.co/fIsTAYa4x8 — Elon Musk (@elonmusk) January 9, 2019

Popular YouTube tech reviewer and Tesla owner Marques Brownlee (known by his YouTube handle of MKBHD) replied to Musk’s tweet saying that he feels as if Musk wasn’t joking in his initial tweet and actually believes that Tesla Roadsters will be flying in 2022. Musk replied that he was indeed serious:

I’m not. Will use SpaceX cold gas thruster system with ultra high pressure air in a composite over-wrapped pressure vessel in place of the 2 rear seats. — Elon Musk (@elonmusk) January 9, 2019

Brownlee did not appear skeptical of Musk’s claim and instead stated that he loved the idea, Musk then said that one of the benefits of this idea is that the Roadster could accelerate “at the limit of human endurance.”

Plus, you can basically accelerate at the limit of human endurance — Elon Musk (@elonmusk) January 9, 2019

When asked if the car would be able to drive a quarter of a mile in less than eight seconds, Musk replied: “No problem.”

No problem — Elon Musk (@elonmusk) January 9, 2019

But a few hours later, Musk returned to Earth when tweeted that Tesla will no longer be taking orders for the popular 75 kWh battery version of their Model S and Model X vehicles, with the 100 kWh battery version becoming the standard model:

Starting on Monday, Tesla will no longer be taking orders for the 75 kWh version of the Model S & X. If you’d like that version, please order by Sunday night at https://t.co/46TXqRJ3C1 — Elon Musk (@elonmusk) January 9, 2019

Recently, John Engle, President of Almington Capital, noted that as Tesla manages to fix some of its production issues, resulting in a 13 percent rise in Model 3 car deliveries in the fourth quarter, the company now faces a new challenge — lack of demand. While Tesla has still failed to meet its previously projected production goal of 5,000 Model 3 vehicles a week, their delivery of 63,150 Model 3 vehicles in the fourth quarter was a solid improvement. But as the company closes up a supposed backlog of 450,000 vehicles, cracks are beginning to appear.

According to what Engle says are Tesla’s reported numbers, approximately 7,000 Model 3 vehicles are being kept in storage and without buyers. This amounts for approximately two weeks worth of vehicles at Tesla’s current production rate. Combined with the $2,000 price slash across all of the company’s vehicles in an attempt to offset the phase-out of a $7,500 tax credit for electric vehicle owners, and a general drop in Model 3 sales, it’s understandable why many investors believe that the coming year will show a lack of demand for Tesla’s vehicles. Even as the company plans to expand their European sales, Goldman Sachs sees an imminent “lull in demand.”