NASA’s administrator expects SpaceX founder Elon Musk to self-quarantine after the billionaire tweeted he twice tested positive for the coronavirus.

Jim Bridenstine made the comments on social media after earlier tweets from Musk that he also tested COVID negative, after four straight tests using the same equipment.

Musk is also the founder of Tesla.

On Thursday, U.S. public health officials announced more than 160,000 new coronavirus cases, the first day over 150,000 since the pandemic began, according to The New York Times.

Hospitalizations for COVID-19 also set a record Thursday, climbing to 67,096, according to the Covid Tracking Project. It was the third straight day of record numbers.

Deaths are rising, too, with more than 1,000 on average each day.

The virus is blamed for more than 242,000 deaths and over 10.5 million confirmed infections in the U.S., with the country facing what health experts say will be a dark winter because of disregard for mask-wearing and other precautions, the onset of cold weather and crowded holiday gatherings.

Deaths per day in the U.S. have soared more than 40% during the last two weeks, from an average of about 790 to more than 1,100 as of Wednesday, the highest level in three months.

That is still well below the peak of about 2,200 deaths per day in late April, in what may reflect the availability of better treatments and the increased share of cases among young people, who are more likely than older ones to survive a bout with COVID-19.

But newly confirmed cases per day in the U.S. have skyrocketed more than 70% during the last two weeks, reaching an average of about 127,000 — the highest on record. And the number of people hospitalized with the virus hit a high of more than 65,000.