President Biden named Bill Nelson, a former Florida senator, to head NASA on Friday.

In a White House statement announcing the nomination, Mr. Nelson said: “He was known in the Senate as a point of contact for our nation’s space program.”

The selection raised concerns that the Biden administration might restore a more traditional space program, relying on large, older aerospace companies like Boeing and Lockheed Martin, rather than more nimble newcomers like SpaceX.

Many people in the field had also hoped that Mr. Biden would nominate the first woman to serve as an administrator.

“Given the allegedly many qualified and talented women being considered, he has great confidence in his former Senate colleague,” said Lori Garver, a former NASA deputy administrator during the Obama administration.

Mr Nelson, who lost his offer for re-election for a fourth term in 2018, was a retired astronaut and long-time NASA supporter in the Senate. He was also a chief architect of the 2010 Act that directed NASA to develop a heavy-lift rocket known as the Space Launch System. Despite having a successful engine test Thursday, the rocket is years behind schedule and billions of dollars over budget.

This has challenged the agency’s ability to achieve goals in space in the years to come. Some wonder if Mr. Nelson, a passionate supporter of the Space Launch System, would be willing to change course when cheaper commercial alternatives such as the StarsX starship, which is currently under development, become available.

“It will be harder for Nelson to leave SLS than it probably would be for anyone else,” said Ms. Garver. “Because he had to acknowledge what he did was not in the agency’s best interests.”

Mr Nelson was initially skeptical of NASA’s plans to turn to commercial companies to get NASA astronauts to and from the International Space Station, but the same 2010 law allowed NASA to do so. As part of this program, known as the commercial crew, SpaceX launched its first two astronaut missions for NASA last year.

President Biden has shown an interest in space by exhibiting a moonstone collected by astronauts on the last Apollo mission in 1972 in the Oval Office at the White House and speaking to scientists and engineers who run the Perseverance robotic rover last landed on Mars month.

He told them, “You did it the most American way: you believed in science, you believed in hard work, and you believed there was nothing you couldn’t do if you put your thoughts together. “

White House press secretary Jen Psaki said the government supports NASA’s current Artemis program to send astronauts back to the moon, but the government has not set broader space policy goals or how it might change Artemis plans . Former President Donald J. Trump had set a goal for the first astronauts to arrive by the end of 2024, but that was generally viewed as unrealistic, even if Mr. Trump was re-elected.

Ms. Garver said that the selection of Mr. Nelson could potentially represent a personal interest on the part of Mr. Biden in space exploration. The familiarity Mr. Biden has with Mr. Nelson from his years as a Senate colleague could mean that “he’s going to increase NASA’s budget,” she said.

As a Congressman, Mr. Nelson flew on a space shuttle mission in 1986. As chairman of the committee in the House of Representatives that oversaw NASA, he said the experience helped provide insight into the agency. Critics viewed it as a space junket at the taxpayer’s expense.

When rumors began to spread in February that Mr. Nelson would be nominated, Simon Porter, a planetary scientist at the Southwest Research Institute in Boulder, Colorado, posted a harsh reaction on Twitter, calling Mr. Nelson an “incredibly stupid” election for the NASA administrator.

Marco Rubio, the Florida Republican Senator who served with Mr. Nelson from 2011 to 2018, offered assistance.

If Mr. Nelson is approved by the Senate, he would be the second consecutive former member of Congress to lead NASA. The position was usually filled by individuals with an engineering or civil service background rather than former elected officials.

In a departure from this custom, Mr. Trump nominated Jim Bridenstine, an Oklahoma congressman who previously ran a small space museum in Tulsa. Mr Bridenstine was barely confirmed in April 2018, more than seven months after his nomination. All 47 Democrats and two independents in the Senate voted against him.

Opponents cited Mr Bridenstine’s derogatory remarks about the science of climate change, an area of ​​research in which NASA plays a key role, and feared it would give bias to an agency that is generally backed by both Republicans and Democrats .

At the head of this opposition was Mr. Nelson.

“I think what is wrong for NASA,” he said during a speech in the Senate, “is an administrator who is politically divided and unwilling to be the last to make this fateful decision about” go “or” go “hits.” no go ‘for the start. “

Mr. Bridenstine also had no experience running a sprawling bureaucracy like NASA. Neither does Mr. Nelson, who has spent much of his career in Congress.

During his confirmation hearing, Mr Bridenstine said his views on climate change had “evolved” – and he generally received high marks for leading the agency and leading its climate research.

In 2019, Mr. Bridenstine appointed Mr. Nelson to the NASA Advisory Board, a group of people outside NASA who provide feedback to the agency.

Mr Bridenstine stayed largely aloof from the partisan messages Mr Trump delivered when he talked about NASA, and some space advocates hoped he would continue to serve as an administrator under President Biden. But Mr. Bridenstine resigned on January 20 when Mr. Biden was initiated.

A longtime NASA official, Steve Jurczyk, is currently serving as the acting administrator.

While Mr Bridenstine was the youngest to serve as NASA administrator – he often stressed that he was the first born after the Apollo program ended – Mr Nelson was the oldest at 78.