SPACE CENTER, Houston (CNN) -- Seventy-seven-year-old astronaut John Glenn was in high spirits Wednesday aboard the shuttle Discovery, cracking jokes during broadcast interviews with NASA administrator Dan Goldin and TV show host Jay Leno.

During a CBS radio interview with Goldin and Walter Cronkite, Goldin mentioned that he was pleased that Glenn had not experienced the illness that some astronauts experience when they go into space.

"You weren't half as glad as I was," Glenn said.

	COUNTDOWN: Mission News CNN Video Archive Panoramic Photos Tour Mission Control FLASHBACK: Whither the Mecury 7? Shuttle Milestones Gallery: Then and Now LAUNCHPAD: Message Boards Space Chat Glenn-Gram e-mail GAMES: Match the Mission Mission Quiz Crossword Puzzle Crew members Brown Duque Glenn Lindsey Mukai Parazynski Robinson

Later, Leno asked Glenn how the food on the Discovery compares with the food on the Friendship 7 capsule he rode three times around the world 36 years ago.

"The first time, I had applesauce and things like that," Glenn said. "I have a lot of choice here. I can mix my Tang with Geritol or Metamucil."

Goldin told Glenn that Goldin's 86-year-old mother had called saying she wanted to know when she could go into space.

"Good for her," Glenn said. "I think too many people live by the calendar and become couch potatoes. I think people should do what they want to do and what they can do."

Leno asked Cmdr. Curtis Brown Jr., "Does Sen. Glenn keep telling you how tough it was in the old days? How cramped it was? How small it was? How lucky you young punks are?

"Well, Jay, no, he actually doesn't always do that," Brown said. "Only when he's awake."

Glenn burst into laughter.

Crew 'a little round-faced'

View of Earth from Discovery

Glenn said that the crew "might look a little round-faced right now" and attributed it to the tendency of certain body fluids to rise to the head in microgravity.

But, he added, "Everybody experiences that."

The interviews, which also included pilot Steve Lindsey, were a break in a busy sixth full day in space for the astronauts.

Brown said that everything was going "quite well. The whole mission is going very, very well. We've accomplished everything planned, and everything so far has been fantastic."

Glenn and fellow astronauts Pedro Duque and Chiaki Mukai spent the morning doing experiments involving plant growth, the creation of an advanced alloy in a miniature furnace and testing the balancing system of fish.

Meanwhile, Brown, Lindsey, flight engineer Steve Robinson and Scott Parazynski used the robotic arm to maneuver the Spartan satellite to test new vision and guidance systems that will be used on the International Space Station. The Spartan was retrieved Tuesday after spending two days collecting hundreds of images of the sun.

And Glenn traded in the electronic sleepwear he has worn for the past two nights for a device he strapped around his waist to monitor other bodily functions.

Morning song: 'Young Spirit'

The crew began its seventh day in orbit when Mission Control awoke them with a Japanese folksong titled "Young Spirit."

"That song always gives me energy to do my best," Japanese astronaut Chiaki Mukai told Mission Control. "Another wonderful day with high energy."

The crew was still glowing over the recapture Tuesday of the 1 1/2-ton Spartan satellite.

Discovery's robot arm grabs the Spartan satellite

Brown maneuvered Discovery alongside Spartan, and Robinson carefully snared the satellite with the shuttle robot arm as they soared 340 miles above South America.

"Got a good grapple of Spartan," Robinson reported.

"Great job," Mission Control replied.

Glenn said he watched the capture from a window 15 feet away, and praised Brown and Robinson for their delicate teamwork.

NASA expects about 1,400 images of the sun's outer atmosphere, or corona, and the charged particles streaming off the sun's surface. About 500 images already have been beamed down to ground controllers, including high-quality pictures of at least one solar eruption.

Mission scientist Richard Fisher said the eruption involved 1 billion tons of charged particles -- enough to fill 10,000 super oil tankers -- hurtling out into space at nearly 700,000 mph. Fisher said he couldn't wait to see the other data when Discovery returns to Earth on Saturday.

"We're going to open this Christmas package," he said. "It just couldn't be more wonderful."