Johnson Space Center, Houston — ''Can you tell us if it's true that Ulf Merbold wouldn't go to bed last night?'' asked a European journalist about the West German physicist who is one of two payload specialists on STS-9/Spacelab.
''I can't confirm that,'' replied mission manager Harry Craft. ''But we sent him to bed, I'll put it that way.''
Dr. Merbold's excitement is shared by scientists on the ground as Spacelab moves into the second day of its nine-day odyssey. During the first 24 hours of flight, some 20 to 25 experiments have been started, running the gamut from life sciences and materials processing to space plasma physics.
''Everything is going extremely well with all of those investigations,'' says Charles R. Chappell, Spacelab 1 mission scientist. Overall, the crew was said to be only about 15 minutes behind on its schedule of activities, and ''we're not terribly uncomfortable'' with that, says Mr. Craft.
Still, the mission's first day was not without problems. Some data from an experiment on space sickness were thought to have been lost. There have been unforeseen lapses in air-to-ground communications.
In addition, trouble developed in one remote acquisition unit (RAU), a complex electronic device that sits on the floor of the pallet and links Spacelab computers to experiments located on the pallet in the payload bay.
As a result, scientists are not getting what Craft described as ''housekeeping data'' from Utah State University's imaging spectrometric observatory and the University of California at Berkeley's far ultraviolet space telescope (FAUST). But these two devices were still able to operate, returning what Craft termed as very good data.
However, for two other experiments - the Jet Propulsion Laboratory's active cavity radiometer, which is designed to measure variations in the output of solar radiation, and a particle accelerator from Japan that will be used to study Earth's ionosphere and mag-netosphere - the RAU problem is more serious. Both devices are designed to trade data with with Spacelab's computer. At this writing, engineers were searching for a way to work around the faulty RAU.
While these troubles are not looked on with great favor by scientists and engineers here, they do serve to reinforce the notion that this mission's major objective is to verify that the entire Spacelab system - from the lab itself to the communications network that supports it - works as advertised.
John Cox, one of three flight directors for this mission, points out that the communications problems ''were mostly expected. There's lots of learning to do on how to operate with TDRS,'' the tracking data relay satellite that is a crucial link in the communications network.
(Other activities yesterday included a ''hop and drop'' simulated gravity test in which one astronaut connected to the wall of the spacecraft by elastic ropes pushed himself away from the wall 30 times and allowed the elastic ropes to draw him back.
(In the second part of this experiment, one of the astronuats pulled the other away from the wall as far as the elastic would allow and then ''dropped'' him back to the wall.)