Science and art have found a place in the payload bay of the shuttle Challenger, scheduled to lift off Friday from Cape Canaveral on an eight-day mission.
At this writing, the countdown was progressing normally toward a launch from Pad 39A at 7:03 a.m. Eastern daylight time. The shuttle's trajectory will take it up the East Coast, rather than toward Africa, to set up an orbital pattern designed to accommodate Earth observation experiments on board.
The shuttle will carry the largest crew to date. Its seven members include mission commander Robert L. Crippen; pilot Jon A. McBride; mission specialists Sally K. Ride, Kathryn D. Sullivan, and Navy Lt. Comdr. David Leestma; and payload specialists Marc Garneau and Paul D. Scully-Power.
Dr. Garneau will be the first Canadian in space. And when Dr. Sullivan dons her spacesuit and moves into the payload bay with Lieutenant Commander Leestma on the fifth flight day, she will be the first American woman to walk in space. In doing so, she will join an exclusive club: The only other member is Soviet cosmonaut Svetlana Savitskaya, who took a 3-hour-and-35 minute walk in space outside the Soyuz 7 space station in July.
This mission, said to represent the most ambitious Earth observation effort since the Skylab program in the 1970s, has four major objectives:
* Launch of the Earth Radiation Budget Satellite. Dr. Ride will use the arm to release the ERBS 81/2 hours after the shuttle's launch. Once clear of the orbiter, the satellite's onboard propulsion units will move it to its operating altitude of 329 statute miles. The satellite is designed to measure the solar energy absorbed by and reflected from Earth at various latitudes. Along with two more satellites scheduled to be placed in orbit by early 1986, ERBS will be part of a system that will collect data on the planet's ''energy budget'' from the entire Earth once a day and from most of Earth at all times of day during every month. The data collected are expected to help scientists gain a better understanding of energy exchanges that generate circulation within Earth's atmosphere and oceans and determine climate.
* Conduct experiments with a package dubbed OSTA-3. Mounted in the payload bay, the instrument package consists of imaging radar, a large format camera, and an instrument designed to make remote sensing devices more efficient. It also includes equipment to measure air pollution from space. Images recorded by radar and the camera will be used for mapping and resource studies. The pollution-detection instrument will be used to measure carbon monoxide in the troposphere - that portion of Earth's atmosphere ranging from the surface to between 6 and 12 miles in altitude.
* Test the orbital refueling system. This is designed to demonstrate the shuttle's capability to refuel satellites in orbit. The immediate goal is to simulate the steps necessary to refuel a Landsat Earth resources satellite. Five fuel-transfer tests will be conducted between the system's two hydrazine storage tanks. During a three-hour space walk in the payload bay, crew members Leestma and Sullivan will use special tools and an adapter to connect the two tanks via a mock-up of the Landsat's fuel inlet. Once the astronauts have returned to the cabin, the crew will transfer the highly toxic and corrosive hydrazine propellant, used in satellite maneuvering systems, from one tank to another.
* Conduct Canex experiments. Garneau will be conducting 10 experiments for Canada's National Research Council. Disciplines involved range from life sciences to studying composite materials. He also will be measuring shuttle glow , a phenomenon that still isn't fully understood, but which can affect readings taken by optical-instrument payloads.
In addition, Dr. Scully-Power, a civilian oceanographer working for the US Navy, will be observing and photo-graphing Earth's oceans. One of his key goals is to study the oceans' circular and spiral eddies, which play a key role in ocean dynamics.
As for art, sculptor Joseph McShane of Prescott, Ariz., has designed a package for one of the mission's eight small ''getaway special'' payloads. Using the weightlessness and vacuum of space, the computerized device will coat eight glass spheres to create sculptures in orbit.