Monday, December 20, 1999 – 10:30 a.m. CST

Trailing the Hubble Space Telescope by about 3,700 nautical miles and closing, the seven Discovery
astronauts were awakened at 9:50 a.m. CST today to the sounds of Bachman-Turner Overdrive’s “Taking
Care of Business.” The wake-up call from Mission Control began the crew’s first full day in orbit. Discovery is
closing on the telescope at a rate of about 340 nautical miles with each hour and a half long orbit of Earth.

Today will be a day of preparation for the crew, gearing up for the rendezvous and capture of HST planned
for Tuesday and the three maintenance spacewalks that will follow later in the week. At about 1 p.m.,
European Space Agency astronaut Jean-Francois Clervoy will power up Discovery’s robotic arm to check its
operation. Clervoy will survey Discovery’s cargo bay using television cameras on the arm, checking the
condition of the equipment planned for installation on the telescope and the cradle that will hold HST during
the spacewalks. While Clervoy operates the arm, Payload Commander Steve Smith and Mission Specialist
John Grunsfeld will power up the payload bay HST support equipment. Later, around 6 p.m., Commander
Curt Brown and Pilot Scott Kelly will check out the laptop computers, navigation aids and flight controls in
Discovery’s cockpit that will be used for tomorrow’s encounter with HST.

Meanwhile, on Discovery’s middeck, Grunsfeld, along with European astronaut Claude Nicollier, will begin a
check of the four spacesuits onboard. Early in the afternoon, about 1 p.m., the crew will lower the cabin
pressure aboard Discovery as part of the spacewalk preparations. This reduces the amount of time the
spacewalkers must breathe oxygen as part of a standard protocol to purge nitrogen from the body prior to
beginning a spacewalk.

At 8:35 p.m. CST, Brown, Smith, Clervoy and Mike Foale will take a break from their work to talk with CBS
news and other television networks about their mission.

As some of their final activities today, the crew will fire Discovery’s large orbital maneuvering system engines
at 10:32 p.m. to slow the rate at which the Shuttle is closing on HST. A second, smaller engine firing will
follow at 11:27 p.m. to further fine tune the Shuttle’s approach toward Hubble. Capture of the telescope
remains scheduled for 6:41 p.m. Tuesday.

Discovery is in excellent condition, orbiting Earth every 95 minutes, 27 seconds. The high point of
Discovery’s orbit is 363 statute miles and the low point is 298 statute miles.

The next STS-103 mission status report will be issued at 11 p.m. Monday or as events warrant.