• Bay 1-2: Orbiter Docking System/External Airlock - 2160 kg including 3 EMU spacesuits
• Bay 4-5: Spacelab Pallet (Fwd) with O2-1/O2-2 oxygen tanks - 2500 kg
• Bay 6-7: Spacelab Pallet (Aft) with N2-1/N2-2 nitrogen tanks - 2500 kg
• Bay 8-12: Station Joint Airlock Adapter beam (6064 kg) with IMAX Cargo Bay Camera (238 kg)
• Sill: RMS arm - 410 kg

The six tonne Airlock consisted of two cylinders of four meters diameter and a total length six meters. The Airlock could be pressurized by the externally-mounted high pressure oxygen-nitrogen tanks, and was to be the sole unit through which all future EVAs were to take place. (Until that point, all EVA entries/exits had been through a Russian module in ISS, with non-Russians having to wear Russian space suits). Another payload was the "EarthKAM" of middle/high school interest. It was to allow pupils to command picture-taking of chosen spots on Earth; they were expected to target 2,000 spots. The shuttle also carried out pulsed exhaust tests during maneuvers to enable better understanding of the formation of HF echoes from the shuttle exhaust. The echoes were obtained by ground based radars in an experiment called SIMPLEX (Shuttle Ionospheric Modification with Pulsed Local EXhaust). The STS-104 crew returned to Atlantis on July 22, and undocked at 0455 GMT. After flying around the station they departed the vicinity at 0615 GMT. Atlantis landed at 0338:55 GMT on July 25, touching down at Kennedy Space Center runway 15. References: 2, 296.

GOES 12 was a 980 kg, 973 W spacecraft that carried an IR imager, a "sounder", and an X-ray imager. The IR imager was a Cassegrain telescope covering five wavelength channels, 0.55-0.75, 3.80-4.00, 6.50-7.00, 10.20-11.20, and 11.50-12.50 microns. It provided images covering 3,000 km x 3,000 km every 41 seconds, by scanning the area in 16 square kilometer sections. The "sounder" provided vertical distribution of temperature, moisture and ozone, by passive monitoring in 18 depth-dependent wavelengths. (Long wave IR: 14.71, 14.37, 14.06, 13.64, 13.37, 12.66, and 12.02 microns. Medium wave IR: 11.03, 9.71, 7.43, 7.02, and 6.51 microns. Short wave IR: 4.57, 4.52, 4.45, 4.13, 3.98, and 3.74 microns. There was also another band at visible wavelength 0.7 microns, to provide pictures of cloud tops.) The sounder covered an area of 3,000 km x 3,000 km in about 42 minutes. Another instrument package named SEM (Space Environment Monitor) monitored the energetic electrons and protons in the magnetosphere and the X-rays from the Sun. The above three had been carried on the earlier GOES missions, but GOES 12 carried also an X-ray imager providing an X-ray (about 0.1-1.0 nm wavelength) picture of the solar disk. For some months, the spacecraft was to be on standby, to be activated and moved to a desired longitude. As of 5 September 2001 located at 89.93 deg W drifting at 0.001 deg W per day. As of 2007 Mar 11 located at 74.73W drifting at 0.014E degrees per day. References: 2, 296.

• Phase 1, by 2005: Lunar flyby or orbiting satellite missions, perhaps using the DFH-3 bus.
• Phase 2, by 2010: unmanned soft-landing missions. Phase 3, by 2020: Robotic exploration using surface rovers. Phase 4, by 2030: Lunar sample return missions.

On September 8, 2004, the Genesis space probe became the first spacecraft to return from beyond lunar orbit to the Earth's surface. The Genesis Sample Return Capsule separated from the spacecraft on September 8, 66,000 km above the Earth. The capsule successfully re-entered the atmosphere over Oregon at 11 km/s, but a wiring error resulted in the drogue parachute release mortar failing to fire at 33 km altitude. The capsule crashed to earth at 90 m/s in the Dugway Proving Ground at 40 07 40 N 113 30 29 W. Although the vehicle was smashed, some of the samples could be retrieved. References: 2, 296.

The 15,107 kg payload consisted of:

• Bay 1-2: Orbiter Docking System/External Airlock and 3 EMU spacesuits - 2160 kg
• Bay 4P: Adapter beam with G-780 (Mayo High School, Rochester, Minnesota experiment to study germination of faba beans) and PSP-1 (NASA-GSFC canister with passive experiments and ballast) - 200 kg
• Bay 5: Integrated Cargo Carrier/KYD - 1280 kg, with the Early Ammonia Servicer for the station's P6 truss- 640 kg and two small exposure experiments PEC-1 and PEC-2, to be installed on the be installed on the ISS Quest module as part of the MISSE materials exposure program
• Bay 7-12: MPLM FM1 (Leonardo) module - 9800 kg total including 3300 kg of payload to be transferred to the Station
• Bay 13P: Adapter beam with G-774 (Microgravity Smoldering Combustion (MSC) experiment) and SEM-10 (canister with 11 school experiments) - 410 kg
• Bay 13S: Adapter beam with Simplesat and ACE avionics - 355 kg
• Sill: RMS arm - 410 kg

The Leonardo MPLM module was lifted out of Discovery's payload bay at 1326 GMT on August 13 and docked to Unity's nadir at 1554 GMT. 3300 kg of cargo from Leonardo was transferred to the Station. Then 1700 kg of station garbage and materials were loaded into Leonardo. It was unberthed from Unity at 1816 GMT on August 19 and returned to the payload bay for the return to Earth at 1917 GMT.

Discovery undocked at 1452 GMT on August 20 with the Expedition 2 crew aboard, leaving Expedition 3 at the Station.

At 1830 GMT on August 20 the Simplesat test satellite was ejected from a GAS canister in the cargo bay. Discovery landed at Kennedy Space Center at 1822:58 GMT on August 22 on runway 15, after a deorbit burn at 1715 GMT. The Expedition Two crew of Usachyov, Voss and Helms had been in space for 167 days. Discovery was taken out of service after the flight for structural inspections. Its last maintenance down period was in 1995-1996. References: 2, 296.

Starshine-3 was a 90 kg, 0.9 m geodetic sphere that was to be observed by students. The NASA satellite was basically a passive light-reflecting sphere, consisting of 1,500 student-built mirrors (polished by kindergarten and grade school students from many countries) and 31 laser "retroreflectors". A few solar cells provide enough power to send a beacon at 145.825 MHz every minute. Ham operators around the world were expected to obtain signal strengths from which the decay (due to magnetic torque) of its spin rate could be determined. The project was managed by NASA GSFC and Starshine was built by the Naval Research Laboratory. References: 2, 296.