Reentry into the Earth's atmosphere was not achieved because the retrorocket failed to ignite. The biosatellite was never recovered. Although the scientific objectives of the mission were not accomplished, the Biosatellite I experience provided technical confidence in the program because of excellent performance in most other areas.

Biological capsule recovered. The scientific payload, consisting of 13 select biology and radiation experiments, was exposed to microgravity during 45 hours of Earth-orbital flight. Experimental biology packages on the spacecraft contained a variety of specimens, including insects, frog eggs, microorganisms and plants. The planned three-day mission was recalled early because of the threat of a tropical storm in the recovery area, and because of a communication problem between the spacecraft and the tracking systems. The primary objective of the Biosatellite II mission was to determine if organisms were more, or less, sensitive to ionizing radiation in microgravity than on Earth. To study this question, an artificial source of radiation was supplied to a group of experiments mounted in the forward part of the spacecraft.

Biological capsule reentered 7/7/69. The intent had been to fly a 6 kg male pig-tailed monkey (Macaca nemestrina) named Bonnie in Earth-orbit for 30 days. However, after only 8.8 days in orbit, the mission was terminated because of the subject's deteriorating health. High development costs were a strong incentive for maximising the scientific return from the mission. Because of this, the scientific goals had become exceedingly ambitious over time, and a great many measurements were conducted on the single research subject flown. Although the mission was highly successful from a technical standpoint, the science results were apparently compromised. Additional Details: here....

Orbiting Frog Otolith. The satellite carrying the OFO-A experiment remained in orbit for almost seven days. Recovery of the spacecraft was not planned. The payload was the Frog Otolith Experiment Package (FOEP). The objective of the experiment was to investigate the effect of microgravity on the otolith, a sensory organ that responds to changes in an animal's orientation within the Earth's gravitational field. Two bullfrogs (Rana catesbeiana) were used as experimental subjects in the flight experiment. Additional Details: here....

Jupiter flyby December 1973; first man-made object to leave solar system. The spacecraft achieved its closest approach to Jupiter on December 3, 1973, when it reached approximately 2.8 Jovian radii (about 200,000 km). As of Jan. 1, 1997 Pioneer 10 was at about 67 AU from the Sun near the ecliptic plane and heading outward from the Sun at 2.6 AU/year and downstream through the heliomagnetosphere towards the tail region and interstellar space. Additional Details: here....

NASA's Atlas/Centaur was launched from Cape Canaveral carrying Pioneer 11 (Jupiter-Saturn). This was the first SLV-3D Atlas booster (vehicle 5011D), and the first SLV-3 to use the new 370,000-pound thrust MA-5 booster package for improved payload performance. Jupiter flyby December 1974; Saturn flyby September 1979. Solar system escape trajectory. Pioneer 11 was the second mission to investigate Jupiter and the outer solar system and the first to explore the planet Saturn and its main rings. Pioneer 11, like Pioneer 10, used Jupiter's gravitational field to alter its trajectory radically. It passed close to Saturn and then it followed an escape trajectory from the solar system. During its closest approach, December 4, 1974, Pioneer 11 passed to within 34,000 km of Jupiter's cloud tops. It passed by Saturn on September 1, 1979, at a distance of 21,000 km from Saturn's cloud tops. The spacecraft has operated on a backup transmitter since launch. Instrument power sharing began in February 1985 due to declining RTG power output. Science operations and daily telemetry ceased on September 30, 1995 when the RTG power level was insufficient to operate any experiments. As of the end of 1995 the spacecraft was located at 44.7 AU from the Sun at a nearly asymptotic latitude of 17.4 degrees above the solar equatorial plane and was heading outward at 2.5 AU/year. Routine tracking and project data processing operations were terminated on March 31, 1997 for budget reasons.

The Pioneer Venus Orbiter was inserted into an elliptical orbit around Venus on December 4, 1978. After entering orbit around Venus in 1978, the spacecraft returned global maps of the planet's clouds, atmosphere and ionosphere, measurements of the atmosphere-solar wind interaction, and radar maps of 93 percent of the planet's surface. Additionally, the vehicle made use of several opportunities to make systematic UV observations of several comets. From Venus orbit insertion to July 1980, periapsis was held between 142 and 253 km (at 17 degrees north latitude) to facilitate radar and ionospheric measurements. The spacecraft was in a 24 hour orbit with an apoapsis of 66,900 km. Thereafter, the periapsis was allowed to rise (to 2290 km at maximum) and then fall, to conserve fuel. In 1991 the Radar Mapper was reactivated to investigate previously inaccessible southern portions of the planet. In May 1992 Pioneer Venus began the final phase of its mission, in which the periapsis was held between 150 and 250 km until the fuel ran out and atmospheric entry destroyed the spacecraft. With a planned primary mission duration of only eight months, the spacecraft remained in operation until October 8, 1992 when it finally burned up in Venus' atmosphere after running out of propellant.

The Pioneer Venus Multiprobe consisted of a bus which carried one large and three small `atmospheric probes. The large probe was released on November 16, 1978 and the three small probes on November 20. All four probes entered the Venus atmosphere on December 9, followed by the bus. The small probes were each targeted at different parts of the planet and were named accordingly. The North probe entered the atmosphere at about 60 degrees north latitude on the day side. The night probe entered on the night side. The day probe entered well into the day side, and was the only one of the four probes which continued to send radio signals back after impact, for over an hour. With no heat shield or parachute, the bus survived and made measurements only to about 110 km altitude before burning up. It afforded the only direct view of the upper Venus atmosphere, as the probes did not begin making direct measurements until they had decelerated lower in the atmosphere.

The Lunar Prospector was designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible polar ice deposits, measurements of magnetic and gravity fields, and study of lunar outgassing events. Data from the 1 to 3 year mission will allow construction of a detailed map of the surface composition of the Moon, and will improve understanding of the origin, evolution, current state, and resources of the Moon. After launch, the Lunar Prospector had a 105 hour cruise to the Moon, followed by insertion into a near-circular 100 km altitude lunar polar orbit with a period of 118 minutes. The nominal mission duration was one year.

First test flight of a large hybrid propulsion system. The Suborbital Aerodynamic Reentry Experiment payload, a joint project between Ames and Wallops, included a 'wave rider' flying wedge, a linear aerobrake (or hypersonic parachute), and a Slotted Compression Ramp Probe (SCRAMP), a super stable planetary reentry probe. The wedge was 127 centimeters long and was to free fly like a glider after deployment.

3U cubesat launched as a secondary payload. A collaboration of NASA, industry, and local universities resulted in this fully-automated, miniaturized spaceflight system that provided life support, nutrient delivery, and performed assays to monitor genetic changes of E. coli bacteria in space conditions.