Beyond_Earth-_A_Chronicle_of_Deep_Space_Exploration_1958-2016.pdf

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[Luna, Ye-6 no. 8]

Nation: USSR (31)

Objective(s): lunar soft-landing

Spacecraft: Ye-6 (no. 8)

Spacecraft Mass: c. 1,470 kg

Mission Design and Management: OKB-1

Launch Vehicle: Molniya-M + Blok L (8K78M no. R103-26, also U15000-22)

Launch Date and Time: 10 April 1965 / 08:39 UT

Launch Site: NIIP-5 / Site 1/5

Scientific Instruments:

• 1. imaging system
• 2. SBM-10 radiation detector

Results: This was the seventh consecutive failure to accomplish a lunar soft-landing by the Soviets. On this mission, engineers redesigned the problematic I-100 control system that had caused most of the previous failures. Previously the I-100 unit had controlled both the Blok L upper stage and the spacecraft itself. On this mission (and subsequent Lunas), the fourth stage and the Ye-6 spacecraft had separate systems. Unfortunately, this probe never reached Earth orbit. During the launch, depressurization of a nitrogen pipe for the liquid oxygen tank on the third stage (Blok I) prevented third stage engine ignition. The spacecraft thus broke up over the Pacific without reaching Earth orbit.

55

Luna 5

Nation: USSR (32)

Objective(s): lunar soft-landing

Spacecraft: Ye-6 (no. 10)

Spacecraft Mass: 1,476 kg

Mission Design and Management: OKB-1

Launch Vehicle: Molniya-M + Blok L (8K78M no. U103-30, also U15000-24)

Launch Date and Time: 9 May 1965 / 07:49:37 UT

Launch Site: NIIP-5 / Site 1/5

Scientific Instruments:

• 1. imaging system
• 2. SBM-10 radiation detector

Results: Luna 5 became the first Soviet probe to head for the Moon in two years. Following a midcourse correction on 10 May, the spacecraft began spinning around its main axis due to a problem in a floatation gyroscope in the I-100 control system unit—the gyroscopes apparently had had too little time to warm up before being used for attitude control. A subsequent attempt to fire the main engine failed due to ground control error. A third attempt also failed, and having lost control of the spacecraft due to the gyroscope problem, controllers stood by helplessly as Luna 5 crashed on to the surface of the Moon at 19:10 UT on 12 May in the Sea of Clouds, about 700 kilometers from its planned landing point. Landing coordinates were 31° S / 8° W. It was the second Soviet spacecraft to impact on the Moon (following Luna 2 in 1959).

56

Luna 6

Nation: USSR (33)

Objective(s): lunar soft-landing

Spacecraft: Ye-6 (no. 7)

Spacecraft Mass: 1,442 kg

Mission Design and Management: OKB-1

Launch Vehicle: Molniya-M + Blok L (8K78M no. U103-31, also U15000-33)

Launch Date and Time: 8 June 1965 / 07:40 UT

Launch Site: NIIP-5 / Site 1/5

Scientific Instruments:

• 1. imaging system
• 2. SBM-10 radiation detector

Results: On this ninth Soviet attempt at a lunar soft-landing, the mission proceeded as planned until a major mid-course correction late on 9 June. Although the main retro-rocket engine (the S5.5A) ignited on time, it failed to cut off and continued to fire until propellant supply was exhausted. An investigation later indicated that the problem had been due to human error; a command had been mistakenly sent to the timer that ordered the main engine to shut down. Although the spacecraft was sent on a completely off-nominal trajectory, ground controllers put the spacecraft through a series of steps to practice an actual landing (such as inflating the airbags, separating the lander, etc.), all of which were satisfactorily accomplished. Luna 6 passed by the Moon late on 11 June at a range of 161,000 kilometers and eventually entered heliocentric orbit. Contact was maintained to a distance of 600,000 kilometers from Earth.

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The Zond 3 spacecraft (of the 3MV-4 type) returned higher resolution pictures, as compared to Luna 3, of the farside of the Moon in 1965 during a flyby. Credit: Don Mitchell

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Zond 3

Nation: USSR (34)

Objective(s): lunar flyby

Spacecraft: 3MV-4 (no. 3)

Spacecraft Mass: 950 kg

Mission Design and Management: OKB-1

Launch Vehicle: Molniya + Blok L (8K78 no. U103-32, also U15000-32)

Launch Date and Time: 18 July 1965 / 14:32 UT

Launch Site: NIIP-5 / Site 1/5

Scientific Instruments:

• 1. imaging system
• 2. ultraviolet spectrograph
• 3. ultraviolet and infrared spectrophotometer
• 4. meteoroid detectors
• 5. STS-5 scintillation and gas-discharge counters
• 6. magnetometer
• 7. ion thrusters
• 8. radio telescope

Results: This "third generation" deep space probe had originally been slated for a Mars flyby in late 1964 but could not be prepared on time. Instead, Soviet designers diverted the mission for a simple lunar flyby in 1965 to test its basic systems and photograph the farside of the Moon. After a successful trans-lunar injection burn, Zond 3 approached the Moon after only a 33-hour flight. Its imaging mission began at 01:24 hours on 20 July at a range of 11,600 kilometers from the near side of the Moon and completed 68 minutes later. Zond 3 carried an imaging system somewhat similar to the one carried on Automatic Interplanetary Station ("Luna 3"), with onboard exposure, development, fixing, and drying prior to scanning for transmission to Earth. The new system, known as 15P52, weighed 6.5 kilograms, was developed by the Moscow-based NII-885 (as opposed to VNII-380, which developed the Luna-3 system). In total, the spacecraft took 25 visual and three ultraviolet images during its flyby. Closest approach was to 9,220 kilometers. These pictures were successfully transmitted back to Earth on July 29, nine days after its lunar encounter when it was 2.2 million kilometers from Earth. Further communications sessions occurred on 23 October (involving photo transmissions) when Zond 3 was 31.5 million kilometers from Earth. Last contact was sometime in early March 1966 when the spacecraft was 153.5 million kilometers away. During the mission, it photographed the unseen 30% of the farside of the Moon. Zond 3 also demonstrated successful course corrections using both solar and stellar orientation, a first for a Soviet spacecraft.

58

Surveyor Model 1

Nation: USA (24)

Objective(s): highly elliptical orbit

Spacecraft: SD-2

Spacecraft Mass: 950 kg

Mission Design and Management: NASA / JPL

Launch Vehicle: Atlas Centaur (AC-6 / Atlas D no. 151D / Centaur D)

Launch Date and Time: 11 August 1965 / 14:31:04 UT

Launch Site: Cape Kennedy / Launch Complex 36B

Scientific Instruments: [none]

Results: This was the second attempt to launch a dummy Surveyor lunar lander spacecraft into a barycentric orbit towards a simulated Moon. Unlike the previous attempt (in March 1965), this time all systems worked without fault; the Centaur fired flawlessly and put the Surveyor dynamic model on a simulated lunar trajectory so precise that it would have impacted on the Moon without a trajectory correction. Orbital parameters were 164 × 822,135 kilometers at 28.6° inclination. The payload reentered after 31 days.

59

Luna 7

Nation: USSR (35)

Objective(s): lunar soft-landing

Spacecraft: Ye-6 (no. 11)

Spacecraft Mass: 1,506 kg

Mission Design and Management: OKB-1

Launch Vehicle: Molniya-M + Blok L (8K78M no. U103-27, also U15000-54)

Launch Date and Time: 4 October 1965 / 07:56:40 UT

Launch Site: NIIP-5 / Site 1/5

Scientific Instruments:

• 1. imaging system
• 2. SBM-10 radiation detector

Results: The first attempt to launch this vehicle took place at 07:05:36 UT on 4 September 1965 but the launch was aborted due to a problem in a sensor that measured relative velocity on the rocket. The subsequent launch a month later went off successfully and the Blok L upper stage successfully sent Luna 7 on its way to the Moon. Unlike its predecessors, Luna 7 successfully carried out its mid-course correction on October 5 on the way to the Moon, in anticipation of a soft-landing two days later (at the time planned for 2208 UT on 7 October). Unfortunately, immediately prior to planned retro-fire during the approach to the lunar surface, the spacecraft suddenly lost attitude control and failed to regain it. One of its attitude control sensors—the one designed to lock on to Earth—stopped functioning, preventing it from reaching the desired orientation for firing its retro-engine. Automatic programmed systems then prevented the main engine from firing. As controllers observed helplessly, Luna 7 plummeted to the lunar surface at a very high speed, crashing at 22:08:24 UT on 7 October west of the Kepler crater, relatively near to the actual intended target. Impact coordinates were 9° N / 49° W. Later investigation indicated that the optical sensor of the Yupiter-M astronavigation system had been set at the wrong angle and had lost sight of Earth during the critical attitude control maneuver. It was the tenth consecutive failure in the Ye-6 program.

60

Venera 2

Nation: USSR (36)

Objective(s): Venus flyby

Spacecraft: 3MV-4 (no. 4)

Spacecraft Mass: 963 kg

Mission Design and Management: OKB-1

Launch Vehicle: Molniya-M + Blok L (8K78M no. U103-42, also U15000-42)

Launch Date and Time: 12 November 1965 / 04:46 UT

Launch Site: NIIP-5 / Site 31/6

Scientific Instruments:

• 1. triaxial fluxgate magnetometer
• 2. spectrometers
• 3. micrometeoroid detectors
• 4. ion traps
• 5. cosmic radio emission receiver
• 6. radio detector
• 7. STS-5 gas-discharge and solid-state detectors
• 8. imaging system
• 9. infrared spectrometer
• 10. 2 other spectrometers

Results: Although the 3MV-3 and 3MV-4 type spacecraft were originally intended for Mars exploration, the Soviets re-equipped three of the series, left over from the 1964 Mars launch periods, for Venus exploration in 1965. This particular vehicle was scheduled to fly past the sunlit side of Venus at no more than 40,000 kilometers range and take photographs. About 3 hours after injection into heliocentric orbit, contact was temporarily lost with the spacecraft, and although it was regained soon after, the event was symptomatic of the mission in general during which communications were generally poor. Before closest approach in late February 1966, ground control switched on all the onboard scientific instrumentation. Closest approach to the planet was at 02:52 UT on 27 February 1966 at about 24,000 kilometers range. After its flyby, when the spacecraft was supposed to relay back the collected information, ground control was unable to regain contact. Controllers finally gave up all attempts at communication on 4 March. Venera 2 eventually entered heliocentric orbit. Later investigation indicated that improper functioning of 40 thermal radiator elements caused a sharp increase in gas temperatures in the spacecraft. As a result, elements of the receiving and decoding units failed (and the solar panels overheated), and contact was lost. Ironically, the scientific instruments may have collected valuable data, but none of it was ever transmitted back to Earth.

61

Venera 3

Nation: USSR (37)

Objective(s): Venus impact

Spacecraft: 3MV-3 (no. 1)

Spacecraft Mass: 969 kg

Mission Design and Management: OKB-1

Launch Vehicle: Molniya + Blok L (8K78 no. U103-31, also U15000-31)

Launch Date and Time: 16 November 1965 / 04:13 UT

Launch Site: NIIP-5 / Site 31/6

Scientific Instruments:

Spacecraft Bus:

• 1. triaxial fluxgate magnetometer
• 2. spectrometers
• 3. SBT-9 cosmic ray sensor
• 4. ion traps
• 5. STS-5 gas-discharge and solid-state detectors

Impact Probe:

• 1. temperature, pressure, and density sensors
• 2. chemical gas analysis
• 3. photometer
• 4. gamma-ray counter

Results: This was the second of three 3MV spacecraft the Soviets attempted to launch towards Venus in late 1965. Venera 3 successfully left Earth orbit carrying a small 0.9-meter diameter 310-kilogram landing capsule to explore the Venusian atmosphere and transmit data on pressure, temperature, and composition of the Venusian atmosphere back to Earth during the descent by parachute. During the outbound trajectory, ground controllers successfully performed a mid-course correction on 26 December 1965 and completed 63 communications sessions during which scientists on the ground recorded valuable information. For example, between 16 November 1965 and 7 January 1966, a modulation charged particle trap (of the same type carried on Zond 2), provided valuable data on the energy spectra of solar wind ion streams beyond the Earth's magnetosphere. Contact was, however, lost on 16 February 1966, shortly before the Venusian encounter. The spacecraft subsequently automatically released its lander probe which impacted inertly onto the Venusian surface at 06:56:26 UT on 1 March 1966, only 4 minutes earlier than planned. It was the first time a human-made object made physical contact with another planetary body other than the Moon. The impact location was on the night side of Venus, near the terminator, in the range of –20° to 20° N / 60° to 80° E. In response to concern from some American and British scientists, the Soviet press emphasized that "prior to liftoff, the descent module was subject to careful sterilization, required to dispose of all microorganisms of terrestrial origin and thus prevent the possibility of contamination." Later investigation confirmed that Venera 3 suffered many of the same failures as Venera 2, i.e., overheating of internal components and the solar panels.