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Blueprints of the E1 spacecraft. Credit: RGANDT


A backup copy of the E1 spacecraft, which was the first to escape the Earth's gravity. Click to enlarge.


A preparation of a E1 mission for launch.


A 8K72 rocket lifts off with one of the lunar probes toward the Moon. Credit: RKK Energia





USSR launches the first artificial planet

55 years ago, the USSR launched the first spacecraft beyond the Earth orbit into a trajectory around the Sun. The E1 No. 4 probe was designed to hit the Moon but missed due to navigation errors.

Previous chapter: Unmanned lunar missions

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Luna-1 mission

Preparations for the launch of the E1 No. 4 lunar probe were hindered by the New Year celebrations on Dec. 31, 1958, formally, still a work day. On the morning of January 1, 1959, as the launch vehicle with the spacecraft was rolled out from the assembly building at Site 2 to the launch pad, an officer responsible for tracking the mission remembered running from one mobile ground station trailer to another to fill in for his "out-of-commission" colleagues. Nevertheless, all final tests and telemetry processing were completed successfully and the launch vehicle was cleared for fueling and liftoff next evening. (202)

On January 2, 1959, after three failed attempts, the USSR finally succeeded in launching a spacecraft beyond the Earth orbit. The three-stage launch vehicle 8K72 No. B1-6, which was based on the R-7 ballistic missile, lifted off from a launch pad No. 1 in Tyuratam at 19:41:24.1 Moscow Time. It carried the E1 No. 4 spacecraft intended to impact the Moon on a direct escape trajectory without first entering the Earth orbit. (52, 202)

The 361.3-kilogram space probe was equipped with a transmitter, a telemetry system, a power battery and a set of scientific instruments designed to study cosmic rays, gas and particle content in the interplanetary space, solar radiation and the Earth's magnetic field. Moreover, the third stage of the rocket, designated Block E, which was intended to send the spacecraft toward the Moon, had its own payloads, including hardware designed to release a sodium cloud in space in order to create an "artificial comet." (2) The main purpose of the experiment was described as a navigational aid helping ground control track the mission. (71)

Slightly more than 12 minutes after the liftoff, the launch vehicle enabled its third stage for the first time to accelerate beyond 11.2 kilometers per second, which was enough to leave the gravitational field of the Earth. Immediately after the engine shutdown, the transmitter RTS-12B onboard the E1 probe was activated and officers at the IP-1 ground station in Tyuratam saw a signal on their monitors, triggering an instant celebration. However, while they were congratulating each other, the east-bound spacecraft went out of range of the IP-1 station. Right thereafter, Yevgeni Gubenko called the station and asked whether officers or his engineers at the site had seen telemetry signals from the "Velocity vector" indicator. Only then controllers realized that neither live indicator, nor a tape recorder had registered this crucial information for predicting the exact path of the probe. They speculated that the telemetry component of the RTS-12B transmitter had failed. It could still be used as a radio-beacon for tracking the mission's trajectory, but turned out to be useless for getting any other data from the spacecraft. (202)

According to a memo sent to the Kremlin, the Obyekt "E" vehicle reached its (solar) orbit 732 seconds after the liftoff, as it was flying 1,290 kilometers above the USSR, east of the town of Tura. At 20:03 Moscow Time (around 22 minutes after the liftoff), the rocket's eastbound ground track went beyond the Soviet territory, taking it over the Aleutian Islands and Hawaii. The Soviet ground stations in Tyuratam, Yeniseisk, Petrapavlovsk-na-Kamchatke and Makat were still able to "listen" to the E1 for the first 40 minutes of the mission. It then went beyond the range of the far-eastern stations. All data gathered during the initial phase of the mission was automatically transmitted to the calculation center of the NII-4 research institute in Bolshevo and to the fastest Strela computers of the Calculation Center No. 1 of the Ministry of Defense, Applied Mathematics Department of the Academy of Sciences and Moscow State University.

In the meantime, as the spacecraft was climbing away from Earth instead of circling it, its eastward motion relative to the Earth surface was slowing down, until the planet's own rotation started overtaking it. As a result, around two hours after the launch, the probe appeared making a giant arc over the Pacific Ocean and drifting back westward and south over northern part of New Guinea, southern Sumatra, the Indian Ocean and Africa. (509) By that time, the spacecraft was flying away from Earth, however due to Earth's rotation, the vehicle's ground track drifted from east to west, giving ground controllers 12-hour windows to listen the probe's transmissions interrupted by 12-hour breaks, as the Earth turned around its axis. (202)

The data analysis from Binokl and Binokl-D trajectory measurement stations, which could track the probe up to a distance between 10,000 and 20,000 kilometers from Earth, did not confirm the rendezvous with the Moon. The measurements from the "Velocity vector" indicator from a backup Yupiter transmitter also did not match the required parameters. (202) The actual velocity was determined to be 11.34 kilometers per second relative to the surface of the Earth. As it transpired later, a two-degree error in pointing of a ground-based radio-control antenna used during the powered flight of the rocket, gave the E1 spacecraft extra 42 meters per second in velocity (202). Essentially, the spacecraft would now cross the lunar path, before the Moon had a chance to come close enough to pull the probe into its gravitational field. The spacecraft was reported to be in a 146 by 197-million-kilometer orbit around the Sun between oribts of Earth and Mars, thus becoming the first artificial planet of the Solar System. (2)

The problem with ground radio-control system affected the operation of the second stage, which was mainly responsible for fine-tuning the mission's trajectory. The autonomous flight control system on the second stage inherited from the R-7 missile would normally cut off its engines based on data from acceleration sensors. However, this mode was not accurate enough to ensure a rendezvous of the payload with the Moon. To resolve the problem, the engine cutoff function during the mission was transferred to a more accurate radio-control system mounted on top of the second stage. However due to wrong setup on the ground, the second stage was cutoff only after it had run out of one of the propellant components and the engine's turbine free of its normal loads went into overdrive and issued the "turbine emergency contact" command or AKT. This delay apparently had a domino effect on a six-minute burn of the Block E third stage, whose autonomous flight control system cut off the engine according to its pre-programmed sequence. (62) (The evaluation of telemetry later showed that engine was cut off after 731.2 seconds in flight.) The flight control system then commanded the probe to separate from Block E, however the operation did not take place. Fortunately, four antennas of the RTS-12B transmitter onboard the E1 probe deployed just 140 seconds into the flight, moments after the release of the payload fairing. As a result, the probe stranded on its third stage still was able to transmit signals to the ground.

However a pair of antennas of the Yupiter-1 transmitter located on the opposite side of the ball-shaped probe and hidden inside the structure attaching the spacecraft to the third stage obviously could not open normally. Still, communications officers were getting signals from Yupiter just fine! Veterans of the project speculated that Yupiter could route signals via antennas of the third stage along with its own short-wave radio, or spring-loaded antennas on the E1 managed to stick out through small openings in the holding structure. Another possibility was that after the release, the antennas could press against the third stage, turning its metal body into a natural antenna. (202)

On January 3, at 03:57 Moscow Time, as the stack was free-flying over the Indian Ocean, 113,000 kilometers from Earth, a sodium cloud was released and captured on film by a station near Karaganda, even though bad weather did prevent observations at most other sites. (509) The "artificial comet" turned out to be a poor aid in tracking the mission. (202, 71)

During a day, a deputy head of the NII-4 research institute (responsible for mission control) Georgy Tyulin sent a memo to the Kremlin reporting that by 11:00 Moscow Time, the spacecraft had reached a distance of 200,000 kilometers from the Earth, as it was drifting across the Atlantic and was about to go out of range of a deep-space ground station in Simeiz. The spacecraft was expected to reenter communications around midnight. Tyulin's memo said that "based on the results of the calculations, it is possible confidently expect reaching the vicinity of the Moon around 7 hours in the morning on January 4." However another memo sent by Tyulin's boss A. Sokolov couple of hours later said that "results of the telemetry processing confirm that the rocket will pass near the Moon and turns into the first artificial planet, or become the artificial satellite of the Sun. The minimal distance of the rocket from the surface of the Moon during a flyby based on measurement will be 6-8 thousand kilometers or two its diameters. The artificial planet's orbital period is still being calculated," Sokolov wrote. Interestingly, Sokolov, Tyulin and a number of other officials signed yet the most detailed memo, apparently few hours after two original documents. In it, they claimed that the orbital elements of the rocket and its predicted pass in the vicinity of the Moon had been determined 2.5 hours after the liftoff, or at 22:15 Moscow Time (on January 2). (509)

Nevertheless, the official telegraph agency of the Soviet Union, TASS, finally announced at 13:00 Moscow Time on January 3 that the "space rocket" would reach the vicinity of the Moon at 7 hours on January 4, 1959. The TASS statement also said that the last stage of the space rocket with a mass of 1,472 kilograms without propellant had been fitted with a special container with measuring equipment for scientific research inside it." Such a phrasing was a clear hint that the spacecraft had not separated from the stage.

On January 4, at 05:52 Moscow Time, or 34 hours after the liftoff, the E1 No. 4 flew by the Moon passing from 5,000 to 7,500 kilometers from its surface or its center, according to various sources. (52, 202, 509)

On January 5, around 10:00 Moscow Time, the probe stopped transmitting after a 62-hour mission, as it reached a distance of 597,000 kilometers from Earth, even though its batteries were certified to work for only 40 hours. (202) The spacecraft was expected to reach the perihelion (closest point to the Sun) of its orbit on Jan. 14, 1959, passing within 146,4 million kilometers from it. By the beginning of September of the same year, the probe would reach the aphelion, located 197.2 million kilometers from the Sun.

Years after the launch of E1 No. 4, the official Soviet sources started identifying the mission as Luna-1. (52)

Much more info and rare images on the space program in the former USSR and beyond can be found in a beautifully illustrated, large-format edition:


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Next chapter: Luna-10

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The Luna-1 mission at a glance (2):

Dry mass of the payload section including the third stage of the launch vehicle with the E1 spacecraft

1,472 kilograms

Payload mass

361.3 kilograms

Geocentric orbit perihelion

146.4 million kilometers

Geocentric orbit aphelion

197.2 million kilometers

Geocentric orbit period

approximately 15 months

Closest distance to the Moon

5,000-6,000 kilometers (52); 7,500 kilometers (202)


Written and illustrated by Anatoly Zak, with a contribution from Paolo Ulivi

Last update: May 28, 2016

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