Lunar mission "Bereshit" - the fourth maneuver was completed successfully, preparations are underway for entering the lunar orbit

Less than 23 days (± several hours) remained before the Bereshit apparatus landed on the Moon, on March 19, 2019 an orbit with an apogee of 405,000 kilometers was reached, testing of on-board systems was ahead, complicated Lunar maneuvers and hours of painful waiting before landing.



Fourth maneuver

Preparation:

On March 18, 2019, a new list of planned commands for executing the maneuver was downloaded and checked into the on-board computer of the Bereshit apparatus, which includes a special algorithm for activating certain software and hardware countermeasures in case of failure at any stage of the maneuver .

Also, SpaceIL engineers planned to organize an additional collection of telemetry data during the execution of this maneuver and take pictures with the on-board cameras of the maneuver process.



The Bereshit apparatus began preparations for the fourth maneuver (the signal from the apparatus is stable)





:

The burn seems to end well. #Beresheet the unstoppable is climbing to the altitude of the Moon now!



The status of the Bereshit apparatus after the analysis of telemetry at the end of the fourth maneuver:



6:04 PP · Mar 19. 2019 year

March 19, 2019 (12:30 UTC. 14:30 Israel Time), the Bereshit apparatus successfully completed the pre-final 60-second maneuver with engines and reached an orbit with an apogee of 405,000 kilometers, which should be enough for the next calculated jump from Earth orbit (this one of the most interesting maneuvers in this mission) and further exit into the lunar orbit.



Ahead of the Bereshit apparatus there are several more micromaneuvers to correct the trajectory, and on April 4, 2019 - a jump into the lunar orbit.

Schedule with the trajectories of the Bereshit apparatus:



Maneuver table for March 19, 2019.


As can be seen from the table, 73 kilograms of fuel has already been spent, 307 kilograms left for Lunar maneuvers.

By the way, new facts about the equipment of the Bereshit device:

- The propulsion system is represented by a chemical rocket engine of the LEROS family (LEROS 2b). The fuel of the Bereshit apparatus is 380 kilograms of monomethylhydrazine, and the oxidizing agent is a mixture of nitrogen oxides (MON). These same components use shunting thrusters. Fuel tanks are made by special order for the Bereshit device in the USA.

- The communication system that is installed on the Bereshit apparatus was originally developed by Space Micro (USA) for the NASA LADEE lunar probe; this communication system operates in the S-frequency range.

Of course, many hams also track the broadcasts of the Bereshit device (at a frequency of 2280.0 MHz):









But what interesting information appeared in connection with the selfie photo of the Bereshit device on the background of the Earth on March 3, 2019, which was officially published on Twitter by SpaceIL.

Here is a photograph of the Earth at the same moment in time (when the Bereshit camera took a picture) made using the DSCOVR (Deep Space Climate Observatory) apparatus for comparing angles (distance of 37,600 km (Bereshit) and 1,609,344 km (DSCOVR) from the Earth ) and the type of surface (DSCOVR picture from top left):





Testing equipment - about a magnetometer and lunar anomaly

On board the Bereshit apparatus there is a SpaceIL Magnetometer (SILMAG) magnetometer, which was developed and manufactured at the Weizmann Institute (Israel, Rehovot).

Using SILMAG, it is planned to carry out a series of measurements of the magnetic field of the moon in the landing zone, and the magnetometer will begin its work at an altitude of 600 km from the lunar surface and will continue to work until the landing.

27 days before the landing, on March 16, 2019, the SILMAG magnetometer was tested on the Bereshit apparatus in outer space, which ended successfully and confirmed that the instrument was operating normally.

The planned landing site of the Bereshit apparatus is the northern part of the Sea of ​​Clarity (lat. Mare Serenitatis). In this region, a "maskon" was discovered - a large positive gravitational anomaly. It is expected that the magnetometer on the Bereshit apparatus will allow a better understanding of the nature of this phenomenon.



Why are the anomalies on the moon so interesting?

For example, a magnetic anomaly with a diameter of 360 kilometers was discovered on the northeastern part of the far side of the Moon, and a 300-kilometer “belt” is formed around it, in which the solar wind moves faster and the particle flux becomes denser.

The magnetic field at the center of the “bubble” is about 300 times weaker than the earth’s above the equator. Thus, scientists believe, it is possible to analyze data on such anomalies, and then using certain calculations to find areas protected from solar radiation on the lunar surface that can be used to locate lunar bases and conduct additional long-term scientific research.

About the place and time of landing on the Moon

This case reminded a bit:

- There is a task - you need to fly to the Sun.
- But it’s hot there and we will burn !?
- Then fly at night!

Only here the situation is this: the

Bereshit device has no thermal protection and cooling systems, the estimated operating time on the lunar surface is about two days (three days maximum), then its electronics and batteries will fail due to overheating, communication with the device will be lost , and it will become the new lunar monument in the Sea of ​​Clarity, next to Lunokhod-2 (Luna-21 missions) and Apollo 17 mission modules.

The date of April 11, 2019 is chosen based on the fact that on the surface of the moon in the landing zone at this time it will be sunny, but not hot. But the temperature on the lunar surface reaches + 127 ° C, depending on the degree of illumination.

Thus, the Bereshit apparatus should land in the northern part of the Sea of ​​Clarity 48 hours after dawn in this region, when the temperature is relatively low.






When landing, the Bereshit on-board computer automatically finds the most suitable landing area (there is still a limitation: the planned landing area is 30 square kilometers).

With the help of engines, the Bereshit apparatus will reduce its speed (from 6000 km / h to 0), after which the engines will be completely turned off at an altitude of five meters above the lunar surface.

Further, the Bereshit apparatus will begin a slow free fall on the lunar surface with subsequent touch. If everything goes smoothly, then at that moment the Bereshit spacecraft will become the first private spacecraft on the moon.



The planned landing site of the Bereshit apparatus is located in this region of the lunar surface:


Why did you choose a landing site in the Sea of ​​Clarity?

Criteria for choosing the landing site for the Bereshit apparatus:

- a large safe area in the landing zone with the ability to maneuver when necessary when lowering and land the first time;

- a site with a relatively small number of craters, freestanding stones or steep slopes in the landing zone;

- the presence in the landing zone of magnetic anomalies for the use of a magnetometer.



It will turn out in fact to land in this planned zone - we will find out after 23 days, but if there are any corrections, it’s only because of the actual decision-making by the Bereshit apparatus already in the process of performing the landing procedure.

A photo of the prototype of the first version of the Bereshit apparatus (this model differs from the real one, which is now in space)

A very beautiful copy of the first prototype of the Bereshit apparatus is exhibited in one of the halls of Ben Gurion Airport (Tel Aviv, Israel).

Here is a picture with the designation of the elements of the device:



And the device itself for comparison:







In reality, the Bereshit device is like this:



Do not forget to follow the Bereshit mission using:

- an online resource with a simulator and real-time data about the current state of the Bereshit mission ";



- NASA's online simulator “ Eyes on the Solar System ”.