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An Israeli spacecraft has a blow Thursday to orbit the moon with a six-minute engine firing, a critical maneuver that will prepare for the historic probe landing attempt financed by a private fund, on 11 April.
The main engine powered by hydrazine, installed at the base of the Israeli lunar lander Beresheet, is expected to ignite around 14:15 GMT (10:15 am EDT). The six-minute shot will reduce Beresheet's speed over the moon by more than 600 km / h (about 1,000 km / h), enough so that lunar gravity can capture the spacecraft in an elongated orbit.
If the robotic spacecraft fails Thursday, it will continue beyond the moon and escape Earth's gravitational pull to sink deeper into the solar system, ending the mission.
"It's a simple maneuver, but it's very important and very critical," said Ido Anteby, CEO of SpaceIL, the non-profit organization that spearheaded the development of the Beresheet mission.
Beresheet aims to become the first privately funded spacecraft to orbit another planetary body after lunar capture maneuver on Thursday. With a successful hit on April 11, the craft will become the first private probe to land on the moon.
The probe will target a landing in the area of Mare Serenitatis, or sea of serenity, in the upper right of the moon, seen from the Earth.
Beresheet has been circling the Earth since its launch on February 21 at Cape Canaveral aboard a SpaceX Falcon 9 rocket. The LG has gone up into space as a payload overlaid on the Falcon 9, joining an Indonesian telecommunication satellite and a US Air Force space surveillance satellite on the same rocket.
The upper deck of the Falcon 9 released Beresheet on an elliptical orbit up to 69,000 kilometers in altitude. After the separation, the spacecraft deployed its four landing legs. With the landing gear extended, Beresheet has a diameter of about 2.3 meters and measures 1.5 meters high.
A series of main engines burns Beresheet in a longer orbit that keeps the probe away from the Earth.
"Since our launch about five weeks ago, we have been circling the Earth in constantly growing orbits and our current orbit takes us about 420,000 kilometers (261,000 miles) above the Earth, just above of the trajectory of the moon. We have successfully crossed our last perigee, which is the closest approach point to the Earth a few days ago, "said Opher Doron, General Manager of Israel Aerospace Industries' Space Division, who built the Beresheet spacecraft and operates the control of the undercarriage. center.
Beresheet has traveled more than 3.4 million miles (about 5.5 million kilometers) since leaving Cape Canaveral.
The ground controllers identified a problem with the spacecraft's star tracking cameras shortly after its launch. The cameras make it possible to locate the position of the stars in the sky, thus helping to determine the orientation of Beresheet in the space. SpaceIL says that star followers are too sensitive to sunlight.
Beresheet also missed one of its engine burns in orbit at the end of February due to a computer reset, but the engineers kept the mission on schedule for its arrival on the moon.
"We made corrections along the way and we are about to intercept the moon … Thursday afternoon (Israeli time), and here we will perform a complex maneuver to get out of Earth's orbit by lunar orbit. Doron said Tuesday. "So, we will be captured by the moon by our maneuver, and after that we are about to land."
Beresheet must perform at least 70% of the planned pulse for Thursday's lunar capture burn to be trapped in orbit around the moon, according to Yoav Landsman, Beresheet's deputy mission director at SpaceIL.
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If Thursday's maneuver proceeds as planned, Beresheet will enter a 14-hour orbit of about 500 km (310 miles) to about 10,000 km (6,200 miles) from the moon. New engine fire over the next week will place the LG in a 200 km (200 km) circular orbit in preparation for landing.
"Once we reach the right point, we will simply give the spacecraft the command to begin the landing phase," said Yariv Bash, co-founder of SpaceIL. "From that moment, the probe will automatically begin to land on the surface of the moon.
"About 5 meters above the surface of the moon, the speed will reach zero, then we will stop the engines and the spacecraft will make a free fall to the surface of the moon," said Bash on Tuesday. . "The spacecraft's legs were designed to withstand this fall, and we hope we can, once on the moon, send back images and videos to Earth."
Three young Israeli engineers and entrepreneurs founded SpaceIL in 2011 with the aim of obtaining the Google Lunar X Prize, which promised a grand prize of $ 20 million to the first team to land on a satellite with a private financing, to render high definition images and to demonstrate its mobility. the lunar surface.
The Google Lunar X Prize contest ended last year without a winner, but the Beresheet sponsors kept the mission alive.
Morris Kahn, an Israeli billionaire born in South Africa, spent 40 million dollars of his fortune on the mission and is president of SpaceIL. Other donors include Miriam and Sheldon Adelson, a casino and resort mogul living in Las Vegas. LG's owner, IAI, has also invested some of its own internal research and development funds into the program.
The Israeli Space Agency has granted SpaceIL about $ 2 million, the only funding for the program.
The entire mission cost about $ 100 million, much less than any government-backed lunar lander. Nevertheless, raising $ 100 million from private donors has proved a challenge.
"I had never dreamed that we were going to reach $ 100 million, but once we went, we went," Kahn said Tuesday. "It was a challenge and, in fact, I like challenges."
The X Prize Foundation, which organized the original Google Lunar X Prize contest, announced on March 28 that it would offer a $ 1 million "Moonshot Prize" to SpaceIL if the Beresheet mission landed on the moon.
"While the Google Lunar X Award has not been claimed, we are delighted to have encouraged teams from around the world to continue their ambitious lunar missions, and we are proud to recognize the success of SpaceIL with this Moonshot award, "said Anousheh. Ansari, managing director of the X Prize Foundation.
"SpaceIL's mission represents the democratization of space exploration," said Peter Diamandis, founder and executive chairman of the X Prize Foundation. "We are optimistic about the fall of this first domino, triggering a chain reaction of increasingly affordable and repeatable trade missions on the moon and beyond."
A successful landing will not only be a first for the private space industry, but will also push Israel into an exclusive group of nations that have installed a spacecraft on the moon. Until now, the United States, Russia and China have successfully put probes on the moon.
"We have the vision to show the best qualities of Israel to the whole world," said Sylvan Adams, a Canada-Israel businessman who helped finance the mission, at a meeting with press conference between the launch of Beresheet and his company. "Little Israel, little Israel, little Israel, is about to become the fourth nation to land on the moon. And it's a remarkable thing, because we continue to demonstrate our ability to weigh far, far beyond our weight, and to show our skills, our innovation, our creativity to solve any difficult problem that may possibly exist. "
Beresheet means "genesis" or "early" in Hebrew.
Video of #BeresheetDeployment of the landing leg, recorded shortly after the separation of the second leg of Falcon9 on 22 February. In the background, the launcher with the main payload corrects the attitude. Always in the background, the moon.@TeamSpaceIL pic.twitter.com/Nf22FIDCA6
– Yoav Landsman ?? (@MasaCritit) March 24, 2019
Due to the project's limited budget – a fraction of the cost of the government-funded lunar landing gear – the Israeli team had to adapt the technology designed for other purposes to the Moon's mission. For example, the main thruster on the undercarriage is a modified engine, typically used to adjust the orbits of large communications satellites.
During the landing sequence, the engine will be turned on and off to control the rate of descent of the undercarriage. He can not be strangled.
Most spacecraft systems were built without backup to control costs.
"Our spacecraft has very little redundancy," said Anteby. "A sensor that fails could fail the whole mission."
After landing, Beresheet will collect data on the magnetic field at the landing site. NASA has also provided a laser reflector on the probe, which scientists will use to determine the exact distance to the moon and to locate the undercarriage. The US Space Agency also provides communication and monitoring services to the mission.
The German space agency DLR has also helped the SpaceIL team to carry out drop tests to simulate the conditions encountered by the spacecraft at the time of landing.
The Israeli-made lander is designed to operate for at least two days on the moon, enough time to transmit basic science data, a series of panoramic images and a selfie. The laser reflector is a passive payload and will be useful long after stopping the spacecraft.
Beresheet also aims to deliver a time capsule on the moon with the Israeli flag and digital copies of the Israeli national anthem, the Bible and other national and cultural artefacts.
Doron said that, initially, IAI did not see much future for the tailor made LG design after the Beresheet mission. But this is changing as NASA and the European Space Agency plan to buy commercial trips to the moon for scientific experiments and possibly people.
IAI and OHB, a German aerospace company, signed an agreement in January that could build on the Beresheet mission by building future commercial landers to carry scientific instruments and other payloads on the surface of the moon for the benefit of from ESA.
According to Doron, IAI is also in discussion with US companies to use Israeli technology developed for the Beresheet project on lunar commercial sites for NASA's Commercial Lunar Payload Services program. Last year, NASA selected nine companies to compete for scientific and technological demonstration payload transportation contracts on the lunar surface.
SpaceIL and IAI were not among the winners, but Israeli engineers could partner with US companies to meet NASA's requirements.
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Follow Stephen Clark on Twitter: @ StephenClark1.
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