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The Guardian - UK
The Guardian - UK
Science
Oliver Holmes

Japan’s ‘Moon Sniper’ craft makes lunar landing but is unable to generate electricity via solar power – as it happened

An artist’s illustration of the Slim lander on the moon. a problem with the lander’s solar panels meant it was operating purely on existing battery power.
An artist’s illustration of the Slim lander on the moon. a problem with the lander’s solar panels meant it was operating purely on existing battery power. Photograph: Jaxa Handout/EPA

Summary

Japan’s space agency says it has made a “successful” landing on the moon, although its probe was not generating solar power and its batteries would drain in a matter of hours.

  • The director of the Japanese space agency, Jaxa, said the landing itself was deemed successful “as the spacecraft sent telemetry data, meaning most equipment on board was operating”.

  • Data sent from the spacecraft back to earth showed the spacecraft made a normal descent and showed it was on the moon’s surface and communicating properly.

  • The spacecraft was designed to land on a slope and then tip over slightly onto its main legs. However, space enthusiasts have suggested the probe might have toppled over too far.

  • Two rovers on board were successfully deployed just before landing and will conduct experiments on the moon, Jaxa officials said.

  • The Slim probe – dubbed the “moon sniper” for its accuracy – sought to show how to make a precise landing. Officials say confirmation of a precise landing could take up to a month.

  • Only four nations - the former Soviet Union, the United States, China and India – have previously achieved a soft landing on the moon’s surface.

A reporter is asking why the space agency officials faces are not looking “happier” at the press conference.

An agency official says the situation is “tough” as they are dealing with the solar panel issue and are thinking of the steps ahead.

A reporter asks about the angle of Slim, and whether it was “upside down”.

Kuninaka, director general of the Japanese space agency, says they cannot answer that as they do not have the data.

Kuninaka, the head of Jaxa’s space lab, says his team is using the limited battery life to prioritise “the transfer of [Slim’s] data” back to earth.

Sunlight might hit the solar cells but it could take over a month

Kuninaka, director general of the Japanese space agency, says that as the moon’s position changes, sunlight could hit the solar cells, which could recharge its battery. However, he adds, this could take over a month.

The spacecraft took photos of the moon’s surface before landing, officials says.

Note: Officials are making clear that they are yet to confirm if the probe – dubbed the “moon sniper” for its accuracy – made a precision descent.

This could take up to a month, a timeframe that was not unexpected.

A key aim of this mission was to land a lightweight craft down less than 100 metres from a predetermined target on the moon’s surface – a dramatic improvement on previous missions, in which the landing zones measured several kilometres.

Kuninaka, director general of the Japanese space agency, says the solar panel issue may have to do with the “attitude” of the probe.

Attitude refers to the position of the spacecraft, suggesting it may be sitting at an unintended angle.

Japan space agency says it considers spacecraft landing to be a 'success'

A reporter asks if the soft landing was “successful” or a “failure”.

Hitoshi Kuninaka, a Jaxa official, replies: “We believe the soft landing itself was successful as the spacecraft sent telemetry data, meaning most equipment on board was operating.”

Updated

Both moon rovers were successfully deployed before landing, Japanese space agency

Both Lev-1 and Lev-2, palm-sized robots, were successfully deployed before the spacecraft landed on the moon, a space official says.

Lev-1 is designed to hop around and take measurements with an onboard thermometer, radiation monitor and slope sensor.

Lev-2, a ball-shaped mini-rover designed with Takara Tomy, the toy firm behind Transformers, is intended to pop open, revealing two cameras.

Japanese probe landed on moon but not generating solar power, space agency says

The Slim spacecraft landed on the moon and is communicating with earth but is not generating electricity via its solar panels, a Japanese space agency official says.

Updated

Key event

The press conference has started.

Updated

The livestream screen says a press conference will be held imminently.

This is very much the current mood of everyone waiting for information on the Slim moon lander:

Staff of Japan Aerospace Exploration Agency (Jaxa) watch a live streaming of the pinpoint moon landing operation by the Smart Lander for Investigating Moon (Slim) spacecraft.
Staff of Japan Aerospace Exploration Agency (Jaxa) watch a live streaming of the pinpoint moon landing operation by the Smart Lander for Investigating Moon (Slim) spacecraft. Photograph: Eugene Hoshiko/AP

Scottish science communicator and astrophysicist Scott Manley thinks it landed and rolled:

You can see here on Nasa’s Deep Space Network, which communicates with spacecraft, that both the Slim lander and one of the rovers, Lev-1, is sending data.

The rovers were intended to be ejected before the landing, so might still be operational even if the Slim itself is having trouble.

Some chatter online (all unconfirmed) that the lander may have made a successful landing, but then tipped over.

Remember, this landing was extraordinary as it took place on a slope.

As part of the unique landing technique, the Slim was supposed to tip over slightly but may have toppled too far.

The Slim lander is still communicating with Nasa satellite dishes, according to Paul Byrne, an Associate Professor of Earth, Environmental, and Planetary Science at Washington University in St. Louis.

How hard is it to make a ‘soft landing’ on the moon?

Space and lunar exploration is notoriously difficult.

Only four nations - the former Soviet Union, the United States, China and India – have achieved a soft landing on the moon’s surface.

This month, the first moon lander to launch from the US in half a century suffered a fuel leak and failed to reach the moon. Peregrine 1 had aimed to become the first commercial space probe to make a soft landing on the moon – a feat that is yet to be achieved.

There have been two failed Japanese missions, one public and one private.

India in August landed a craft near the Moon’s south pole, a historic triumph for its low-cost space programme. Its success came a few days after a Russian probe crashed in the same region, and four years after a previous Indian attempt failed at the last moment.

Nasa has also delayed future moon missions. It plans to put humans back on the lunar surface this decade, and build a space station that orbits the moon.

The Slim was launched in September and travelled for four months in space:

No final confirmation of successful landing, officials say

Just as everyone is on the edge of their seats, officials say the Japanese space agency livestream is closing down!

A press conference will be held, they add, without giving details. Technicians are still “checking the status” of the lander.

We can’t be sure, but this does not sound very promising.

There are no cheers in the Japanese space agency live stream, presumably because they are nervously trying to confirm that the landing was a success.

Officials say they are “checking the status” of the Slim lander.

The data says it had landed but they are assessing the telemetry data.

Japanese lunar probe lands, data shows

A live data feed from the spacecraft shows the Slim spacecraft has made a successful landing on the moon.

If confirmed, it makes Japan the fifth country to touch down safely on the lunar surface.

Seconds away now…

The Slim lander is 5 km above the moon’s surface.

We are in the “vertical descent” mode, the final part of the landing process.

Five minutes until landing

Slim’s engines have started firing again to slow it down before touchdown

Once its touches down, the Slim landing craft is going to tip over … but that is part of the plan.

The landing site is near a crater and therefore has a 15 degree slope, the Japanese space agency says.

Therefore, the lander has a “two-step landing method”, in which the main landing gear first touches the ground and then rotates forward to stabilise itself.

Here is what it should look like:

Officials say the trajectory of the spacecraft is matching what was planned (a good sign)

(I’m really enjoying the soft piano music being played in the background of this Japanese space agency live feed. Very calming in a tense situation!)

The probe is now “scanning the surface” and looking for a place to land, space agency officials say.

The two robots on board the probe

Our science editor, Ian Sample, has some more info on the two robots onboard the spacecraft:

Here’s a little more on what are called the rovers, but should probably have called “lunar excursion vehicles” – one doesn’t so much rove as hop:

The Slim lander carries a couple of quirky “lunar excursion vehicles’’, or Levs, that will hopefully travel around on the moon’s surface, taking measurements and snapping pictures of the lander and its landing site.

Known as Lev-1 and Lev-2, they are both palm-sized robots that should be released by Slim shortly before touchdown. Rather than driving over the surface, Lev-1 is designed to hop around and take measurements with an onboard thermometer, radiation monitor and slope sensor.

The second, a ball-shaped mini-rover designed with Takara Tomy, the toy firm behind Transformers, uses the same shape-changing technology to pop open, revealing two cameras and turning the two hemispheres into wheels. The hope is for the vehicles to hop and trundle over the surface for the couple of hours that their battery life allows.

A member of staff shows a real size model of the palm-sized Lunar Excursion Vehicle 2 (LEV-2).
A member of staff shows a real size model of the palm-sized Lunar Excursion Vehicle 2 (LEV-2). Photograph: Eugene Hoshiko/AP

Updated

Japanese lunar lander begins its descent

Japanese space agency officials say the probe has begun its powered descent.

The process should take 20 minutes.

Live data is being sent from the spacecraft to earth, although there is no live video feed.

The powered descent (which will start in about 10 minutes) will begin from 15 km above the lunar surface, Japnese space agency officials say.

The vertical descent will start at 7 km.

Just before landing, at 2 metres, the probe will release two small rovers.

A miniature model of the Smart Lander for Investigating Moon (Slim) is displayed at Japan Aerospace Exploration Agency (JAXA)'s facility in Sagamihara, south of Tokyo.
A miniature model of the Smart Lander for Investigating Moon (Slim) is displayed at Japan Aerospace Exploration Agency (JAXA)'s facility in Sagamihara, south of Tokyo. Photograph: Kim Kyung-Hoon/Reuters

In this livestream, Japanese space agency officials are referring to a “rabbit” on the moon.

While people in the west see the image of a face on the moon, in East Asia people have long seen the shape of a rabbit instead!

How the probe will make such a precise landing

Our science editor, Ian Sample, has some fascinating details on how the probe plans to make such a precision landing:

There’s more to this mission than simply joining the soft lunar landing club.

The aim is to demonstrate technologies that future missions will need to land precisely where they need to. Until now, space agencies have been happy for landers to touchdown anywhere in an area a few km square - they’ve just gone for the safest options.

But this probe is hoping to demo technologies that give you more pinpoint landings which is going to be important - if you want to mine a certain crater, you don’t want to land 5km away, you want to land right next to it.

This probe has similar AI to that used in facial recognition which it’ll use to recognise patterns of craters on the moon as it flies over. This then feeds into the lander’s calculations for trajectory and engine burns.

Updated

Shin Toriumi, from the Japanese space agency, Jaxa, says the descent phase of the lunar lander (happening in about half an hour) is known internally as “20 minutes of terror”.

You’ll see above we have a live video feed from the Japanese space agency to take us through the landing.

It is being hosted by Shin Toriumi from the Institute of Space and Astronautical Science at the Japan Aerospace Exploration Agency, Jaxa.

Opening summary

A Japanese spacecraft is en route to the moon on a mission prove a highly precise landing can be made on the lunar surface.

In less than an hour, the probe – dubbed the “moon sniper” for its accuracy – will begin its descent. It aims to make a “soft” and safe landing.

If successful, the Smart Lander for Investigating Moon (SLIM) will make Japan the fifth country to touch down safely on the lunar surface. The Japan Aerospace Exploration Agency (Jaxa) hopes pinpoint technology will put the lightweight craft down less than 100 metres from a predetermined target on the moon’s surface – a dramatic improvement on previous missions, in which the landing zones measured several kilometres.

Jaxa officials say the moon sniper is a “technology demonstrator” that will provide vital information for future crewed missions, and the eventual establishment of moon bases. Slim also carries instruments that will aim to “unravel the origins of the Moon” by analysing lunar rocks, Jaxa says.

Oliver Holmes here. I’ll be your guide today as Japan seeks to move the human race another step closer to building a permanent presence on our nearest neighbour, only 380,000 km (239,000 miles) away.

Updated

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