Tag: spaceflight

Hayabusa-2’s successfully bombs Ryugu

7:51 am

impact on Ryugu

Japan’s Hayabusa-2 probe yesterday successfully impacted an explosive charge on the surface of the asteroid Ryugu, creating a crater for observing the interior geology.

The image to the right was taken by a camera that has separated from Hayabusa-2 and stayed closer to the impact. It shows material flying off the asteroid’s surface, at the horizon line.

Hayabusa-2 — which moved to the other side of the asteroid to stay clear of any ejecta — will next arc around and get close to this impact site to study it. They first need to make sure the ejecta has cleared.

4 comments

Monitoring the ice scarps on Mars for changes

1:30 pm

Scarp #1 in 2011
Click for full image.

Scarp #1 in 2018
Click for full image.

Back in January 2018 planetary scientists released a paper announcing the discovery of a number of Martian cliff faces, or scarps as they called them, that all appeared to expose an underground layer of ice.

Those cliffs were mostly located to the southeast of Hellas Basin, the basement of Mars that is also advantageous for human colonization because its lower elevation means its atmosphere is thicker. (For example, that thicker atmosphere would make air transportation more practical.)

The two images to the right show what they listed as scarp #1 in their paper, rotated, cropped, and reduced to post here. The first image was taken in May 2011, with the second taken in December 2018, and was part of the March image release from the high resolution camera of Mars Reconnaissance Orbiter (MRO).

The December 2018 image was taken almost a year after the paper release, and was titled “Scarp Monitoring.” I therefore wondered whether the scientists had identified any changes. They theorize that these scarps form when the exposed ice slowly sublimates to gas into the atmosphere, causing the cliff face to collapse and retreat, which in the case of scarp #1 would be a retreat to the north. The terraces below the scarp suggest previous cliff locations. In their paper they noted evidence of some changes in the studied scarps, including some fallen boulders, as well as color changes that suggest some evolution.

The rate of that retreat is not known with precision, but based on the facts presently at hand, the scientists have estimated that it took about a million years to form this scarp. Whether any evidence of this retreat would be visible in only seven years is the purpose of these scarp monitoring images.

Do you see any difference? I don’t, but because I also don’t trust my expertise I decided to email the paper’s lead author, Colin Dundas of the U.S. Geological Survey’s Astrogeology Science Center. His emailed comments are most interesting.
» Read more

2 comments

Amazon to build its own giant satellite constellation

10:25 am

Capitalism in space: Amazon has officially joined the race to build own giant satellite constellations for providing internet access worldwide.

[They] plan to put 3,236 satellites in low Earth orbit — including 784 satellites at an altitude of 367 miles (590 kilometers); 1,296 satellites at a height of 379 miles (610 kilometers); and 1,156 satellites in 391-mile (630-kilometer) orbits.

In response to GeekWire’s inquiries, Amazon confirmed that Kuiper Systems is actually one of its projects. “Project Kuiper is a new initiative to launch a constellation of low Earth orbit satellites that will provide low-latency, high-speed broadband connectivity to unserved and underserved communities around the world,” an Amazon spokesperson said in an emailed statement.

The competition now includes Amazon, SpaceX, OneWeb, and others, each of which will provide a lot of business for the launch industry. All told, more than 15,000 satellites will need to be launched by these companies before the middle of the next decade.

6 comments

Curiosity films partial solar eclipses by both Phobos and Deimos

10:15 am

Phobos partial eclipse of Sun

Last week Curiosity successfully captured partial solar eclipses by both Phobos and Deimos as the Martian moons crossed the face of the Sun.

The movie on the right shows Phobos eclipsing the Sun. The speed is ten times faster than real time.

The press release can be seen here. It notes how these observations, of which 8 in total have been made since Curiosity arrived on Mars, have helped pin down the orbits of both moons.

3 comments

Air Force confirms more Rocket Lab launches

9:46 am

Capitalism in space:: With the successful launch of a DARPA satellite by Rocket Lab last week, the Air Force yesterday confirmed the purchase of several more launches on the company’s Electron Rocket.

Three satellites will be launched to low Earth orbit later this month from Mahia, New Zealand, using Rocket Lab USA’s Electron rocket.

…The upcoming Rocket Lab launch is one of five planned in 2019. … Five small launches will send 21 experimental satellites to space by the end of December, said Lt. Col. Andrew Anderson, chief of the DoD Space Test Program Branch.

One of the five will be by Vox Space later this year. The company will use Virgin Orbit’s LauncherOne rocket that is air launched from a Boeing 747 mothership.

Anderson said there is possibly another vendor in the mix but only Rocket Lab and Vox Space so far can be identified.

I suspect that the unnamed vendor is Vector, but the Air Force is likely not going commit to this until Vector gets farther along in its test program.

Leave a comment

Chandrayaan-2’s new delay is due to damage during test

9:38 am

The new colonial movement: It appears the reason for the new delay in the launch of India’s Chandrayaan-2 lunar lander is that the spacecraft suffered minor damage during a landing test.

A source in the know, said: “The rover and orbiter are in good health and tests met all the parameters. However, after the ‘Lander Drop Test’, we found that Vikram (the lander) needed to be strengthened in its legs. Prima facie, it appears that not all parameters were set correctly before the test, it could also be that the additional mass—a result of the new configuration—caused the problem.”

They still seem determined to launch in May, though I suspect this is not realistic. It depends on exactly when this test occurred. The article does not say, and if it occurred several months ago then the May date might make sense. Otherwise, expect further delays.

Leave a comment

Beresheet enters lunar orbit

9:02 am

The privately-built lunar lander Beresheet today successfully entered lunar orbit.

They achieved this by completing an engine burn that changed their Earth orbit to an elliptical lunar one.

At 5:18 p.m. Israel time on April 4, the spacecraft’s engine activated for six minutes and reduced its speed by 1,000 km/hour, from 8,500 km/hour to 7,500 km/hour, relative to the moon’s velocity. The maneuver was conducted with full communication between Beresheet’s control room in Israel and the spacecraft, and signals in real time match the correct course. In the coming week, with expected intense engineering activities, many more maneuvers will take Beresheet from an elliptical to a round orbit, at a height of 200 km. from the moon. The maneuvers will aim to reduce the spacecraft’s distance from the moon and reach the optimal point to conduct an autonomic landing in the Sea of Serenity in the evening Israel time, April 11.

You can see a video of their mission control at the completion of this burn here.

Leave a comment

Future of InSight’s heat probe dim

2:26 pm

Blocked after drilling down only one foot instead of fifteen, engineers are increasingly worried that they will not be able to get InSight’s heat probe past whatever is blocking to so it can begin getting data of Mars’s inner thermal environment.

They are considering a bunch of options, including using InSight’s robot arm to either give the probe a nudge to help it get past the obstruction, or even use the arm to push the probe.

None of the options are encouraging it seems.

9 comments

A decade of changes at the Martian south pole

1:54 pm

A decade of changes at the Martian south pole
Click for full image.

The image above, cropped, reduced, and annotated to post here, was released this week by the Mars Reconnaissance Orbiter (MRO) team. It shows the changes that have occurred at one location at the Martian south polar cap in the past decade. As planetary geologist Alfred McEwen wrote,

The south polar residual cap of carbon dioxide ice rapidly changes. This image was planned as an almost exact match to the illumination and viewing angles of a previous one we took in August 2009.

The pits have all expanded and merged, and we can just barely see the patterns in the 2009 image compared to this January 2019 picture. The 2009 image is also brighter and bluer, with more seasonal frost and/or less dust over the surface. These images were both taken in late southern summer, but our 2019 picture is slightly later in the Martian season by about two weeks.

You can get a better idea how much is changed by seeing the full image from which the above small area was cropped.
» Read more

One comment

The Viking landers and its possible discovery of extraterrestrial life

9:37 am

Link here. One of the scientists involved in the Viking project has written a memoir of her experience, and the article interviews her.

Patricia Straat served as co-experimenter on one of the most controversial experiments ever sent to Mars: the Labeled Release instrument on the Viking Mars landers. The experiment’s principal investigator, Gilbert Levin, insists to this day that the project found extraterrestrial life. Most scientists doubt this interpretation, but the issue has never been fully settled.

Read it. It illustrates how uncertain science can be, even when an experiment produces a result that everyone involved dreamt of. As Straat notes,

The results met the pre-mission definition of a positive life response. But of course as soon as we got it everyone came up with alternative proposals to account for the results nonbiologically.

The problem was that though their experiment found evidence of life, none of the other Viking experiments did. Most significant was the apparently complete lack of organic material (based on carbon) in the soil.

To this day, no one has a good explanation for these results on Viking. The results remain a mystery, one that really will only be solved when we can return to Mars in force, and find out what it is really like.

5 comments

Global map of Bennu

9:26 am

Global map of Bennu

The OSIRIS-REx science team today released a global map of Bennu, compiled from images taken in December.

The map is above. It was released with no commentary. In comparing it with this global map of Ryugu, created by the Japanese probe Hayabusa-2, I am struck by how much both asteroids resemble each other.

This fact is in many ways a first. Since the first planetary probes left Earth in the 1960s the one reliable expectation that has consistently proven true is that no planetary object, be it planet, dwarf planet, moon, asteroid, or comet, was going to resemble any other planetary object. Each has been entirely unique, and unique in very startling and obvious ways.

Ryugu and Bennu represent the first planetary objects that actually look pretty much the same. Scientist will of course be able to note differences, but overall these objects clearly belong to a specific class of asteroids, which in this case is the rubble pile.

In a sense, this similarity marks a significant advancement in our knowledge. Up until now, we had observed so few objects that our knowledge base wasn’t large enough to start seeing patterns within our general classifications of planet, asteroid, or comets. That is now finally changing.

4 comments

Boeing confirms delay till August for first unmanned Starliner launch

10:17 pm

No surprise here: Boeing today confirmed that it is delaying until August for first unmanned Starliner test launch.

A statement issued by Boeing on Tuesday confirmed previous reports that the company’s CST-100 Starliner spacecraft, designed and built under a $4.2 billion contract from NASA, would miss its previous target launch date for an unpiloted test flight to the International Space Station in April. NASA and industry sources have said for months that an April launch date was not feasible, but NASA and Boeing had not officially published a revised schedule since early February.

The first Starliner test flight with astronauts on-board was previously scheduled for August. In Boeing’s schedule update released Tuesday, the company only said it expects the Crew Flight Test to occur “later this year,” but sources said the Starliner could fly with astronauts in November, at the earliest.

It appears that the fuel leak during a thruster test in June of last year has been the main cause of the delay.

None of this should effect SpaceX, which is primed to fly its mission during the summer. It does however cause more problems for Boeing, which is now also faced with pressure to finish NASA’s SLS rocket, bogged by years of delays and cost overruns.

7 comments

More Martian Pits!

1:11 pm

More pits on Mars!

As I said in my last post in February showing recent pit discoveries on Mars, I could almost make this a monthly series. In the March image download from the high resolution camera of Mars Reconnaissance Orbiter (MRO) were three (maybe four) more pits, all likely skylights above lava tubes and all located near the giant volcano Arsia Mons in the region dubbed the Tharsis Bulge. The image to the right shows all three, with a possible fourth just northwest of pit #2 and visible in its full image. For the full images of the other two pits go here (#1) and here (#3). In all three cases, click on the “black & white map projected” link to see the full image with scale.

Overview map

The overview map on right shows where these three pits are located. If you compare this map with my previous overview maps from November 12, 2018 and February 22, 2019 you can see that while these pits are all found on the volcanic slopes surrounding Arsia Mons, they are all different pits. Moreover, the ten pits listed in these three posts are only a small sampling of the more than hundred already found.

Whether these pits are deadend sinks or skylights into underground lava tubes that connect is at this point unknown. It would be a reasonable speculation to assume that some are deadends, and some link to extensive tubes of varying lengths. It would also be dangerous. Mars is alien. While the geology will be based on the same physical laws found on Earth, the lighter gravity is going to produce things differently.

The three images above however do show some intriguing details.
» Read more

Leave a comment

India’s Chandrayaan-2 lunar lander delayed until May

9:10 am

The new colonial movement: India has once again delayed the launch of its Chandrayaan-2 lunar lander, pushing the launch back to May.

Previously they had said they’d launch in mid-April.

The article implies that the month delay has to do with scheduling the lander’s arrival so that it arrives at the best time during the long lunar day.

This mission was originally set to launch in April 2018, then October 2018, then January 2019. Because of these delays, Israel’s Beresheet lunar lander leap-frogged them to the Moon, and now stands poised to make Israel the fourth nation to achieve a lunar landing, beating India.

Leave a comment

Beresheet makes course adjustment just prior to entering lunar orbit

8:59 am

Earth as seen by Beresheet

The Israeli privately-funded lunar lander Beresheet yesterday completed a one-minute engine burn to adjust its course slightly in preparation for entering lunar orbit on April 4.

This morning’s 72-second-long burn helped make some “final adjustments” ahead of capture into lunar orbit, mission team members said in an update this morning. It’s unclear if any further such tweaks will be needed. “The teams are assessing the results to determine if another alignment will be required before Beresheet enters the lunar orbit this Thursday,” project team members said.

The image to the right was taken by Beresheet of the Earth during its last close approach on March 31. It appropriately shows the Middle East, with the Arabian peninsula visible just below center.

The landing is still scheduled for April 11.

Leave a comment

Vector delays next test launch until June

8:56 am

Capitalism in space: Vector Launch has now delayed its next suborbital test launch three months to June.

Previously they had hoped to get this suborbital test launched in March/April. The company has not set any firm date in June, and cautions that further delays should not be unexpected. Assuming this suborbital launch happens this summer, they then hope to get their first orbital rocket launched by the end of the year.

Leave a comment

Yutu-2 and Chang’e-4 awake for fourth lunar day

8:43 am

The Chinese rover Yutu-2 and lander Chang’e-4 were awakened on March 30, 2019 to begin work for their fourth lunar day on the surface of the Moon’s far side.

The rover was designed to last for three lunar days, but much like NASA missions that regularly outlive their initial mandates, Yutu 2’s mission may stretch on longer, the Chinese space agency hopes. (The current rover’s predecessor, Yutu, lost its roving ability on its second day on the moon.)

The China Lunar Exploration Program, which heads up the mission, has not provided any details about its scientific plans for the fourth day of Chang’e 4, which is focused on exploring the far side of the moon and how it differs from the near side.

Based on the images taken by Lunar Reconnaissance Orbiter, it appears they will be heading west, following the smoothest route away from Chang’e-4. This will place Yutu-2 in an area of small craters.

Leave a comment

Mars Express confirms Curiosity 2013 methane detection

8:40 pm

The uncertainty of science: The Mars Express science team today announced that a reanalysis of the orbiter’s data showed the same spike spike of methane detection as seen by Curiosity on June 15, 2013.

The study exploited a new observation technique, allowing the collection of several hundred measurements in one area over a short period of time. The teams also developed a refined analysis technique to get the best out of their data.

“In general we did not detect any methane, aside from one definite detection of about 15 parts per billion by volume of methane in the atmosphere, which turned out to be a day after Curiosity reported a spike of about six parts per billion,” says Marco Giuranna from the Institute for Space Astrophysics and Planetology in Rome, Italy, the principal investigator for the PFS experiment, and lead author of the paper reporting the results in Nature Geoscience today.

“Although parts per billion in general means a relatively small amount, it is quite remarkable for Mars – our measurement corresponds to an average of about 46 tonnes of methane that was present in the area of 49 000 square kilometres observed from our orbit.”

Ten other observations in the Mars Express study period that reported no detections at the limit of the spectrometer’s sensitivity corresponded to a period of low measurements reported by Curiosity.

The data, along with their estimate about the source location for the methane, suggests that this was a geological event, not the result of biological life. They think the methane was trapped in ice-filled fissures, and released when that ice either broke or melted. Whether the methane itself was formed by past microbial life sometime in the past remains completely unknown.

To put it mildly, there are a lot of uncertainties in this result.

Leave a comment

NASA head says that Falcon Heavy remains a future option for Orion

4:56 pm

At an agency meeting for employees NASA administrator Jim Bridenstine reiterated that NASA is still seriously considering the use of SpaceX’s Falcon Heavy for future Orion lunar missions instead of SLS.

Bridenstine then laid out one scenario that has huge implications, not for a 2020 launch, but one later on. Until now, it was thought that only NASA’s Space Launch System could directly inject the Orion spacecraft into a lunar orbit, which made it the preferred option for getting astronauts to the Moon for any potential landing by 2024. However, Bridenstine said there was another option: a Falcon Heavy rocket with an Interim Cryogenic Propulsion Stage built by United Launch Alliance. “Talk about strange bedfellows,” he mused about the two rocket rivals.

This plan has the ability to put humans on the Moon by 2024, Bridenstine said. He then emphasized—twice—that NASA’s chief of human spaceflight, William Gerstenmaier, has yet to bless this approach due to a number of technical details. His reservations include the challenge of integrating the Falcon Heavy rocket in a horizontal position and then loading Orion with fuel in a vertical configuration on the launchpad. The Falcon Heavy would also require a larger payload fairing than it normally flies with. This would place uncertain stress on the rocket’s side-mounted boosters.

All the problems outlined in the second paragraph are the result of bad past management at NASA. Just as you design your rocket based the rocket engines you have — in order to save time and money — you design your capsule and manned vehicles based on the rockets that are available. NASA did not do this. It built Orion in a fantasy la-la land, without addressing the real world rocket options available. Now it has to either reconfigure, or get SpaceX to rethink the Falcon Heavy. Neither option will be cheap.

Regardless, Bridenstine’s statement is another shot across the bow to the porkmeisters in Congress. SLS is on shaky financial ground. It cannot compete in price with the commercial options. More significantly, it cannot come close to matching the launch rates of the private rockets. In the time NASA could put together one SLS launch, SpaceX could likely fly five to ten Falcon Heavies, and still do it for less money overall.

SLS is now tasked with a December 2020 deadline for launching that first unmanned test flight. Should it fail to meet that date, the political battle lines are now being laid for replacing it.

10 comments

Circular feature on Mars?

2:52 pm

A circular feature on Mars?
Click for full resolution image.

Today’s cool image is cool for two reasons. First and foremost, the image, found in the archive of the high resolution camera of Mars Reconnaissance Orbiter (MRO), is titled “Circular Feature.” On the right is the full image, reduced to post here. I have searched it high and low, at low resolution as well as full resolution, and can find nothing, nothing at all, that invokes a circular feature to me.

This strange terrain is located very close to the southern icecap. If anything, the knobs and features that fill this image remind me of brain terrain, partly obscured by a layer of partly melted snow or frost. Nothing however seems circular in the slightest.

The second reason this image is cool is that it is very representative of its very large surrounding region. For what appears to be several hundred miles in all directions this is all that one can see, in a variety of MRO images, here, here, here, here, here, and here, to show only a few. Ever so often a craterlike feature pops out, like in the last example, but generally the surface continues in this undulating bland manner, endlessly. The only changing aspect is the dark streaks that cut across, likely dust devil tracks made over a long period of time.

Below the fold is a section of the full resolution image, at full resolution. It doesn’t really matter where I took the crop, as anywhere in the full image everything looks pretty much the same. The only slow change that I can perceive is that the surface seems to be descending to the north, with the lighter areas implying the existence of terraces.

Take a look, and try to figure out for yourself what is going on here.
» Read more

4 comments

India launches military satellite plus 28 smallsats

8:47 am

Capitalism in space: India today successfully used its PSLV rocket to launch one Indian military satellite plus 28 smallsats.

The rocket’s fourth stage demonstrated an additional capability.

Monday’s launch, the second of the year for India’s Polar Satellite Launch Vehicle (PSLV), was tasked with a series of maneuvers for the rocket’s upper stage to insert twenty-nine deployable payloads into their pre-planned orbits over the first two hours of its flight.

Following separation of the last payload, the upper stage will maneuver to a final orbit where it will operate as a research platform, hosting three attached payloads to demonstrate this capability for future missions. The launch also tests out a new configuration for the PSLV, a further intermediate between the lightest and heaviest versions of the rocket.

UPDATE: Yesterday China also launched a communications satellite designed to facilitate in-space communications, using its Long March 3B rocket.

The leaders in the 2019 launch race:

4 China
3 SpaceX
3 Europe (Arianespace)
2 Russia
2 India

The U.S. continues to lead China in the national rankings 6 to 4.

Leave a comment

Scientists propose widespread deep groundwater on Mars

9:40 am

In a new study, scientists are now suggesting that widespread deep groundwater exists on Mars, and is the cause of the recurring slope lineae seen on many Martian slopes.

Previous theories for the cause of lineae proposed both dry and wet processes, all related to either near surface or atmospheric phenomenon. This new hypothesis is different, as it proposes deep groundwater as the source.

“We propose an alternative hypothesis that they originate from a deep pressurized groundwater source which comes to the surface moving upward along ground cracks,” Heggy says. “The experience we gained from our research in desert hydrology was the cornerstone in reaching this conclusion. We have seen the same mechanisms in the North African Sahara and in the Arabian Peninsula, and it helped us explore the same mechanism on Mars,” said Abotalib Z. Abotalib, the paper’s first author.

The two scientists concluded that fractures within some of Mars’ craters, enabled water springs to rise up to the surface as a result of pressure deep below. These springs leaked onto the surface, generating the sharp and distinct linear features found on the walls of these craters. The scientists also provide an explanation on how these water features fluctuate with seasonality on Mars.

This conclusion is most intriguing, but it is far from certain. Scientists have found a lot of lineae. For all of them to come from deep groundwater rising under pressure through fractures seems unlikely.

Nonetheless, this research indicates the growing belief among Mars researchers that water exists everywhere on Mars, and is accessible.

7 comments

Mars helicopter completes first test flight

9:28 am

The small helicopter that will fly autonomously as part of the Mars 2020 rover mission has successfully completed its first test flights here on Earth.

“We only required a 2-inch (5-centimeter) hover to obtain all the data sets needed to confirm that our Mars helicopter flies autonomously as designed in a thin Mars-like atmosphere; there was no need to go higher. It was a heck of a first flight,” [said Teddy Tzanetos, test conductor for the Mars Helicopter at JPL.]

The Mars Helicopter’s first flight was followed up by a second in the vacuum chamber the following day. Logging a grand total of one minute of flight time at an altitude of 2 inches (5 centimeters), more than 1,500 individual pieces of carbon fiber, flight-grade aluminum, silicon, copper, foil and foam have proven that they can work together as a cohesive unit.

This helicopter drone is a technology experiment, more focused on testing helicopter flying on Mars that doing science. If it proves to work, it will open up a whole new unmanned option for exploring the Martian surface. Imagine a helicopter that takes short hops from point to point. It will be able to reach locations a rover never could, and do it faster.

4 comments

Beresheet to win $1 million if it succeeds in lunar landing

9:13 am

Capitalism in space: The X-Prize Foundation today announced that it will award the Israeli company SpaceIL a million dollar award should its privately-funded spacecraft Beresheet successfully soft land on the Moon on April 11.

The foundation also stated that it is considering offering other similar awards for similar private achievements. In that context, this article in Science today gives a nice summary of the private companies now working to buiild and launch private planetary probes.

Two companies, Moon Express and TeamIndus, appear ready to fly their lunar landers in 2020. Four others have announced plans, but their schedules and status are less firm. In all cases, these companies are establishing themselves as commercial alternatives to the expensive, government-built planetary probes of the past. Rather than build their own spacecraft, scientists in the future will hire these companies, and attach their instruments to their spacecrafts. And get things build faster and for less money.

Moreover, NASA itself has been encouraging this transition.

One comment

Parker about to do its second close fly-by of Sun

8:48 am

The Parker Solar Probe is now approaching its second close fly-by of the Sun, set to occur on April 4.

During this solar encounter phase, which lasts until April 10, the spacecraft’s four suites of science instruments are fully operational and storing science data collected from within the Sun’s corona. As designed, Parker Solar Probe will be out of contact with Earth for several days during the solar encounter. This allows the spacecraft to prioritize keeping its heat shield, called the Thermal Protection System, oriented towards the Sun, rather than pointing its transmitter towards Earth. Science data from this second solar encounter phase will downlink to Earth over several weeks later in spring 2019.

This fly-by the spacecraft will match the record of 15 million miles set during the first orbit as the closest any human spacecraft has ever gotten to the Sun. Future orbits however will get closer.

3 comments

Rocket Lab launch a success

4:44 pm

Capitalism in space: Rocket Lab today successfully placed a DARPA technology satellite in orbit using its smallsat Electron rocket.

Expect there to be an increase in the pace of launches from this company in the coming months.

The leaders in the 2019 launch race remain the same however:

3 SpaceX
3 China
3 Europe (Arianespace)
2 Russia

The U.S. however now leads in the national rankings, 6 to 3, over China and Europe. I list Rocket Lab as an American company because that’s what the company calls itself, even though it launches from New Zealand and right now builds the bulk of its rockets there.

3 comments
1 … 212 213 214 215 216 … 434