SpaceX Dragon capsule docks with space station

The Dragon capsule lifted its nose cone to make the docking

America’s new astronaut capsule has successfully docked with the International Space Station (ISS) as part of its demonstration mission.

The Dragon vehicle, launched by California’s SpaceX company on Saturday, made the attachment autonomously.

It is the latest in a series of tests the capsule must pass in order to get approval from Nasa to transport people.

All this particular mission is carrying is a test dummy and 90kg of supplies.

But if everything goes according to plan, astronauts could be launching in the Dragon as early as July.

The capsule’s “soft capture” contact with the ISS occurred at 10:51 GMT, when the station was flying over ocean just north of New Zealand. A full and secure docking was confirmed about 10 minutes later.

Watch the Dragon capsule launch to orbit atop a Falcon rocket

The Dragon approached the 400 km-high (250 miles) station from the front and used its computers and sensors to guide itself in.

Astronauts aboard the ISS watched closely on HD cameras to make sure the capsule performed as planned.

The capsule advanced on the station slowly, stepping through a series of planned waypoints.

US astronaut Anne McClain and Canadian astronaut David Saint-Jacques oversaw events from the station’s big bay window, or Cupola. They had the facility to command the Dragon to hold, retreat and even abort the docking.

After some rehearsals, the “go” was given for the final approach.

US astronaut Anne McClaincopyright NASA
US astronaut Anne McClain was soon able to climb inside the Dragon capsule

Attachment was made to a new type of mating adaptor on the ISS’s Harmony module.

This has a spring system which initially dampens the movement of the incoming vehicle, before applying a series of hooks to pull it in and make an air-tight seal – so-called “hard capture”.

Saint-Jacques and ISS commander Oleg Kononenko were able to enter the Dragon a couple of hours later, after the air pressures inside the capsule and the station had been equalised.

Dragon capsule
Presentational white space

The docking procedure is a step up for SpaceX because the cargo ships it normally sends to the lab have to be grappled by a robotic arm and pulled into a berthing position. The freighters do not have the sophistication to dock themselves.

The Dragon capsule is due to stay at the ISS until Friday when it will detach and begin the journey back to Earth.

This is the phase of the mission that SpaceX founder Elon Musk says worries him the most – the fiery, high-speed descent through the atmosphere.

The Dragon’s backshell, or heatshield, has a somewhat irregular shape and that could lead to temperature variations across the base of the capsule at hypersonic speeds.

“It should be fine, but that’ll be a thing to make sure it works on re-entry,” said Mr Musk.

“Everything we know so far is looking positive. Unless something goes wrong I should think we’ll be flying (people) this year; this summer, hopefully.”

Elon Muskcopyright GETTY IMAGES/NASA
Elon Musk with astronauts Doug Hurley and Bob Behnken who will make the first crewed flight

The American space agency wants to contract out crew transport to SpaceX.

Whereas in the past, Nasa engineers would have top-down control of all aspects of vehicle design and the agency would own and operate the hardware – the relationship with industry has been put on a completely new footing.

Today, Nasa sets broad requirements and industry is given plenty of latitude in how it meets those demands.

Agency officials still check off every step, but the approach is regarded as more efficient.

Dragon capsulecopyright NASA
 Two docking views: What Dragon saw on approach (L) and what the ISS saw (R)

Nasa chief Jim Bridenstine said it was a new era where “we are looking forward to being one customer, as an agency and as a country.

“We’re looking forward to being one customer of many customers in a robust commercial market place in low-Earth orbit, so we can drive down costs and increase access in ways that historically have not been possible.”

Nasa is also working with Boeing on crew transport. The company has developed a capsule of its own called the Starliner. This will have its equivalent demo flight in the next couple of months.

Tech Tent: 5G, Huawei and a question of trust

1 March 2019
Chua Sock Kooong, from Singtel, giving a keynoteImage copyrightGETTY IMAGES
Image captionMobile World Congress kicked off this week in Barcelona with a bunch of keynotes and lots of new phones

It was the star turn of Mobile World Congress with a folding phone that was 5G ready. But on this week’s Tech Tent we ask should the mobile industry trust Huawei?

When I first attended the giant Barcelona mobile gathering more than a decade ago, it was the likes of Nokia, Samsung and even Microsoft, with its Windows phones, which made the headlines.

Podcast available now

Huawei was an obscure Chinese telecoms equipment maker that occupied a large shed on the showground but struggled to generate much interest from the media.

This year the company’s press conference on Sunday was the hottest ticket, with swarms of journalists queuing up for an hour to get in.

Rory Cellan-Jones with Huawei's Mate X
Rory gets his hands on a Huawei folding phone and he didn’t break it, much to the firm’s relief

At the heart of the loud and slightly clunky presentation was the Huawei Mate X, a phone with a foldable screen that the presenter suggested was bigger and better in every way than the Samsung Galaxy Fold, unveiled a few days earlier.

Despite the fact that at $2,600 (£1,960) it was also even more expensive, most analysts agreed that it trumped the Samsung device. I even managed to get my hands on it the following day though the Huawei executive who produced it out of an inside jacket pocket seemed terrified that I might fold it too far and break it.

But if Huawei was rather more open about its new device than Samsung, there was one issue that was firmly off the agenda, The company did not want to talk about the allegations from the United States that it poses a security threat to the new 5G networks.

US government officials were in Barcelona to press home their message that Huawei owes its allegiance to the Chinese Communist Party and should not be trusted by the mobile operators to provide secure equipment for their new networks.

Graphic showing speeds of 3G, 4G and 5G
What can 5G do?

The Europeans were keen to be seen as sharing some of those concerns. Security consultant David Rogers tells Tech Tent the operators do realise that they may have become over-reliant on cheap Huawei equipment: “The mobile networks have paid bottom dollar in a lot of cases for certain network equipment and that equipment might not be the same quality as other providers and now they’re reaping what they’ve sown.”

But the operators also appear to share Huawei’s view that the United States has failed to provide evidence of any wrongdoing in the form of backdoors in its equipment.

The consensus is that all providers, whether from China or elsewhere, need to be subjected to greater scrutiny as 5G networks are rolled out and become embedded in vital infrastructure.

With 5G demos everywhere across the vast halls of Mobile World Congress, it was apparent how central this technology is to this industry’s ambitions and how important security will be.

We saw how in Toronto 5G sensors have been installed across the water system to identify water pressure and improve efficiency by spotting any leaks. A team from the UK’s University of Surrey showed off a 5G-enabled McLaren sports car which could receive live information about other cars and hazards from sensors mounted by the roads.

5G graphiccopyright REUTERS
5G could be vital for smart city services but can the operators make money?

In both cases, you would want to be certain that the networks and the devices connected to them could not be hacked.

Along with all these security concerns, the operators and manufacturers face another nagging question – can they actually make money from 5G? As we emerged from the event where the Chinese firm Xiaomi had unveiled a 5G handset for $679, I ran into the leading mobile analyst Ben Wood of CCS Insight.

He described that price as “eye-popping” – and he meant low not high. With the Chinese firm offering a state-of-the-art 5G handset at a price way below Samsung and Apple’s 4G flagships, Ben reckons middle market manufacturers like Sony and LG will struggle to make any kind of margin.

5G looks certain to bring another wave of disruption to the mobile industry. And whatever the issues of trust and security, Chinese firms like Xiaomi and Huawei look likely to prosper.

Spider silk could be used as robotic muscle

David L. Chandler | MIT News Office
March 1, 2019

Spider silk, already known as one of the strongest materials for its weight, turns out to have another unusual property that might lead to new kinds of artificial muscles or robotic actuators, researchers have found.

The resilient fibers, the team discovered, respond very strongly to changes in humidity. Above a certain level of relative humidity in the air, they suddenly contract and twist, exerting enough force to potentially be competitive with other materials being explored as actuators — devices that move to perform some activity such as controlling a valve.

The findings are being reported today in the journal Science Advances, in a paper by MIT Professor Markus Buehler, head of the Department of Civil and Environmental Engineering, along with former postdoc Anna Tarakanova and undergraduate student Claire Hsu at MIT; Dabiao Liu, an associate professor at Huazhong University of Science and Technology in Wuhan, China; and six others.

Researchers recently discovered a property of spider silk called supercontraction, in which the slender fibers can suddenly shrink in response to changes in moisture. The new finding is that not only do the threads contract, they also twist at the same time, providing a strong torsional force. “It’s a new phenomenon,” Buehler says.

“We found this by accident initially,” Liu says. “My colleagues and I wanted to study the influence of humidity on spider dragline silk.” To do so, they suspended a weight from the silk to make a kind of pendulum, and enclosed it in a chamber where they could control the relative humidity inside. “When we increased the humidity, the pendulum started to rotate. It was out of our expectation. It really shocked me.”

The researchers were able to decode the molecular structure of the two main proteins, shown here, that make up spider dragline silk. One of these, MaSp2, contains proline, which interacts with water molecules to produce the newly discovered twisting motion.

The team tested a number of other materials, including human hair, but found no such twisting motions in the others they tried. But Liu said he started thinking right away that this phenomenon “might be used for artificial muscles.”

“This could be very interesting for the robotics community,” Buehler says, as a novel way of controlling certain kinds of sensors or control devices. “It’s very precise in how you can control these motions by controlling the humidity.”

“This is a fantastic discovery because the torsion measured in spider dragline silk is huge, a full circle every millimeter or so of length,” says Pupa Gilbert, a professor of physics, chemistry, and materials science at the University of Wisconsin at Madison, who was not involved in this work. Gilbert adds, “This is like a rope that twists and untwists itself depending on air humidity. The molecular mechanism leading to this outstanding performance can be harnessed to build humidity-driven soft robots or smart fabrics.”

Spider silk is already known for its exceptional strength-to-weight ratio, its flexibility, and its toughness, or resilience. A number of teams around the world are working to replicate these properties in a synthetic version of the protein-based fiber.

While the purpose of this twisting force, from the spider’s point of view, is unknown, researchers think the supercontraction in response to moisture may be a way to make sure a web is pulled tight in response to morning dew, perhaps protecting it from damage and maximizing its responsiveness to vibration for the spider to sense its prey.

“We haven’t found any biological significance” for the twisting motion, Buehler says. But through a combination of lab experiments and molecular modeling by computer, they have been able to determine how the twisting mechanism works. It turns out to be based on the folding of a particular kind of protein building block, called proline.

Investigating that underlying mechanism required detailed molecular modeling, which was carried out by Tarakanova and Hsu. “We tried to find a molecular mechanism for what our collaborators were finding in the lab,” Hsu explains. “And we actually found a potential mechanism,” based on the proline. They showed that with this particular proline structure in place, the twisting always occurred in the simulations, but without it there was no twisting.

“Spider dragline silk is a protein fiber,” Liu explains. “It’s made of two main proteins, called MaSp1 and MaSp2.” The proline, crucial to the twisting reaction, is found within MaSp2, and when water molecules interact with it they disrupt its hydrogen bonds in an asymmetrical way that causes the rotation. The rotation only goes in one direction, and it takes place at a threshold of about 70 percent relative humidity.

“The protein has a rotational symmetry built in,” Buehler says. And through its torsional force, it makes possible “a whole new class of materials.” Now that this property has been found, he suggests, maybe it can be replicated in a synthetic material. “Maybe we can make a new polymer material that would replicate this behavior,” Buehler says.

“Silk’s unique propensity to undergo supercontraction and exhibit a torsional behavior in response to external triggers such as humidity can be exploited to design responsive silk-based materials that can be precisely tuned at the nanoscale,” says Tarakanova, who is now an assistant professor at the University of Connecticut. “Potential applications are diverse: from humidity-driven soft robots and sensors, to smart textiles and green energy generators.”

It may also turn out that other natural materials exhibit this property, but if so this hasn’t been noticed. “This kind of twisting motion might be found in other materials that we haven’t looked at yet,” Buehler says. In addition to possible artificial muscles, the finding could also lead to precise sensors for humidity.

These researchers “have used silk’s known high sensitivity to humidity and demonstrated that it can also be used in an interesting way to create very precise torsional actuators,” says Yonggang Huang, a professor of civil and environmental engineering and mechanical engineering at Northwestern University, who was not involved in this work. “Using silk as a torsional actuator is a novel concept that could find applications in a variety of fields from electronics to biomedicine, for example, hygroscopic artificial muscles and humidity sensors,” he says.

Huang adds, “What is particularly noteworthy about this work is that it combines molecular modeling, experimental validation, and a deep understanding by which elementary changes in chemical bonding scale up into the macroscopic phenomena. This is very significant from a fundamental science point of view, and also exciting for applications.”

The work included collaborators at Huazhong University of Science and Technology and Hubei University, both in Wuhan, China, and Queen Mary University of London. It was supported by the National Natural Science Foundation of China, the National Science Foundation of Hubei Province, the Young Elite Scientist Sponsorship Program by CAST, the National Institutes of Health, the MIT Undergraduate Research Opportunities Program, and the Office of Naval Research.