{"id":13903,"date":"2018-04-01T18:57:09","date_gmt":"2018-04-01T10:57:09","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/eliminating-space-junk-could-take-step-toward-reality-with-station-cargo-launch\/"},"modified":"2018-04-01T18:57:09","modified_gmt":"2018-04-01T10:57:09","slug":"eliminating-space-junk-could-take-step-toward-reality-with-station-cargo-launch","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/eliminating-space-junk-could-take-step-toward-reality-with-station-cargo-launch\/","title":{"rendered":"Eliminating space junk could take step toward reality with station cargo launch"},"content":{"rendered":"
\"\"
Artist\u2019s illustration of the RemoveDebris satellite de-orbiting at the end of its mission with the assistance of a dragsail. Credit: SSTL<\/figcaption><\/figure>\n

European engineers who developed a small satellite hitching a ride to the International Space Station aboard a SpaceX supply ship Monday are gearing up for a first-of-a-kind experiment to examine ways to snare a chunk of space junk and tug it back to Earth.<\/p>\n

Developed in a public-private partnership, the RemoveDebris mission will test the utility of nets and harpoons to capture tumbling objects in orbit, repurposing devices commonly used in fishing to pluck debris out of orbit and bring them into Earth\u2019s atmosphere to burn up.<\/p>\n

Guglielmo Aglietti, principal investigator for the RemoveDebris mission, calls the project a \u201cproof-of-concept.\u201d<\/p>\n

They crux of the mission, Aglietti said in an interview, is to prove that cleaning up space junk can be relatively inexpensive \u2014 something that could be affordable by commercial companies, or governments operating under budget limitations.<\/p>\n

\u201cWe want to learn as much as possible,\u201d said Aglietti, who is also director of the Surrey Space Center, a research institute affiliated with the University of Surrey and Surrey Satellite Technology Ltd., a British manufacturer of small satellites. \u201cEven if some experiment doesn\u2019t go exactly as planned, provided we get all the data, it\u2019s still a positive outcome.\u201d<\/p>\n

The RemoveDebris satellite will launch in a container inside a SpaceX Dragon cargo craft set for launch at 4:30 p.m. EDT (2030 GMT) Monday from Cape Canaveral. The commercial supply ship is carrying more than 5,800 pounds (2.6 metric tons) of food, provisions and experiments to the space station\u2019s six-person crew.<\/p>\n

RemoveDebris accounts around 220 pounds, or 100 kilograms, of the Dragon\u2019s cargo load.<\/p>\n

But the small spacecraft, developed by SSTL in the United Kingdom, punches above its weight. The RemoveDebris mothership contains two CubeSats, a net and a harpoon, a laser ranging instrument, and a \u201cdragsail\u201d designed to unfurl behind the main satellite and hasten its fall back into Earth\u2019s atmosphere using aerodynamic resistance.<\/p>\n

Assuming the Dragon resupply mission takes off Monday, the cargo capsule is due to reach the space station early Wednesday. Astronauts will unpack the RemoveDebris satellite, along with tons of other equipment, in the following weeks.<\/p>\n

\"\"
The RemoveDebris spacecraft during final assembly at SSTL. Credit: SSTL\/Max Alexander<\/figcaption><\/figure>\n

Some time this spring, the crew will take the one-meter cube-shaped spacecraft from its shipping container, remove shields used to protect it during launch, then place it on a sliding tray inside the Japanese Kibo lab module airlock.<\/p>\n

Fixed to a NanoRacks carrier, the spacecraft will transfer through the airlock to the Japanese lab\u2019s outside science deck, where the Kibo module\u2019s robotic arm will grab it and move to a predetermined position for release.<\/p>\n

Aglietti said RemoveDebris is currently slated for deployment from the space station in late May, but the schedule is not yet confirmed.<\/p>\n

\u201cThe mission will really start once we are deployed out of the space station, hopefully at the end of May or the beginning of June,\u201d he said.<\/p>\n

RemoveDebris will be the biggest satellite launched from the space station. That has placed the mission under extra scrutiny from NASA managers, who want to ensure the satellite poses no hazard to the orbiting outpost or its crew.<\/p>\n

The launch of RemoveDebris was supposed to happen last year, but officials bumped it to a later SpaceX cargo flight.<\/p>\n

\u201cIt took a little bit longer to make sure that all the right boxes were ticked,\u201d Aglietti said.<\/p>\n

The demo craft\u2019s high-flying experiments will not begin until the satellite is well away from the space station, Aglietti said. In fact, the satellite will remain in a dormant mode for around a half-hour after its release, before switching on to begin checkout procedures.<\/p>\n

Ground controllers at SSTL\u2019s campus in Guildford, England, will put the spacecraft through four primary experiments.<\/p>\n

\u201cBasically, it has a net, a harpoon and a dragsail on-board,\u201d said Jason Forshaw, the RemoveDebris mission\u2019s project manager at SSTL. \u201cThe concept is it\u2019s going to go up there, and it\u2019s going to eject small little satellites that will be used as artificial space junk.\u201d<\/p>\n

\"\"
File photo of a SpaceX Dragon spacecraft arriving at the International Space Station. Credit: NASA<\/figcaption><\/figure>\n

One of the CubeSats, about the size of a loaf of bread, will inflate a balloon to mimic the dimensions of a bigger piece of tumbling space junk. Flying a short distance away, RemoveDebris will release a net to envelop the CubeSat \u2014 named DebrisSat 1 \u2014 which will be cut loose to re-enter the Earth\u2019s atmosphere.<\/p>\n

\u201cThe net, as a way to capture debris, is a very flexible option because even if the debris is spinning, or has got an irregular shape, to capture it with a net is relatively low-risk compared to \u2026 going with a robotic arm, because if the debris is spinning very fast, and you try to capture it with a robotic arm, then clearly there is a problem,\u201d Aglietti said. \u201cIn addition, if you are to capture the debris with a robotic arm or a gripper, you need somewhere you can grab hold of your piece of debris without breaking off just a chunk of it.\u201d<\/p>\n

Another CubeSat, named DebrisSat 2, will separate from the RemoveDebris mothership to test out tracking and ranging lasers and algorithms. The RemoveDebris satellite will use DebrisSat 2 to test out close-up navigation technology needed for an orbiting garbage collector to approach an out-of-control piece of space junk.<\/p>\n

The LIDAR instrument \u201ccan observe debris, and figure out all the parameters of what this debris is doing in order to plan your capture,\u201d Aglietti said. \u201cWe have a normal camera, and then a LIDAR, which uses lasers to illuminate the object and figure out what the object is doing, and try to quantify the parameters, not just looking and seeing it, but also trying to see the spin rate, for example.\u201d<\/p>\n

The third RemoveDebris experiment will test the functionality of a harpoon, which would be used to fire at a dead satellite and spear it, allowing the junk to be maneuvered out of orbit for a fiery re-entry.<\/p>\n

But RemoveDebris will not test the harpoon on an actual satellite. The technology is still untried in space, and there are legal concerns about using it to lasso someone else\u2019s spacecraft without permission.<\/p>\n

\u201cMaybe it\u2019s a bit more risky because you have to hit your debris in a place that is suitable to be captured by the harpoon,\u201d Aglietti said. \u201cClearly, you have to avoid any fuel tanks \u2026 That would produce some undesired effects.\u201d<\/p>\n

Instead, RemoveDebris will extend an arm with a target for the harpoon on the end, then fire the projectile on a tether.<\/p>\n

\u201cWe have harpoons, we have nets,\u201d Forshaw said in a TEDx talk last year. \u201cThese all seem like simple concepts, and they are. They\u2019ve been used for thousands of years underwater to capture things such as sea creatures. However, taking technologies that are mature on Earth, in the oceans, and actually bringing them up there into space and seeing (if) these concepts work for the first time \u2014 nobody has ever used a net or a harpoon for these purposes in space before.\u201d<\/p>\n

Finally, RemoveDebris will open up an expandable sail to act like an airbrake or spoiler, generating drag from collisions with air molecules in the rarefied outer atmosphere. At the space station\u2019s altitude of around 250 miles (400 kilometers), the dragsail will bring the RemoveDebris satellite back into the denser layers of the atmosphere, where it will burn up.<\/p>\n