{"id":17267,"date":"2023-08-29T22:29:14","date_gmt":"2023-08-29T14:29:14","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/spin-control-starfish-space-makes-use-of-magnetism-to-stop-satellites-death-spiral\/"},"modified":"2023-08-29T22:29:14","modified_gmt":"2023-08-29T14:29:14","slug":"spin-control-starfish-space-makes-use-of-magnetism-to-stop-satellites-death-spiral","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/spin-control-starfish-space-makes-use-of-magnetism-to-stop-satellites-death-spiral\/","title":{"rendered":"Spin control: Starfish Space makes use of magnetism to stop satellite\u2019s death spiral"},"content":{"rendered":"<figure class=\"wp-block-image size-full-width\"><img fetchpriority=\"high\" decoding=\"async\" width=\"630\" height=\"441\" src=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/230828-starfish2-630x441.jpg\" alt=\"\" class=\"wp-image-787702\" srcset=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/230828-starfish2-630x441.jpg 630w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/230828-starfish2-1260x882.jpg 1260w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/230828-starfish2-768x538.jpg 768w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/230828-starfish2-1536x1075.jpg 1536w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/230828-starfish2.jpg 1543w\" sizes=\"(max-width: 630px) 100vw, 630px\"><figcaption data-nosnippet=\"\" class=\"wp-element-caption\">An artist\u2019s conception shows Starfish Space\u2019s Otter Pup satellite docking craft. (Starfish Space Illustration)<\/figcaption><\/figure>\n<p>Two and a half months after Starfish Space\u2019s first orbital mission teetered on the edge of failure because its Otter Pup satellite docking system took a wild tumble, the Kent, Wash.-based startup says that it has stopped the spin and is moving ahead with preparations to rendezvous with another satellite.<\/p>\n<p>Mission controllers still have to make sure that Otter Pup is in working order, and they still have to identify a satellite they can link up with. But Starfish co-founder Austin Link said the team has gotten over the highest hurdle: \u201cde-tumbling\u201d a spacecraft that had been rotating at a rate of roughly one revolution per second.<\/p>\n<p>\u201cThis is the first time that we as a company have gone and done something really unique and really extraordinary in space,\u201d Link told GeekWire. \u201cIt wasn\u2019t the thing that we set out to do with this mission. We still have that ahead of us. But to do that is, to me, another proof point for how excited I am to get to work with all the incredible folks we have at Starfish.\u201d<\/p>\n<p>The challenge began shortly after Otter Pup and dozens of other spacecraft were sent into low Earth orbit by a SpaceX Falcon 9 rocket on June 12. Starfish\u2019s spacecraft, which is about the size of a dorm-room fridge, was designed to be deployed from an orbital space tug. <\/p>\n<p>That space tug that would then serve as the target for a months-long demonstration showing how Otter Pup \u2014 and eventually, Starfish\u2019s full-size Otter \u2014 can rendezvous and dock with other spacecraft for servicing.<\/p>\n<p>Unfortunately, the space tug went into a rapid spin after separating from the Falcon 9 upper stage, with Otter Pup still attached. Mission controllers made an emergency decision to release Otter Pup immediately, but Starfish\u2019s spacecraft continued to tumble. Atmospheric drag slowed down that tumble somewhat; nevertheless, the Starfish team worried about the solar-powered spacecraft\u2019s ability to recharge itself.<\/p>\n<p>\u201cIt\u2019s disheartening when you put so much effort into a mission and it ends up at risk,\u201d Link said. \u201cI mean, the Otter Pup died twice during the de-tumbling process, and it just happened to come back to life.\u201d<\/p>\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\">\n<iframe loading=\"lazy\" title=\"Otter Pup by Starfish Space\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/QLWut6TFJBs?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen=\"\"><\/iframe><figcaption data-nosnippet=\"\" class=\"wp-element-caption\">A video by Starfish Space lays out the company\u2019s plan for the Otter Pup docking demonstration mission..<\/figcaption><\/figure>\n<p>To stop the spin and get the solar arrays pointing at the sun again, Starfish\u2019s engineers devised an algorithm that made use of the interaction between Earth\u2019s magnetic field and three magnetized torque rods on Otter Pup. The rods are basically electromagnets that can be turned on and off to slow down (or speed up) the rotation of a spacecraft. <\/p>\n<p>\u201cEarth\u2019s magnetic field is pointing a certain direction in space, and when your satellite rotates through it, the way that you need to turn on your torque rods changes,\u201d Link said. \u201cIf you have a one-second delay in your system, well, if you\u2019re rotating 5 degrees per second, that\u2019s OK. But if you\u2019re rotating 300 degrees per second, you\u2019ll be way off from where you thought the magnetic field was aligned.\u201d<\/p>\n<p>Starfish\u2019s engineers devised software code that checked the alignment on the order of 10 times per second, and they spent weeks testing the code in simulated space conditions. \u201cWe were making super-quick-turn engineering decisions \u2026 and then you\u2019d say, OK, this worked, or this didn\u2019t work,\u201d Link said. \u201cIt was pretty fast-paced and exciting, really.\u201d<\/p>\n<p>At the end of July, the team uploaded the code for a 30-minute test run and waited for the results. Link said he and Starfish\u2019s other co-founder, Trevor Bennett, made a bet on how much improvement they\u2019d see after the test. \u201cIt ended up right between our bets,\u201d Link recalled.<\/p>\n<p>As soon as they could, engineers uploaded another batch of code for a three-hour run. That brought the rate of spin down to zero. <\/p>\n<p>\u201cWe managed to get the Otter Pup stable and pointing toward the sun and not spinning along the way,\u201d Link said. \u201cI\u2019ll confess, it happened much faster than I expected we\u2019d be able to do it.\u201d<\/p>\n<figure class=\"wp-block-image size-full-width\"><img loading=\"lazy\" decoding=\"async\" width=\"630\" height=\"353\" src=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/Otter-Spin-630x353.jpg\" alt=\"Otter Pup total rotation rate over time\" class=\"wp-image-787725\" srcset=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/Otter-Spin-630x353.jpg 630w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/Otter-Spin-1260x706.jpg 1260w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/Otter-Spin-768x430.jpg 768w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2023\/08\/Otter-Spin.jpg 1389w\" sizes=\"(max-width: 630px) 100vw, 630px\"><figcaption data-nosnippet=\"\" class=\"wp-element-caption\">This chart shows how Otter Pup\u2019s spin slowed down. Click on the image for a larger version. (Starfish Space Infographic)<\/figcaption><\/figure>\n<p>Starfish\u2019s team was supported by partners including Astro Digital, which built Otter Pup\u2019s frame to fit Starfish\u2019s requirements; Advanced Solutions Inc., a subsidiary of Rocket Lab that contributed some of Otter Pup\u2019s onboard flight software; and Vast as well as its Launcher team, which provided the Orbiter SN3 space tug.<\/p>\n<p>Chris Biddy, co-founder and CEO of Astro Digital, told GeekWire that rescuing Otter Pup \u201cwas a big recovery effort and the most difficult we have been involved with.\u201d<\/p>\n<p>\u201cThings can get very weird and scary when a satellite is not under three-axis control and spinning at rates that are nearly 100 times what is normal,\u201d Biddy said in an email. \u201cOff-nominal temperatures, power generation and communications are big threats to the survival of the satellite under these conditions. To have recovered fully from that and to have the satellite now under three-axis control is a huge relief, and a testament to the teams involved and the design of the hardware.\u201d<\/p>\n<p>The Starfish team still needs to determine whether Otter Pup can do the things it needs to do.<\/p>\n<p>\u201cIt was never designed to spin this fast,\u201d Link said. \u201cIt hit conditions that may have stretched the satellite in multiple ways. We need to go test and turn on a bunch of different parts, and that\u2019s a process that we\u2019ve been doing and will continue to do. We need to see if everything works in the way that it needs to for the satellite to do proximity operations, to maybe go try to dock with another satellite.\u201d<\/p>\n<p>Starfish is also looking for another satellite to fill in as the mission\u2019s target. The original target, Orbiter SN3, is out of the picture because of the anomaly it suffered.<\/p>\n<p>\u201cEven if we do both of those things well, then that just means that we get to do the initial mission, which was already a really challenging mission,\u201d Link said. \u201cSo there are definitely hurdles in front of us here. But in a weird way, it\u2019s exciting. \u2026 The engineer in you just loves solving crazy-hard problems.\u201d<\/p>\n<p>As the Otter Pup saga continues, Link is keeping the bigger picture in mind.<\/p>\n<p>\u201cIt\u2019s a great moment for the team to go de-tumble the satellites, and what that means as a technical accomplishment,\u201d he said. \u201cBut it\u2019s also a great moment in that we get a chance to continue with our Otter Pup mission. If we\u2019re able to dance around another satellite, or even dock with another satellite, then that\u2019s paving the way for the Otter in the future \u2014 and paving the way for it becoming a more regular and common thing for humans to go interact with satellites on orbit.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"<p>An artist\u2019s conception shows Starfish Space\u2019s Otter Pup satellite docking craft. (Starfish Space Illustration) Two and a half months after Starfish Space\u2019s first orbital mission teetered on the edge of failure because its Otter Pup satellite docking system took a wild tumble, the Kent, Wash.-based startup says that it has stopped the spin and is [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[20,442,4344],"class_list":["post-17267","post","type-post","status-publish","format-standard","hentry","category-news","tag-satellite","tag-satellites","tag-starfish-space"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/17267"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=17267"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/17267\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=17267"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=17267"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=17267"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}