The objectives of the mission are ambitious to the extreme<\/a>: The two spacecraft \u2014 an orbital transfer vehicle called Quark-LITE and a target vehicle called Gluon \u2014 will eventually demonstrate extremely complex maneuvers including rendezvous, docking, orbital transfer and on-orbit refueling.<\/p>\nThe company has faced two main issues related to communications and the spacecraft rotation rate \u2014 and it\u2019s (largely) solved both problems, despite enormous constraints, infrequent data packets and extremely limited bandwidth. (So limited, in fact, that the team has had to cap its flight software updates to a string of text that is just 145-characters long.)<\/p>\n
\u201cIt\u2019s been relentless,\u201d Atomos CEO and co-founder Vanessa Clark told TechCrunch.<\/p>\n
The company\u2019s COO and co-founder, William Kowalski, agreed. \u201cWhat makes it so hard, even in our situation, we\u2019re trying to extrapolate the status of a very complicated system from maybe 100 bytes of data,\u201d he said. \u201cIt\u2019s a lot of, you\u2019re making guesses as to what is driving this, knowing that some of those guesses could take you down a path where you never recover.\u201d<\/p>\n
The issues started just hours after the two spacecraft, which are mated together, deployed from the Falcon 9 upper stage. Deployment was nominal, and Atomos received its first ping from the spacecraft seven minutes after deployment. The mood was celebratory.<\/p>\n
But then 40 minutes went by until the company got its next ping. Then eight hours.<\/p>\n
Atomos was expecting data packets every couple of minutes.<\/p>\n
\u201cThe worst [day] was the Monday when we launched, that evening,\u201d Kowalski said. \u201cIt was 11 o\u2019clock at night, it was me and the chief engineer \u2026 and we haven\u2019t heard anything, and we\u2019re just thinking, did we fail? Did they die? We gave it a shot, and it just didn\u2019t work. That was really a gut punch.\u201d<\/p>\n
Mission controllers only identified the root cause 24 to 48 hours after deployment, and they did so with the help of another company with assets on orbit. After pulling some strings, they were able to get on the phone with the chief systems engineer of satellite communications company Iridium. The spacecraft were using third-party modems that leveraged Iridium\u2019s inter-satellite link network, in addition to using Iridium\u2019s constellation as their relay satellites. Atomos\u2019 spacecraft were moving too fast, and in direct opposition, such that they couldn\u2019t perform the data \u201chandshake\u201d with those Iridium satellites to actually transmit information back down to Earth.<\/p>\n
Atomos engineers ended up pushing a series of software updates that reduced the duty cycling and ensured the radios would always be on, even if the spacecraft was in a low-power state.<\/p>\n
As engineers were trying to fix the communications problem, however, they faced a different issue: The spacecraft were tumbling at an extremely rapid rate of 55 degrees per second (they were designed to deal with a roll rate up to 5 degrees per second). In addition, the spacecraft were slowly rotating so that the solar arrays were no longer facing the sun. That meant it was a race against time \u2014 and against the spacecraft batteries dying completely.<\/p>\n
\u201cWe had two graphs,\u201d Kowalski said. \u201cWe graphed out our power trend on when we think we\u2019d be pointed away from sun and be [at] zero power, and our detumble rate. It was get the detumble rate to zero before the power goes to zero.\u201d<\/p>\n
The issue was exacerbated by the limited comms; the teams weren\u2019t able to definitively confirm something was wrong until the fourth day after deployment, and the spacecraft could only digest new commands in-between long periods of what were essentially communications blackouts.<\/p>\n
Slowly, over a period of days, they were able to slow the spacecraft. The team got another major win when it managed to establish high-bandwidth comms, a space-to-space link on the Quark-LITE that talks over the Inmarsat network. The company made the first attempt to get on the high-bandwidth comms Thursday, and they successfully maintained comms with the spacecraft for six minutes.<\/p>\n
During that period, mission controllers received 17 times more data than they had since launch. This has provided mission controllers with immense amounts of data on the spacecraft health. Not all the news was positive \u2014 one of the battery packs on the OTV was hit hard by the aggressive cycling, and it seems like the GPS needs to be reset onboard one of the spacecraft \u2014 but these are easy fixes, Clark said.<\/p>\n
By Tuesday or Wednesday, the company is aiming to start commissioning the propulsion system. If all goes to plan, and engineers can establish that the prop system is providing pointing accuracy and control, they will test operations with torque rods and reaction wheels off. The company aims to separate the spacecraft in around a month\u2019s time, with the aim of completing all the mission objectives by the end of June.<\/p>\n
Kowalski and Clark credit some of the startup\u2019s success to the fact that it\u2019s highly vertically integrated. The team \u2014 which pulled a 100-hour week in that first week after deployment \u2014 was able to bring its intimate knowledge of the spacecraft design to problem-solve the issues that came up.<\/p>\n
\u201cIt\u2019s obviously been very painful, but it\u2019s like the CEO of Nvidia says: \u2018I wish upon you great suffering.\u2019 We have gone through that and it wasn\u2019t great in the moment, but now that we\u2019re through the thick of it, we\u2019re definitely more accomplished,\u201d Clark said.<\/p>\n<\/p><\/div>\n
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Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Few missions more acutely embody the maxim \u201cspace is hard\u201d than Atomos Space\u2019s first demonstration mission, which the company has managed to pull back from the brink of disaster \u2014 more than once. That demonstration mission, dubbed Mission-1, launched to orbit on a SpaceX Falcon 9 rocket on March 4. The objectives of the mission […]<\/p>\n","protected":false},"author":1,"featured_media":84667,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14],"tags":[],"class_list":{"0":"post-84666","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-tech"},"_links":{"self":[{"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/posts\/84666","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/comments?post=84666"}],"version-history":[{"count":0,"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/posts\/84666\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/media\/84667"}],"wp:attachment":[{"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/media?parent=84666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/categories?post=84666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/entertainment.runfyers.com\/index.php\/wp-json\/wp\/v2\/tags?post=84666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}