From e7e495691608fcedeb3054bc272180139ebfa212 Mon Sep 17 00:00:00 2001 From: Hazel Levine Date: Mon, 25 May 2020 22:38:06 -0400 Subject: [PATCH] good plan great plan --- space/good-plan-great-plan/README.md | 58 ++++++++++++++++++++++++++++ space/good-plan-great-plan/plan.txt | 13 +++++++ 2 files changed, 71 insertions(+) create mode 100644 space/good-plan-great-plan/README.md create mode 100644 space/good-plan-great-plan/plan.txt diff --git a/space/good-plan-great-plan/README.md b/space/good-plan-great-plan/README.md new file mode 100644 index 0000000..cbfdc7a --- /dev/null +++ b/space/good-plan-great-plan/README.md @@ -0,0 +1,58 @@ +# Good Plan? Great Plan! +**Category**: Space and Things +**Points (final)**: 77 +**Solves**: 54 + +> Help the Launchdotcom team perform a mission on their satellite to take a picture of a specific location on the ground. No hacking here, just good old fashion mission planning! + +> The current time is April 22, 2020 at midnight (2020-04-22T00:00:00Z). +> We need to obtain images of the Iranian space port (35.234722 N 53.920833 E) with our satellite within the next 48 hours. +> You must design a mission plan that obtains the images and downloads them within the time frame without causing any system failures on the spacecraft, or putting it at risk of continuing operations. +> The spacecraft in question is USA 224 in the NORAD database with the following TLE: +> +> 1 37348U 11002A 20053.50800700 .00010600 00000-0 95354-4 0 09 +> 2 37348 97.9000 166.7120 0540467 271.5258 235.8003 14.76330431 04 +> +> You need to obtain 120 MB of image data of the target location and downlink it to our ground station in Fairbanks, AK (64.977488 N 147.510697 W). +> Your mission will begin at 2020-04-22T00:00:00Z and last 48 hours. +> You are submitting a mission plan to a simulator that will ensure the mission plan will not put the spacecraft at risk, and will accomplish the desired objectives. + +## Write-up +by [hazel (`arcetera`)](https://qtp2t.club/) + +In the time range [2020-04-22 00:00:00, 2020-04-23 23:59:00], the USA 224 +satellite as given in the TLE above reaches the Iranian space port twice: +- Around 09:28 on 2020-04-22 +- Around 09:50 on 2020-04-23 +This was found in GPredict after loading in the TLE given in the netcat. + +Additionally, the USA 224 reaches the ground station in Alaska twice: +- Around 10:47 on 2020-04-22 +- Around 11:10 on 2020-04-23 + +The rest of the strategy is pretty much just to use trial and error: +- Image for as long as possible until the battery runs dry or we're out of range +- Downlink for as long as possible until the battery runs dry or we're out of + range +- Desaturate the wheels about an hour before they exceed maximum velocity + +### Full plan +``` +2020-04-22T00:00:00Z sun_point +2020-04-22T09:28:00Z imaging +2020-04-22T09:35:00Z sun_point +2020-04-22T10:47:00Z data_downlink +2020-04-22T10:50:00Z wheel_desaturate +2020-04-22T11:30:00Z sun_point +2020-04-23T08:50:00Z wheel_desaturate +2020-04-23T09:30:00Z sun_point +2020-04-23T09:50:00Z imaging +2020-04-23T09:56:00Z sun_point +2020-04-23T11:10:00Z data_downlink +2020-04-23T11:14:00Z sun_point +2020-04-23T22:00:00Z wheel_desaturate +``` + +## Resources and other writeups +- http://gpredict.oz9aec.net/ +- https://en.wikipedia.org/wiki/Two-line_element_set diff --git a/space/good-plan-great-plan/plan.txt b/space/good-plan-great-plan/plan.txt new file mode 100644 index 0000000..823acf6 --- /dev/null +++ b/space/good-plan-great-plan/plan.txt @@ -0,0 +1,13 @@ +2020-04-22T00:00:00Z sun_point +2020-04-22T09:28:00Z imaging +2020-04-22T09:35:00Z sun_point +2020-04-22T10:47:00Z data_downlink +2020-04-22T10:50:00Z wheel_desaturate +2020-04-22T11:30:00Z sun_point +2020-04-23T08:50:00Z wheel_desaturate +2020-04-23T09:30:00Z sun_point +2020-04-23T09:50:00Z imaging +2020-04-23T09:56:00Z sun_point +2020-04-23T11:10:00Z data_downlink +2020-04-23T11:14:00Z sun_point +2020-04-23T22:00:00Z wheel_desaturate