Our friends at the Swedish Institute of Space Physics (IRF) have successfully landed with their Advanced Small Analyzer for Neutrals (ASAN) instrument on the far side of the Moon, on board the Chinese Chang’E-4 spacecraft.
Chang’E-4 is the first-ever spacecraft to soft-land on the Moon’s far side (the side we usually don’t see), in the Von Kármán crater in the South Pole-Aitken Basin. The ASAN instrument in on board the Yutu-2 rover. This of course means the IRF has beat us in having Sweden’s first scientific instrument on the moon, so our hats are off to them 🌝
This week our new boards arrived. After a bit of grief due to picking a faster crystal than what Atmel/Microchip guarantees will work at 3.3 Volt, we managed to cobble together a test this Saturday evening. Things are looking promising, especially our new rotor grounding method. We shall see how well it works after some more rigorous testing.
There are more things that remain to be seen. For example, we’re hoping the improved shielding in our new fieldmill PCBs will reduce/eliminate how much of any synchronous unwanted signals we pick up. Previous versions would pick up the voltage changes in the IR tachometer signal, from several centimeters away. This because when measuring with 100 MOhm transimpedance amplifiers, any stray dV/dt’s get picked up. If they’re in sync with the rotor’s rotation then that pickup appears as an undesired offset in our signal!
Besides the minor crystal issue, we’ve so far not had much problems with the PCBs. We’re currently focusing on mechanical and software issues, both of which are important for final integration with the lander. Hopefully more on that in the future! For now we’re aiming for more vibration testing at the start of 2019.
The project moves forward. For the last couple of months we’ve kept busy finalizing the design of the instrument, trying to minimize noise and pickup of unwanted signals. We currently have two sets of boards being manufactured, which should hopefully arrive fully assembled in about a month. We’ve also had a much-needed vacation right in the middle of the current heat wave 😅
Next up is providing more accurate mass, center-of-mass and moment of inertia measurements to PTScientists. We’re also working on finalizing the data format, since that decides how much bandwidth we need. So far it’s looking like around 200 B/s while the instrument is running. We can probably cut that down with some compression, at the cost of increased latency. Possibly more on that in a future post.
Just some pictures of the vacuum test setup which our MSc student has built.
The stainless steel mesh allows us to apply some known static electric fields to calibrate and evaluate the performance of our instrument.
Ytterligare ett år håller på att lida mot sitt slut, och vilket år det har varit! Vi har hunnit med massor av roliga saker och träffat intressanta personer.
Vi har bland annat träffat forskare och ingenjörer vid IRF i Kiruna. Vi har under våren arbetat intensivt mot satta deadlines för att se om vår “organisation” kan leverera under stor tidspress, det kan vi! Och nu under december månad fick vi möjligheten att hjälpa till i Musikhjälpens årliga insamling som i år samlade in 74 miljoner!!! till arbeten för att motverka barnsexhandel. Vår egen auktion drog in över 30 000 kr!
Nu ser teamet fram emot en välförtjänt semester över julhelgen och nyår.
Vi ses i januari!
God Jul och ett Gott Nytt År!
//Yet another year is looming to its end, and what a year it has been! We have had tons of fun and meet amazing people.
We have, as an example, meet up with scientists and engineers at IRF in Kiruna. During the spring we stress tested our organization and worked towards strict deadlines to see if we can deliver top quality under heavy time-press, and we did! We have also been helping Musikhjälpen with there annual fundraising. This years theme was to raise awareness and money to battle child trafficking. The total amount of donations accumulated to 74 million sek! And our own auction helped raise over 30 000 sek!
The team is now looking forward to an well deserved vacation and we will be back in full swing in January.
Merry Christmas and a Happy New Year!//
Här är ett urklipp från Musikhjälpen 2017 då vi gästade glasburen (det är på svenska).
//A cutout from the show Musikhjälpen 2017 when we visited the glas box (it is in Swedish).//