L+66, L+67: Logbook

In the last logbook I’ve mentioned that the ISS is a very busy laboratory these days, with many experiments going on in parallel in multiple disciplines. At the same time, this is also a spaceport where spaceships full of goods come and go. And right now, we have two vehicles, Dragon and ATV, which are going to leave in the next couple of weeks and need to be readied for departure and reentry. So, for a couple days I have (mostly) doffed my virtual lab coat, I have rolled up my sleeves and gotten into cargo-packing-and-loading mode.

Loading a vehicle for reentry into the atmosphere is a delicate process: the overall mass and how this mass is distributed (hence the center of mass) need to be known quite precisely in order to properly calculate the reentry burns for the desired reentry trajectory. That is especially true for a vehicle that is recovered on Earth, like Dragon, but it’s also extremely important for ATV5, because this ship will perform a special controlled reentry in the initial phases to gather data that will help prepare for Space Station de-orbiting (when that time comes, which is not any time soon). I’m sure you’ll be able to read everything about ATV5’s so called “shallow reentry” on the ATV blog!

As you probably know, ATV is destroyed in the atmosphere, so we load it with trash: waste, packing material, old clothes and discarded items. And we are making sure that we fill it up to the maximum, because  after the loss of the Orbital -3 mission on launch last October, the logistics onboard has become challenging: we have a lot of “stuff” (very technical space term), that was supposed to be long gone by now! Also for this reason, we are even putting a limited amount of trash into Dragon, although this vehicle is recovered intact on the ground (or more specifically in the ocean) and therefore its main job is to take return cargo back home.

But how does this all work, if the distribution of mass needs to be so precise? Well, actually I don’t quite know. There is some miracle of planning and coordination happening on the ground and we receive two products onboard: a cargo list, that lists all the bags, their content, where to get them, where to put them and special packing instructions; and a choreography message, that tells you in which order to do the packing and, again, any special instructions (like taking pictures, reporting a serial number, packing an item in a particular direction). If there’s any free space in the bags, we fill it up with filler foam that cargo goods were launched in and with ziplocs of old clothes. And then hopefully they will fit in their assigned stowage areas – which of course have a location code, so we always know exactly where each bag is supposed to go.

On Wednesday, as we were busy planning, flight controllers flipped the Station around 180 degrees – instead of flying with Node 2 forward, we ended up flying with the Russian Service Module leading the way. It was absolutely unnoticeable to me – in fact, I had forgotten about it. I would have noticed immediately if I had looked out of the Cupola, of course, but that was not possible, because the shutters had to be closed all day due to the series of maneuvers. Here’s a new psychological disorder for you: Cupola Withdrawal Syndrome!

So, why did we fly “backwards” on Wednesday? Well, we had to point the thrusters of ATV forward, so that they could be fired to brake the Station just a little bit, enough to lower the apogee (the higher part of the orbit) by a couple of km. We typically use ATV to do just the opposite – raise the orbit periodically, with a so-called reboost – but this time a “deboost” was necessary to make our orbit just right for the next Progress vehicle coming up.

The deboost lasted about 4 min: I floated still in the US Lab and I let myself being propelled to the other side of the module as ATV was pushing the Station around me. It was fun!

Futura mission website (Italian): Avamposto42
avamposto42.esa.int

#SamLogbook #Futura42  #SamLogbook #Futura42  

(Trad IT)  Traduzione in italiano a cura di +AstronautiNEWS qui:
http://www.astronautinews.it/tag/logbook

(Trad FR) Traduction en français par +Anne Cpamoa ici:
 https://spacetux.org/cpamoa/category/traductions/logbook-samantha

(Trad ES) Tradducción en español por +Carlos Lallana Borobio     aqui: http://laesteladegagarin.blogspot.com.es/search/label/SamLogBook

(Trad DE)  Deutsch von http://www.logbuch-iss.de
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