The second Automated Transfer Vehicle (ATV) to be orbited by Arianespace has been installed on its Ariane 5 launch vehicle, keeping preparations on track for a February 15 mission to service the International Space Station.
With a total mass of over 20 metric tons, this flight’s payload will be the largest ever orbited by Ariane 5. The cargo spacecraft is named after German astronomer and mathematician Johannes Kepler, and is the first operational ATV. It follows the qualification flight of ATV Jules Verne, launched by an Ariane 5 in March 2008.
In the past three weeks, teams at Kourou have been loading cargo into ATV - a challenging and complex process that requires extensive planning and preparation.
Now that the final, late-load cargo has been lowered into ATV, the hatch shut, and the fairing fitted over Johannes Kepler, ESA's Cargo Integration Engineer, Kirsten MacDonell, who is at Kourou overseeing cargo activities, has taken time to send us a detailed, 'behind-the-scenes' description of the intense work needed to get the vessel fully loaded.
All aspects of cargo loading on the ground must take into account the priorities of the ISS astronauts and the constraints of zero-gravity operations. Her post is incredibly detailed - perhaps better to print and read on paper - and shows just how much top-notch engineering, effort and planning are required to get ATV buttoned-up for flight and the cargo delivered to the ISS. Thank you, Kirsten, for an excellent and very informative update!
Here are a couple of key extracts from her report before you click on 'continue reading' below to access the full text.
In addition to dry cargo, ATV-2 is carrying a very high amount of propulsive support propellant (4534 kg), refuel propellant (850.6 kg) and gas (100 kg O2)
Everyone working on the late cargo integration operations had to wear a full 'bunny suit'. The ATV was disinfected before and after the nominal cargo loading and, in order to limit the amount of bacteria and viruses that can be transferred to the crew, the bunny suits were mandatory.
Every astronaut is allowed one small cargo transfer bag (CTB - about 13kg) called a 'crew care package'. They may fill it with personal items such as family photos, CDs with music, chocolate or other candy.
ESA's newest press release was published today reporting loud and clear that ATV Johannes Kepler is ready for launch to the International Space Station on Tuesday, 15 February, at 22:08 GMT (23:08 CET) from Europe’s Spaceport in Kourou, French Guiana. The unmanned vessel will deliver essential supplies and reboost the Station during its mission lasting three-and-a-half months.
ESA TV has aired today an excellent background video highlighting the cargo loading activities (we'll have a detailed report & photos from Kourou in the blog within tomorrow). Watch the video below (very nice job by our colleague Martin Ransom) and read the rest of the press release after the jump.
In anticipation of the vessel's upcoming launch, scheduled for 15 February, ATV Johannes Kepler is now being 'tanked up' with fuel at Europe's Spaceport in Kourou.
Of all the vessels that can deliver cargo to the ISS, ATV can deliver the largest quantity of fuel, up to 5.5 tonnes maximum.
With this fuel, ATV can regularly reboost the Station's orbit, which suffers a natural decay of 50 to 100 m each day (what goes up must come down - unless reboosted by ATV - Ed.) due to drag caused by traces of atmosphere at the ISS orbital altitude (roughly, 400km) .
By any measure, ESA's ATV-2 cargo vessel is a behemoth in space, both in complexity and size! And it's pretty well designed and built, too. Despite a mass of over 20 tonnes, Johannes Kepler can manoeuvre and dock with an accuracy of just a couple centimetres.
Times in UTC
6/05 - ATV-4 moves to the BAF for final preparations
8/05 - ESA Operations Readiness Review
20/05 - Late-cargo loading
31/05 - Launch Readiness Review
03/06 - IMMT GO/NO-GO for launch & docking
05/06 - Lift-off Arianespace VA213 23:52 CEST
15/06 - Docking 15:46 CEST
28/10 - Undocking 9:55 CET
2/11 - Reentry 13:05 CET All future dates subject to change