[meteorite-list] European Cargo Ship Departs International Space Station for Earth Reentry

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 21 Jun 2011 08:16:08 -0700 (PDT)
Message-ID: <201106211516.p5LFG8OK027395_at_zagami.jpl.nasa.gov>

http://www.spaceflightnow.com/news/n1106/20atvundocking/

European cargo ship departs International Space Station
BY STEPHEN CLARK
SPACEFLIGHT NOW
June 20, 2011

After delivering more than 5,000 pounds of cargo, fuel and oxygen, a
European automated resupply freighter undocked from the International
Space Station on Monday and headed for a destructive plunge back into
the atmosphere.
 
The Automated Transfer Vehicle, christened Johannes Kepler after the
German astronomer and mathematician, separated from the complex at 1446
GMT (10:46 a.m. EDT). One minute later, after backing away from the
station's Zvezda service module, the ATV fired thrusters to accelerate
its departure.

The ship is carrying more than 2,600 pounds of trash for the re-entry.
Almost all the spacecraft will burn up in the atmosphere, but the
hardiest components could survive to impact the Pacific Ocean.

Two engine burns are on tap Tuesday to lower the craft's orbit. The ATV
will dive back into the atmosphere at 2024 GMT (4:24 p.m. EDT) and its
remnants will reach the surface about 2059 GMT (4:59 p.m. EDT),
according to the European Space Agency.

A data recorder strapped to the spacecraft will record the ATV's final
moments, capturing information on temperatures, accelerations and tumble
rates as the ship breaks apart in the atmosphere.

Designed and built by the Aerospace Corp., the Re-entry Breakup
Recorder, or REBR, is protected inside its own heat shield to survive
the scorching environment. It will transmit the data via satellite back
to engineers in the United States before hitting the ocean and sinking.

Officials believe data collected by the REBR device will yield insights
into how spacecraft end their lives during re-entry. A similar unit was
stored inside a Japanese cargo freighter on its trip back into the
atmosphere in March.

The ATV's last duty before leaving the space station was boosting the
lab's orbit by 35 kilometers, or about 22 miles. The spacecraft fired
its thrusters over three days between June 12 and June 17 to raise the
station's orbit.

The complex is now circling the planet at an average altitude of 237
miles, higher than the space station has ever flown before. The reboosts
were conceived to place the lab higher above the drag effects of Earth's
atmosphere.

Although the atmosphere at the station's orbit is almost non-existent,
there is enough air resistance to gradually slow the lab's velocity and
cause it to drop altitude. After the reboosts, engineers say the station
will need fewer correction maneuveers to maintain its orbit, so future
cargo vehicles could deliver more experiments and spare parts instead of
refueling propellant.

The space station flew at a lower altitude during construction to allow
visiting space shuttles to deliver more gear and heavier modules to the
outpost. With the shuttle's retirement looming, there's no longer a need
to keep the station's orbit lower.

The higher orbit will cut the station's annual fuel usage nearly in
half, according to ESA.

The Johannes Kepler spacecraft launched Feb. 16 and reached the space
station Feb. 24. It stayed docked to the lab for 116 days.

Built by EADS Astrium, the ATV measures 32 feet long and nearly 15 feet
wide. Its four solar array wings stretch more than 70 feet across. Four
main engines and 20 smaller thrusters guide spacecraft in orbit.

The Johannes Kepler mission, the ATV's second flight, hauled about 3,500
pounds of dry cargo in its pressurized cabin. Astronauts manually
unloaded that equipment during the craft's stay.

The spacecraft also carried refueling propellant and oxygen to replenish
the station's tanks.
Received on Tue 21 Jun 2011 11:16:08 AM PDT