Leonard David's INSIDE OUTER SPACE

Credit: The Aerospace Corporation

The European Space Agency’s Space Debris Office in Darmstadt, Germany has updated its prediction of when China’s Tiangong-1 space lab will reenter.

The posted January 26 estimate is roughly March 18 to roughly April 12 – noting that this current estimated window “is highly variable.”

According to the ESA office, due to the orbital inclination of the Tiangong-1, approximately 42.8 degrees, and the likely uncontrolled nature of the reentry, the final impact point can be anywhere on Earth between 42.8 degrees North and 42.8 degrees South in latitude, e.g. Spain, France, Portugal, Greece, etc. Areas outside of these latitudes can be excluded, they add.

Credit: ESA CC BY-SA IGO 3.0

Controlled/uncontrolled?

ESA explains that in March 2016 the Tiangong-1 space station ceased functioning but maintained its structural integrity.

“In so far as can be fully confirmed,” notes the ESA office, “ground teams lost control with the craft, and it can no longer be commanded to fire its engines. It is, therefore, expected to make an ‘uncontrolled reentry.’”

Earlier this month, a Chinese space engineer indicated that the country’s Tiangong-1 space lab is not out of control.

“We have been continuously monitoring Tiangong-1 and expect to allow it to fall within the first half of this year,” explains Zhu Congpeng, an engineer at the China Aerospace Science and Technology Corporation, notifying the state-run Science and Technology Daily newspaper.

“It will burn up on entering the atmosphere,” Zhu said, “and the remaining wreckage will fall into a designated area of the sea, without endangering the surface,” he said, remarks also relayed via a January 7 story by Reuters.

Credit: ESA CC BY-SA IGO 3.0

Limited control

“I think the confusion comes from the fact that control is limited to the attitude of the space lab – but not to the orbit,” explains Holger Krag, Head of the Space Debris Office for ESA in Darmstadt, Germany.

Attitude control has (hardly) no impact on the orbit, Krag said, “and a deorbit impact point cannot be achieved. Orbit control requires a meaningful propulsion function, which is not available/defunct,” he told Inside Outer Space.

With its 8.5 metric tons of (initial) mass, Tiangong-1 (whose name means “Heavenly Palace” in Chinese) was rocketed into Earth orbit in late September 2011. It is the first space station built and launched by China. It was designed to be a crewed lab as well as an experiment/demonstration for the larger, multiple-module space station.

Credit: The Aerospace Corporation/CORDS

Guessing game

The Aerospace Corporation’s Center for Orbital and Reentry Debris Studies (CORDS) is sponsoring a “live on green event” guessing game. Entrants can compete for Aerospace swag with the closest estimate to the actual reentry date and time of China’s Tiangong-1 space lab.

Enter your information for a chance to win some Aerospace booty with the closest guess to the actual reentry date and time of China’s Tiangong-1.

Submit your guess by going to:

http://www.aerospace.org/cords/live-on-green/