Tiangong-1 (TG-1)

China (PR)

Spacecraft nº:

Chinese spacecraft nº: 166

Launch & orbit data:

Designation	37820 / 11053A
Launch date - time	29 Sep 2011 - 13:16:03 UT (9:16 am. EDT)
Launch site	Jiuquan, 921
Launch vehicle	CZ-2F (T1)
Application	Space station module
LEO Earth orbit on Sep 30 - 08:09 UT:
- Perigee / Apogee	336 x 353 km
- Eccentricity	8,20E-04
- Inclination	42.79°
- Period	91.23 min
Reenter date - time	02 Apr 2018 - 00:16 UTC
Reenter location	South Pacific 164.3W 13.6S
Flight Duration (d:hr:min)
Nbr orbits

Unmanned launch, 1st flight rocket version & 1st Chinese space station

Spacecraft data:

Prime manufactor
Platform
Operator	Beijing Aerospace Flight Control Center
Mass at launch	8506 kg
Dry Mass	kg
Basic shape
Dimension (m)	dia: 3.35 m, length: 10.4 m
Pressurised volume	14 m³
Equipment
Solar array	2 deployable solar arrays, span: 18.4 m
Stabilization
Propullants	N2O4/MMH
DC power

Completed maximum form of Chinese Tiangong Space Station (Phase 1) since 3 November 2022.

Note:A rendering of the station with the Tianhe at centre of picture, a Tianzhou on its aft port, the Wentian on its starboard port to the left, the Mengtian on its portside port to the right and two Shenzhou spacecraft, sharing its multi-docking hub.

TG-1 being processed for launch before integration into the launcher.

Docking system

History:

In the 1970s and 1980s China funded its space program at a low level, with only about one satellite launch a year. In the 1990s they started a crash program to catch up with the US and Russia, ticking off each space first one by one: human-in-space, moon-probe, moon-lander, spacewalk, docking and so on. The Shenzhou spaceship, carrying 2 to 3 astronauts, is similar to Soyuz; the Tiangong spacelab is like Russia′s 1971 Salyut-1 spacelab, and the associated program replicates both Russia′s Salyut-1/Salyut-4 and NASA′s Gemini missions.
Tiangong-1 was launched in 2011 and hosted two astronaut crews in 2012 and 2013. China *should* then have deorbited it under control over the South Pacific. But they were worried that if the 2016 launch of Tiangong-2 failed, their program would be stalled. So, they decided to keep Tiangong-1 in orbit beyond its design life, in hibernation as a backup for Tiangong-2. In the event, the Tiangong-2 launch went just fine but Tiangong-1 had by then broken down. Since 2016 it has been inert, orbiting the Earth without any active control, its initial 364 x 382 km orbit inclined 42.8 deg to the equator slowly decaying.
Tiangong-1′s initial mass was 8500 kg, but propellant usage and usage of food and water by the crews had reduced this to at most 7500 kg according to calculations. Although most spacecraft of this mass are nowadays usually not allowed to make uncontrolled reentries, since 1957 there have in fact been 48 such uncontrolled reentries of objects more massive than it. The most recent was in January 2018, involving an 8000 kg Russian rocket stage launched only a month earlier.
By 0h UTC on Apr 1, 2018 the orbit of Tiangong-1 was 161 x 171 km (apogee and perigee relative to a fictional 6378 km radius sphere). By this stage atmospheric drag was quickly changing the orbital elements.
The US Air Force 18SPCS issued a number of updated TLE element sets during the day, based on fits to data obtained by a number of ground-based radars around the world. The final such set had an epoch of 16h UTC and showed the orbit to be 144.5 x 152.3 km.

Mission details:

China launched the Tiangong-1 spacelab on Sep 29 into a 198 x 332 km x 42.8 deg orbit.
The 19,000-pound Tiangong 1 module lifted off at 1316 UT (9:16 a.m. EDT) aboard a Long March 2F rocket. Chinese engineers modified the 170-foot-tall rocket for the launch of Tiangong 1, which is heavier and larger than China's manned Shenzhou capsules that previously flew on the rocket seven times.
The upgraded rocket, called the Long March 2F T1, flew with a larger nose shroud and longer liquid-fueled boosters than previous missions.
Separation of the boosters takes place at T+155s and first stage separation takes place at T+159s
On-board rocket cameras showed the hydrazine-fueled launcher soaring into the night sky, shedding its four strap-on boosters and first stage to drop back into the darkness along the way.
At 1758 UTC on Sep 29, 2011 TG-1 raised its orbit to 197 x 345 km; at 0809 UTC on Sep 30 the orbit was further raised to 336 x 353 km.
On Oct. 10, the Tiangong 1, China′s first space lab module, released the first photo of itself in space. The photo shows half of this module. The surface of the resource cabin and relay satellite antenna can be easily distinguished in the photo.
On Mar 21, 2016 China announced the end of "data service" with the Tiangong 1 space laboratory. The 8500 kg lab is in a 377 x 394 km x 42.8 deg orbit; it had made reboost manuevers about twice a year, the most recent on 2015 Dec 16. Scott Tilley reported on the SeeSat list that regular radio transmissions from the spacecraft were not received during passes on Mar 31, 2016. If the spacecraft is now inactive, it will reenter the atmosphere sometime in the next few years.
Tiangong-1 reentered 0016 UTC Apr 2, 2018 over the South Pacific at 164.3W 13.6S, between Samoa and Tonga.

External links:

Astrophilately covers:

Launch Tiangong 1. Credit: #411a

Launch Tiangong 1. Credit: #411

Launch Tiangong 1, with cancel: 2011.9.29 Credit: #411

Ref: #6n, #7(JR648,724,747), #12, #98, #102, #226, #233, #411 - update: 18.11.25

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