Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 09-29-2011 07:22 AM
Tiangong-1: mission viewing, questions, comments
This thread is intended for members' comments and questions about China's Tiangong-1 mission and the updates posted under the topic: China's Tiangong-1 unmanned space module.
The Tiangong-1 unmanned space module is a prototype for a space station and an experimental space laboratory. It will be primarily used to carry out rendezvous and docking tests to gain experience for the construction, management and operation of future manned orbiting laboratory.
Glint Member
Posts: 1040 From: New Windsor, Maryland USA Registered: Jan 2004
posted 09-29-2011 10:35 AM
Launch video from CCTV here.
issman1 Member
Posts: 1042 From: UK Registered: Apr 2005
posted 09-29-2011 11:20 AM
I'm pleased that Tiangong-1 was successfully launched into orbit, but what is the inclination?
If it's 42 degrees, like all previous Shenzhou missions, then it will not be visible from the UK.
Philip Member
Posts: 5952 From: Brussels, Belgium Registered: Jan 2001
posted 09-29-2011 11:40 AM
Jiuquan Satellite Launch Center is about 40° inclination...
Well done to the Chinese space program!
Jay Chladek Member
Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
posted 09-29-2011 05:22 PM
I wish them continued success. Looking at an artist's rendering, it reminds me a little of the early Salyut/Almaz cores with its stepped cylinder configuration.
It can't be very big though as according to my references on the Long March, it can only lift payloads of about 12.3 tons into LEO, which is about half of what the Proton can do (23.15 tons, a little heavier capacity compared to what it had for Salyut 1). As such, the development of docking systems and a modular building block approach will be critical to a Chinese station program.
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 09-29-2011 05:38 PM
quote:Originally posted by Jay Chladek: It can't be very big though as according to my references on the Long March, it can only lift payloads of about 12.3 tons into LEO...
According to state media, the Long March 2F T1 (the modified Long March 2F for lifting Tiangong-1) has a launch capability of 8.6 tons.
Tiangong-1 is 10.4 meters (34 feet) long, has a maximum diameter of 3.35 meters (11 feet) and had a liftoff mass of 8.5 tons.
Glint Member
Posts: 1040 From: New Windsor, Maryland USA Registered: Jan 2004
posted 09-30-2011 09:37 AM
quote:Originally posted by issman1: If it's 42 degrees, like all previous Shenzhou missions, then it will not be visible from the UK.
Even with its inclination of 42.7 degrees, it's still visible from the UK, although its passes will be low. From UK cities such as as London, at Latitude N 51.5, pass altitudes will be under +15 degrees. Using binoculars, even satellite passes under +10 degrees in altitude aren't difficult to observe -- especially ones as large as Tiangong-1.
The 28.5 degree inclination of HST doesn't prevent it from being seen from N 39.5 here despite the 11 degree difference. HST is frequently visible during its passes through our southern sky.
Granted, HST's greater height helps, but Tiangong-1 should be visible from some, though not all, of the UK when lighting conditions are favorable. However, with winter approaching, those opportunities will become fewer and farther between.
dom Member
Posts: 855 From: Registered: Aug 2001
posted 09-30-2011 10:38 AM
A bizarre footnote to the launch is reported by the BBC.
China's state TV accompanied coverage of the historic launch of the country's first space laboratory with a patriotic US song, America the Beautiful.
The song is regarded by many as an unofficial national anthem for the US, and features the line: "America! America! God shed his grace on thee."
Some Chinese people say that CCTV must have made a mistake with the music. The broadcaster has not commented.
Prospero Member
Posts: 94 From: Manchester, UK Registered: Mar 2006
posted 10-02-2011 05:11 AM
I know it's a bit on the small side, but I'm surprised the Chinese government are referring to this as a "space lab" and not a "space station". It's a pressurised facility in orbit that's designed to be visited by crews and worked in. If there's some other definition of a space station, I don't know what it is. I'm assuming the sole distinction is size? In which case, how big does a "space lab" have to be before it's a "space station"?
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 10-03-2011 07:04 AM
Tiangong-1 is the modern-day equivalent of the Agena target vehicle used during the Gemini program. Its primary purpose is teach China how to dock. That it can host experiments and brief crew visits reflects the legacy hardware on which it was based.
Jay Chladek Member
Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
posted 10-07-2011 07:49 AM
The main definition I can think of for why this module would be called a space lab as opposed to a station would be that it is a relatively small experimental vehicle. It has some capabilties, but can't necessarily be the primary habitat with its power being the exclusive provider to a crew onboard (with the Shenzou spacecraft in a hybernation state). The term Space Station tends to imply that the station can operate fully independent of another craft, or can act as the primary spacecraft when another vehicle is docked to it (with the other craft shut down).
Granted the name "Skylab" kind of blurred that difference somewhat between a lab and a station since it was more of a station than a laboratory. But, Skylab was also NASA's first pass at an orbiting station and they used it as a laboratory for practically every type of experiment in living and working in space from medical and life sciences, to astronomy studies, to even simple questions about if a space shower would work.
So since Tiangong-1 is essentially China's first pass at a station module, laboratory would work well here as well since it is a place where experiments are being conducted. Dock at least a couple specialized modules together, and then you have the beginnings of a space station I would think. And as Robert has said, right now it is closer to an Agena target vehicle than say an early Salyut.
GACspaceguy Member
Posts: 2476 From: Guyton, GA Registered: Jan 2006
posted 10-07-2011 08:21 AM
Would it be short sighted to say that in today's spaceflight culture an orbiting laboratory is used for intermittent habitation for a few years? A space station is for continuous habitation for long duration five plus years.
Jay Chladek Member
Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
posted 10-07-2011 07:11 PM
I suppose that is one way to look at it. Of course, the Soviets called their first Salyuts space stations and those were relatively short term occupations. The continuous manning didn't really begin to happen until Salyut 6, 7 and Mir and even then, there were occassional gaps where no crew occupied the station. The ISS is I believe the first station that has stayed manned continuously from Expedition 1 onwards.
The ESA Spacelab and the Spacehab laboratory modules are a bit of a weird placement in the whole definition as they can't fly independently as they needed a shuttle to keep them powered. But when in operation, they essentially turned the shuttle into a short duration space laboratory of sorts. Even the ASTP docking module had some of those attributes as well as it contained some experiment packages that were conducted in orbit after the primary docking mission was concluded and the Soyuz returned home.
SkyMan1958 Member
Posts: 867 From: CA. Registered: Jan 2011
posted 10-31-2011 07:26 PM
The mission, if successful, will make China the third nation to master the technology after the United States and Russia, paving the way for the nation to place a space station into orbit around 2020.
How about the European ATV? Aside from the autonomous aspect of it, wasn't that controlled by ESA/CNES?
issman1 Member
Posts: 1042 From: UK Registered: Apr 2005
posted 11-01-2011 12:37 AM
Technically that is true, although the ATV uses Russian hardware and can only dock with the Russian segment.
cspg Member
Posts: 6210 From: Geneva, Switzerland Registered: May 2006
posted 11-02-2011 03:01 PM
Docking took place "at night"- because the Chinese do not want to provide clear pictures of both vehicles?
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 11-02-2011 03:07 PM
According to Chinese officials, the first docking was planned to occur during the night phase of Tiangong-1's orbit to avoid sun glint (the glare from the sun) which could interfere with the rendezvous sensors.
The next docking, which will occur after Shenzhou 8 detaches in 12 days time, will be during the day.
Jay Chladek Member
Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
posted 11-07-2011 10:07 AM
Sun glare can be a big problem for manned craft at least. Stafford mentioned it was tough to see his alignment targets in the COAS on ASTP when they did the first docking with a Soyuz. As such, I am not surprised the Chinese went for a night pass. Besides, it seems as though many of the shuttle ISS dockings tended to occur at night as well (although their approach paths probably negated the problems with sun glint since they were using an R bar approach, where they would come upwards under the station as opposed to coming in from the front or rear).
One thing I notice about the Chinese docking system is it utilizes an androgynous hardware configuration, like the type designed for ASTP and utilized on the US nodes and PMAs of the ISS. The Russians are still using a pin and cone arrangement on their Soyuz docking ports.
If the Apollo CSM probe-and-docking mechanism would have had that many, Michael Collins would really have had nightmares about it!
Jay Chladek Member
Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
posted 11-19-2011 06:29 PM
quote:Originally posted by music_space: 10,000 mechanical parts, really?
China's system seems to be based on the APAS systems originally utilized on Apollo Soyuz and eventually refined for use on the ISS. The Apollo probe and drogue had its uses, but the thing had a few problems late in Apollo and during Skylab's missions, starting with Apollo 13. The APAS system was more complicated (maybe not quite 10,000 parts, but the final design had a lot more mechanisms to it), but even Tom Stafford even said he was more concerned with the Apollo probe and drogue possibly having another foul up on ASTP as opposed to the APAS system designed for the Soyuz side.
I hope 10,000 parts is an exaggeration as I have this line spoken by Mr. Scott from Star Trek 3 running through my head: "The more they overthink the plumbing, the easier it is to stop up the drain."
chet Member
Posts: 1506 From: Beverly Hills, Calif. Registered: Nov 2000
Months after its scheduled re-entry into Earth's atmosphere — and a surprise cameo appearance in hit space flick Gravity — China's first space station boosted into a higher orbit. It still speeds around the planet, doing ... what, exactly?
No one outside of China's popular but opaque space program seems to know.
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 09-27-2014 09:21 AM
Tiangong-1 has been in orbit for three years, Xinhua notes.
The space lab, which is in sound condition, is able to complete more operation time in orbit, according to Wang Zhaoyao, director of China's manned space program office.
Careful maintenance and monitoring will be carried out to ensure that the space lab, which was initially designed to stay in orbit for two years, will still be operational.
The article further notes that the Tiangong-2 space lab is scheduled to be launched in 2016, after which crewed Shenzhou flights will resume.
China's first space station is now slated to be complete by 2022.
MrSpace86 Member
Posts: 1618 From: Gardner, KS, USA Registered: Feb 2003
posted 11-12-2014 10:24 AM
Are all the Shenzhou flights done? I can't seem to find the information on any future flights. Any ideas?
Editor's note: Threads merged.
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 11-12-2014 10:25 AM
As noted above, crewed Shenzhou flights are expected to pick up again after the deployment of Tiangong-2 in 2016.
SkyMan1958 Member
Posts: 867 From: CA. Registered: Jan 2011
posted 03-21-2016 05:38 PM
According to the China People's Daily, after an operational orbit of 1,630 days, China's first space lab Tiangong-1 terminated its data service.
The functions of the space laboratory and target orbiter have been disabled after an extended service period of about two and a half years, although it remains in designed orbit, according to the [manned space engineering office] office.
...the flight orbit of the space lab, which will descend gradually in the coming months, is under continued and close monitoring, according to the office, which said the orbiter will burn up in the atmosphere eventually.
SpaceAholic Member
Posts: 4437 From: Sierra Vista, Arizona Registered: Nov 1999
posted 07-12-2016 12:12 PM
China space station Tiangong-1 could secretly be hurtling towards Earth, astronomers say:
...an amateur astronomer called Thomas Dorman has been watching the movement of the satellite and believes that China has lost control of it. The fact that China has given no public statement on its safety could mean that it is lost, he told Space.com.
"If I am right, China will wait until the last minute to let the world know it has a problem with their space station," Mr Dorman said.
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
"It seems it may be much ado about nothing," said T.S. Kelso, a senior research astrodynamicist at the Center for Space Standards & Innovation (CSSI), a research arm of Analytical Graphics.
Kelso has plotted the altitude history of Tiangong-1 from just after its launch to more recent times. He told Space.com that the Chinese space lab's orbit was reboosted relatively recently, in mid-December 2015.
"That reboost put it higher than it had been anytime prior to that in its mission," Kelso said.
Kelso said he does not have "any direct way to measure" Tiangong-1's stability. "But we might expect to see the rate of decrease in altitude — the slope between reboosts— increase if it was tumbling, since the station would have higher drag," he added. "Instead, we see the slowest decrease in altitude in recent years — consistent with the lower drag at a higher altitude."
Kelso said his reading of the data suggests that Tiangong-1 is dormant but stable.
SpaceAholic Member
Posts: 4437 From: Sierra Vista, Arizona Registered: Nov 1999
Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 11-07-2017 10:04 AM
The European Space Agency (ESA) will host an international campaign to monitor the reentry of Tiangong-1.
ESA will host a test campaign to follow the reentry, which will be conducted by the Inter Agency Space Debris Coordination Committee (IADC).
IADC comprises space debris and other experts from 13 space agencies/organizations, including NASA, ESA, European national space agencies, JAXA, ISRO, KARI, Roscosmos and the China National Space Administration.
IADC members will use this event to conduct their annual reentry test campaign, during which participants will pool their predictions of the time window, as well as their respective tracking datasets obtained from radar and other sources. The aim is to cross-verify, cross-analyze and improve the prediction accuracy for all members.
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
posted 12-26-2017 07:26 PM
Journalist Leonard David reports that 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.
To take part in the "high stakes" guessing game, please note that you must be over the age of 13, and by submitting an entry you are signing up to receive other news and information from The Aerospace Corporation in El Segundo, California.
denali414 Member
Posts: 593 From: Raleigh, NC Registered: Aug 2017
posted 03-06-2018 10:18 AM
Who has North America and late March?
China's Tiangong-1 is expected to re-enter the atmosphere and crash into Earth in just a few weeks, scientists have warned.
The Aerospace Corporation, a California-based non-profit research and development organization, predicted the 8.5-ton space station will collide into the earth's atmosphere in the first week of April, with the error of margin at a week on either side. The European Space Agency estimates the module will crash sometime between March 24 and April 19.
Although experts have not yet determined exactly where the out-of-control module will land, an Aerospace report detailed that it will likely re-enter somewhere in the northern U.S. states, parts of South America, northern China, the Middle east, central Italy, northern Spain, New Zealand, the south of Africa or Tasmania in Australia.
SpaceAholic Member
Posts: 4437 From: Sierra Vista, Arizona Registered: Nov 1999
posted 03-06-2018 02:12 PM
Well I used to be a fan of Chinese delivery...
quote:Originally posted by SpaceAholic: Aerospace Corp reentry forecast page.
Thanks! That website is still being updated. From Aerospace.org:
How Difficult is it to Accurately Predict a Reentry?
Due to the uncertainties involved it is very difficult to predict the exact timing of a space object’s reentry.
There are several sources of uncertainty which include:
significant variation in the density of the upper layers of the atmosphere,
significant uncertainties in the orientation of the spacecraft over time, uncertainties in some physical properties of the spacecraft such as the exact mass and material composition, and
uncertainties in the exact location and speed of the space station. When aggregated, these factors translate into a reentry timing uncertainty that is roughly 20% of the “time to go” (the time between the date of the prediction and the predicted date of reentry).
PeterO Member
Posts: 399 From: North Carolina Registered: Mar 2002
posted 03-15-2018 10:29 AM
Although experts have not yet determined exactly where the out-of-control module will land, an Aerospace report detailed that it will likely re-enter somewhere in the northern U.S. states, parts of South America, northern China, the Middle east, central Italy, northern Spain, New Zealand, the south of Africa or Tasmania in Australia.
Thank you for confirming that it will reenter somewhere along its orbital path.
Robert Pearlman Editor
Posts: 42988 From: Houston, TX Registered: Nov 1999
Now the best prediction is that the space station will de-orbit and crash back to Earth between March 30 and April 6, according to the European Space Agency (ESA). Marco Langbroek, an archaeologist who also tracks satellites, put the window for the eight-ton space station to fall from orbit within three days of March 31.
My latest reentry estimate for Tiangong-1: 31 March +/- 3 days. The geomagnetic storm of yesterday does seem to have given it a bump.
Philip Member
Posts: 5952 From: Brussels, Belgium Registered: Jan 2001
posted 03-22-2018 04:01 PM
The 8000 Kg Tiangong-1 can re-enter between 43 degrees North and 43 degrees South latitudes... what a 40th anniversary for the Kessler syndrome (space debris collision cascading effect).
David C Member
Posts: 1015 From: Lausanne Registered: Apr 2012
posted 03-22-2018 04:34 PM
Don't think the Chinese read that paper (and don't mention Fengyun 1C).
SpaceAholic Member
Posts: 4437 From: Sierra Vista, Arizona Registered: Nov 1999
posted 03-26-2018 04:49 PM
Aerospace Corp. has narrowed its reentry window forecast to and uploaded a video depicting conceptual reentry of the spacecraft.
Tiangong-1 is currently predicted to reenter the Earth’s atmosphere around April 1st, 2018 +/- 2 Days.
posted 09-29-2011 07:22 AM
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