China launches a 'Reusable Experimental Spacecraft' - a Space Plane? [UPDATED MULTIPLE TIMES]

Early September 2020, the space tracking community was in nervous anticipation of a rather mysterious Chinese launch. Amidst tight security measures, a Changzeng-2F (CZ-2F) rocket was readied at SLS-1 of Jiuquan's Launch Area 4. Chinese tracking ships were taking up positions near South America and in the Arabian Sea. Two NOTAM's appeared suggesting a launch between 5:20 and 6:00 UT on September 4. Something was afoot! Speculation was, that this was the long anticipated inaugural launch of a robottic Space Plane, a version of the Shenlong, China's answer to the American Air Force's X-37B robottic Space Plane.

Then, on September 4th, the Chinese news agency Xinhua published a very brief news item announcing that a CZ-2F from Jiuquan had launched a 'Reusable Experimental Spacecraft' earlier that day. 

The bulletin was scarce in information but stated that "after a period of in-orbit operation, the spacecraft will return to the scheduled landing site in China. It will test reusable technologies during its flight, providing technological support for the peaceful use of space".

No further details were given on launch time, orbit or character of the spacecraft. The description of the spacecraft is a bit ambiguous. Instead of a space plane, a 'reusable spacecraft' could in theory also be some sort of capsule (e.g. like the SpaceX Dragon): but most analysts think this indeed refers to the long rumoured space plane, China's answer to the US X-37B.

Pre-launch, and based on the positions of the hazard zones from the two NOTAM's, I calculated a launch into an orbital inclination of ~45 degrees, incidentally similar to the orbital inclination of the X-37B OTV 6 mission currently on-orbit. What's more, the launch window given (the NOTAM windows were from 5:23 to 6:05 UT) indicated the possibility of a launch into the orbital plane of OTV 6! The orbital plane of OTV 6 passed over Jiuquan at 6:00 UT - near the end of the launch window.

I published the following expected track for a launch into a 45 degree inclined orbit (which we now know is wrong):

Initial pre-launch trajectory guess. Click map to enlarge

When later that day the first orbital elements by the US military tracking network appeared on the CSpOC portal, it turned out that the orbital inclination was not ~45 degrees, but 50.2 degrees, 5 degrees higher than I anticipated. The reason for the mismatch, is that the rocket apparently did a dog-leg manoeuvre during ascend. This is very clear when we plot the orbital ground track in relation to the launch site and hazard zones from the two NOTAM's: it passes obliquely between them rather than lining up.

Actual orbital track. Click map to enlarge

 A 'dog-leg' manoeuvre is usually done for safety reasons, to avoid overflying a particular area downrange (e.g. a city or a foreign nation), but can also be done to insert the spacecraft into an orbital inclination that otherwise cannot be reached from the launch site. The latter is however not the case here - [editted] the orbital inclination is higher than the launch site latitude (you cannot reach an orbital inclination that is lower than your launch site latitude without a dog-leg, but higher you can.). So the reason must be range safety.

It is clear that the launch occurred well outside the NOTAM time window (why, is not clear). My analysis, based on a proximity analysis using the orbits of the spacecraft, the upper stage of the CZ-2F rocket, and that of four engine covers ejected upon spacecraft separation, indicate spacecraft separation and insertion into orbit around 7:41 UT on September 4th, over the Chinese coast with the orbital plane lining up with Jiuquan (see image below which depicts the orbital position at orbit insertion). The launch itself then should have occured some 8-10 minutes earlier i.e. around 7:30 UT, give or take a few minutes.

Moment of orbital insertion. click to enlarge

 

The spacecraft was inserted into a 50.2 degree inclined, initially 332 x 348 km orbit. During the hours after launch, the spacecraft made small orbital manoeuvres (see diagram below). At the time of writing (5 September 20:45 UT) it is in a 331 x 347 km orbit.

click diagram to enlarge

The later than initially expected launch time and, through a dog-leg manoeuvre, insertion into a 50.2 degree inclined orbit moved the orbital plane away from that of the X-37B OTV 6, although the two orbital planes are still near. Igor Lissov has pointed out some resemblance to the orbital plane of another US classified payload, USA 276, which has a similar orbital inclination to the Chinese spacecraft (but 50 km higher orbital altitude). The RAAN difference is 8 degrees:

click to enlarge

Based on the current orbits of all three spacecraft, there will be no close approaches of the Chinese spacecraft to either of these classified US payloads over the coming two weeks.

OTV 6 is currently in a 383 x 391, 45.0 degree inclined orbit. The difference in RAAN with respect to the Chinese spacecraft is 13.4 degrees, with a 5.2 degree difference in inclination and about 40-50 km difference in orbital altitude.

USA 276, the mysterious spacecraft that made a close approach to the ISS in May 2017 (see my July 2017 article in The Space Review), is currently in a 397 x 395, 50.0 degree inclined orbit. The difference in RAAN with respect to the Chinese spacecraft is 7.9 degrees, with a 0.2 degree difference in inclination and about 50-60 km difference in orbital altitude.

The Chinese 'reusable' spacecraft was launched from SLS-1, one of two launch platforms at Launch Area 4 of the Jiuquan Space Launch Center. Below is a Copernicus Sentinel 2B image of the launch complex, taken on September 2nd, two days before the launch. The two launch platforms are indicated: the southernmost one is the platform used for this launch.

click image to enlarge

It will be interesting to see where the 'reusable spacecraft' will eventually land. One likely candidate is a military airfield, the Dingxin Test and Training Base, that is located some 75 km southwest of the launch site. I have indicated both the launch site (A) and the potential landing site (B) in the Copernicus Sentinel 2B image below. The second image gives a more detailed look on the airbase.

Click image to enlarge

 

Click image to enlarge

We have no clue how long the spacecraft will stay in orbit. It will be interesting to see when and where it lands.

The 'reusable spacecraft' has the CSpOC catalogue entry #46389 (COSPAR ID 2020-063A). The CZ-2F upper stage is object #46390 (2020-063B). The four ejected engine covers (with apogees in the 458 to 566 km range), have numbers 46391-46394 (2020-063A to 202-063F).

UPDATE 6 Sept 2020 8:45 UT:

Xinhua reports on Sept 6 that the spacecraft has landed after 2 days on-orbit. Depending on the landing site, landing should have been (based on orbital overpass) either around 1:55 UT at Lop Nor (an alternative landing site suggested), or 6:45 UT at Dingxin Airbase.

UPDATE 2, 9:30 UT:
As the Chinese version of the Xinhua bulletin dates to an hour after the first option (1:55 UT), it seems that the landing was near 1:55 UT near Lop Nur in the Taklamakan desert (HT to Jonathan McDowell).

UPDATE 3, 10:30 UT:
This is the potential landing site, a triangular arrangement of 5 km long landing strips in the Taklamakan Desert. The orbital track of the spacecraft passed some 42.5 km northwest of it around 1:54 UT, more or less parallel to what appears to be the main landing strip:

Click image to enlarge

Click image to enlarge

UPDATE  4, 14:00 UT:
This is an updated diagram of the orbital evolution over the test flight. It seems no large manoeuvers were tried during this flight.

Click diagram to enlarge

UPDATE 5, 16:00 UT:

Jonathan McDowell noted that a new object related to the launch has been catalogued, object 2020-063G, #46395. My analysis suggests it was ejected from the experimental spacecraft near 22:25 UT on the 5th, two revolutions before landing. It likely is a cubesat of some sort. It is in a  332 x 348 km, 50.2 degree inclined orbit. (Update 8 Sept: on Twitter, Bob Christy has suggested that it might be a small inspector satellite, used to inspect the outside of the experimental spacecraft prior to deorbit)

The Chinese ICBM test of August 7 [UPDATED]

Just after local midnight of August 7-8, 2019, the South Korean amateur astronomer Mr Lee Won-Gyu was taking images of the night sky at Mount Jiri in Korea when he observed and photographed a cloud-like illuminating phenomena in Corona Borealis that to the expert eye is clearly the exhaust cloud from a rocket engine burn.

Mr Lee Won-Gyu's images of the cloud are featured in this article in the Korea Times, where they were presented as a 'UFO'. The images were taken between 00:14 and 00:24 Korean time (corresponding to August 7, 15:14-15:24 UT). Mount Jiri, the location of the sighting, is at approx. 35.34 N, 127.73 E. In this blogpost, I will identify this 'UFO' as a Chinese ICBM test.

Initial speculation on the internet was that this was perhaps related to the AEHF 5 geosynchronous satellite launch from Florida on August 8, 10:13 UT. The observation was however done 19 hours before this launch (there was some initial confusion due to the date difference in local time and UT), and the cloud was seen in a wrong part of the sky for a launch to geosynchronous altitude. So I suggested it could be a Russian or Chinese ICBM test launch.

As it turns out, additional evidence suggests this indeed was an ICBM test, by China. As the result of a private request by me, Twitter user @Cosmic_Penguin managed to dig up NOTAM's for the date and time of the event posted on a Chinese forum by a forum member nicknamed 'kktt'. These NOTAM's with temporary airspace closures from "ground to unlimited" in two parts of China corroborate an ICBM test launch:


A4092/19 NOTAMN
Q) ZBPE/QRTCA/IV/BO/W/000/999/3909N10940E019
A) ZBPE B) 1908071449 C) 1908071511
E) A TEMPORARY RESTRICTED AREA ESTABLISHED BOUNDED BY:
N392016E1092107-N391413E1100213-N385819E1095815-N390419E1091716
BACK TO START.VERTICAL LIMITS:GND-UNL. ALL ACFT SHALL BE FORBIDDEN
TO FLY INTO THE RESTRICTED AREA.
F) GND G) UNL


A4094/19 NOTAMN
Q) ZWUQ/QRTCA/IV/BO/W/000/999/3712N08311E108
A) ZWUQ B) 1908071451 C) 1908071548
E) A TEMPORARY RESTRICTED AREA ESTABLISHED CENTERED AT
N371133E0831033 WITH RADIUS OF 200KM. ALL ACFT ARE FORBIDDEN TO
FLY INTO THE TEMPORARY RESTRICTED AREA. VERTICAL LIMITS:GND-UNL.
F) GND G) UNL


The NOTAM's have a time window between 14:49 UT and 15:48 UT on 7 August 2019, which fits the phenomena observed from Korea (7 August 15:14-15:24 UT). They also fit the direction of the sky phenomena as seen from Korea: the exhaust cloud was seen at 30 degrees elevation in the sky at azimuth 290-291 degrees (west-northwest). This sightline points directly to the area designated in NOTAM A4092/19.

The map below plots the two areas designated in the NOTAM's. The smaller rectangular area from NOTAM A4092/19 represents the launch area near Hongjian Nur in Shaanxi province. The larger circular area from NOTAM A4094/19 at the southern edge of the Taklamakan desert represents the RV target area. The two areas are some 2300-2400 km distant from each other:

click map to enlarge

I have depicted the sightline from Mr Lee Won-Gyu's photographs from Mt. Jiri in Korea on the map as well (white): it points towards the launch area and it lines up with the direction of that rectangular area. Both time and direction therefore fit the Korean sighting. So does the character of the photographed cloud, which is similar to missile exhaust clouds observed during other ICBM launches.

This was an interesting ICBM launch in that it appears to have been highly lofted, with an apogee at approximately 3000 km altitude. This is based on both the estimated flightime (about 37 minutes) deduced from the NOTAM time window durations; and from an assessment of the exhaust cloud sightings from Korea, the direction and elevation of which point to a burn at 3000 km, close to apogee of the orbit, when combined with a ballistic trajectory between the two areas of the two NOTAM's. The launch happened near 15:00 UT (August 7), the missile engine burn seen from Korea happened some 15 minutes later close to mid-course and was probably meant to change the direction of the missile.

The situation is spatially depicted in the diagram below. The sightline from Korea crosses a 3000 km apogee trajectory twice, at about 2300 km altitude when the missile is ascending, and near apogee at 3000 km altitude. The latter altitude is the most likely location of the engine burn. At these altitudes, exhaust clouds are well above the earth shadow and hence brightly sun-illuminated.

click image to enlarge

When launched on a less lofted trajectory, this missile would have had a ground range of at least 6300 km. The reason to launch it into a lofted trajectory, rather than a more typical trajectory with apogee at 1200 km, is that in this way the test could be done completely within the borders of China. We have seen such lofted trajectories earlier with some early North Korean ICBM tests.

The ICBM appears to have done a dog-leg manoeuvre near apogee, changing the course just before mid-course. One piece of evidence for this is that the orientation of the launch hazard area from NOTAM A4092/19 does not match with a simple ballistic trajectory towards the target area. Neither does the sightline direction from Korea. They would result in a target area more to the north than the area from NOTAM A4094/19.

This can be well seen in the map, where I depicted both a direct ballistic trajectory (solid black line) between the two areas from the NOTAM's, as well as a 'dog-legged' trajectory (dashed black line), with the dogleg at the near-apogee burn imaged from Korea and initial launch direction according to the orientation of the NOTAM A4092/19 area:

click map to enlarge

The direct trajectory clearly does not fit the launch area direction and Korean sighting well, whereas a launch into the direction of the NOTAM A4092/19 area and a dogleg near apogee does, with the latter also clearly fitting the Korean sighting.

A reason for such a dog-leg manoeuvre might be to confuse and evade mid-course anti-Ballistic missile intercepts. So I am wondering if this perhaps was an anti-ballistic missile test as well.

This missile test must in theory (and ignoring cloud cover) have been widely visible over Eastern Asia. The Korean Times article presents one other observation, also from Korea, but I have not seen other observations so far.

UPDATE: Twitter user @LaunchStuff sent me this link to a Weibo page, which includes several photographs of the event from various parts of China and a very cool video shot from Inner Mongolia, showing the spiralling behaviour seen during other ICBM tests as well.


Acknowledgement: I thank Ravi Jagtiani for bringing the Korea Times article to my attention; @Cosmic_Penguin for digging up the NOTAM's; and Jim Oberg and Jonathan McDowell for discussions.