NROL-101: probably a HEO mission [or maybe not! See update at bottom]

click map to enlarge

EDIT 4 Nov 2020 22:30 UT: 

post UPDATED with new maps and new value for inclination parking orbit

EDIT 2, 22:50 UT (Nov 4): the launch has been SCRUBBED for at least 48 hours...

EDIT 3, 7 Nov 22: launch is now currently scheduled for 11 Nov, 22:22 UT 

EDIT 4, Nov 13:  NROL-101 cleared the tower at 22:32 UT (Nov 13)

If weather cooperates,ULA will launch NROL-101, a classified payload for the NRO, on November 11 (postponed from November 3 and 4). Based on Navigational Warnings, the launch window is from 22:00 UT (Nov 11) to 02:45UT (Nov 12), with ULA indicating a launch window start at 22:22 UT. 

[ EDIT: eventually, NROL-101 launched on 13 Nov 2020 at 22:32 UT ] 

The launch is from platform 41 on Cape Canaveral, using an Atlas V rocket in 531 configuration (5-m fairing, 3 strap-on boosters, 1 single engine Centaur upper stage). It would have originally flown in 551 configuration but this was changed. It is the first Atlas V flight to feature the new GEM 63 solid fuel strap-on boosters.

This Navigational Warning has appeared in connection to this launch (updated):

062038Z NOV 20
NAVAREA IV 1074/20(GEN).
WESTERN NORTH ATLANTIC.
FLORIDA.
1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING
   112200Z TO 120245Z NOV, ALTERNATE
   122200Z TO 130245Z AND 132200Z TO 140245Z
   IN AREAS BOUND BY:
   A. 28-38-50N 080-37-34W, 29-58-00N 079-28-00W,
      29-54-00N 079-21-00W, 29-34-00N 079-36-00W,
      29-15-00N 079-45-00W, 28-36-00N 080-23-00W,
      28-30-57N 080-33-15W.
   B. 30-01-00N 079-33-00W, 31-08-00N 078-36-00W,
      30-54-00N 078-14-00W, 29-47-00N 079-11-00W.
   C. 36-38-00N 073-35-00W, 39-03-00N 071-00-00W,
      38-30-00N 070-13-00W, 36-05-00N 072-46-00W.
   D. 51-37-00N 049-45-00W, 53-32-00N 044-58-00W,
      52-54-00N 044-15-00W, 51-03-00N 049-07-00W.
2. CANCEL THIS MSG 140345Z NOV 20.

The launch azimuth from the location of the hazard zones in this Navigational Warning and the initial launch azimuth depicted in a map tweeted by ULA point to an initial lauch into a [value updated] ~56-degree ~57.75 degree inclined orbit:

 

click map to enlarge

However: this is likely only a temporary parking orbit. The 531 rocket configuration has never been used for a launch into LEO so far, but always for launch into GEO. Given the launch azimuth, NROL-101 will certainly not be launched into GEO. 

So either the payload is destined for LEO but unusually heavy or (more likely) the final orbit aimed for is a HEO orbit (also known as a  Molniya orbit) with inclination ~63 degrees, perigee at ~2000 km over the southern hemisphere and apogee near 37 8000 km over the Arctic. [But: see major update at bottom! It might have been MEO rather than HEO, but this remains uncertain!]

A 63-degree inclined Molniya orbit cannot be reached directly from the Cape, because of overflight restrictions. Hence the initial launch azimuth corresponding to a ~58-degree inclined orbit. If NROL-101 goes into a Molniya orbit, it will do a dog-leg some time after launch, or (more likely) coast in a ~58-degree inclined parking orbit for perhaps several hours before being boosted into a Molniya orbit by the Centaur.

This appears to be underlined by the fact that to date (Sunday Nov 1) no Navigational Warnings have been issued for the reentry area of the Centaur upper stage. This could indicate that the upper stage will be left orbiting in a ~2000 x 37 8000 km transfer orbit, or is disposed into a Heliocentric orbit.

The NRO so far launched three kinds of  satellites into HEO orbits:

1) Data communication satellites (SDS);

2) SIGINT satellites (Trumpet FO);

3) combined SIGINT (Trumpet FO) and SBIRS Early warning satellites.

The last SIGINT/SBIRS combination launched into HEO was USA 278, launched in 2017. The last SDS launch into HEO was USA 198 in 2007 (there was also a launch in 2017 but this was into GEO, not HEO). As Ted Molczan pointed out in  a private com, SIGINT launches into HEO usually were done from Vandenberg, SDS launches from Cape Canaveral. So perhaps NROL-101 will carry a new SDS satellite, but this is far from certain. Radio observations after launch might shed some light on both orbit and payload character.

The initial trajectory will take it over NW Europe some 23 minutes after launch, but in Earth shadow, so the pass will not be visible:

click map to enlarge

 

UPDATE 15 Nov 2020 15:20 UT

Around 2:30 UT on Nov 14, four hours after launch, sightings of a fuel venting event were observed from the western USA.

This image tweeted by  Marc Leatham shows the V-shaped cloud in Saggitarius, imaged from Joshua Tree National Park:

🔎**EXPAND**🔍 Early in the evening last night in Joshua Tree, California, I was taking some test shots of the Milkyway. While editing, something popped out at me. If I'm not mistaken, that diffuse V shape must be #NROL101 launched from Florida! @torybruno, Am I right?!? 🔭☄️✨ pic.twitter.com/j2tNAICqji

— Marc Leatham (@quarkmarc) November 14, 2020

There is also allsky imagery of the fuel cloud from Taos, New Mexico (look low at the horizon where the milky way touches the horizon(right side), for a 'moving' piece of Milky Way. This is the fuel cloud):

These sightings lead us to believe that the payload perhaps went into the lower part of MEO, not HEO. This is however (emphasis) not certain at this moment.

The launch sequence then could have been insertion into a LEO parking orbit; an apogee raising burn; a perigee raising/circularization burn bringing it into HEO; and fuel vent/orbit separation burn by the Centaur rocket. That latter event caused the observed fuel cloud, at about 8500 km altitude.

ULA reported 'mission successful' around 1:48 UT. For the launch provider, their mission is completed upon payload separation. 1.48 UT corresponds to a pass through the southern apex of the orbit, suggesting payload separation was at that point. This, in combinbation with the observed Centaur vent, would argue against insertion into HEO but does fit insertion into MEO.

If my guess is correct, then this should be the approximate orbit (orbital position is the approximate position for the time of the Joshus Tree fuel cloud sighting):

click to enlarge

 

Both the Centaur and payload have been catalogued (but without orbital elements) by CSpOC, as #46918 (2020-083A) USA 310 and #46919 (2020-083B) Atlas V Centaur R/B.

If USA 310 indeed went into HEO, then the identity/character of the payload remains a big guess.

Added note, 4 Nov 2020, 21:30 UT: the maps and inclination of the initial parking orbit have been updated based on a map showing the initial trajectory up to fairing jettison tweeted by ULA boss Tory Bruno.

This post benefitted from discussions with Cees Bassa, Scott Tilley, Ted Molczan and Bob Christy.

Observing HEO objects

In wintertime at latitude 51 degrees North, satellites in Low Earth Orbit are mostly invisible except for twilight, as all their passes are completely within the Earth shadow.

This season is therefore the season that I focus on HEO and GEO objects. HEO stands for Highly Elliptical Orbit and is almost synonymous with the more informal name 'Molniya orbit', after a class of Russian communication satellites employed in such orbits.

Military SDS COMSAT USA 198 (SDS 3F5), imaged in Cassiopeia on 4 Jan 2014

Satellites in a Molniya orbit have an orbital period of about 2 revolutions per day, an orbital inclination near 63.4 degrees, perigee at a few hundred kilometers altitude over the southern hemisphere and apogee at altitudes near 36000 km over the Arctic. They spend most of their orbital time near their apogee.The 63.4 degree orbital inclination ensures that perigee keeps at a stable position over the southern hemisphere.

US military payloads and 'unknowns' in Molniya orbit

The advantage of a Molniya orbit is that it allows a good, long duration view of high northern latitudes, including the Arctic region, which are not well visible from a geostationary orbit. This is ideal for communications satellites serving these regions, for SIGINT satellites, and other applications (such as infrared ICBM early warning systems, e.g. SBIRS) that benefit from a long 'stare' and good view of high Northern latitudes.

The US military has several systems in a Molniya orbit (see image above): communication satellites (e.g. two components of the SDS system), several SIGINT satellites (TRUMPET and TRUMPET-FO), and components of the SBIRS system (piggybacked on three TRUMPET-FO SIGINT satellites). Identifiable payloads include:

- TRUMPET 1, 2 and 3 (SIGINT);
- TRUMPET-FO and SBIRS USA 184, 200 and 259 (SIGINT and SBIRS);
- SDS COM satellites USA 179 and 198

There are a couple more which we cannot (yet) tie to a specific launch and function (see note at end of post).

Near their apogee, satellites in Molniya orbit are located high in the sky for my location, and because of their high northern position, they are sun-illuminated and hence visible (typically at magnitudes near +9 to +12) even at midnight and in winter. They move very slowly when near apogee, creating tiny trails on the images.

On December 13, the NRO launched (as NROL-35) a new SIGINT and SBIRS platform into a Molniya orbit: USA 259 (see a previous post). It is currently still actively manoeuvering to attain its final orbit, which makes it an interesting object to track. The image below was taken in late twilight of Jan 4, when the satellite was past its apogee and on its way to perigee. It was 4 minutes early against orbital elements based on observations of only a few days old.

SIGINT/SBIRS satellite USA 259 (NROL-35) imaged in Andromeda in the evening of Jan 4

I image these objects with an old but good Zeiss Sonnar MC f2.8/180 mm telelens (made in the former DDR and sturdy -and heavy- as a tank). This lens has a 67 mm aperture at f 2.8, which means it shows faint objects. As these objects move very slowly, the relatively small FOV is no problem. My observational data from January 4th can be found here and here.

Note: the 'unknowns' in the orbital plot above are objects we track that are not in public orbital catalogues and which we cannot tie to a specific launch. Although some of them certainly are, not all of these need to be payloads: some might be spent rocket stages from launches into HEO.

Observing USA 259 (NROL-35)

On December 13th, 2014, the NRO launched NROL-35 out of Vandenberg AFB into a Molniya orbit. The payload, USA 259 (2014-081A) is most likely a SIGINT, and possibly piggybacks a SBIRS sensor, according to analysts.

USA 259 (NROL-35) imaged by me on 28 December 2014

Our tracking network quite quickly picked up the payload. Peter Wakelin first picked it up from Britain on December 13, followed by Scott Tilley in Canada and Cees Bassa in the Netherlands a few hours later. In the two weeks since, the payload has been observed to be manoeuvering in order to get into its intended orbit.

My own first observations of the payload were done in the evening of December 28 (see image above, taken with the F2.8/180mm Zeiss Sonnar) during short clearings. It had been a clear day, but clouds rolled in around nightfall. The satellite was located high over the Northern Atlantic near aphelion at this time at an altitude of 34500 km, and situated high in the sky in Cepheus as seen from Leiden.

orbital position at time of the photograph

view from the satellite

Observing HEO objects

Friday evening I missed the LEO window because of a dinner. When back home near midnight, conditions were dynamic: intermittent clear skies and roving cloud fields.

A HEO (Highly Elliptical Orbit) object called "Unknown 051230" (2005-864A) was well-placed near the zenith, in Cepheus. I targetted it using the 2.8/180mm Zeiss Sonnar MC lens, snapping pictures during clear spells. It shows up well, as a tiny but clear trail (indicated by the arrow in the image):

click image to enlarge

This object is one which our analysts cannot link to any particular launch - hence the designation "Unknown". It is being tracked by us for quite a couple of years now (since Greg Roberts discovered it on 30 December 2005). It could be either a (defunct) payload, or an old rocket booster.

At the time of my observations it was at an altitude of 36650 km, close to its apogee, situated over the Arctic circle roughly above Iceland:

orbital position of Unknown 051230 at the time of observation

click image to enlarge

Nadir view from orbital position of Unknown 051230 at the time of observation

click image to enlarge

Highly Elliptical Orbits (also called a Molniya orbit) typically have an orbital inclination near 63.4 degrees, an apogee near 36000 km, and perigee at only a few hundred km altitude, usually over Antarctica.

63.4 degree orbital inclination of Unknown 051230

click image to enlarge

The ~63.4 degree inclination with these orbital parameters ensures that the perigee is stable, i.e. always stays over the southern hemisphere.

An object in this orbit has a period of 0.5 day, so it makes 2 revolutions per day. Its residence time in perigee over the southern hemisphere is only brief: most of the time it is at high altitude over the northern hemisphere, allowing many hours of  continued presence above that area (see image above).

Objects in these orbits are therefore typically used to provide communications at high Northern latitudes, or for SIGINT and infra-red surveillance.

Fireball seen over Eastern Australia, 13 June 2013 6:05 pm AEST, was NOT the decay of Molniya 3-53

On June 13, 2013, near 6:05 pm local time (AEST - corresponding to 10:05 UTC), many people in Eastern Australia observed a bright fast light falling down in the sky. It was even recorded by one of those new-fangled dashboard-cams (one of these days, I must get me one for my bike).

The Australian news website "The Chronicle" claims it was a satellite decay - more exactly, that of the Russian Molniya platform Molniya 3-53 (2003-029A).

It was however most definitely not a satellite decay.

All descriptions talk about a fast object. The dashcam video shows a pretty fast fireball indeed.

It is much too fast to be a decaying satellite. The latter move at relatively slow speeds - 8.5 km/s. At that speed, it takes them several minutes to traverse your sky, not just a few seconds. As low over the horizon as the dashcam video shows it, it would have been very, very slow, taking several tens of seconds to traverse the distance it does in the video.

In addition to it being too fast to be a satellite decay, the proposed connection to Molniya 3-53 can be rejected right away.

First: Molniya 3-53 did not decay on June 13. Orbital data by Strategic Space Command ("NORAD") show it was still in orbit in the early hours of June 15 - two days after the Australian fireball. At the moment of writing (12 UTC, June 15), the last available orbit is for epoch 13166.42726929 ( = 15 June 2013, 10:15 UTC). The moment of decay is currently predicted as 15 June 14:04 UTC, with an uncertainty of 2 hours. [Update 22/6: SSC's final TIP-message issued 15 June 15:30 UTC gives 15 June, 14:10 UTC +/- 26 minutes for the moment of decay)

Now, given that the apogee of the satellite was at a very low altitude already, could it have been the case that it briefly started to burn but survived after it passed perigee?

The answer is "no" in this case and brings us to a second point against the identification with this satellite: Molniya 3-53 was not over Australia at June 13, 10:05 UTC. It was at very high altitude over Northern Europe at that time (see map below). It would not pass over (central) Australia untill 10:55 UTC (6:55 pm AEST), i.e. a full hour later than the fireball sighting.

So what was it then? Given the speed, it is very clear this was a meteoric fireball, a small piece of cosmic rock or ice (debris from a comet or an asteroid) entering the atmosphere.

USA 179 and 184

After a month-long absence due to amongst other a hollidays in Canada, I was able to do some observations again last Saturday evening. It was very clear (and rather cold).

Due to a social activity earlier in the evening I had missed the LEO window (which is very short this time of the year at 52 degrees latitude), so I popped the EF 100/2.8 Macro USM on the camera and targetted two Molniya objects high in the sky: USA 179 (2004-034A) and USA 184 (06-027A). The first is an SDS-3 communications satellite, the second an advanced Trumpet SIGINT and SBIRS platform.

Both objects showed up brightly on the images, USA 184 nearly stellar and USA 179 creating clear short trails. Here's a part of one of the USA 179 (2004-034A) images, a small field in Cassiopeia:

click image to enlarge

I obtained the launch patches of these two objects recently.

USA 179:



USA 184:

Molniya orbits and a Keyhole flare again

The evening of September 10 saw more than a nice Space Shuttle pass (see previous post) and the ISS.

In fact, it was a prolific evening which yielded data on the Lacrosse 2 SAR (91-017A), the USA 186 KH-12 Keyhole (05-042A) and two objects in Molniya orbits: the ELINT and SBIRS satellite USA 184 (06-027A) and the SDS-3 communication satellite USA 198 (07-060A).

USA 184 was imaged in two sessions 1h 45m apart. It is interesting to see the effect of it moving towards its apogeum (see below: in these images, which are on the same scale and at full pixel resolution, 1 pixel equals 10" (arcseconds)): while during the first session the satellite still creates a recognizable trail in the 10 second exposures (taken with the EF100/2.8 Macro USM), it appears as an almost static stellar object in the exposures taken 1h 45m later:

click image to enlarge

The Keyhole USA 186 flared brightly to -1 at about 20:25:43 UTC, just before the start of an exposure. I captured the descending branch of the flare. As I had mispointed the camera in haste, the satellite unfortunately runs out of the FOV (the sat is moving from right to left on the image):

click images to enlarge

More flashing Iridium 33 wreckage, ISS, USA 200 and other high objects

As I wrote in my previous post with the image of USA 129 flaring, yesterday evening I hauled a rich batch of objects.

It started in twilight with a nice pass of the International Space Station (ISS). The image below shows it rising through Orion:

(click image to enlarge)

Next I photographed passes of Lacrosse 3 (97-064A) and the NOSS 3-4 rocket (07-027B).

The wreckage of Iridium 33 (97-051C) was observed flashing again. Two photographs yielded five flashes, and like 3 days ago they fit a flash periodicity of 4.6 to 4.7 seconds. The timings were derived by measuring the flash positions astrometrically, and fitting the obtained positions to the most recent Iridium 33 tle. Here are the two images, with the flashes indicated:

(click images to enlarge)

I also targeted some HEO (High Earth Orbit) objects again, this time experimenting with different camera settings. USA 200 (08-010A) was captured again, this time somewhat better than 3 days ago:

(click image to enlarge)

I combined 4 of the images into an animated GIF, showing the movement of the sky and the satellite over a 1 minute period:



On the same image series I captured a piece of debris, USA 144 debris (99-028C), as a stray. In addition, I imaged another object in a Molniya orbit, USA 179 (04-034A) and the USA 198 rocket (07-060B) this evening.

Imaging distant objects: USA 200

Recently, I bought a new lens for my camera: a Canon EF 100/2.8 Macro USM. As this lens has a larger diameter than the EF 50/2.5 Macro I use for my regular satellite imagery, it is able to capture fainter stellar objects. Of course, the Field of View (FOV) is half as small, which makes it less fit for imaging objects in LEO (Low Earth Orbit).

It is more suitable though for imaging distant objects in HEO (High Earth Orbit): satellites which are at thousands of kilometers altitude (including, but not restricted to, Geostationary satellites). The brightest of these are around magnitude +8.5.

Yesterday I did some first succesful experiments on one of those objects: USA 200 (08-010A, NROL 28), an NRO ELINT satellite launched on 13 March 2008. It is in a Molniya orbit and as I imaged it, it was at an altitude of 29 564 km above the earth, and a distance to me of about 29 920 km! Hovering (well: not really. It is slowly moving in its orbit) high over Iceland at that moment, it keeps a watchful signals eye over the northern Atlantic and arctic.

I shot a series of 20 second exposures, from stationary tripod. The satellite showed some movement during these exposures. below photograph shows one of the images: the satellite has made a faint short trail perpendicular to the star trails.

(click image to enlarge)

The images below show the orbit of USA 200. The Molniya-type orbit means it orbits about twice a day, spending only little time in its perigee at low altitude over the southern hemisphere, and most of its time in the hight altitude parts of its orbit over the high northern hemisphere, its surveillance area.

(click images to enlarge)