A serious problem on Phobos-Grunt
Posted by Emily Lakdawalla
2011/11/08 05:29 CST
Updated 8:20 PST. Google translation of RIA Novosti story replaced by a bilingual human translation -- thanks very much to commenter Olga!!Updated 7:02 PST. I have been told that the posts by russianhalo117 on nasaspaceflight.com -- the ones quoting an unnamed DSN source -- are not reliable. Just to make things more confusing.Updated 6:41 PST. Google translations of official statements from RIA Novosti now appended.Updated 5:45 PST. The anonymous Deep Space Network source quoted below apparently edited the original statement, removing a critical word "not" from the text. As a result, the statement now indicates that contact WAS picked up by European tracking stations. Indications now are that the spacecraft is in safe mode, and the engine burn was never performed. The spacecraft could be reset, and the mission might be recoverable. Stay tuned.Updated 4:53 pm and 5:09 PST.
It looks like something has gone wrong with Phobos-Grunt. According to amateur astronomers, the spacecraft's orbit has not changed from before to after the first of two planned burns that would have sent Phobos-Grunt from Earth orbit to an interplanetary trajectory. More worrying is the report that they are seeing two objects in that orbit instead of one. Also, on the official Phobos-Grunt website, Anton Ledkov states that they are not receiving telemetry from the spacecraft ("ЧП, нет телеметрии"). The story is developing. I'll update this post when (if?) I find out more information.
From this site, home of a mailing list for visual satellite observers:
I have just received word from the project that there seems to be a serious problem.
After the planned first burn of the engine, the spacecraft was not found in the predicted orbit. Alternative radar observations preliminarily show that there are two objects in the orbit with parameters the same as before the planned engine burn. Observers are requested to attempt to discover the spacecraft in the initial LEO parking orbit.
This is the official pre-launch estimated TLE of the LEO parking orbit
1 55500U 11000A 11312.95486111 -.00010748 00000-0 -11606-4 0 14
55500 51.4279 0.6058 0106375 25.7555 298.8256 15.98414689 33
I imagine that one of the two objects seen on the radar could be the final stage of the booster. Accurate descriptions and counts of the number of objects seen, as well as position and time would be useful.
Further information, from the nasaspaceflight.com forum.
I do not know the ultimate source of this information but it seems sufficiently detailed as to be from a knowledgeable source. I have been told that this source is NOT reliable, but I leave the text in here because it forms part of the history of this confusing evening. Some of the information does appear to be true, some is more questionable.
As of 6:40 PST, official comment had appeared on a RIA Novosti news story. "Baikonur Space Agency head Vladimir Popovkin" is repeatedly quoted.
U.S. DSN's Goldstone Antenna Complex received one ping from Spacecraft. SC performed TM downlink via all available channels, this is indicating an anomaly detected by SC computer. During SC testing, Roscosmos inserted an SC slew commanding sequence in the flight program to point the SC's antennas toward the North (to be pointing at U.S., European, Russian ground stations) in the event of a problem before the burn(s) so that data can be more quickly obtained. This allows them to analyze the data and try again another day since MDU is completely powered by SC's solar panels. Goldstone DSN is indicating that SC is in a contingency safe mode. Contact was lost at planned LOS (with no first burn) and was picked up by Europe's first tracking station, TM unreadable at moment. Sun pointing for solar panels may not have been established before battery charging was commenced by flight computer. SC can be commanded to reset if need be.
"We've had a rough night. We could not locate the spacecraft, and now found its coordinates. It turned out that the propulsion installation did not activate. There was no first or second burn." said Popovkin.An update at 7:05 PST on RIA Novosti's website quotes an unnamed source as saying that if it's a software problem, it can be fixed, but if a hardware problem, it can't. That seems like a fairly obvious statement though.
According to his statement, it is possible that the spacecraft "could not reorient itself from the Sun to the stars".
"It is a difficult path, and it is possible that the instruction to turn on the propulsion system was not relayed to the sensors," noted Popovkin.
He remarked, that this was an unusual situation, but a workable one. It was an anticipated one during the development of the project, and the order of actions in a situation like this was prepared. [NOTE: This confirms something that Lou told me -- which is that this is one of the failure modes that they had prepared for in their contingency planning. It does not mean they have solved the problem, but it does mean they do have a plan already developed to work through to attempt to solve it. --ESL]
"We will reinstall (re-initiate) the program on the spacecraft. The orbit, at which the craft is located is stable, no tanks were dumped, no fuel was used up" said the head of Roskosmos.
He added that the time for the re-initiation of the program that is available to the specialists is three days. [This time limit could result from several different causes. Two that I can imagine have to do with the power situation and with the time they have before they will no longer be in position to inject onto their interplanetary trajectory. But there's no official statement on the reason for this three-day limit. --ESL]
"For the duration of the day we will definitely inform everyone about further situations" said Popovkin.
Other related posts:
Or read more blog entries about: