[JSR] Jonathan's Space Report, No. 649

Jonathan McDowell jcm at planet4589.org
Wed Oct 26 12:24:09 EDT 2011

Jonathan's Space Report
No. 649                                       2011 Oct  25 Somerville, MA, USA

ROSAT reentry 

ROSAT reentered between 0143 and 0157 UTC on Oct 23 according
to data from USSTRATCOM. Including the final orbital data released later
on Oct 23, the uncertainty range covers the Indian Ocean, the Andaman Sea,
Myanmar, Laos and China. There have been no confirmed sightings of the reentry.

Germany's ROSAT satellite (Rongtensatellit) was the third X-ray mission to
image the extrasolar X-ray sky, following Einstein and Exosat. It made
the first imaging all-sky survey; its telescope observed at lower energy
(`softer', longer wavelengths) than Chandra and XMM and so it was
particularly sensitive to the (relatively) lower temperature nearby
interstellar gas. It discovered X-rays from comets interacting with the
solar wind, cataloged high redshift X-ray galaxy clusters and measured
their dark matter, and identified many new quasars.

The ROSAT X-ray telescope (XRT) and its main cameras, the two PSPC
(Position Sensitive Proportional Counter), PSPC-B and PSPC-C, were
developed under the leadership of the Max-Planck-Institut fur
extraterrestriche Physik (MPE) in Garching bei Munchen. The XRT could
also image onto the HRI microchannel-plate camera developed at 
Smithsonian Astrophysical Observatory (SAO) in Cambridge, Massachusetts,
while Leicester University's EUV Wide Field Camera was a separate
telescope bolted on the side. The spacecraft was controlled from GSOC
(Oberpfaffenhofen/Weilheim) while US participation included the GSFC
guest observer facility and the SAO science data center.

Launched to a 564 x 584 km x 53.0 deg orbit on 1990 Jun 1, ROSAT was in
a 244 x 250 km orbit as of 2011 Oct 10. The PSPC-C carried out the X-ray
all-sky survey between launch and an accident on 1991 Jan 25, when
PSPC-C was destroyed by accidentally observing the Sun during a system
failure. The PSPC-B took over for the pointed-target phase of science
observations, together with the HRI. PSPC-B was retired in 1994 when its gas
supply was near empty and the HRI was the sole instrument between 1994
and 1998. It had higher spatial resolution than PSPC, but didn't
have the energy resolution that enabled PSPC to distinguish different
X-ray spectra.

ROSAT was damaged after an attitude control problem on 1998 Sep 20. When
performing a slew (change of pointing direction), the reaction wheels
that manage the satellite's angular momentum were unable to keep up and
the satellite's aperture followed the wrong track across the sky,
crossing the Sun and resulting in destruction of the ultraviolet filter
on the HRI. This makes it the only astronomy satellite I know of
to have attempted suicide-by-solar-observing on two separate occasions.

The science program was declared abandoned on 1998 Oct 28; however, the
last dribble of PSPC-B detector gas was used for test observations between
1998 Dec 6 and 18. The spacecraft was abandoned on 1999 Feb 12.

Debunking a tall tale

The Wikipedia page for ROSAT includes a story which says that a 1999 NASA
internal report raised the possibility that ROSAT's demise was instead
due to some kind of hacker attack. In 1998 there was an intrusion of
some kind into the NASA-Goddard network which contained the source code
for the flight software of several NASA satellites. According to the
author of the report, `exploitation of the comm link could not be ruled
out' - presumably the fear was that someone could use knowledge of the 
code to use their own ground station to command a satellite, or separately
hack in to the NASA ground station.

 But despite the report, this just can't have happened with ROSAT. As
I've confirmed with Rob Petre who ran the Goddard part of ROSAT, all we had
were copies of the downlinked science data. All commanding, scheduling
and operations of ROSAT were done from Germany at GSOC - NASA had no
role in the spacecraft commanding. 

ROSAT was an elderly satellite in 1999, its main mission long completed.
Its failure is not surprising and is fairly well understood. I've talked
with several scientists involved in senior roles with the ROSAT mission 
and the unanimous opinion is that the story is ludicrous.

To summarize: Someone did gain inappropriate access to an internal NASA
network in 1998. As far as I know there's no evidence that restricted
satellite flight software was actually downloaded. But whatever
happened, it was definitely nothing to do with the malfunction of ROSAT
that damaged the HRI.

PSLV launch

India launched PSLV-C18, a PSLV-CA core-alone variant, from Sriharikota
on Oct 12. The main payload of PSLV-C18 is the Megha-Tropiques
satellite, a joint Indian-French remote sensing satellite with a mass of
around 1000 kg and based on the IRS bus. It carries the MADRAS microwave
imager, the Saphir water vapor profile instrument, and the ScaRaB
radiation budget sanner.

Also carried were three small satellites: SRMSAT, from SRM University in
Chennai, is a 10 kg satellite for greenhouse gas monitoring. Jugnu, from
the Indian Inst. of Technology in Kanpur is a 3U cubesat-class
technology satellite. VesselSat is a 29 kg small satellite built by
OHB LuxSpace of Luxembourg to provide AIS (ship tracking) services for

The five objects are in orbits with an apogee of 867 km and perigees
ranging from 780 to 850 km; the low perigee object is probably the rocket


Europe's first two Galileo navigation satellites were launched on Oct 21.
This was also the first Soyuz launch from the Centre Spatial Guyanais.
The new Ensemble de Lancement Soyuz pad is a copy of the pads at Baykonur.
The Soyuz ST-B launch vehicle is the Soyuz-2-1B variant; an uprated Fregat-MT
upper stage was used for the first time.

The two satellites have been given the nicknames Thijs and Natalia
after competition winners Thijs Paerlman (b. 2000) and Natalia Nikolaeva
(b. 2002). 

Two earlier test satellites, GIOVE A and GIOVE B, were launched in
2005 and 2008.


ViaSat-1 is a Ka-band broadband data satellite launched by a Proton
from Baykonur. It will provide capacity over North
America. The heavy (6740 kg launch) Loral-1300 satellite
is owned by ViaSat, a California-based company; the payload includes
9 Canadian spot beams owned by Telesat in addition to the 63
US beams owned by ViaSat. As of Oct 25, ViaSat-1 was in a 
12291 x 35781 km x 9.5 deg orbit on its way to a geostationary
location at 115W.

Suborbital flights

The PICTURE payload, NASA 36.225UG, was launched from White Sands in
an attempt to image an exoplanet. The CHAMPS flights, one nighttime and
one daytime, were launched from Andoya to study meteoritic dust
in the upper atmosphere.

Table of Recent (orbital) Launches 
Date UT       Name            Launch Vehicle  Site            Mission    INTL.  
Sep 10 1308   GRAIL-A   )       Delta 7920H        Canaveral SLC17B  Lunar     46A    
              GRAIL-B   )                                            Lunar     46B
Sep 18 1633   Zhongxing 1A      Chang Zheng 3B(E?) Xichang           Comms     47A
Sep 20 2247   Kosmos-2473       Proton-M/Briz-M    Baykonur          Comms     48A
Sep 21 2138   Arabsat 5C  )     Ariane 5ECA        Kourou ELA3       Comms     49A
              SES 2       )                                          Comms     49B
Sep 23 0436   IGS O-4           H-2A 202           Tanegashima       Imaging   50A
Sep 24 2018   Atlantic Bird 7   Zenit-3SL         SL Odyssey, Pacific Comms    51A?
Sep 27 1549   Tacsat-4          Minotaur 4+        Kodiak            Comms     52A
Sep 29 1316   Tiangong-1        Chang Zheng 2FT1   Jiuquan           Module    53A 
Sep 29 1832   Quetzsat-1        Proton-M/Briz-M    Baykonur LC200/39 Comms     54A
Oct  2 2015   Glonass-M No. 42  Soyuz-2-1B         Plesetsk          Navsat    55A
Oct  5 2100   Intelsat IS-18    Zenit-3SLB         Baykonur LC45     Comms     56A
Oct  7 0821   Eutelsat W3C      Chang Zheng 3B(E)  Xichang           Comms     57A
Oct 12 0531   Megha-Tropiques ) PSLV-CA            Sriharikota       EarthObs  58A
              SRMSat          )                                      Tech      58
              VesselSat-1     )                                      Comms/AIS 58
              Jugnu           )                                      Tech      58
Oct 19 1848   ViaSat-1          Proton-M/Briz-M    Baykonur          Comms     59C
Oct 21 1030   Galileo IOV PFM ) Soyuz-2-1B         Kourou ELS        Navsat    60A
              Galileo IOV FM2 )                                      Navsat    60B

Table of Recent (suborbital) Launches

Date UT     Payload/Flt Name  Launch Vehicle  Site                   Mission    Apogee/km

Sep 1  1353   ARAV?            Terrier Oriole?    Kauai               Target       150?
Sep 1  1354   Aegis KV         SM-3 Block 1B      CG-70, Kauai        Interceptor  150?
Sep 3  0946   RV               Topol'             Plesetsk            Test        1000?
Sep 26 0320   Prithvi RV       Prithvi-2          Chandipur IC3       Test         100?
Sep 29        10 RVs?          Layner             K-114, Barents Sea  R&D         1000?
Sep 30 0400?  Agni RV          Agni 2             Chandipur IC4       Test         220
Oct  5 0556?  FTT-12 Target    SRALT?             C-17, Kauai         Target       100?
Oct  5 0556?  FTT-12 Target    ? Target SRBM      MLP, Kauai          Target       100?
Oct  5 0600?  THAAD KV         THAAD              Kauai               Intercept    100?
Oct  5 0600?  THAAD KV         THAAD              Kauai               Intercept    100?
Oct  8        NASA 36.225UG    Black Brant 9      White Sands         Astronomy    200?
Oct 11        NASA 41.094UE    Terrier Orion      Andoya              Atm. Sci     130?
Oct 13        NASA 41.093UE    Terrier Orion      Andoya              Atm. Sci     130?

|  Jonathan McDowell                 |  phone : (617) 495-7176            |
|  Somerville MA 02143               |  inter : planet4589 at gmail       |
|  USA                               |          jcm at cfa.harvard.edu       |
|                                                                         |
| JSR: http://www.planet4589.org/jsr.html                                 |
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