Conference 7.286::space

I have got only few more information :

The Ariane exploded in about 10 km height.

Seemed to be a problem with the main engines.

Satellites weight 2.5 and 1.2 tons, worth DM 718 Mio.

	Detlef.

    I watched the launch and the failure appeared to happen at about
    t+2min, about the time you would expect the Viking 6 strapons to shut
    down and jettison. In fact that is what it looked like, except there
    was a fireball which was the explosion. They didn't hjave many details
    last night, and I missed this morning's press conference (what timezone
    is Kourou btw?).
    
    gary

    
    (Edited version of article which appeared in The Daily Telegraph
    on Sat Feb 24th - by Roger Highfield, Science Editor.)
    
      A panel of up to 15 experts will be set up next week to find out
    why the rocket failed just after lift-off from Kourou, in French
    Guiana, on Thursday, destroying its first all-Japanese payload of
    two telecommunications satellites.
    
      The Ariane 44L launcher is the most powerful configuration of
    its type. The explosion resulted from a pressure drop in one of
    its eight Viking engines, an engine design used successfully more
    than 200 times.
      At the time of the explosion, which destroyed the first stage,
    the rocket was 7.5 miles from the launch pad at an altitude of 5.6
    miles. Technicians on the ground then triggered another explosion
    to destroy the remaining two stages.
      Debris rained over the coast and the Iles du Salut just offshore,
    but no injuries were reported. Winds carried a cloud of the fuel
    back to land, forcing the launch staff and the 12,000 residents
    of Kourou indoors until it passed.
    
      Ariane's Japanese payload, a direct broadcast satellite and a
    communications satellite, disintegrated. The direct broadcast
    satellite, BS-2X, was being launched for the television network
    Nippon Hoso Kyokai (NHK) at a total cost of �75 million.
      The communications satellite, Superbird-B, was owned by Japan's
    Space Communications Corporation (SCC) and built as half of a
    two-satellite, two-launch package costing �350 million.
    
    >There was also a diagram, which I shall attempt to reproduce below.
                               
    View from below engines:
    
                         X          6.2 seconds: Pressure drops by half
                                    in engine D, a split second later
                       A   B        engines A and C swivel by 1.2� to
                    X        X      compensate.
                       D   C
    
                         X
    
    X = liquid strap-on booster
                        
    101 seconds: Excessive loads build up and the first stage explodes.
                                                                       

    Interesting, thanks.
    
    That may explain why the exhaust plume hit the launch tower just after
    the vehicle cleared it. I don't recall seeing it do that before.
    
    gary

Newsgroups: sci.space
Subject: Ariane V36: Mission lost
Date: 27 Feb 90 14:56:49 GMT
Reply-To: [email protected] (Neil Dixon)
Organization: ESTEC/YCV, Noordwijk, The Netherlands
 
    The following is copied from ESTEC News 14 Feb 1990:
 
-----------------------------------------------------------------------
	Ariane V36: Mission lost
 
    The series of successful Ariane flights, 17 perfect launches in a
row since September 1987, has unfortunately stopped on February 22
with flight V36. About 1 minute and 40 seconds after lift-off, the
Ariane 4 launcher exploded In the sky above Kourou, French Guiana. 
 
    The launcher, which was carrying two Japanese satellites, lifted
off at 20:17 hrs, Kourou time, after a nominal countdown. The pressure
in the chambers of the 4 engines of the 1st stage propulsion bay and
of the 4 liquid strap-on boosters was nominal till 6.2 seconds after
ignition (HO + 6.2s). 
 
    At that moment, the pressure in the combustion chamber of one of
the 4 engines (engine D) dropped, in half a second, from the nominal
value of 58 bars down to approximately 30 bars and remained around
this value until HO + 101 s. 
 
    Within HO + 6 and HO + 8.5 s, the attitude control system had sent
to engines A and C swivelling commands of 1,2 degrees amplitude in
order to compensate for the insufficient thrust of engine D. At
approximately HO+90 s, no further corrections were possible as the
engines of the 1st stage propulsion bay had reached the maximum of
their swivelling range. 
 
    At H0+101 s, the high dynamic pressure attained created excessive
stresses on the structure and triggered the explosion of the launcher
at an altitude of about 9 km and 12.5 km away from the launch pad. 
 
    An inquiry board is at work as of today.  All Ariane flights are
suspended until the causes of this accident have been fully understood
and corrected.  
-- 
Neil Dixon <[email protected]> UUCP:...!mcvax!esatst!neil, BITNET: NDIXON@ESTEC
Thermal Control & Life Support Division (YC) 
European Space Research and Technology Centre (ESTEC),
Noordwijk, The Netherlands.

I heard comments (right after the failure, not recently) about how viewers
could see what appeared to be a fire around one of the engines.   Might that
be part of the failure of the bad engine, or might it be the odd plume
angle that people reported seeing?

Also, when does staging normally occur?  I heard that the final explosion
happened at just about staging time.  Gary mentioned that the solids should
have just been falling off then.  Maybe that was what the report I heard meant.

It seems odd to me that it would take so long to die after the engine failure.
Given that engine "A" lost some amount of chamber pressure at +6 but then was
constant till the blowup, I would think that either the other three engines
would have enough gimbal control authority to compensate or they would not.  If
they did, then the problem becomes one of having enough delta-v available to
meet the mission requirements or not.  Dynamic pressure would not be a factor.

Putting everything together, I would infer that the engine gimballing was
sucessfully compensating for the failed Viking until the solids staged.
Then, either there was less compensation available (do the solids gimbal?)
or else now the imbalance is a much higher proportion of the total thrust and
thus became a much more serious problem, or else the moment of solid
cutoff/staging requires some extra compenstation from the Vikings which they
could not manage since they were already taxed to the limit.

(Who needs a review board...want me to speculate on why the A engine failed? :-)

Burns

      None of the reports I've seen mention anything about solids. The
    Ariane first stage has four main engines, and four strap-on boosters.
    In the Telegraph article the boosters are explicitly referred to
    as liquid (fuelled), with the same engine type (Viking) as the first
    stage itself. The explosion occurred at 101 seconds after launch; by
    this time the rocket was seriously off course, and the impression
    I have from other reports was that it could not have reached orbit.
    
      There is an article in the current New Scientist (not with me, and
    I shall be away for the next few days-anyone care to type it in?)
    on the loss. If I remember aright, there is some criticism of the
    fact that the partial loss of the thrust from one engine out of
    eight could cause the complete loss of the rocket. The same article
    stated that after the sudden drop in pressure at 6.2s, the pressure
    in the faulty engine remained constant up until the blowup. This
    indicated that there was some failure in the fuel supply system
    (eg a turbopump) rather than the engine itself. If this is so, then
    any apparent fire would simply have been due to the unusual plume
    angle, which actually damaged the tower. The blowup was also again
    stated to be due to dynamic stresses caused by the other engines
    swivelling to try to compensate for the failure.
    
      The second stage normally fires at about 120s after launch.
       
    Ken
                   

    The ARIANE involved was a 44L type, wich means 
    
    		ARIANE 4 + 4 boosters type Liquid.
    
    The ARIANE 4 can use either liquid or solid booster or even a
    combination of both. The designations are then (as far as I remember)
    
    			42L , 42S, 44L , 44S , 44LS
    
    I don't remember the designation for the no_boosters model.
    
    The configuration choosen depends on the payload and the orbit
    required.
    

    P = solid (poudre) strapons
    L = liquid strapons
    
    The model with no strapons is the Ariane 40, so far only used for polar
    orbits (e.g. Spot 2). Others are 42P, 44P, 42L, 44LP, 44L, in order of
    increasing payload to GTO.
    
    AvLeak have an interesting report on the failure in this week's issue.
    One of the inboard engines did experience a drop in combustion pressure
    at approx T+6 seconds. The two adjacent engines gimballed to compensate
    causing the vehicle to translate sideways, towards the umbilical tower.
    It apparently came within two meters of the tower, which is why the
    exhaust plume hit the top of the tower.
    
    The vehicle was tracking close to nominal trajectory but the vehicle
    attitide was diverging from nominal. The engines adjacent to the
    malfunctioning engine were at their maximum gimbal angle. Eventually
    the lateral forces caused it to break up and the RSO operated the
    destruct mechanisms.
                                          
    The fact that it was close to strapon burnout is probably irrelevant,
    although I'd expect the off center thrust line to become worse after
    the strapons shutdown.
    
    There's more detail in the article. I can copy it if anyone is
    interested (its also in most DEC libraries).
    
    gary

    Just a hello from an ex-secretary of ARIANESPACE.
    
    (ARIANESPACE HQ is in the same town than DIGITAL HQ France !)
    
    Annie
    

    FWIW:
    
    Isn't the 100 second mark the approximate point of max dynamic
    pressure?  I realize this varries from design to design/launch config
    but it a number that somewhat sticks out...Les
    

        The explosion of an Ariane rocket carrying two U.S.-built Japanese
    communications satellites was caused by a water pipe blockage in one
    of the four engines.  Arianespace Chairman Frederic D'Allest,
    presenting the report of the investigation into the loss, said Ariane
    booster launches will be resumed "by next summer."  The precise date
    is to be announced later this spring. 

        "It is due to an almost total obstruction of the water-feeding
    circuit of Viking Motor D. Its operation is not at fault. This
    obstruction is located immediately upstream of the motor, before the
    water pump," the report said. "The precise cause of the incident is
    either the untimely presence of a foreign object in the water pipes or
    a failure in the main water valve. The inquiry board felt that the
    second explanation was the less probable," 

        The report also said that "another anomaly occurred at 2.4 seconds
    after firing of the motors in the propulsion bay of one of the liquid
    strap-on boosters.  A propellant leak (N204) caused an incipient fire
    at the same time a small combustible leak occurred." 

        "At the completion of its research the inquiry board was not able
    to establish any correlation between both incidents," said the statement.

        Lost with the Ariane 4 rocket was Superbird-2, the second in a
    series of high-power Japanese communications satellites, and BS-2X, a
    three-channel direct broadcast relay station. 

From: [email protected] (Henry Spencer)
Newsgroups: sci.space,sci.space.shuttle
Subject: Space news from March 5 AW&ST, etc.
Date: 16 Apr 90 01:05:43 GMT
Organization: U of Toronto Zoology
 
    Ariane pieces being recovered, failure investigation underway.
Looking at the telemetry, it seems water flow to one of the main
engines was cut off by a misplaced cloth (The water is used to
regulate combustion pressure).  There has been one past case of a
momentary drop in engine pressure thought due to interruption in water
flow.  This time, at T+6.2s, chamber pressure of one main engine
dropped from 58 atmospheres to 30 atmospheres quite abruptly, and
stayed there.  The guidance system gimballed the other engines to
compensate, but as speed and acceleration built up, they had to gimbal
further and further.  At about T+90s, they hit their stops.  The
unbalanced thrust started to turn the booster sideways, and it quickly
broke up under the aerodynamic stresses.  The range safety officer
then triggered the destruct system to be sure that the launch was
completely destroyed. There was some concern about the cloud of toxic
fuel vapors resulting from the explosion, but it was blown out to sea
and caused no problems. 
 
    Arianespace is basically assuming that the interruption in flights
will be short, and is still signing customers for new launches and
building Arianes at full production rate.  The next mission probably
will be delayed several months.  It was meant to go up April 3,
carrying a pair of European comsats.  The first and second stages of
the Ariane for that mission, and its strap-on boosters, were assembled
and are being held in the vertical assembly building at Kourou.  The
satellites similarly had arrived and are in storage at Kourou. 
 
    One real concern that has been raised is that the failing Ariane
passed within about 2m of the top of the umbilical mast, because the
ailing engine was the one closest to the mast.  The exhaust struck the
mast, in fact, although damage was minimal and repairs will not be a
problem. The trouble is, if the booster had *hit* the mast, it and 420
tons of fuel could have crashed back down onto the pad.  A working
group is looking at pad hardening and what would be involved in
rebuilding it after a major pad accident.  [Score one successful
prediction for me: a year or so ago I said that Arianespace would
regret being dependent on a single operational pad.  They are now
taking that vulnerability a bit more seriously...] 
 
    Arianespace's tenth-anniversary celebrations, set for March, will
be postponed! 
 
    Arianespace is unhappy about the commercial implications.  It has
been trying hard to establish itself in the Japanese market, and both
of the destroyed comsats were Japanese.  Competition is getting
stronger, and although most of Arianespace's competitors formally
expressed sympathy, privately there were few tears:  customers are
suddenly more interested in hedging their bets, and inquiries are up. 
There is also a definite possibility that Japan will boost funding for
development of its own H-2 launcher. 
 
    The insurers say this is the biggest loss in history, although
recent launches have generally been successful, the industry is
healthy, and insurance rates have been slowly dropping from their
all-time peak in 1986 (a very bad year).  Rates probably won't rise,
but they aren't going to fall much in the near future. 
-- 
        Henry Spencer at U of Toronto Zoology
        uunet!attcan!utzoo!henry [email protected]

    Notice that there is none of the beating of hearts by Ariane as there
    was for Challenger "Should we be in Space? Isn't this a deadly waste of
    Money?"
    
    I understand that there was no loss of life, and hence nowhere near the
    trauma. But the French aren't about to (publicly, anyway) completely
    redesign the Hermes program to deal in this sort of disaster, are they?
    
    This sounds quite crass. Please do not misunderstand me - Challenger
    was a disaster, and accident, and could have been and should be
    prevented for happening again!
    
    But I kinda miss the early sixties when rockets blowing up did not
    overly concern folks (because they had no people in 'em). It would have
    been nice to have worked on fixing the Challenger problems without
    completely stopping the manned space program for two years....
    
    					-**Ted**-

From: [email protected]
Newsgroups: clari.tw.space,clari.tw.aerospace,clari.news.aviation
Subject: Ariane 4 rocket launched
Date: 13 Oct 90 00:18:17 GMT
  
	KOUROU, French Guiana (UPI) -- A French-built Ariane 4 rocket
successfully boosted two American communications satellites into orbit
Friday in the European rocket program's 39th flight. 

	Equipped with four strap-on liquid-fueled boosters, the
192-foot three-stage rocket roared to life on time at 6:57 p.m. EDT
and swiftly climbed away from its firing stand at the European Space
Agency's jungle launch complex on the northern coast of South America.

	Nestled in the rocket's nose cone were two communications
satellites: SBS-6, a commercial television relay station, and
Galaxy-6, built for video and newsgathering operations. But satellites
were built by Hughes Aircraft Co. and both are owned by Hughes
Communications Inc. of Los Angeles -- a first for the Ariane program. 

	The launching was flawless and about 21 minutes after liftoff,
SBS-6 was gently ejected into space. Galaxy-6 followed suit about four
minutes later. 

	``We're just extremely pleased ... it went as smoothly as it
did,'' said Douglas Heydon, president of the U.S. subsidiary of
Arianespace, the European consortium that markets Ariane rockets. 

	He said the launch was significant because it marked the first
time in the program's history that two satellites from a single
company were launched atop one rocket. 

	``These two satellites are going to play a vital role for key
customers in the next two or three years. We're just very, very
pleased that everything has gone so well in the launch,'' said Eddy
Hartenstein, a senior vice president for Hughes Communications. 

	On-board rockets were scheduled to fire later to propel the
satellites toward their final altitude of 22,300 miles over the
equator. At that altitude, objects take 24 hours to complete one orbit
and thus appear stationary in the sky, eliminating the need for
steerable ground antennas. 

	Ariane missions are conducted by the European Space Agency and
Arianespace, the 11-nation European consortium that markets Ariane
rockets and controls more than 50 percent of the world's commercial
launch market. 

	It was the third mission for Arianespace since an Ariane 4
launched Feb. 22 veered out of control and exploded 101 seconds after
liftoff. Lost along with the rocket were two Japanese communications
satellites insured for $189.4 million. 

	The failure later was blamed on a piece of cloth that blocked
a critical water supply line needed by one of four Viking 5 strap-on
engines. Water is used by the engines to regulate the mixture of
rocket fuel, to control engine chamber pressure and to cool gases used
to pressurize the fuel tanks. 

	It was the fifth failure in 36 launches for Arianespace,
lowering the rocket's success rate to around 86 percent, far lower
than most U.S. rockets. 

	But Arianespace mounted a major investigation and openly
reported on the progress and results of the probe, despite the
embarrassing nature of the failure. Far from losing business, the
consortium signed several new launch contracts during the course of
the investigation. 

	The Ariane 4 is the most powerful rocket in the Ariane family
of rockets, capable of boosting 10,000-pound satellites into
geosynchronous orbit and comparable to the American Titan-class
rockets used to launch heavy military spy satellites. 

I would suggest that the previous note be moved.  I had momentary heart failure
when I saw a note whose title said that Ariane exploded!

Burns

I didn't find a more appropriate topic, so I changed the title of this one to
make it more general.  I'll delete this note and .16 in a couple of days.

Mike H

From: [email protected] (M.S.Bennett  Supvs= Prof Pendry)
Newsgroups: sci.astro,sci.space
Subject: Ariane launches ON TIME!(again)
Date: 9 Nov 90 14:55:16 GMT
Organization: UKSEDS
 
    Ariane Returns to Business.   By Neville Kidger.
 
     Arianespace, the company which markets and flies the Ariane launcher,
has resumed operations following the loss of the V36 launcher in February
1990.
     The loss of the rocket - with two Japanese commercial satellites aboard
- was found to have been due to the presence of a piece of cloth in the
water supply line to one of the four Viking first stage engines. Fredric
d'Allest, the recently-retired Chairman and Chief Executive Officer of
Arianespace called the incident "not only shocking but hard to accept."  He
also noted that the incident in no way questioned the basic design of the
Ariane series of launchers and called for more rigorous efforts in quality
control at the assembly factory. 

     The V36 loss came after seventeen straight launch successes for the
Ariane rocket in its various guises. 
 
    Ariane V37.
 
     The V37 flight was launched at 06:25 GMT on July 24th from the ELA-2
launch facility at Kourou, French Guiana.  The Ariane 44L (with four liquid
propellant boosters around the first stage) placed two satellites into a
geostationary transfer orbit (GTO) of 299.7 km x 35,933 km, inclined at 4.04
degrees to the equator, well within the pre-fight intended parameters.  
     From that orbit the two satellites were manoeuvred by their own engines
to their respective positions.  The two satellites were:
 
- TDF-2, the second French direct broadcast satellite.  The satellite, built
by the Eurosatellite consortium, had a lift-off mass of 2,054 kg.  It is 6.5
metres in height with a span of 19 m when its solar panels are deployed.  It
has 5 high power TV channels.
 
- DFS-2 KOPERNIKUS, a German telecommunications satellite built by R-DFS
consortium for the German Bundespost Telekom.  Like TDF-2, it is 3-axis
stabilised and had a lift-off mass of 1,419 kg.  It has a height of 4.15 m
and a span of 15.4 m with solar panels deployed.  It carries 11
transponders.
 
     TDF-2 was placed at 19 degrees West in a shared location above the
equator and KOPERNIKUS was placed at 28.5 degrees West. 
     Speaking about the launch, Charles Bigot, the new Chairman and CEO of
Airianespace (but at that time the Director General) said: "Thanks to the
contribution of the European space industry community, tonight's launch
followed a short three and a half month recess which allowed for the
enhancement of the launcher's reliability by improving the control and
assembly procedures. This successful resumption of launches demonstrates
once again Arianespace's ability to respond to the many signs of confidence
expressed by the whole international space community."
 
    Ariane V38.
 
     At 10:46 GMT on August 10th the company launched the V38 mission which
again delivered two satellites to GTO.  The Ariane 44LP (two liquid strap-on
boosters and two solids) was launched from the ELA-2 facility marking a
record short time between launches from the facility and from Arianespace.
     The launch was significant for the UK because it carried a military 
communications satellite for the Ministry of Defence - Skynet 4C. 
The full payload for V38 was:
 
- Skynet 4C.  Built by British Aerospace and Marconi Space Systems, the
satellite had a lift-off mass of 1,430 kg and an orbital mass of 751 kg.
The height is 2.1 m with a span of 16 m with two solar panels deployed.
Stabilisation is 3-axis and it operates in 4 SHF bands and 2 UHF bands
serving military communications for British land, air and sea forces.  The
orbital location is 1 degree West. 
 
- Eutelsat IIA.  Built by Aerospatiale and weighing 1,878 kg at launch, this
satellite is to provide telephone, telex, data transmission and TV services
to Europe.  It has a capacity of 25,000 telephone half-circuits and 9 TV
channels (or equivalent traffic) and is stationed at 13 degrees East, over
the Equator, with a coverage zone ranging from Ireland to Turkey and from
the Arctic to North Africa.  At 2.5 m in height it has a span of 22.4 m with
its solar panels extended.
 
     Following the launch, Charles Bigot said: "This success, five weeks
after Flight 37, marks the continuity of European space activity, in
particular the confidence shown in us by the British Ministry of Defence
after the successful launch of Skynet 4B by Ariane in 1988; also the
confidence of the Eutelsat organisation which has chosen Arianespace to put
into orbit three satellites of its new generation.  With this launch,
Arianespace also confirms the ability to increase, if necessary, the launch
capacity to respect our commitments, thanks to the dual launch system which
allowed us to put four satellites into orbit for Europe in the last five
weeks."
     As of August 31st Arianespace's order book stood at 35 satellites to be
launched, worth approximately 15 billion French Francs, or about #1.4
billion, and represented a four year work load.  
     On September 3rd Arianespace announced that it had secured the
contracts to launch two new-generation Brazilian satellites for the EMBRATEL
organisation.  The two Brasilsat B1 and B2 satellites will weigh about 1.750
kg at launch and will provide conventional telecommunications services for
Brazil and South America in general.   
     The launches are planned for 1994.
 
    Ariane V39.
 
     On October 12th Flight 39 was launced carrynig the American
communications satellites SBS-6 and GALAXY VI.  Both satellites were
launched for Hughes Communications Galaxy, Inc.  A 44L varient was used.
 
Acknowledgements: Arianespace.
Ariane V39 news added by the editor.
-- 
/------    -------    -----\       /------   |  ======================  |
|          |          |      \    |          |  M. Sean Bennett         |
\-----\    |----      |       |    \-----\   |  UKSEDS TECH.OFF.        |
       |   |          |      /            |  |  Janet:[email protected]  |

From: [email protected] (Bruce Dunn)
Newsgroups: sci.space
Subject: The Ariane V36 failure
Date: 12 Nov 90 01:43:42 GMT
Organization: MIND LINK! - British Columbia, Canada
 
> [email protected] writes:
> 
> [commenting on a report that a piece of cloth in a water-line to an engine
> caused the Ariane V36 failure on February 22]
> 
> I've never been part of a failure investigation (thankfully ;-)) since I
> joined NASA, so I don't know much about the procedure.  I hope someone can
> offer insight on the following questions:
> 
> (1) the failure was due to a piece of cloth.  How could this have been
>     isolated after the failure?
> (2) what is the mechanism by which a piece of cloth was able to cause the
>     failure?  By that I mean
>     - was the cloth of sufficient size/porosity to totally restrict water
>       flow?  or did it have to be?
>     - how is a piece of cloth able to be in the water line anyway?
>     - what is the sequence of events leading to the failure, given the
>       presence of the cloth?
> (3) how can Arianespace ensure no repeat of this mechanism/sequence of
>     events?
 
     The following information, abbreviated from 3 issues of Spaceflight, may
be of interest.
 
    May, 1990:

     The Ariane V36 Inquiry Board has presented its findings.  They
identify a blocked water line as the cause of the accident.  The
launcher exploded shortly after its launch on February 22. ...  The
loss of the mission was due to the decrease in thrust of one of the
four Viking V motors on the first stage.  The drop in thrust occurred
6.2 seconds after motor ignition.  It was due to an almost total
obstruction of the water feeding circuit of Viking motor D.  The
engine itself is not at fault.  The obstruction occurred upstream of
the motor before the water pump.  The precise cause of the obstruction
is either a foreign object in the pipe or a failure of the main water
valve.      [The article goes on to talk about how debris from the
exploded launcher fell at the shoreline and just off-shore of the
launch site.]       A search of mangrove swamps in zone 2 located some
350 different objects from the first, second and third stages.  In
particular, this search located external tubing of engine D as well as
water tank elements.  The first stage propulsion bay along with the
four Viking motors was found.  Despite extremely difficult conditions,
the suspect elements of the water circuit were recoverd shortly before
this issue of Spaceflight went to press. 
 
    June, 1990:

     The loss of Ariane V36 was caused by a small piece of cloth that
blocked the water supply to one of the vehicle's first stage engines. 
...  The rag was probably left in the pipe when the tubing was
dismantled and readjusted during first stage integration before
transfer to French Guiana.  Arianespace Chairman Frederic c'Allest
said the cause of the failure was "not only shocking but hard to accept." 
 
    September, 1990:

     The investigation into the loss of V36 revealed that a first
stage engine lost thrust because a small piece of cloth blocked a
water pipe.  In an unconnected incident a small fire broke out in one
of the strap-on liquid boosters due to a fuel leak. From flight V37,
the water line and the N2O4 feed line of each engine will be examined.
The inspection will take place at Kourou, using a fibroscope type
video camera with integrated light source. ... Additional leak checks
were made on the first stage and strap-on fuel lines to ensure that
there was no repeat of the fire on the previous mission.  Also, new
thermal protection inside the propulsion bays of the first stage will
protect electrical systems in the event of a fire. 
 
    Spaceflight is an excellent journal received by members of the British
Interplanetary Society. Address: 27/29 South Lambeth Road, London, SW8 1SZ,
England.
 
     My understanding is that as the engine lost thrust, the remaining
engines gimbeled to correct for the thrust imbalance.  When the
running engines reached the end of their gimbel limits the vehicle
could no longer be kept on course, and in effect started to skid
sideways through the air.  Breakup due to aerodynamic forces followed
shortly.  What I have not been able to find out is why Viking engines
need a water supply.  This is presumably for cooling, however I have
never heard of an engine that used anything other than its own
propellants as a cooling source.  Can someone familiar with the Viking
engine explain the function of the water, and what happens when its
supply is interrupted. 
--
Bruce Dunn   Vancouver, Canada    [email protected]

    re -.1
    
    The author asks why the Viking engines need water.  I think it is
    obvious that the water is the fuel and that the N2O4 is the oxidizer.
    
    This is just a different type of non-cryogenic fuel.
    
    Tony

    re .20
    
    Nope.
    
    UDMH is the fuel. I think you'd have a hard time getting water and N2O4
    to react in any useful way.
    
    I've never been able to find out for certain what they use the water
    for. I think the Viking engines are throttleable and they achieve this
    by diluting fuel and/or oxidiser with water to keep flow rates and
    tubopump speeds constant. I would like to find a definitive answer.
    
    gary

From: [email protected]
Newsgroups: sci.space
Subject: Ariane Launch Manifest (Nov. 1990)
Date: 19 Nov 90 02:17:55 GMT
Sender: Steven Pietrobon
Organization: Dept. of Elec. Eng., Uni. of Notre Dame, IN
 
Here is the Ariane launch manifest that was published in the October 1990
issue of Spaceflight.  I will try to post any other manifests I can obtain
on Ariane, Delta, Atlas, Titan, and other launch vehicles.
 
Flight    Date       Vehicle   Payload
-------------------------------------------------------------------------
 V40    20 Nov. 90   Ar 44P    Satcom C1, Gstar 4
-------------------------------------------------------------------------
 V41    15 Jan. 91   Ar 44L    Eutelsat II-F2, Italsat 1
 V42       Feb. 91   Ar 44LP   Astra 1B, MOP-2
 V43       Mar. 91   Ar 44P    Anik E1
 V44       Apr. 91   Ar 40     ERS-1, Datasat X, Tubsat, Uosat F, SARA
 V45       Jun. 91   Ar 44L    Intelsat VI-F5
 V46       Jul. 91   Ar 44LP   Eutelsat II-F3, Inmarsat II-F3
 V47       Sep. 91   Ar 44P    Anik E2
 V48       Oct. 91   Ar 44L    Intelsat VI-F1
 V49       Nov. 91   Ar 44L    Superbird E, Inmarsat II-F4
-------------------------------------------------------------------------
 
Notes:
1) The payloads for V46 and V47 may swap.
2) In V49, Superbird E has a relaunch priority. Telecom 2A may 
   substitute for the V49 payload. 
--
Steven Pietrobon, [email protected]
Department of Electrical Engineering, University of Notre Dame, Indiana, USA

     V41    15 Jan. 91   Ar 44L    Eutelsat II-F2, Italsat 1
    
    Successfull lunch last night. 

From: [email protected]
Newsgroups: clari.tw.space,clari.tw.aerospace,clari.news.aviation
Subject: Ariane rocket puts two satellites in orbit
Date: 16 Jan 91 05:41:28 GMT
  
	KOUROU, French Guiana (UPI) -- An Ariane 4 rocket boosted two
European communications satellites into orbit Tuesday in the 41st
flight of the French-built rocket system and the first of 1991. 

	The 192-foot three-stage rocket took off on time at 6:09 p.m.
EST and smoothly climbed away from its firing stand at the European
Space Agency's jungle launch complex on the northern coast of South
America. 

	Perched atop Europe's premier rocket were two satellites:
Italsat-1, an experimental communications satellite built by Selenia
Spazio for the Italian Space Agency; and Eutelsat-2 F2, the second in
a series of advanced radio relay stations built by Aerospatiale for
European communications. 

	Both satellites were safely ejected into preliminary
elliptical orbits within 23 minutes of liftoff as planned. 

	Small on-board rockets were scheduled to fire later to propel
the satellites toward their final altitude of 22,300 miles over the
equator. At that altitude, objects take 24 hours to complete one orbit
and thus appear stationary in the sky, eliminating the need for
steerable ground antennas. 

	Ariane missions are conducted by the European Space Agency and
Arianespace, the 11-nation European consortium that markets Ariane
rockets and controls more than 50 percent of the world's commercial
launch market. 

	The Ariane 4 is the most powerful rocket in the Ariane family
of rockets, capable of boosting 10,000-pound satellites into
geosynchronous orbit and comparable to the American Titan-class
rockets used to launch heavy military spy satellites. 

	Italsat-1 is an experimental satellite built for digital
communications across Italy. The solar-powered relay station is
equipped with nine radio transponders and an experimental radio system. 

	Eutelsat-2 F2 was built to relay telephone, television and
data across Europe as part of a commercial communications network. The
solar-powered satellite is capable of providing service from up to 16
simultaneously operating transponders. 

    I have been meaning to ask this question for some time. Every time
    I see an Ariane launch on the tube I see several dozen "plates"
    falling off of the midsection of the booster. Can anyone tell
    me what exactly these are and what there purpose is?
    
    Thanks in advance.
    
    
    Roger

    Nothing to worry about...
    
    Just some heat shields in expanded polyester loosely attached on
    temperature sensitive areas. They are meant to fall at lift off.
    
    
    

    re: .26
    
    Thanks for the information.  I always thought they were ice sheets
    caused by the cryo fuels.
        John Sauter

From: [email protected]
Subject: Ariane 4 rocket launched
Date: 17 Jul 91 02:35:16 GMT
 
 
	KOUROU, French Guiana (UPI) -- An Ariane rocket successfully boosted
the first in a new series of advanced European environmental remote
sensing satellites into orbit Tuesday in the 44th flight of the French-
built launcher.
	The 192-foot three-stage rocket took off on time at 9:46 p.m. EDT and
quickly thundered away from the European Space Agency's jungle space
complex on the northern coast of South America.
	Twenty minutes later, the rocket's major payload, the ERS-1 remote
sensing satellite, was safely ejected into its planned orbit around
Earth's poles after a thundering ride into space that carried the
French-built booster across Newfoundland and northeastern Canada.
	``It was a successful mission,'' said Michelle Lyle, a spokeswoman
for the European consortium that markets Ariane rockets. ``It was a
beautiful mission.''
	Hitchhiking into space along with ERS-1 were three small,
experimental communications satellites and one built to study natural
radio emissions from Jupiter to complement data from European and
American spacecraft currently en route to the giant planet.
	Charles Bigot, chairman and chief executive officer of Arianespace,
the consortium that markets Ariane rockets, said the launch of the ERS-1
satellite marked ``a great event for Europe and the European space
industry. We are proud of our role in helping the European Space Agency
implement this new high-performance system.''
	The Ariane launch came just one week before the U.S. shuttle
Atlantis's planned takeoff from the Kennedy Space Center next Tuesday to
put a NASA communications satellite into space.
	Ariane rockets once competed head-to-head with NASA's shuttle for
commercial launch business, but in the wake of the Challenger disaster,
such payloads were banned from the manned orbiter.
	ERS-1, built by Dornier, is a 5,200-pound solar-powered satellite
equipped with a radar system and other instruments to study Earth's
oceans, ice packs and land areas in great detail. It is the first in a
series of advanced satellites built for the European Space Agency.
	With a planned lifetime of three years, ERS-1 will orbit the Earth's
poles at an altitude of 480 miles. In such polar orbits, satellites can
observe the entire planet as it spins below.
	It was the 44th flight of an Ariane rocket and the third so far this
year. The vehicle's launch record now stands at 39 successes and five
failures.
	Ariane missions are conducted by the European Space Agency and
Arianespace, the 11-nation European consortium that markets Ariane
rockets and controls more than 50 percent of the world's commercial
launch market.
	The Ariane 4, the most powerful rocket in the European inventory, is
marketed in a variety of versions based on how many satellites are on
board and their weight.
	The most powerful version is capable of boosting 10,000-pound
satellites into geosynchronous orbit and comparable to the American
Titan-class rockets used to launch heavy military spy satellites.