Astra 1K Communications Satellite now Space Junk 246
bachelor#3 writes "Astra 1K, which was to replace 3 other satellites, didn't make it. Launch services were being provided by International Launch Services. Here's a timeline, from T-minus 30 minutes onwards."
Perhaps adding this ... (Score:4, Informative)
The French-made Astra satellite is the world's biggest communications satellite, with antennae spanning 37 metres. It was due to be used for radio and television broadcasts as well as for mobile telephone and Internet services in western Europe.
Re:Iridium (Score:5, Informative)
Lifetime Launch Vehicle Reliability (Score:5, Informative)
Table 5. Lifetime Vehicle Reliability Rates
Vehicle-----Launch Attempts----Reliability
Atlas 1 & 2------49---------------95.9%
Delta 2----------73---------------98.6%
Delta 3-----------1----------------0.0%
Ariane 4---------81---------------96.3%
Ariane 5----------2---------------50.0%
Proton----------254---------------89.4%
Soyuz-----------958---------------99.3%
Long March-------54---------------90.7%
(Source: STAR Database, October 14, 1998)
?sp
Re:"No Danger" (Score:4, Informative)
But a perversely arrow-shaped piece of debris that did not tumble, that could be bad news. Then you just have to rely on statistics.
Trivia: the Shuttle SRB casing fall at about 350 MPH without parachutes, and 50 MPH with. Hey, I was curious....
Re:Not good. (Score:3, Informative)
Re:Not good. (Score:3, Informative)
Re:Cheaper? (Score:5, Informative)
Re:To Russia With Love (Score:2, Informative)
Ion booster (Score:2, Informative)
Although not fast enough to be the primary final booster (may take years to get to right orbit), it can be a nice backup booster.
I wonder why they did not do that for this one? I suppose they figured the cost of the ion engine and related weight was greater than the projected risk of failure.
Re:Alcatel. (Score:3, Informative)
Absolutely not. The failure was due to an anomaly in the 2nd firing of the upper stage engine. The satellite had nothing to do with it.
Re:Lifetime Launch Vehicle Reliability (Score:3, Informative)
Launchers come in versions. After any failure, things are studied and problems corrected. 'Ariane 4.0beta' is much more likely to fail than 'Ariane 4.6.22' The newest lauchers (like 'Ariane 5.0beta' in that table) have much more undiscovered problems. After these are weeded out, the new ones are much better.
Looking at the failure rates of last 100 launches would make Proton look much better. Looking at the newer half of launches would make Ariane 5 look much better. Today, Ariane 4 has something like 60 subsequent succesful launches, but Ariane 5 is considered so much better that Ariane 4 will soon be phased out. (Or is it already?)
The well-understood 'workhorse' launchers with dozens of lauches, like Soyuz, Proton or Ariane 4 will probably have similar figures in newer reports. ESA Annual report for 2000 is the latest I've seen, and it gives a success rate of 97.3% for Ariane 4.
Re:Astra 1k (I'm trashed and just dreaming...) (Score:3, Informative)
Firstly the shuttle has trouble getting into any useful orbit. As a later comment mentions, Columbia is going to be scrapped because it can't even get into the oribit of the ISS. Unless your sick satellite happens to have gone into a reasonably stable LEO, then the shuttle has no chance of getting to it.
Secondly, even once they got to the satellite, there would be no way for the astronauts to work with the satellite. The Hubble was specially designed to be openable by astronauts as the regular service missions were planned before it was designed. This means that they can't access the satellite to to the major modifications which would be needed to either launch it into it's original orbit, or modifify to to be a comms platform. That means that any modifications would have to be done on earth which brings me to
Thirdly, under the modern safety rules, a satellite fully fueled with propellant isn't allowed to be in the shuttle for landing. And as they can't access the satellite to safely jetison the fuel, that means that it can't be brought back to earth either.
Even if that wasn't true, what do you think that a TV broadcast satellite would do at the ISS? It's designed to take a signal broadcast from the ground, and rebroadcast it over it's target area. It's basically a solar panel hooked upto a amplifer joining the transmitter to the receiver. Nothing which isn't already on the ISS.
Re:Yeah? (Score:3, Informative)
To be fair the causes of the N1 failures (4 out of 4) were varied. The N1 had been designed to cope with multiple engine failures and still achieve orbital velocity.
However, the death of Korolev - its designer, the appointment of the inexperienced Mishin and the ongoing wrangling between the Soviet design bureux (they had 3 Moon programmes running simulataneously) meant that the N1 was always a risk.
There were no full test facilities so they couldn't perform a static engine test, the budget was minimal and the deadlines insane - that they got anything was a near miracle. That they got such incredible engines (which are now being used in Atlas rockets) was a miracle.
For the record the N1 failures were caused by:
- An uncontained fire from a leaking fuel pipe which caused the computerised engine management system to shut down motors. The rocket lost thrust and was destroyed. The engineers increased the resilience of the piping to deal with resonances.
- An explosion in the liquid oxygen line to one engine after it ingested a fragment of welding slag. The failure itself was not critical, but the computers shut down the wrong engines, the rocket lost thrust and toppled back onto the launch pad, completely destroying the pad. The engineers improved welding techniques and fitted filters to piping.
- A failure in the attitude control system, the rocket tumbled in flight and was destroyed.
- A fire in the engine compartment which burned out of control. The rocket was destroyed from the ground, but was within seconds of achieving second stage ignition. It might well have made it to orbit had the controllers not intervened.
A fifth N1 was prepared for launch but the programme was cancelled on the direct orders of the Kremlin. America had won the race to the Moon and the Soviets were concentrating on space stations and a race to Mars.As for the N1 being unusually unreliable, not necessarily so. The Soviets were always much more willing to fire their rockets and pick through the wreckage to determine problems than those in the West. So it was clear that the N1 was being debugged in the same manner.
The Proton which launched the Astra satellite had a terrible record in its first few years. It is quite possible that the USSR could have sent men around the Moon in a Zond capsule before Apollo 8 - however, the mission was cancelled when the Proton booster developed cracks whilst sitting on the launch pad, (a problem that also delayed the N1).
Nowadays the Proton is a genuine star - old but very reliable.
a twin with an engine out IS very dangerous because of the risk of losing control authority to the working engine, or of shutting down the good engine in a panic.
Not just a theoretical risk either
Indeed (see the N1), or most tragically the Kegworth disaster [bbc.co.uk] here in the UK when the crew shut down the wrong engine of a British Midland 737. They had been dealing with an engine fire and trying to make an emergency landing at East Midlands Airport. For some reason, which has never been clear, both pilots came to the same conclusion which engine needed shutting down. They chose the wrong engine, the plane lost all power and crashed into the M1 motorway, 47 people died, amazingly 79 survived.
Best wishes,
Mike.