NASA Alternative timeline

[Kyle]

I wanted to create a alternate timeline, what do you think would have happened to NASA if STS-51L scrubbed on January 28th like they almost did, so the Challenger accident would never happened?

Each post will be one step in the timeline. I'll start.

The next few flights would go on as planned, and then STS-62A would be primed for launch out of SLC-6.

 

[Star Voyager]

HST would've been deployed in August 1986:

http://www.spacefacts.de/cancelled/english/sts-61j.htm

 

[JEL]

what do you think would have happened to NASA if STS-51L scrubbed on January 28th like they almost did, so the Challenger accident would never happened?

It's guess-work, but I guess another spaceshuttle would have blown up instead.

Without challenger to learn from, the risk-assessment would be the same as it was pre-challenger: IE not able to prevent the blowing up.

 

[Voyager]

Endeavour would have never been built.

 

[Andy44]

A better alternative timeline, one with a happier ending at least, would have the 51L as a scary near-miss in which the vehicle and crew survived but NASA was frightened into standing down and redesigning the SRBs like they knew they were going to have to do sooner or later anyway.

 

[Izack]

A better alternative timeline, one with a happier ending at least, would have the 51L as a scary near-miss in which the vehicle and crew survived but NASA was frightened into standing down and redesigning the SRBs like they knew they were going to have to do sooner or later anyway.

Hmm...I like that idea. Endeavour still would never have been built, but maybe Enterprise would have flown instead.
Unfortunately, it doesn't look like the same could be done for Columbia. That really couldn't have been prevented.

 

[Andy44]

Hmm...I like that idea. Endeavour still would never have been built, but maybe Enterprise would have flown instead.
Unfortunately, it doesn't look like the same could be done for Columbia. That really couldn't have been prevented.

Sure it could have; it was known as far back as STS-1 that there were lots of debris strikes. Same story: taking the vehicle out of service long enough to fix the debris problem was a difficult decision to make. They haven't fixed it completely, but since Columbia the number of strikes has been severly reduced, proving this problem can at least be minimized.

The thing about playing "what-if" is that it's easy to see things in retrospect, of course. At the time of the 51L accident, NASA was still more worried about the SSMEs than they were about the SRBs.

 

[Izack]

The thing about playing "what-if" is that it's easy to see things in retrospect, of course.

Yes, that's the thing. But that's also the point of 'what-if' scenarios, isn't it? If we were to limit ourselves to the knowledge, speculation and conjecture available to NASA at the time, our decisions would be mostly identical, no?

 

[Unstung]

There could have still been a failure like STS-107 due to the external tank.

 

[KosmoKen]

There could have still been a failure like STS-107 due to the external tank.

Butterflies and hurricanes. If you're going to change one event as large as the Challenger tragedy, you have to pretty much disregard anything that happened afterward on our time line (though you're right that something else may have happened eventually).

 

[Andy44]

There could have still been a failure like STS-107 due to the external tank.

2 posts earlier:

Sure it could have; it was known as far back as STS-1 that there were lots of debris strikes. Same story: taking the vehicle out of service long enough to fix the debris problem was a difficult decision to make. They haven't fixed it completely, but since Columbia the number of strikes has been severly reduced, proving this problem can at least be minimized.

 

[GregBurch]

If you're interested in alternative history of space development, check out the documentation with the X-15 Delta addon. It posits the X-15 providing a pathway to a completely different line of development that doesn't include STS at all. IMnsHO, that would have been a MUCH more fruitful path ...

 

[RisingFury]

Long Duration Exposure Facility would have been retrieved by March 19th, 1985 (+ a few scrubs...).

It was later retrieved from a decaying orbit on January 12th 1990, by Columbia.

 

[garyw]

I think a lot of people are missing the point of WHY 51-L happened. Sure the technical root cause was down to a failure of both O-Rings but look past that and look at NASA.

What were NASA trying to prove at the time?

Remember that the shuttle programme was over budget and running late, so let's assume that STS-51L launches, the crew survives. It's a near miss - what happens?

Simple answer is nothing. If you read "The challenger launch decision" you'll see that other flights suffered O-Ring blow by but waiver were raised for each launch. During the review after 51-L there were some 500 launch waivers which were dealt with and the problems actually fixed.

So, in the spirit of alternative history let's say that 51-L is a near miss.
It becomes another statistic, more information for the flip charts (powerpoint was a relatively near idea then).
Roger Boisjoly is proven wrong and is forced out of Morton Thiokol.
The rapid turn around continues unabated.
More waivers are added simply to get shuttles ready & shuttles end up flying with a quarter of systems not available, safety factors are being eroded.

At this point *SOMETHING* would give leading to the Rogers commission. It doesn't matter when it would happen, it would have happened.

 

[Linguofreak]

Well, as far as I'm concerned, the whole shuttle stack design was an accident waiting to happen. While the Challenger, and possibly Columbia, accidents could have been prevented individually, they still demonstrate weaknesses of the shuttle design that are there by virtue of the shuttle being the shuttle, eg, "Crew on the side of the stack with no good escape option before SRB sep," and "Orbiter heat shield exposed during launch".

A capsule design with an LES tower would have made the Challenger accident survivable, and would have prevented the Columbia accident entirely.

 

[garyw]

A capsule design with an LES tower would have made the Challenger accident survivable, and would have prevented the Columbia accident entirely.

I fail to see how a LES which is discarded during launch would help during entry?

 

[Messierhunter]

I think he's saying a capsule wouldn't have had its head shield exposed during launch in the first place, thus would not have been damaged. Out of curiosity, had the o-ring failure resulted in the blow out facing away from the ET, would challenger have made it to orbit safely?

 

[Andy44]

I think he's saying a capsule wouldn't have had its head shield exposed during launch in the first place, thus would not have been damaged. Out of curiosity, had the o-ring failure resulted in the blow out facing away from the ET, would challenger have made it to orbit safely?

Most likely. I don't think it caused a serious drop-off in SRB performance.

For the record, I don't see anything inherently dangerous in a side-stack, as long as you can keep the reliability of the system high. A jetliner gets away with no abort options whatsoever for its passengers because of high reliability, for instance. Having an ejectable, heat-shielded capsule-like crew module, similar to the B-58, could've been designed into the system from the start, but only with a huge weight penalty.

But I think we're getting off-topic at this point. What if the O-rings were designed right in the first place?

Well, for starters, the lack of a Challenger accident means that a few months later the first humans to fly in a polar orbit would've launched out of Vandenberg aboard Discovery. This would've had profound implications for the history of US military space.

 

[Wally]

If Challenger's tragedy wouldn't happened in 1986, I'm sure other space shuttle tragedy would have happened in the following missions. Remember the rate on wich NASA was launching the shuttles in that period.

I'm still amazed by the survival rate of launches in Mercury, Gemini and Apollo missions. No manned Redstone, Atlas, Titan or Saturn V rocket ever exploded. I think they were VERY lucky.