> “Boeing is not going to do an in-flight abort test,” said Jon Cowart, deputy manager of the mission management office for NASA’s commercial crew program, before the pad abort test. “They’re just going to do the ground one. They think that they can get enough data and then extrapolate that out, with good analytical techniques that we’ve endorsed. They will go and do it in that particular way, versus SpaceX, which is going to do both.
They really don't want it to blow up on the launch pad. They've put a lot of work into the ground service equipment, and depending on how bad the damage is, blowing up on the pad could set them back months. It also isn't clear if they will have completely finished all the protections on the launch equipment (cladding, deluge, etc) before this test flight, so blowing up on the pad this time around might actually be worse than if it happened in some future test instead.
Once it is well-clear of the pad – blowing up is a lot less bad. But still, ideally they want it to make at as far through the flight plan as possible. If it blows up early in the flight, there's a lot of stuff that happens later they won't even get the chance to test this time around. Sure, they'll get the chance to test it next time around – but that'll be another delay in an already delayed project.
"so that the shuttles could be tested and demonstrated without humans in danger, to verify safety after Challenger and Columbia."
You could demonstrate, but I don't think it was possible to verify safety with such small a fleet in a decent timeframe. Let's say you accept a 1:100 chance of disaster, and you want to verify that experimentally. You certainly can't do that with fewer than 50 normal launches. That would have taken NASA over 5 years (assuming a vastly sped up launch schedule made possible by the lack of danger to humans)
Alternatively, suppose you decide to test beyond the normal flight parameters, and launch a few shuttles with ice on them, a few with O-rings that aren't 100% up to standard, a few in high winds, etc. Even if you try to stay just on the edge of destructive testing, you would run out of shuttles to launch before you know it.
The thing is that NASA doesn't want to put anyone on something has the chance of doing that. The emergency system is for emergencies. Ideally it should NEVER be used. Vetting for manned missions is a lot different than cargo. That's all I'm getting at here. When rockets have recently exploded NASA gets pretty worried about putting humans on it.
There isn't anything wrong with your reasoning, it just isn't the reasoning that NASA came up with.
NASA has the entire history of US Spaceflight in its collective memory. It has many memories of accidents occurring during fueling that resulted in the loss of the spacecraft. It has no memories of a crew being saved by the crew abort systems because it has only happened once[1] and that was with a Russian rocket.
Thus, going by what they "know", NASA knows that rockets can blow up when they are being fueled and they know that SpaceX blew up one of their rockets while fueling it, but they do not know if a launch escape system would save astronauts in that situation. Therefore SpaceX's plan is "risky" because they are exposing the crew to a "known" danger and relying on an "unknown" system to protect them from that danger. It is this kind of thinking that keeps NASA moving slowly and carefully.
SpaceX has essentially said, "Trust us, if anything went wrong the crew escape system would save them." Unfortunately they don't have a launch pad they can blow up on purpose to demonstrate that for NASA (it would help if they could). The last time they blew up a rocket while fueling it, it took months to recondition the pad for launches again.
[1] In 1983, an escape rocket pulled the three cosmonauts of Soyuz T-10-1 to safety when its booster exploded on the launch pad. As of 2015, this is the only case where an abort system saved a crew from a launchpad accident. -- https://www.space.com/29260-how-spacecraft-launch-aborts-wor...
It was intended to on this test, but it failed. Hydraulic issues (just like SpaceX!). No video, presumably because they thought a nice video of part of they system exploding would be bad press.
Or maybe they estimated the chances of the launch pad being entirely obliterated during the launch attempt as pretty high and didn't want to invest more money into it than absolutely necessary?
This is a bit of spin by SpaceX. Blowing up the pad would be a serious failure and would be a large and costly setback. But they obviously didn't achieve the goal of the test flight here. It is a test flight, so it's not a complete failure and not entirely unexpected. But it's not a full success either, significant parts that were planned to be tested could not be tested because the rocket failed early.
> There are reasons there hasn't ever been even one other human-rated craft to use solid rocket motors.
That's about to not be true. Atlas V + starliner has flown two people and has strap-on boosters, I think it only gets the rating once it returns from the test flight though.
The shuttle didn't have a propulsive launch abort system, and could only abort during a percentage of its launch. The performance quoted for starliner's abort motor is "one mile up, and one mile out" based on what the presenter said during the last launch. You're plenty safe as long as you don't intersect the SRB's plume.
There have been two public full scale tests of this spacecraft. A pad abort test (launch the abort system from the ground to make sure it can escape a launch vehicle failure) and this.
In the pad abort test a parachute failed, this wouldn't have been a deadly failure since the remaining parachutes are sufficient, but it is pretty damn concerning.
Now this test suffered a major failure too.
This does not bode well for the reliability of this vehicle.
> are there launch failure scenarios that involve complete loss of crew but successful orbit?
Explosive decompression. Not sure if shuttle crews wore pressure suits. Happened on a Russian mission once, during reentry. They opened the capsule on landing and everyone was dead.
> One was a ground incident that wouldn't have had people nearby even with a manned mission, and the other would have saved its passengers with the abort system.
Not sure how that would mitigate the risk of explody Space-X rockets?
That's why you can't just "move fast and break things" when dealing with rockets. SpaceX is not allowed to launch a rocket that they don't have confidence will not explode on the pad. If one ever does, they will surely have to dismantle the site and move somewhere that is not a protected wildlife reservation.
In fact, they were also not really supposed to launch a rocket they didn't have confidence they could detonate if it veered off course - which they did (remember, the FTS failed to detonate the rocket on demand, and we were lucky that it was far enough away from anything after the attempt that it didn't put anyone in danger before structural forces destroyed it). The FAA investigation will determine whether they did their due diligence and simply made a mistake, or whether they acted irresponsibly on that front as well.
Those comparisons make no sense and are just plain wrong.
First point: When looking at safety we care about injuries and deaths, not the launch failure rate. A broken parked car might not be reliable but it certainly is safe. Don’t confuse reliability and safety.
The two are certainly related – but not one and the same. The biggest problem with the Space Shuttle, for example, is that there is no plan B (most of the time). If you have a launch abort system you can decrease the reliability of your rocket (and thus change the failure rate for the worse) while still being just as safe.
Second point: It just makes no sense to compare manned and unmanned launch systems. Bringing Atlas and Ariane in the mix just makes no sense at all. You can’t meaningfully compare the safety between those launch systems and the Shuttle, if only because it’s impossible for humans to be injured or killed in those rockets.
On a deaths per humans brought to space metric the Shuttle is a horrible performer and very unsafe.
I used to be a mechanical engineer for several space shuttle missions. You're missing a critical element. Human space flight is insanely dangerous with today's technology. Astronauts accept this and NASA's engineers accept this. The safety requirements for a shuttle launch are voluminous and arcane - to the point where they restrict the freedom of engineers to solve problems to a significant degree. Most people don't know that spaceflight technology has barely improved since the 60's. The primary reason is safety.
That a shuttle (and it's crew) blows up is regrettable, but when you strap a cargo truck to a giant tank of hydrogen and light it on fire, someone is going to die from time to time. It's not like they don't know what they're getting into.
Figuring out how to keep the crew alive after the shuttle's main tank explodes is just a bad idea. Wouldn't it make more sense to figure out a way to keep the rockets from coming apart in the first place? How many additional failure points would you introduce by creating a failsafe for that unlikely case (of which there are thousands if not millions).
Of course we should learn from failures, but the surest way to kill the space program is force it to be safer. If anything, they need to inject more risk into space flight so that better technologies can gain the ever-elusive "flight heritage". Trust me, astronauts would still line up for a chance to fly even if you doubled the risk of death.
It is possible to damage the rocket and systems when mating the payload in the faring, which would not become apparent without further testing and somewhat negates the purpose of this test itself.
IMO their space program is very cavalier. This was apparently a secret facility near a residential area so they should have at least been distributing safety and emergency information. Not even telling the people living next to it that the facility exists is inexcusable.
Why can't NASA provide one for such purposes? Safety systems should be tested.
reply