Depends on why it failed. As we've seen in many hypersonic launch attempts it's possible to fail many times and not even get a chance to test the flight vehicle. ASALM (the PTV anyway) was apparently very successful.
"ASALM-PTV flew 7 times in flight tests at Eglin AFB in the 1979-1980 time frame. The first test experienced a throttle runaway incident, and so it unintentionally set a hypersonic speed record for vehicles powered by airbreathing propulsion, and furthermore it did that at low altitude! That speed record stood for nearly a quarter century, until NASA broke it with its X-43A scramjet test article in 2004, at very high altitude with a brief 3-second airbreathing burn, rocket-boosted all the way to test speed at Mach 7.
ASALM-PTV accidentally reached about Mach 6 in that runaway ramjet burn, starting from a Mach 2.5 ramjet takeover at end of rocket boost, after a 20,000 foot launch for that first test. The original intent for the first test was for the vehicle to fly a racetrack pattern, at 20,000 feet and a sedate Mach 2.5, to fuel exhaustion, using simple timed turns, in order to check out the ramjet systems. Because of the throttle runaway problem, it left the range and reached fuel exhaustion at hypersonic speed, before the first timed turn could occur.
We found it 3-4 days later, stuck like a big steel dart, in a farmer's field, about 10 miles outside the airbase. The final telemetry from the vehicle just before we lost it, translated as "I am at Mach 6 and still accelerating as my skin begins to melt. I just ran out of fuel. Goodbye." Well, at least the other ramjet systems besides the throttle control worked just fine, obviously. So we counted that one as "half-successful".
The other 6 ASALM-PTV flight tests were letter-perfect, including the design cruise missile mission: subsonic air launch, supersonic climb to cruise altitude (80,000 feet), high supersonic cruise (Mach 4) for a long range, and high-supersonic dive (terminal about Mach 5) onto its target. With the first one "half-successful", that made us 6.5 for 7. Not too bad!"
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