Musk: Dragon Abort Test Successful

Dragon abort test with SuperDraco engines.  (Credit: SpaceX)
Dragon abort test with SuperDraco engines. (Credit: SpaceX)

SpaceX CEO Elon Musk also held a brief press conference after the test. Here are the highlights:

  • Test vehicle went from zero to 100 mph (160 kph) in 1.2 seconds “That’s pretty zippy.”
  • Dragon reached top speed of 345 mph (555 kph)
  • “If there had been people on board they would’ve been in great shape.”
  • One of SuperDraco thrusters had a lower than expected thrust due to a fuel mixture ratio that was “slightly off”
  • Only four of the eight SuperDragos need to fire for an abort
  • SuperDragos can be used for propulsive touch downs on land
  • Up next: an in-flight abort test out of Vandenberg Air Force Base
  • SpaceX will conduct an uncrewed flight to the International Space Station followed by a second test with a crew
  • Musk expects to be transporting astronauts to ISS within two years, give or take six months

The pad abort test was one of two remaining milestones under SpaceX’s Commercial Crew Integrated Capabilities agreement with NASA. The other is the in-flight abort test. Each milestone is worth $30 million.

Dragon's trunk separates from capsule during pad abort test. (Credit: SpaceX)
Dragon’s trunk separates from capsule during pad abort test. (Credit: SpaceX)
Dragon pad abort test article descends under parachutes. (Credit: SpaceX)
Dragon pad abort test article descends under parachutes. (Credit: SpaceX)
Dragon pad abort test. (Credit: NASA)
Dragon pad abort test. (Credit: NASA)

  • Hug Doug

    Fantastic pictures 🙂

  • therealdmt

    Schweet

  • Snofru Chufu

    There is a discussion at another blog that maybe two of the eight engines did not deliver the required performance and were even shut-down earlier and caused the loss of overall velocity and distance.

  • Chief Galen Tyrol

    Today was a Good Day!

  • Larry J

    The only thing that would’ve made the pictures better under today’s visibility conditions would be if the capsule was some high contrast color. Can’t have everything.

  • Michael Vaicaitis

    Musk has said that only 4 engines are required for abort escape. The velocity and distance you refer to are those that they predicted for this test. They are not the minimum benchmark numbers required for a successful escape. All thats required for a successful escape is to get away from any potentially exploding rocket and to reach a high enough altitude for the parachutes work.
    That’s not to say that they won’t want to use the data from this test to make sure the system works as perfectly as possible.

  • Snofru Chufu

    A question: What does usage of 4 engines mean in this case? Only 1.9 g’s instead small 3,8 g’s as demonstrated yesterday? Thanks.

  • stoffer

    We don’t know if they throttled the engines back to keep the g comfortable for the occupants, we don’t know how much weight they have put in the capsule. I don’t know how to compare this LES to e.g. Apollo or Soyuz. G are not everything, it is the total deltaV that matters. Maybe Dragon can compensate by thrusting longer. More data is needed.

  • Michael Vaicaitis

    Elon Musk:
    “Max acceleration was 6X gravity, altitude 1187m, lateral distance 1202m and velocity 155 m/s. Main chutes deployed 970m.”
    What is your source for 3.8g.

    I suspect you are fixated on a scenario where the spacecraft escapes an exploding rocket just milliseconds ahead of the flame and shock wave. Whilst not implausible, such a circumstance is likely only a corner case of possible escape scenarios. The purpose of a pad escape is to reach an altitude and distance away from the pad where parachutes can be safely deployed. One must presume that there is a minimally acceptable rate of escape and also a maximum acceleration that are considered both viable and safe. If you escape too slowly and are killed by an exploding rocket, then the attempted escape was irrelevant. If you accelerate so fast that all crew members will black-out and some may be killed by the accelerative forces, then that escape is also useless. In the 21st century, astronauts are no longer elite test pilots, they are scientists, engineers, doctors and rich tourists. Bear in mind too that if NASA were not in complete agreement with SpaceX’s method they would not have allowed them to pursue it. If you do not trust NASA’s judgement that this escape system is acceptable, how do you trust them that a 16g escape is acceptable?.

    also see stoffer’s comments

  • Snofru Chufu

    My source is SpaceX’s official statement that 160 km/h (100 miles/hour) were reached in 1.2 s. Devide both you have the acceleration of 37 m/s².

  • Saturn13

    The g’s are low. The Soyuz in flight abort was 20 g’s. 1 was injured and one not. Race car drivers can have 50gs in a wreck. Most of the time ok. Sometimes the concussion is bad enough to end their career. The Soyuz was latches did not release the 3rd stage. Could be the same problem with the recent Progress. I agree it is no likely to have a fuel leak and LOX leak big enough to have an explosion. A fuel only fire would just burn. Solids are a problem as seen in several videos of large chunks going large distances. Only after launch of course. I doubt range would destruct sitting on the pad. Since the next abort will be at max Q, it will be far enough out to sea and headed out that range may not destruct. It is the destruct soon after lift off were the capsule may get hit from destruct. If Range does not destruct at the right time, it may be right beside the capsule.

  • Snofru Chufu

    You are right, it seems that we do not much about details of Space’s design. At most true for all SpaceX systems and components.

    You have to fullfill both initial acceleration and delta-vee (which depends here mainly from propellant mass and is not questioned here). Because delta-vee is always fullfilled, the acceleration is what makes the difference. I would not use a ejection seat, which delivers only 4 g’s.

  • Snofru Chufu

    Take a look how fast explosion occured (immediately) after ones structural failure of tank happened. Here is Challenger accident as example. See after 1:30 min. Every split of second counts.

    https://www.youtube.com/watch?v=j4JOjcDFtBE

  • Saturn13

    So, if the LOX tank bursts, the force would be great enough to break open the fuel tank, combining and a spark sets off an explosion. Unlikely, but possible. Have to be really fast to abort in that situation. LOX tanks are designed to take pressure.

  • Snofru Chufu

    Safety provisons have to take in account also the unlikely case, if this case is devasting and deathly.

  • Saturn13

    They do. Many years of knowledge are used. Got to quit sometime. Have to assume tanks will not burst. Do you worry about the Sun not coming up tomorrow? There is no way to clear an explosion. Debris moves faster than Dragon.There were some that was afraid that Dragon would crash into ISS.

  • stoffer

    We don’t get much of details on anything. I tired to look for detailed performance of Orion, Apollo and Soyuz LES and I couldn’t really find any details.

  • windbourne

    You likely will not get your data. Spacex depends on trade secrets for their IP. Spacex has given the data required to NASA and NASA has approved.

    To be honest, this should be just fine for this launch vehicle. As long as no O2 is in the rp1 tank, you will not get a fast explosion. Instead, any disaster will start rather slow and sensors will pick it up.

    Now, if they have solid boosters, this would not work. it would be way too slow.

  • Snofru Chufu

    About Apollo and Saturn can find every detail in internet (see NASA database) what you want, also about LES.

  • stoffer

    So, how does the SpaceX LES compare to Apollo LES? In terms of acceleration, total impulse and total deltaV? Inquiring minds want to know!

  • Snofru Chufu

    “Instead, any disaster will start rather slow and sensors will pick it up.”

    Your statement is not correct and misguiding. Any major structural failure (as that of Challengers external tank for example) will result in destruction of the vehicle in fractions of second.

  • Snofru Chufu
  • Larry J

    I recall reading that the Saturn V had cables running the length of the rocket stages. If there was a break in the cable, it meant the stage was coming apart and signaled an abort. It was a simple approach that fortunately was never needed but it would give you some small amount of warning if a tank is rupturing.

  • windbourne

    Actually, you are wrong again:

    https://www.mahal.org/articles/space/the-space-shuttle-challenger-accident

    “At 58.8 seconds into flight on enhanced film a flame was seen coming from the right SRB.”

    “The first sight that the flame was hitting the External Tank was at 64.7 seconds, when the color of the flame changed. Color change indicated that flame color was being produced by the mixing with another substance. This other substance was liquid Hydrogen ”

    “From 72 seconds there was a very sudden chain of events that destroyed Challenger and the seven crew members on board. All of these events happened in less than two seconds.”

    Read those 3 clips.
    First, the initial flame leaving the SRB was at 58.8.
    Secondly, it was at 64.7 second later that the flame is mixing with LH2. That is about 6 seconds. Note that pressure was dropping already in the LH2 tanks.

    Third at 72 seconds is when the explosion actually starts and then takes slight less than 2 seconds.
    That is 8 seconds after the initial cutting into the LH2 tank.

    So, from the first point of a flame until the explosion STARTS is more than 14 seconds.
    Well, F9 is covered with loads of sensors. In addition, RP1 burns/explodes MUCH SLOWER than does LH2.

    Finally, D2 is already far away from the vehicle in less than 1 second, let alone 2.

    So your stuff about fraction of a second is not misleading, it is simply wrong.

  • pathfinder_01

    Actually the sad part about challenger is that the crew survived the explosion part. The forces were insufficient to kill the crew. We know that because some switches were found in an different position than launch and someone turned on oxygen mask for the pilot. Also the main engines were attempting to shutdown, so if the computer or the crew had an escape system it could have been used. What killed was either depressurization or hitting the ocean at high velocity.

  • windbourne

    with all of the sensors that SpaceX is supposed to have, I suspect that they will KNOW when a tank bursts and will then blow the dragon.

  • Snofru Chufu

    Thank you for giving this information.

  • Snofru Chufu

    Why do you not start the chain of events in Utah at Thiokol already hours before launch, where manager gave NASA the wrong decision to allow launch at very temperature? Well, we all know in detail what happened in 1986. The pre-causes (initial row of events) are not important for my case, even if LH2 tank was punctured locally, because it was not detected in flight, it affected the flight not really (until final moment) and it had no consequences for mission control. The actual structural breakdown happened very fast, I would say faster as the total time that summarized for duration of explosion (less as two second). The fact that not all of the crew was already killed at this event is no argument against a fast rescue system. What happened with Challenger is only example of structural collapse.

  • windbourne

    Again, you get it wrong.
    Here is the DIRECT data from NASA:

    “http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Chapter-3.txt”

    1) 39:06.774 Start ET LH2 ullage pressure deviations 66.764
    2) 39:13.054 Start of sharp MPS LH2 inlet pressure drop 73.044
    3) 39:13.153 All engine systems start responding to loss of fuel and LOX inlet pressure 73.143
    4) 39:13.172 Sudden cloud along ET between intertank and aft dome 73.162

    The pressure started dropping back in 66.7 second.
    7 seconds later you have a sharp drop.
    Then about .1 second later is the start of the explosion.

    Point is, that if SpaceX is to be believed that all of their sensors would pick up the original pressure drop and jettison the craft.

    You keep trying to claim that it is not good enough or that the shuttle (with solids) proves that the dragon V2 is not good enough, and yet, all of the data over and over and over proves you wrong.

    You need to get over your hatred of Musk and simply look at the engineering for what it is.

  • windbourne

    and yet, it was known 6 seconds ahead of that, that there was issues.

    The data that NASA presented shows that even the Challenger gave plenty of notice that it was headed for a disaster.

  • windbourne

    what is certain is that hitting the ocean DID kill at least 1.
    The question remains, were they conscious? It is possible (hopeful) that the decompression knocked them out after they had done the aforementioned changes.

  • MrFriendly B

    Snofru, the Dragon LAS is approved by NASA and the pad abort test was successfull, get over it.

  • BeanCounterFromDownUnder

    Yep on to the in-flight abort.
    Cheers

  • Saturn13

    I was thinking strain gauges also. But the period of the abort where the capsule is floating down, debris could fall on the parachutes if the explosion sends debris that far.

  • Saturn13

    Yes and maybe the blast will just help propel Dragon upwards. Dragon does not move as fast as the debris. On the up side ,it may not penetrate the pressure vessel, but the parachutes might have holes in them. There may not be as many hot pieces to burn the parachutes the way SRM chunks keep burning.

  • Saturn13

    I don’t think anything could be done. The solids could not be shut down. Maybe they could have ejected them and the tank. A sad subject.

  • Larry J

    If you watch the video of the crew walking out before launch, they weren’t wearing pressure suits. They were wearing jump suits with lightweight helmets. The crew compartment lost pressurization very quickly after the breakup. Their momentum carried the crew compartment to an altitude of over 60,000 feet. Without a pressure suit or cabin pressure, they would’ve passed out within 30 seconds or so of the explosion. It’s unlikely they woke up before hitting the water several minutes later – at least I sincerely hope none of them did.

  • windbourne

    Oh, there was nothing that could be done for the challenger.
    It was never designed to deal with an explosion.

    My issue is that snofru kept claiming that there was no warning ahead of time. Far from it. They had multiple seconds, which the dragon is already headed away in the first second of notice.
    So, with the dragon it would be able to clear it quickly and easily since it is going orthogonal to the blast and was a KM away. I assume that the in-flight will do the same.

  • windbourne

    Lets hope so.
    May they rest in peace.

  • windbourne

    We will find out in about 2 months how that works 🙂

  • windbourne

    Personally, I would rather put them on the outside of the tank.
    But that is a nice simple idea.

  • windbourne

    I could see that as a problem. Hopefully, when the inflight abort occurs, more fuel is used to go away, rather than up.
    With the ground flight, I would assume that a great deal of fuel was used in going up, not away.

  • windbourne

    That is quite probably the real issue. None of these systems will pull the craft away to avoid 100% of the debris.

  • Sebastian Mai

    there would have been no chance to escape in-time from this one. structural-failures propagate to quick in solid rocket’s as that anything could escape them.
    and exactly this is the reason bolting the shuttle sideways was one of the biggest mistakes in its inception