2
$\begingroup$

The cropped and sharpened screenshots below are from the Blue Origin video Replay: New Shepard Mission NS-19 Webcast after about 02:03:16 (T+08:07) and show a subset of all the things that happen when the New Shepard capsule deploys its parachutes.

The drogue chutes appear at about T+08:16 when a very bright flash indicates some pyrotechnic event. They quickly deploy but then they remain that way for about ten seconds before they are allowed to pull the main parachute system out of the capsule between T+08:28 and T+08:30.

Each main parachute merges from a large yellow container, and the lengths of its lines emerge from a smaller white container several meters above the capsule.

It's quite beautiful to watch!

Question: Why do New Shepard's drogue chutes just "hang there" for ten seconds before deploying the main parachutes? What (if anything) is happening during that time?

For example, are there things being monitored and decisions to be made? Or is that just a fixed delay giving them ample time to unfurl and separate?

screenshot from the Blue Origin video "Replay: New Shepard Mission NS-19 Webcast"

screenshot from the Blue Origin video "Replay: New Shepard Mission NS-19 Webcast"

Improve this question
$\endgroup$
1
  • 1
    $\begingroup$ because they are actual drogue parachutes, not just pilot parachutes to pull the main parachutes into deployment. $\endgroup$
    – CuteKItty_pleaseStopBArking
    Dec 13, 2021 at 6:30

2 Answers 2

Reset to default
3
$\begingroup$

I believe this is a controlled deceleration sequence. The capsule slows from 210-137 mph at .75g while the drogues are deployed, then down to 48 mph at 1.3g while the main cutes are half-deployed, then to 14 mph at 1.8g when the main cutes are fully deployed.

Improve this answer
$\endgroup$
11
  • $\begingroup$ Interesting! In order to know if the drogue chutes contributed significantly to deceleration, it would be helpful to establish that the capsule had reached terminal velocity before they were deployed and was not still decelerating by itself. $\endgroup$
    – uhoh
    Dec 13, 2021 at 2:06
  • 2
    $\begingroup$ @uhoh, terminal velocity is the maximum speed a body reaches in an atmosphere, during a re-entry sequence a capsule is at terminal velocity at all times until the chutes deploy. Terminal velocity reduces as the atmosphere thickens due to increased resistance. $\endgroup$
    – GdD
    Dec 13, 2021 at 11:10
  • 3
    $\begingroup$ @uhoh it could be argued that reentry vehicles are at extremely to slightly superterminal velocity at nearly all times during their descent. $\endgroup$
    – Anton Hengst
    Dec 13, 2021 at 17:29
  • 1
    $\begingroup$ Nonetheless, the argument is simple that the vehicle had reached terminal velocity already: the vehicle has been decelerating the entire time through the atmosphere. There is only a period where you are not at terminal velocity if you must accelerate (from gravity) to reach it. $\endgroup$
    – Anton Hengst
    Dec 13, 2021 at 17:30
  • 1
    $\begingroup$ The speed readout on the video showed the descent rate was stable before chute deployment. $\endgroup$
    – Woody
    Dec 13, 2021 at 19:37
3
$\begingroup$

What happens in that time is that the drogue parachutes slow the vehicle down from about 207 mph at deployment to 136 mph at main parachute deployment. You can see from the speed display that it doesn't slow down instantaneously, the speed is changing throughout the drogue phase (with the rate of change being highest at the start, and reducing over time, as it asymptotically reaches what would be the terminal speed under the drogue). For comparison, in the 15 s before drogue deployment, the speed changes from about 225 to 207 mph.

It's worth noting the distinction between a drogue parachute, which does work on the capsule, and an auxiliary or pilot parachute which is just there to deploy the main parachute.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.