Private Spanish company plans to launch reusable rocket

[ecarfan]

Saw a news story about PLD Space planning to build a “reusable” rocket so had to learn more. Turns out it’s a sub-orbital vehicle “designed for microgravity research and technology development” with a 1,000kg payload capacity. Each flight will provide 3-4 minutes of microgravity time.

I have to wonder if there is really a market for such a vehicle.

Here’s a diagram showing the launch and recovery. A parachute will come out of the tail end of the rocket as it descends and it will land in the ocean nose first, then be recovered for reuse. Points for originality.

 

[Electroman]

Parachutes will be tucked under/near the engine bay?

 

[ecarfan]

I guess. Very unusual approach. Won’t they melt during ascent?

 

[Electroman]

That almost is too simplistic like a design from a middle schooler

 

[Watts_Up]

Since most of the weight will be near the rocket engine at the bottom of the rocket,
how would it be possible to keep the rocket vertical with the top below the heavy bottom ?

Hower, this recuperation was previously used by NASA:

The Space Shuttle Rockets Falling From Space

Every time NASA launched the Space Shuttle, two 45 m (149 ft) tall rockets called the Space Shuttle Solid Rocket Boosters (SRBs) were used.​

The Space Shuttle's Solid Rocket Boosters provided thrust for the first part of the ride, and were then jettisoned ​

at an altitude of around 46 km (148,000 mi). They landed with parachutes and were then recovered by ships and refurbished for reuse.​

​

 

[bxr140]

Since most of the weight will be near the rocket engine at the bottom of the rocket,
how would it be possible to keep the rocket vertical with the top below the heavy bottom ?

Let’s give it up for some FBDs!

 

[ecarfan]

Since most of the weight will be near the rocket engine at the bottom of the rocket,
how would it be possible to keep the rocket vertical with the top below the heavy bottom ?

Because when the chutes open the rocket is descending nose down and the chutes are attached to the end that is “up” from the nose.

Hower, this recuperation was previously used by NASA:

Good point. Thanks for posting that photo. I had known the shuttle boosters were reused but had never seen a photo of them landing in the ocean.

 

[scaesare]

Let’s give it up for some FBDs!

Fat Bottomed...??

 

[Mike1080i]

Because when the chutes open the rocket is descending nose down and the chutes are attached to the end that is “up” from the nose.

Good point. Thanks for posting that photo. I had known the shuttle boosters were reused but had never seen a photo of them landing in the ocean.

Drifting off topic, but the SRB onboard video was equally good. Quite a dynamic ride and impact on the ocean surface.

 

[Watts_Up]

Drifting off topic, but the SRB onboard video was equally good. Quite a dynamic ride and impact on the ocean surface.

On the video, from 5:18 to 7:15 it seems that the booster was reignited?
But it seems that the back of the booster was not always toward the earth,
so did reigniting the booster could really help reducing its speed?

 

[Electroman]

On the video, from 5:18 to 7:15 it seems that the booster was reignited?
But it seems that the back of the booster was not always toward the earth,
so did reigniting the booster could really help reducing its speed?

I don't think it reignited. The booster hit the upper parts of atmosphere and the remnants of the fuel which was still smoldering is what we see as the embers were getting scattered due to moving through air.

Also it was a bit odd to see the booster still moving at more than 2k miles per hour, but tumbling end-on uncontrollably.

 

[Watts_Up]

I don't think it reignited. The booster hit the upper parts of atmosphere and the remnants of the fuel which was still smoldering is what we see as the embers were getting scattered due to moving through air.

Also it was a bit odd to see the booster still moving at more than 2k miles per hour, but tumbling end-on uncontrollably.

I wonder what would be the terminal velocity speed when the parachutes of the booster get open ?

 

[Electroman]

I don't think it reignited. The booster hit the upper parts of atmosphere and the remnants of the fuel which was still smoldering is what we see as the embers were getting scattered due to moving through air.

Also it was a bit odd to see the booster still moving at more than 2k miles per hour, but tumbling end-on uncontrollably.

What was also interesting is if you look at both the boosters, they were tumbling exactly in synch with each other.

 

[Watts_Up]

What was also interesting is if you look at both the boosters, they were tumbling exactly in synch with each other.

Especially when splashing at the same time, this was a very lucky picture taken.

 

[Mike1080i]

On the video, from 5:18 to 7:15 it seems that the booster was reignited?
But it seems that the back of the booster was not always toward the earth,
so did reigniting the booster could really help reducing its speed?

There was no reignition, that's just bits and pieces of the remaining solid propellant burning and smoldering. No real usable thrust or propellant at the point they separated from the rest of the shuttle stack.

 

[Mike1080i]

Especially when splashing at the same time, this was a very lucky picture taken.

View attachment 917923

I believe that's the frustum from one of the SRBs (likely the one that this camera is from) still attached to the drogue shoots. You can read more about the process here under "Descent and recovery".