Grasshopper

[doug]

Patience grasshopper...

About a week before Elon's National Press Club talk, SpaceX filed this draft environmental assessment with the FAA (http://www.faa.gov/about/office_org...0110922 SpaceX Grasshopper Draft EA.Final.pdf (pdf)) for permission to test a reusable launch vehicle called the Grasshoppper at a site in Texas.

2.1.1 Grasshopper RLV

2.1.1.1 Description

The Grasshopper RLV consists of a Falcon 9 Stage 1 tank, a Merlin-1D engine, four steel
landing legs, and a steel support structure. Carbon overwrapped pressure vessels (COPVs),
which are filled with either nitrogen or helium, are attached to the support structure. The Merlin-
1D engine has a maximum thrust of 122,000 pounds. The overall height of the Grasshopper
RLV is 106 feet, and the tank height is 85 feet.

The propellants used in the Grasshopper RLV include a highly refined kerosene fuel, called RP-
1, and liquid oxygen (LOX) as the oxidizer. The Grasshopper RLV has a maximum operational
propellant load of approximately 6,900 gallons; however, the propellant loads for any one test
would often be lower than the maximum propellant load. Even when the maximum propellant
load is used, the majority of the propellant would remain unburned and would serve as ballast to
keep the thrust-to-weight ratio low.
...

Btw, here's video of the Press Club talk: Future of Human Space Flight - C-SPAN Video Library

 

[raymond]

But still, don't air brakes make much more sense? At least to complement thrust? At those speeds air brakes are extremely efficient. Anybody here who knows as much about this as I would like to know myself?

 

[JRod0802]

But still, don't air brakes make much more sense? At least to complement thrust? At those speeds air brakes are extremely efficient. Anybody here who knows as much about this as I would like to know myself?

Elon said that the animation was slightly inaccurate for two reasons. One reason was because they wanted to have it done in time for the announcement, and they just didn't have time to fix some inaccuracies. The other reason is because they didn't want to give away some of their corporate secrets on how they're actually doing it. Even though they don't show air brakes, they still might use them in the final product.

 

[doug]

Grasshopper Takes Its First Hop / 9-21-12 - YouTube

 

[jcstp]

"one small jump for spacex, a big jump for .......":tongue:

 

[TEG]

Grasshopper Takes Its First Hop / 9-21-12 - YouTube

Go Grasshopper, go!

 

[doug]

View from landing leg camera on Falcon rocket test rig (aka Grasshopper Project)

- - - Updated - - -

Twitter / elonmusk: Launching our Falcon 9 rocket ...

SpaceXs First Contract Cargo Mission Set for Next Month | Autopia | Wired.com

Orbital Sciences, SpaceX Ready to Launch | Autopia | Wired.com

... SpaceX was busy over the weekend with the static fire test of its Falcon 9 rocket, scheduled to make its first contracted commercial cargo trip to the ISS on Sunday. During the test at Launch Complex 40 in Florida, the Falcon 9 successfully fired its nine Merlin engines on Saturday. The SpaceX team went through the entire launch process as if it were a normal launch and while firmly locked to the ground, the Falcon 9 engines went to full power for two seconds before being shut down.

The SpaceX team is currently reviewing the data from the static fire, and if everything looks good the company will launch at 8:35 p.m. ET on Sunday. Should something cause a delay, SpaceX has backup launch times on Monday and Tuesday.

 

[doug]

On 11/1/12, SpaceX's Grasshopper vertical takeoff and landing test vehicle (VTVL) hops nearly two stories (17.7 feet/5.4 meters). Duration was 8 seconds using closed loop thrust vector and throttle control.

SpaceX is working to develop vehicles that are fully and rapidly reusable, a key element to radically reducing cost and increasing the efficiency of spaceflight. The 10-story Grasshopper test vehicle consists of a Falcon 9 first stage, a Merlin-1D engine, four steel landing legs, and a steel support structure. It is being tested in successively higher jumps at SpaceX's rocket development facility in Texas.

 

[doug]

Nice progress on the Grasshopper. Two story hop was posted here. Now here's a 12 story hop:

Single Camera: Grasshopper 12-Story Test Flight 12/17/12 - YouTube

Multi-Angle: Grasshopper 12-Story Test Flight 12/17/12 - YouTube

 

[Norbert]

Nice progress on the Grasshopper. Two story hop was posted here. Now here's a 12 story hop:

Seems difficult to notice any sign of instability. Probably the kind of thing that looks much easier than it is.

The rocket seems pointing to the right (at least when lowering), relative to the horizon. The wind seems to come from the right, but not sure if that could be the reason. Doesn't seem to be strong wind.

 

[doug]

Given yesterday's passing of the great Gerry Anderson, this seems appropriate:

 

[aronth5]

Looks like the next grasshopper test will happen fairly soon. Posted 2/9 by Elon

 

[aronth5]

It appears Grasshopper may have gone hopping yesterday.

 

[aronth5]

3rd Grasshopper test. Video now available on Youtube. Go SpaceX.

 

[doug]

3rd Grasshopper test. Video now available on Youtube. Go SpaceX.

Hmm... a bit anti-climatic. I saw Elon's tweet "The Johnny Cash hover slam!" and figured the Johnny Cash tune was Ring of Fire. So ring of fire and hover slam... I was expecting to see the thing smash down with a cool explosion leaving a crater and a ring of fire. But no such luck. Just a lot of smoke. Still cool. Anyone know the significance of this test?

 

[Objective1]

Hmm... a bit anti-climatic. I saw Elon's tweet "The Johnny Cash hover slam!" and figured the Johnny Cash tune was Ring of Fire. So ring of fire and hover slam... I was expecting to see the thing smash down with a cool explosion leaving a crater and a ring of fire. But no such luck.

They were expanding the envelope- 200 ft elevation maybe? Elon had mentioned that he worried that this test would end in a big crater. I guess you hoped it would, Doug.

I hope they can keep testing Grasshopper without any big craters. It would be a first in VTOL rocketry, IMO. Their control is impressive so far.

 

[Doug_G]

I see there was a Johnny Cash doll along for the ride. How wonderfully nerdy!

Hugely impressive control system - I love how it hovered there completely motionless.

 

[Objective1]

I see there was a Johnny Cash doll along for the ride. How wonderfully nerdy!

Actually, the Cowboy was along for the previous ride, too. It's my understanding from following the comments on nasaspaceflight.com that the mannequin is life-size, and was put there to give viewers a sense of the Grasshoppers impressive size. The hat was added just 'cause. I don't know if Johnny Cash was any kind of inspiration for the mannequin.

 

[aronth5]

Here is some interesting information from the FAA that summarizes the testing phases. Looking
forward to phase 3.
http://www.faa.gov/about/office_org/headquarters_offices/ast/media/20110922%20spacex%20grasshopper%20draft%20ea.final.pdf
"Draft Environmental Assessment for Issuing an Experimental Permit
to SpaceX for Operation of the Grasshopper Vehicle at
the McGregor Test Site, Texas September 2011"

 

[Grendal]

So this was either a Phase 1 or Phase 2 test?

I can't wait to see a Phase 3 test. That will be very exciting.

I also wonder how the numbers are looking. They are still testing, so on paper it has look like the numbers are viable. The other question is durtability of the used parts...