Starhopper test flight scrubbed

The planned 150-meter-high test flight of SpaceX’s Starhopper test prototype was aborted at T-0 seconds last night when the Raptor engine did not ignite as expected.

A live video feed provided by SpaceX showed the squat, 30-foot-wide (9-meter) Starhopper vehicle counting down to a planned liftoff shortly after 6 p.m. CDT (7 p.m. EDT; 2300 GMT) Monday from the company’s facility in South Texas. The vehicle’s single methane-fueled Raptor engine could be seen swiveling side-to-side in a preflight steering check, as the Starhopper pad’s sound suppression system dumped water under the vehicle.

But the Raptor engine did not ignite as the countdown clock reached zero.

“Test aborted just after T-0,” read a text banner on SpaceX’s webcast. “Teams evaluating next test opportunity.”

They say they will try again today. If you want to watch this link provides some suggestions.

These test flights are testing the Raptor engine more than they are testing vehicle take-off and landing. This engine is a significant advancement from not only SpaceX’s Merlin engine but from almost every rocket engine previously built. It has the potential to set the record for the most efficient and powerful engine. It is therefore not unexpected that there will be issues during these test flights.

Comparing today’s modern rocket engines

For the geeks among us, below the fold is a really really good video describing the engineering designs and considerations that have gone into the launch industry’s most important rocket engines, both now and in the future, with the goal of understanding the design choices SpaceX made for its Raptor engine.

The video is almost 50 minutes long, but if you set the speed at 1.25 you can still understand it and save some time.

Hat tip reader Michael Nelson.
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SpaceX ramps up Raptor engine tests

Capitalism in space: SpaceX has conducted another Raptor engine test, this time running the engine at full power.

“Raptor just achieved power level needed for Starship [and] Super Heavy,” Musk tweeted just after 3 a.m. EST (08:00 GMT) Feb. 7.

Musk did not say how long the test was or if it was at full power. The Feb. 3 burn was only about two seconds and at about 60 percent power. However, he said the latter test reached a chamber pressure of 257 bar, or about 3,700 pounds per square inch, and an estimated force of about 172 metric tons with “warm propellant.”

Musk has said that they will be doing hopper test flights with their Starship prototype this spring, but they can’t do that until they have three working Raptor engines. It seems to me that it will be at least a few months before this engine is tested sufficiently to be ready for flight. Then they need two more finished engines.

Don’t expect the first Starship hopper flights for at least six more months, if that soon.

A detailed look at SpaceX’s Raptor engine

Link here. This story confirms for me a thought I had had while I watched Elon Musk’s talk last week outlining his proposed Interplanetary Transport System: SpaceX is still a good long way from actually building this rocket, since they have barely begun developing the rocket engine. They have made excellent progress in engine development, but they have a lot to do, with many pitfalls certain.

I therefore think that the company will be relying on its Falcon 9 and Falcon Heavy rockets, with their Merlin engines, for many more years to come.