Spaceflight Insider

Raptor fired at power level needed for Starship, Super Heavy

Less than a week after the first test, SpaceX fired up its Raptor flight engine again, increasing its performance to levels required for Starship and Super Heavy. Photo Credit: Elon Musk / SpaceX

Less than a week after the first test, SpaceX fired up its Raptor flight engine again, increasing its performance to levels required for Starship and Super Heavy. Photo Credit: Elon Musk / SpaceX

SpaceX’s first Raptor flight engine performed another test fire, this time increasing its force and chamber pressure to required levels for the company’s giant next-generation rocket.

Raptor was moved to a test stand at SpaceX’s McGregor, Texas, facility late last month and fired for the first time on the evening of Feb. 3, 2019. Now, less than a week later, company founder and CEO Elon Musk tweeted that another test took place.

“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.”

The Starship and Super Heavy design requires at least 170 metric tons, Musk said, and added that with deep cryogenic propellant, another 10-20 percent performance could be achieved.

For comparison, each of the nine kerosene and liquid oxygen-consuming Merlin 1D engines used at the base of the Falcon 9 rocket’s first stage produce about 86 metric tons of thrust.

Raptor is a full-flow staged combustion engine that consumes liquid methane and liquid oxygen. Three of these engines will be used to power the under-construction prototype Starship hopper at SpaceX’s Boca Chica launch site, which is also under construction. The hopper is expected to be used for low-altitude tests of the vehicle. It’s first “hops” could come later this year.

Once operational, the 207-foot (63-meter) Super Heavy rocket is expected to use 31 Raptor engines, while the 180-foot (55-meter) Starship upper stage/spaceship is designed for seven. The first orbital flight could occur in 2020, however, Musk has admitted that is a highly-ambitions target.

When it does get off the ground, the first version of the fully-reusable, now stainless steel rocket is planned to be able to send over 100 metric tons of payload into low-Earth orbit and be capable of on-orbit refueling, which could potentially allow for that same payload to be sent to the Moon, Mars or other deep-space destinations.

Its first major mission is currently anticipated to be the #dearMoon private lunar mission being funded by Japanese billionaire Yusaku Maezawa. He and eight artists are hoping to fly around the Moon on a week-long trip as early as 2023.

An artist's rendering of SpaceX's Big Falcon Spaceship (the upper part of the Big Falcon Rocket), flying by the Moon. Image Credit: SpaceX

An artist’s rendering of SpaceX’s Big Falcon Spaceship (the upper part of the Big Falcon Rocket), flying by the Moon. Image Credit: SpaceX



Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.

Reader Comments

James Lunar Miner

How much added time and mission risk do we add with each docking and deep cryogenic liquid methane and liquid oxygen “refueling” event, and how many slow and risky docking and refueling events do you need to do a Lunar landing mission with the overweight, low 380 Isp, grossly propellant inefficient, and CO2 spewing “stainless steel rocket”?

Perhaps NASA led international Lunar missions with highly propellant efficient Russian, Indian, European, Chinese, Japanese, and Iranian 900+ Isp to 14,000+ Isp nuclear or solar powered propulsion system space tugs would significantly reduce Lunar mission risks and eliminate the CO2 pollution caused by hauling of massive amounts of low energy fossil fuel up through our atmosphere and across Cislunar Space.

A huge and grossly propellant inefficient and CO2 polluting “stainless steel rocket” is probably a risky and really bad political idea in the upcoming green age of zero CO2 manufacturing and zero CO2 transportation systems.


“The Green New Deal (GND)[1][2] is any of several proposed[3][4] economic stimulus programs in the United States that aim to address both economic inequality and climate change. The name refers to the New Deal, a combination of social and economic reforms and public works projects undertaken by President Franklin D. Roosevelt in response to the Great Depression.[5] Supporters of a Green New Deal advocate a combination of Roosevelt’s economic approach with modern ideas such as renewable energy and resource efficiency.[6]”

And, “Throughout late 2018 and early 2019 congresswoman Alexandria Ocasio-Cortez has made the Green New Deal into a major talking point in American politics. Her proposals, in conjunction with many other congressional and senate Democrats, are based on achieving a carbon free US economy by 2035.[2]”

From: “Green New Deal” Wikipedia

James Lunar Miner

Yikes! The Raptor’s low energy and low Isp and grossly inefficient methane propellant and other fossil fuels are headed to extinction just like the big old snarling and meat chomping dinosaurs!

“The Green New Deal, which has so far been a campaign catchphrase about solving climate change and inequality in one fell swoop, just got real.”

And, “Democratic New York Rep. Alexandria Ocasio-Cortez and Sen. Ed Markey of Massachusetts are introducing a joint resolution Thursday laying out the main elements of a legislative plan. It describes a 10-year ‘economic mobilization’ that would phase out fossil fuel use and overhaul the nation’s infrastructure while building whole new layers into the existing social safety net.”

From: “Ocasio-Cortez’s Green New Deal: What’s in it”

James Lunar Miner

Why are highly propellant efficient spacecraft with solar and nuclear powered propulsion systems that have high 900+ Isp to 14,000+ Isp of critical importance to Russia, China, Iran, Japan, India, and many other nations, and why is a grossly propellant inefficient and fossil fueled Raptor rocket engine powered overweight ‘Starship’ spacecraft probably not very important for both Space Dominance and commercial Cislunar Space missions?

High Isp (and thus highly propellant efficient) spacecraft have inherent high delta-v capabilities and can cost effectively haul lots more cargo to a low Lunar or asteroid orbit (and probably with much lower risk and far less environmental damage to the Home Planet) than can the low energy, low delta-v, fossil fueled, and rich in CO2 pollution Raptor engine powered ‘Starship’ spacecraft.


“Since the 1990s, the Colorado School of Mines has had a center that researches the development of space resources.”

And, “George Sowers, a professor of space resources at the School of Mines, said in a statement that creating a space resources program within NASA would ensure the U.S.remains a leader in the field.”

And, “‘As NASA solidifies its plans to return to the moon and then go on to Mars, the utilization of space resources will play a critical enabling role,’ Sowers said. ‘Furthermore, bringing the resources of space within the economic sphere of Earth will spur the next great economic revolution for humankind.’”

From: “Colorado congressmen want to help NASA take longer missions to faraway spots”
By Judith Kohler at The Denver Post February 7, 2019

James Lunar Miner

“Alexandria Ocasio-Cortez has used a speech before finance watchdogs to expose the vast conflicts of interest which shape American politics.”

And, “In just three minutes the Democrat congresswoman laid bare the almost total absence of rules stopping lawmakers from being bought off by wealthy corporations.”

And, “’We have a system with right now which is fundamentally broken,’ she concluded after her question and answer session with a panel of senior figures from campaign finance watchdog groups.”

From: “Alexandria Ocasio-Cortez delivers devastating dissection of US financial system and political corruption in congress speech”
By Tim Wyatt at The Independent 2/8/2019

Is this new and loud politician going to ask some real questions about a mythical and not so great rocket company that went from near financial ruin in December 2008 to sitting pretty with a whole lot of money and assets via perhaps ‘a little’ indirect government contracts help from a President who was a political friend of the financially troubled rocket company’s owner?


OK. Forget about Alexandria Ocasio-Cortez ever asking real rocket questions. Back to chewing on cigars and promoting smoky cigar shaped rockets and making sweet government deep state dark money billion dollar ‘deals’ for government selected ‘friends’ and having Presidents and lots of other politicians who suddenly get much richer after they are no longer in office. What a system!

clearly you don’t know the meaning of the word ‘troll’ or you wouldn’t be inundating this blog with your pointless commentary.
Btw just answer my previous question: how much of what you are posting is funded and an addendum to that, when are any of these wonderful technologies likely to fly operational orbital vehicles?
Until that happens it’s all just all smoke and mirrors.

Excellent! This is a fully demonstrated and viable technology base. Blue Origin and SpaceX are leading the way. Nice Article Derek covering genuinely functional space hardware.

Seriously, you need therapy, until then, you need banned from Spaceflight Insider! Just saying.

Feb. 10, 2019

Hi John, please review our Commenting Rules.
Sincerely, Jason Rhian – Editor, SpaceFlight Insider

James Lunar Miner

The reality of the highly propellant efficient 1,600 Isp to 2,600++ Isp electric propulsion revolution is in orbit all around the Home Planet and out as far as the asteroid Ceres.

Unfortunately, the grossly propellant inefficient 380 Isp fossil fuel Raptor/Starship Mars colonies soon cult folks seem incapable of grasping the current commercial satellite electric propulsion situation and the obvious and ongoing benefits to be derived from cost effective and high delta-v capable electric propulsion spacecraft.

“The VASIMR electric plasma rocket could be used to power a high-efficiency space tug, using only 9 tons of Argon propellant to make a round trip to the moon, delivering 34 tons of cargo from Low Earth Orbit to low lunar orbit. As of 2014, Ad Astra Rocket Company had put forward a concept proposal to utilize the technology to make a space tug.”

From: “Space tug” Wikipedia

How much added time and mission risk do we add with each docking and deep cryogenic liquid methane and liquid oxygen “refueling” event?

And how many risky launches and slow and risky docking and refueling events do you need (and how many tons of low energy methane and oxygen propellants need to be hauled into Low Earth Orbit and Low Lunar Orbit) for the overweight, yet to be built, and grossly propellant inefficient 380 Isp Raptor powered stainless steel Starship to make the round trip in delivering “34 tons of cargo from Low Earth Orbit to low lunar orbit”?

James Lunar Miner

Modern spacecraft builders appreciate and make regular use of the propellant efficiency, inherent high delta-v capability, and cost savings that are enabled by high Isp electric propulsion systems.


“The NEXT engine is a type of electric propulsion in which thruster systems use electricity to accelerate the xenon propellant to speeds of up to 90,000 mph (145,000 km/h or 40 km/s).”

And, “It can be throttled down to 0.5 kW power, and has a specific impulse of 4,190 seconds (compared to 3,120 for NSTAR).”

And, “The first two flight units will be available in early 2019, in time for possible use on a New Frontiers-4 mission. After that, the NEXT-C engine will be made commercially available for purchase by both NASA and Industry through Aerojet Rocketdyne.”

From: “Thrusters”

James Lunar Miner

Both Russia and America are working on electric propulsion systems that replace the expensive xenon propellant with the denser, safer, and cheaper iodine propellant.

Electric propulsion system powered spacecraft using iodine propellant could safely, propellant efficiently, and cost effectively move military space dominance and commercial satellites and cargo carrying space tugs around in Cislunar Space.


“Iodine Satellite (iSat) is a technology demonstration satellite of the CubeSat format that will undergo high changes in velocity from a primary propulsion system by using a Hall thruster and iodine as a propellant.[1][2][3][4]”

And, “A key advantage to using iodine as a propellant is that it provides a high density times specific impulse,[5][2] it is three times as fuel efficient as the commonly flown xenon,[6] it may be stored in the tank as an unpressurized solid, and it is not a hazardous propellant.”

From: “Iodine Satellite” Wikipedia

James Lunar Miner

Is it “predicted that by 2020, half of all new satellites will carry” grossly propellant inefficient Raptor engines? Nope!


“Electric propulsion is now a mature and widely used technology on spacecraft. Russian satellites have used electric propulsion for decades[4] and it is predicted that by 2020, half of all new satellites will carry full electric propulsion.[5]”

And, “As of 2013, over 200 spacecraft operated throughout the Solar System use electric propulsion for station keeping, orbit raising, or primary propulsion.[6]”

And, “In the future, the most advanced electric thrusters may be able to impart a Delta-v of 100 km/s, which is enough to take a spacecraft to the outer planets of the Solar System (with nuclear power), but is insufficient for interstellar travel.[2][7]”

From: “Electrically powered spacecraft propulsion” Wikipedia

James Lunar Miner

Do we want affordable colonies and mines on the Moon and asteroids and across all of our Solar System?

Do we want high delta-v capable, cost effective, and super propellant efficient spacecraft doing space dominance and commercial missions?

Do we want robust, high delta-v capable, cost effective, and super propellant efficient spacecraft capable of reaching and deflecting or destroying a distant incoming NEO that could kill thousands, millions, or even billions of people on our Home Planet?

If we want those things and a lot more, then we need the electric propulsion and super propellant efficiency and cost reductions offered by AEPS and similar systems that make the idea of a grossly propellant inefficient and overweight Raptor powered Starship spacecraft seem beyond silly.

“But if we want to go into deep space, we can’t just rely on bigger and bigger rockets. We need more sophisticated propulsion. NASA has taken this challenge seriously and started looking into new approaches. One of them, the Advanced Electric Propulsion System (AEPS) has now passed a critical test.”

And, “AEPS is a next-generation ion-thruster. It creates propulsion by accelerating ionized atoms with an electric field. It creates a modest amount of thrust compared to traditional chemical rockets, but it is capable of doing so for a longer time and with a lot less fuel. Less fuel means less weight to carry with you into orbit and beyond.”

From: “NASA’s New Propulsion System That Will Take Us To Deep Space Just Passed A Critical Test”

Ion drive has some real future potential for non planetary usage. The raptor is designed for planetary applications.

“AEPS is seen as a key component of the propulsion of large-scale science missions and cargo transport.” Other than satellites (including ISS) there’s nothing related to transporting humans actively being planned.

From: “NASA’s New Propulsion System That Will Take Us To Deep Space Just Passed A Critical Test”

Clarissa MacDougall

JLM used to be James at Americaspace, same $h!t different day.

James Lunar Miner

“Ion drive has some real future potential for non planetary usage.” JBURN

Such condescension ignores the real world electric propulsion historical facts of the above noted: “Russian satellites have used electric propulsion for decades[4] and it is predicted that by 2020, half of all new satellites will carry full electric propulsion.[5]”

Note that zero space missions have flown the grossly propellant inefficient Raptor rocket engine and the real political issues of any such possible future inefficient fossil fueled Raptor rocket engine powered overweight launchers and Starship spacecraft doing unwanted, unnecessary, unjustifiable, and real damage to our planet’s environment.

Spin it away with condescension or deny it as the Mars cult folks repeatedly try to do, in the real and tough Cold War II with Russia, China, North Korea, and Iran, these nations will fly lots of propellant efficient 900+ Isp nuclear thermal rocket engine powered spacecraft and Landers and have huge fleets of super propellant efficient 3,000 Isp to 14,000+ Isp electric propulsion spacecraft doing commercial and military Space Dominance missions that will leave the overweight, risky, slow, and propellant inefficient 380 Isp fossil fuel powered and pollution rich Raptor powered Starship spacecraft far behind them.

Clarissa – I suspect the space elevator doesn’t go to the top …

Sorry if I hurt your feeling James lunar minor. I’ll try to be more delicate with you.

James Lunar Miner

Endless poorly thought out attacks across the Internet against folks who support NASA and its serious efforts to enable America to use large numbers of highly cost effective spacecraft powered by super propellant efficient 2,600 Isp to 14,000+ Isp electric propulsion systems and highly propellant efficient 900+ Isp nuclear thermal rockets will continue.

Nonetheless, the overweight, endless orbital refueling loss of mission and loss of crew risks incurred, and grossly propellant inefficiency of the 380 Isp Raptor powered Mars colonies soon Starship isn’t and inherently cannot be competitive with current and future highly propellant efficient electric propulsion system powered spacecraft built in Russia and other countries.

Which James? Little Jimmy Hillhouse and his butt hurt brigade? I stop going there when those idiots posted a made up story about the Air Force blowing up a Falcon first stage.

Why James, you have such great condescension towards a NASA premiere contractor — SpaceX. If the technology you suggest was ready for human space flight, NASA would order it to be built. But, it isn’t ready and won’t be for at least 20 years.

James Lunar Miner

The first of many human crewed spaceships to use cost effective and super propellant efficient electric propulsion systems will be the upcoming Gateway spaceship that will be able to efficiently move to various orbits in Cislunar Space.


“As reflected in NASA’s Exploration Campaign, the next step in human spaceflight is the establishment of U.S. preeminence in cislunar space through the operations and the deployment of a U.S.-led Gateway.”

And, “The power and propulsion element will be the initial component, and is targeted to launch in 2022. Using advanced high-power solar electric propulsion, the element will maintain the Gateway’s position and can move the Gateway between lunar orbits over its lifetime to maximize science and exploration operations.”

And, “As part of the agency’s public-private partnership work under Next Space Technologies for Exploration Partnerships, or NextSTEP, five companies are completing four-month studies on affordable ways to develop the power and propulsion element. NASA will leverage capabilities and plans of commercial satellite companies to build the next generation of all electric spacecraft.”

From: “NASA’s Lunar Outpost will Extend Human Presence in Deep Space” May 2, 2018

Perhaps by 2022 it will finally be obvious to almost all space cadet folks on the Home Planet that the risky, limited delta-v, 380 Isp, grossly propellant inefficient, overweight, fossil fueled, and CO2 spewing Raptor Starship is both a really bad environmental choice and an obsolete product.

Perhaps, closer to 2033 Raptor and BE4 may be facing obsolescence challenges but until then they will be workhorse rockets of this era.

James Lunar Miner

The risky Star Wars II satellite launcher/Prompt Global Strike space bomber/Mars Starship/airliner replacement/flying smokestack powered by grossly propellant inefficient, fossil fueled, CO2 spewing, and Ozone Layer damaging Raptor rocket engines is facing obsolescence and major political, economic, and environmental obstacles today.

JBURN’S childish Internet insults demonstrates all the endless and self-serving Geo-political ignorant claims of Elon Musk and his cult loudly pushing for America to prioritize his political friend’s Lost in Space President Obama NASA/national defense suicidal plan of ignoring the Moon and its strategic resources while talking nonsense about using the grossly propellant inefficient BFR/Starship to build goofy, useless, and unfunded Potemkin colonies on the Red Planet.

Interesting to hear about your endless exhilarating but hurting experiences found on the internet. Don’t think there’s a global cabal out there suppressing ions.

James Lunar Miner

“Don’t think there’s a global cabal out there suppressing ions.” – JBURNS

Yikes! JBURNS is right about something!

Russia has effectively used highly propellant efficient solar electric propulsion powered spacecraft for many decades and will continue to do the same thing into the future with its upcoming nuclear-powered 7,000 Isp electric propulsion system (that may have the useful option of also being able to sometimes work as a 900+ Isp nuclear thermal rocket engine).

Elon Musk’s crazy Russian Roulette ‘Potemkin Mars colonies soon cult with the grossly propellant inefficient, overweight, 380 Isp, and technologically obsolete BFR/Starship’ is mostly an American form of ignorant Neo-luddite foolishness that probably is fed by the space frustrations of Americans because we are unable to launch American astronauts on American spacecraft to the International Space Station and have to rely on Russia who likes to threaten America and other nations with nuclear weapons and invade some countries whenever it thinks that is feasible and useful.

There probably isn’t much trust for American politicians that have ignored the Moon’s many nearby resources, opportunities, and useful national strategic options while they promoted the off-shoring of our human launch capability to Russia and spouted unfunded nonsense about far distant Mars and gave sweet government space contracts to a Mars huckster and good political friend of a lost in space President.

However, important things can get funded.

“Of that total, $180 million will go to Restore-L, a satellite servicing mission also previously threatened with cancellation, and $100 million to nuclear thermal propulsion research, including planning for a flight demonstration mission by 2024.”

From: “Final fiscal year 2019 budget bill secures $21.5 billion for NASA”
By Jeff Foust 2/17/2019


⚠ Commenting Rules

Post Comment

Your email address will not be published. Required fields are marked *