The Aerospike Engine Was Considered for the Shuttle, But Never Flew. That’s About to Change

The aerospike engine is a time-honored concept. In the past, NASA tested the concept extensively on the ground and hoped to incorporate it into the Space Shuttle and their next-generation Venture Star program (a Single-Stage-To-Orbit (SSTO) vehicle). However, due to budget constraints, the Space Shuttle ended up being equipped with bell-shaped nozzles instead, and the Venture Star never saw the light of day.

But thanks to New Mexico-based aerospace company ARCA, the aerospike engine is getting a new lease on life. This coming August, they will conduct a test flight of the aerospike engine using their Demonstrator 3 rocket, which will constitute the first space flight of the engine. If all goes well, it will be a major step towards the creation of a fleet of Single-Stage-To-Orbit (SSTO) rockets.

What makes the aerospike engine appealing is the fact that it offers efficient thrust over a wide range of altitudes, and is also more fuel-efficient than current engines. With traditional bell-shaped nozzles, reliable thrust tends to occur only at sea level. Beyond that, the engine isn’t capable of taking advantage of decreases in atmospheric pressure since the gases are contained by the nozzle.

The test of twin Linear Aerospike XRS-2200 engines, originally built for the X-33 program, was performed on August 6, 2001 at NASA’s Sternis Space Center, Mississippi. Credit: NASA’s Marshall Space Flight Center

In contrast, the aerospike engine’s exhaust is capable of expanding from sea level all the way up to space, which ensures both fuel-efficiency and a high degree of specific impulse (Isp) at all flight levels. Already, ARCA and NASA have scheduled ground and vacuum tests for the engine. But in the meantime, they also want to gather data on how it performs in flight. This is where the Demonstrator 3 test comes into play.

In addition to testing the engine’s efficiency, it will also test the aerospike’s super-cold fuel storage technology. Basically, the engine relies on a decomposing 70% concentration of hydrogen peroxide at a temperature of only 250 °C to generate thrust. The byproduct of this is oxygen and water, which makes the aerospike the most environmentally-friendly rocket concept to date. As Dumitru Popescu, the CEO of ARCA, said in a recent statement:

“By sending the Demonstrator 3 rocket in space using a super cold engine, with only 250 °C instead of 3500 °C in the reaction chamber, paired with the aerospike technology, we are going to demonstrate the impressive potential of the aerospike.”

Ultimately, the goal here is to demonstrate that SSTO rockets are feasible, which ARCA is exploring with their Haas 2CA concept. The latest in the Haas rocket family, named in honor of Austrian-Romanian rocketry pioneer Conrad Haas, this launch vehicle uses hydrogen peroxide and kerosene for fuel and is capable of generating 22,900 kg (50,500 lbs) of thrust at sea level, and about 33,565 kg (74,000 lbs) in a vacuum.

Compared to multi-stage rockets, SSTOs offer both lower costs and greater flexibility when it comes to launching small payloads into orbit. According to estimates produced by Space Works and Eurostat, this small satellite market will be growing by $5.3 billion in the next decade. As such, aerospace companies that can offer competitive launch rates and flexibility will be able to take advantage of this growth.

The company unveiled the Haas 2CA back in March of 2017 at their company headquarters in Las Cruces, New Mexico. In 2018, ARCA hopes to conduct their first test launch of the Haas 2CA from NASA’s Wallops Flight Facility in Virginia. But before that can happen, the company needs to make sure the aerospike engine performs as well as expected. As Popescu explained:

“The Haas 2CA Single Stage to Orbit is just the beginning of a new generation of space vehicle, shaped by innovation that will generate lower cost. We are going to answer one of the industry’s most asked questions: can an aerospike deliver in flight the pressure compensation generated by altitude variation and deliver the expected performance by saving fuel? We want to pick up where NASA left off and prove that this technology is actually the way to go for space flights.”

The test flight, which will take place at Spaceport America in the New Mexico desert, will consist of a suborbital space flight that will take the Demonstrator 3 up to an altitude of 100 km. If this flight is achieved, ARCA will have demonstrated that the engine technology is flight qualified, that SSTO rockets are feasible, and that super cold engines paired with aerospike technology will allow for environmentally friendly suborbital rockets.

Artist’s impression of the Haas 2C rocket ascending into orbit. Credit: ARCA

The test will also be a milestone for the commercial aerospace industry, which was founded on the desires to make space more accessible and lowering the costs associated with individual launches. And as Popescu was sure to indicate, the best way to do this is not to merely improve upon existing concepts, but leverage cutting-edge and time-tested technologies to create new ones.

“We are confident that the aerospike engine combined with composite material fuel tanks and dense fuels will significantly lower the costs for orbital and suborbital launches,” he said. “We truly believe that the answer for cost reduction of space flight is innovation, not trying to make old technologies a little bit more efficient. This will never generate significant price drop of space launches, but merely small improvements. With this philosophy in mind we expect to increase the registered value of our company from its current $20 million to at least $200 millions by 2019.”

The development of SSTOs are just one way that the commercial aerospace industry is making space exploration more economical. Other examples include SpaceX’s developments of reusable rockets, and Rocketlab‘s use of lightweight materials to create two-stage disposable rockets.

These measures are not only allowing for the commercialization of Low-Earth Orbit (LEO), but are opening up possibilities that were previously thought to be impossible for the time being – like space-based solar power and space habitats!

Stay tuned for more on this and other upcoming tests. And be sure to check out this video on how ARCA is preparing for the upcoming aerospike test flight, courtesy of ARCA:

Further Reading: ARCA, ARCA News

ARCA Unveils the World’s first Single-Stage-to-Orbit Rocket

Since the beginning of the Space Age, scientists have relied on multi-stage rockets in order to put spacecraft and payloads into orbit. The same technology has allowed for missions farther into space, sending robotic spacecraft to every planet in the Solar System, and astronauts to the Moon. But looking to the future, it is clear that new ideas will be needed in order to cut costs and expand launch services.

Hence why the ARCA Space Corporation has developed a concept for a single-stage-to-orbit (SSTO) rocket. It’s known as the Haas 2CA, the latest in  a series of rockets being developed by the New Mexico-based aerospace company. If all goes as planned, this rocket will be the first SSTO rocket in history, meaning it will be able to place payloads and crew into Earth’s orbit relying on only one stage with one engine.

The rocket was unveiled on Tuesday, March 28th, at their company headquarters in Las Cruces. The rocket is currently seeking FAA approval, and ARCA is working diligently to get it ready for its test launch in 2018 – which will take place at NASA’s Wallops Flight Facility located on Virginia’s eastern shore. If successful, the company hopes to use this rocket to deploy small satellites to orbit in the coming decade.

Artist’s impression of the Haas 2C rocket ascending into orbit. Credit: ARCA

Established in 1999 by a group of Romanian rocket enthusiasts (led by company CEO Dumitru Popescu), ARCA’s original focus was on balloon-launched rockets. In the course of the company’s history, ARCA has launched two stratospheric rockets, four large scale stratospheric balloons, and has been awarded some lucrative governmental contracts to test aerospace and space exploration technologies.

In 2003, the company joined the $10 million Ansari X Prize Competition and began work on their first demonstrator rocket. Known as the Demonstrator 2B – a single stage suborbital rocket – the rocket was successfully launched on September 9th, 2004, from Cape Midia Air Force Base. In the years that followed, they expanded their repertoire to include other concepts – like the Helen rocket, the Stabilo crewed vehicle, and the Excelsior Aerospike.

In 2013, ARCA was contracted by the European Space Agency (ESA) to create a Drop Test Vehicle (DTV) that would test the atmospheric deceleration parachutes being used by the Schiaperelli lander (as part of the ExoMars mission). Being the same weight and using the same parachute deployment systems as Schiaperelli, the DTV conducted a freefall exercise which simulated the dynamic pressure conditions of entering the Martian atmosphere

In that same year, ARCA relocated to New Mexico, where they have continued working on their rocket series and other aerospace ventures from their headquarters at the Las Cruces Airport. It was here that they introduced the Haas rocket series – named in honor of Austrian-Romanian rocketry pioneer Conrad Haas – which now consists of the Haas 2B and 2C rockets.

The Haas 2CA rocket berthed at ARCA’s headqaurters at Las Cruces Air Port in Las Cruces, New Mexico. Credit: ARCA

The 2B is a proven concept, designed for suborbital flight for the sake of space tourism. But as of this week, the 2C is now part of ARCA’s rocket family. Relying on single stage and single Executor engine, this rocket will small satellites into orbit. The rocket is fueled by hydrogen peroxide and kerosene (which combines to create a nontoxic fuel), and measures (53 feet) long and (5 feet) in diameter.

The 2C weights about 550 kg (1210 pounds) empty, and 16280 kg (35,887 pounds) when fully fueled. It will also be able to provide 22900 kg (50,500 lbs) of thrust at sea level, and about 33,565 kg (74,000 lbs) in a vacuum. In this configuration, the rocket is capable of delivering 100kg (220lbs) to Low Earth Orbit (LEO), at a cost of $1 million per launch (or $10,000/kg; $4,545/lb).

This several times less what SpaceX can do with its Falcon 9 rocket, which can deliver 22,800 km payloads to orbit for $62 million a launch – which works out to about $2719/kg or $1233/lb. However, one must take into account that the Falcon 9 is a heavier launch vehicle, and that there are additional issues that come into play where larger launch vehicles are concerned. As Dumitru Popescu told Universe Today via email:

“With the Haas 2C, the customer can launch on the desired orbit parameter, when he/she wants. Basically, the launch will be tailored on the customer needs. A more fair comparison will be between the Haas 2CA and Falcon 1 and Electron. Falcon 1 had a launch cost of $6.7 millions for a proposed payload of 670kg, or a demonstrated one of 180kg. In the best case scenario, this leads us to the same price of $10,000/kg. In the case of the Electron rocket, the cost per launch is $4.9 million for a 150kg payload. This leads us to a price of a $32.600/kg. Falcon 1, Electron, Haas 2CA have their market and a comparison with a big launcher isn’t fair in my opinion. Overall, if we will be able to keep this price, the Haas 2CA, at $1 million/launch will become the cheapest launcher in history.”

Artist’s impression of the Haas 2C rocket, shown in its launch (top) and deployment configurations (bottom). Credit: ARCA

In addition, the Haas 2C rocket benefits from the fact that it is cheaper and easier to manufacture, and that it’s SSTO configuration offers greater flexibility and reliability. 

“In the case of staged rockets, we are literally talking about more rockets combined in one vehicle to achieve orbit,” said Popsecu. “It is definitely more cost effective to operate one rocket than a vehicle made of multiple rockets, as it requires less time, less qualified manpower and less demanding transport and launch operations. The SSTO may also offer the possibility to launch from an inland spaceport, as there are no first stages that will fall on the ground after burnout.”

To prepare the rocket for its 2018 launch, ARCA is currently collaborating with NASA through its Cooperative Opportunity Program and with the help of the Ames, Kennedy, Marshall,  Stennis, and Johnson Space Centers. Popescu is also entering into discussions with the New Mexico Spaceport Authority to conduct launches from Spaceport America, and is looking to secure a partnership with a US defense agency.

If all goes well, this little aerospace company will be making spaceflight history. As Popescu said in a company press release:

“When the Haas 2CA rocket launches, it will be the first rocket in history to place itself entirely into orbit. This opens new frontiers for exploration of the Solar System as the rocket can be refueled in-orbit and re-utilize its aerospike engine thus eliminating the need for additional upper stages. After the full qualification, the vehicle could be operated from inland spaceports as there are no stages that fall on the ground at burnout. Staged rockets, even though they provide more payload performance for the same takeoff mass, are less reliable because of an increased number of parts due to flight events requested by staging and ignition of the upper stage engine. Also, staged rockets are deemed to be more expensive because they are literally made up of more than one rocket. Manufacturing and assembling more rockets in one launcher requires more, time, money, and personnel. The SSTO technology, once implemented, will increase the space flight responsiveness and lower the cost to values expected by the industry for decades. This rocket will also be the fastest vehicle to reach orbit, taking less than 5 minutes.”

In addition, the aerospace industry will have another company looking to lower the costs of launches and expanding domestic launch capability. Be sure to check out the company’s video detailing the Haas 2C and its unique characteristics:

Further Reading: ARCA