Houston startup gears up to deliver geothermal energy

ready to drill

Criterion Energy Partners is aiming to be a next-gen energy company. Photo via Getty Images

Sean Marshall and Danny Rehg founded Criterion Energy Partners in 2020 with the hope that geothermal energy could be the cleaner, safer wave of the future. Less than three years later, the team is close to making their plan a reality thanks to a geothermal well that they hope to drill this year.

Entrepreneurship wasn’t always part of the plan for either partner. When Marshall enrolled in the MBA program at Rice University’s Jones School of Business in 2016, he had a successful career at Credit Suisse and had his eye set on a future political career. But then he met classmate Rehg, whose background was in petroleum engineering. Their wives were both attorneys in the Houston district attorney’s office and the couples became fast friends. They also realized that, as Marshall now puts it, Rehg knew how to drill wells and he knew how to make deals.

In the ensuing years, both Rehg and Marshall's careers evolved and, eventually, the pair started looking for other opportunities. That’s when they read an article in Rolling Stone about geothermal energy.

“It was really a place where it really felt like this was something we were put here to do,” says Marshall.

Marshall and Rehg spent the ensuing months “like rats in a dumpster” learning about the players and opportunities in the geothermal industry and built from there. They learned about Pleasant Bayou Power Plant, a 1989 geothermal energy project based in Brazoria County that was backed by the U.S. Department of Energy.

Last summer, Criterion Energy Partners, a member of Greentown Houston, closed on a 10,000-acre lease around the site of Pleasant Bayou.

"We hope by the end of this year we will be generating electrons,” says Marshall.

Though the company has a patented technology that connects wells to the grid, called Criterion Geothermal System, Marshall says that some of the best advice he’s gotten was, “Don’t fall in love with your technology; fall in love with the problem.” The 2021 Texas freeze reminded the founders what that was.

“People were looking for cleaner, lower-emission power sources and [there was] a need for energy resiliency,” says Marshall, explaining that the freeze created an ideal situation for the company, as people began to think more outside the grid.

The year 2022 was a big one for Criterion Energy Partners. Oil and gas powerhouse Patterson-UTI invested in the company, followed by funding from the Department of Energy. The money not only allowed Criterion Energy Partners to lease their land, they are also now paying 12 salaries, including those of the founders. The team offices in The Cannon’s Esperson coworking space.

“Our mission is to make geothermal commercially viable everywhere,” says Marshall. “I still believe in that.”

However, Criterion Energy Partners may be even bigger than proving an alternative energy source. Marshall says that geothermal is the foundation on which they are building “a next-generation energy company.” Criterion Energy Partners could be the more stable basis for a whole new energy system.

Sean Marshall and Danny Rehg founded Criterion Energy Partners in 2020. Photos courtesy

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24 Houston-based companies named best places to work by U.S. News

Best Places to Work

A new U.S. News & World Report ranking of the best employers has named 95 Texas companies among the best companies to work in the South, and two dozen of them are based right here in the Houston metro.

U.S. News' prestigious "2026-2027 Best Companies to Work For" ratings examine 3,900 public and privately owned companies across 14 industries to help employees and job seekers make decisions about workplaces that may be a good fit.

Each company is rated on a scale of 1-5 across six metrics: quality of pay and benefits; work-life balance and flexibility; job and company stability; physical and psychological comfort; belongingness and esteem; and career opportunities and professional development.

"Job seekers' definitions of 'best' evolve with their needs," said Carly Chase, vice president of Careers at U.S. News. "From new grads in the AI era and seasoned pros seeking a career change, to HR leaders researching organizational trends, the ratings are a central hub that highlights businesses that U.S. News found effectively support their staff."

The number of employers headquartered in the Houston area that made the cut for 2026-2027 has skyrocketed over previous years. A total of 24 local public and private companies made the list this year, up from 16 companies in 2024 and 11 in 2025.

The highest concentration of top employers is located in Houston proper (20), followed by two companies in The Woodlands and one each in Kingwood and Spring.

A few familiar names Houstonians will recognize include petroleum corporation Occidental (Oxy), oil and gas giant Chevron, electrical engineering and manufacturing company Powell Industries, and home builder David Weekley Homes.

Here are the remaining best Houston-based companies to work for:

  • PROS, Houston
  • EOG Resources, Houston
  • Targa Resources, Houston
  • TechnipFMC, Houston
  • Cheniere, Houston
  • DXP, Houston
  • Comfort Systems USA, Houston
  • Corebridge, Houston
  • Baker Hughes, Houston
  • KBR, Houston
  • CenterPoint Energy, Houston
  • Phillips 66, Houston
  • S&B, Houston
  • Cornerstone Home Lending, Houston
  • Farouk, Houston
  • Hines, Houston
  • Insperity, Kingwood
  • HPE, Spring
  • Sterling Infrastructure, The Woodlands
  • LGI Homes, The Woodlands
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This article originally appeared on CultureMap.com.

Venus Aerospace closes $91 million Series B to scale hypersonic engine

flight funding

Houston-based Venus Aerospace has closed a $91 million Series B round and plans to scale the production of its hypersonic engine.

The round was led by Houston-based Mercury Fund with participation from Lockheed Martin Ventures, MESH, PEAK6, Draper Associates, Starboard Star Venture Capital, Green Sands Equity and other investors, according to a news release.

The investment comes about a year after Venus completed the first U.S. flight test of its high-thrust rotating detonation rocket engine (RDRE). The engine is expected to enable vehicles to travel four to six times the speed of sound from a conventional runway and is about 15 percent more efficient than traditional alternatives, according to the company.

Venus Aerospace says the latest round of funding will allow it to move the RDRE from demonstration to deployment and meet customer requirements for the near-term defense and space industries. The company says that the reusable RDRE is designed with a "common propulsion architecture" that can work for multiple industries and mission types.

“This financing marks an important step in moving Venus from breakthrough demonstration to scaled capability,” Sassie Duggleby, co-founder and CEO, said in the news release. “Our customers need propulsion systems that go farther, can be produced reliably and are built on supply chains they can trust. We are advancing that capability with American engineering and manufacturing talent to strengthen U.S. defense, expand space access and support the future of high-speed flight.”

Venus Aerospace raised a $20 million Series A in 2022, led by Wyoming-based Prime Movers Lab. At the time, the company said it would put the funding toward three main technologies: a next-generation rocket engine, aircraft shape and leading-edge cooling system.

The company also picked up an investment from Lockheed Martin Ventures, the investment arm of aerospace and defense contractor Lockheed Martin, in November 2025—in addition to funding from other investors over the years.

“Since our initial investment, Venus has progressed very quickly in its technology development," Chris Moran, vice president and general manager of Lockheed Martin Ventures, added in the release. "Our reinvestment in Venus recognizes Venus’ accomplishments to date and focus on speed to manufacture, cost management and reduction of supply chain constraints. Venus is working effectively to position its propulsion system for the production scale required by defense programs.”

"Venus is exactly the kind of company Houston capital should be backing," Blair Garrou, co-founder and managing partner at Mercury Fund, added in the release. "It combines multiple frontier technologies, domestic manufacturing and clear commercial and national security relevance. We believe this team is positioned to lead an important new chapter in defense and space, and we are proud to support a company building breakthrough technology here in Texas."

Venus Aerospace and Houston clean tech startup Vaulted Deep were named to the World Economic Forum's Technology Pioneers community earlier this summer. Read more here.

Intuitive Machines lands $148M as part of NASA Moon Base funding

to the moon

Houston-based Intuitive Machines has been awarded $148.3 million to deliver its Nova-C lander to the moon by 2028. The funding is part of $600 million that NASA recently awarded to three companies as part of the agency’s Moon Base Program.

The contracts aim to support sustained human presence and commercial operations on the Moon. Austin-based Firefly Aerospace was awarded $144.2 million by NASA for one mission and Pittsburgh-based Astrobotic netted $297.9 million for two lunar landings. Intuitive Machine's award is the company's sixth task order under NASA's Commercial Lunar Payload Services (CLPS) program.

“We’re building a proving ground for Moon Base operations,” Ryan Stephan, NASA’s Moon Base acting director of cargo landers, said in a news release. “Accelerating our Moon mission ordering cadence and launch opportunities enable us to move quickly to learn, iterate, and improve.”

Under the latest task order, Intuitie Machines will deliver three scientific and operational payloads to the moon, which include a:

  • Linear Energy Transfer Spectrometer (LETS) radiation monitor to gather critical environmental safety data
  • Advanced stereo cameras to analyze surface-plume interactions (SCALPSS)
  • Laser retroreflector array (LRA) for precise cislunar positioning

The funding breakdown includes a $68.6 million base contract and a $79.7 million performance incentive for Intuitive Machines.

The company says the funding will allow it to create a standardized and repeatable "lunar utility pipeline" for delivering cargo to the moon.

"We are shifting the paradigm from custom aerospace engineering to commercial mass production of lunar infrastructure," Steve Altemus, CEO of Intuitive Machines, said in a separate news release. "Our flight-proven Nova-C platform allows us to build, test, and deploy multiple landers in parallel using Industry 4.0-powered manufacturing. This contract directly advances our core mission to provide persistent, reliable, and commercial baseline of transport, connectivity, and operations that allows our customers to stay longer and achieve more on the Moon."

NASA also shared that it is exploring plans to send PROMISE, a rover based on the Mars Perseverance and Curiosity rovers, to the moon and it plans to seek proposals for additional lunar lander missions, technology demonstrations, a communications and navigation satellite network, and new science payloads to support its lunar outpost. NASA is developing its Moon Base near the lunar South Pole. The agency expects it to come to fruition sometime after 2032.

Intuitive Machines had received its last CLPS award for $180.4 million in March 2026. It will be the first mission to utilize the company's larger cargo lunar lander, Nova-D. The company was also recently awarded a $1 million grant from Maryland Gov. Wes Moore to expand its robotics operations in the state.

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