Innovation Example: Large Reaction Wheel Design

Smallsats have defined the last decade of space, but their limitations are clear: low power, limited throughput, and fragile unit economics. K2 Space is betting on the opposite. The company is building mega class and giga class satellites, platforms measured in tons rather than kilograms, that deliver unprecedented power, capacity, and resilience. By vertically integrating 80 percent of their systems in house, K2 is cutting costs by an order of magnitude and making industrial scale spacecraft a reality.

On this episode of Valley of Depth, we’re joined by Neel Kunjur, cofounder and CTO of K2 Space. Neel traces the journey from early Slack messages about the promise of MEO to a 160 person team building the largest commercial satellites ever attempted. He shares how K2 has reimagined subsystems like reaction wheels, high voltage power, and 20 kW propulsion to unlock entirely new mission architectures in MEO, GEO, and beyond.

We also discuss:

• Why MEO is such an underexplored orbital regime
• The engineering breakthroughs behind large reaction wheels and high voltage power systems
• How stackable satellites change constellation design
• The long term vision for space infrastructure, from in space compute to energy harvesting

…and more.

• Chapters •

00:00 – Intro
00:56 – What's happened in the past two years since K2 has been on the pod
02:13 – The thesis behind K2
03:51 – What does Neel mean by aperture?
04:40 – Why do satellites need to grow in size and power?
06:59 – The rise in Medium Earth Orbit (MEO) chatter
08:49 – Why did Neel leave SpaceX and start K2 with his brother?
12:04 – Building K2 for a post Starship world
14:10 – Current and future K2 offerings
15:32 – 20 Kilowatts vs a small LEO satellite
17:10 – Giga-scale satellite
18:40 – How K2 is able to deliver $15m satellite
21:13 – K2's innovations so far
23:01 – Engineering problems that larger satellite builders have to worry about
25:08 – K2's propulsion solution to get MEO
28:11 – Engineering for Starship's current MEO blindspot
29:18 – Neel's prediction on Starship's refueling rollout
30:14 – Innovation through simplicity
33:24 – How is K2 hiring the talent for their niche challenges
35:52 – How big is K2's team today
36:43 – Key takeaways from K2's first mission
38:22 – Mission Gravitas
39:59 – Orbit race
40:39 – Mission Gravitas: Commercial or DoD?
41:33 – K2's scaling plans
43:03 – Customized vs standardized
45:17 – Overspec'd by design
45:40 – Will K2's success spur more competition?
47:23 – Will satellites become robust, industrial hardware?
48:48 – What's enabled by these large platforms?
51:01 – The paradigm shift happening in engineering for space
52:42 – Will SpaceX own LEO?
55:05 – The name and branding behind K2

• Show notes •

K2’s website — http://www.k2space.com/

K2’s socials — https://x.com/K2SpaceCo

Mo's socials — https://twitter.com/itsmoislam

Payload’s socials — https://twitter.com/payloadspace / https://www.linkedin.com/company/payloadspace

Ignition’s socials — https://twitter.com/ignitionnuclear /  

https://www.linkedin.com/company/ignition-nuclear/

Tectonic’s socials  — https://twitter.com/tectonicdefense / https://www.linkedin.com/company/tectonicdefense/

Valley of Depth archive — Listen: https://pod.payloadspace.com/

• About us •

Valley of Depth is a podcast about the technologies that matter — and the people building them. Brought to you by Arkaea Media, the team behind Payload (space), Ignition (nuclear energy), and Tectonic (defense tech), this show goes beyond headlines and hype. We talk to founders, investors, government officials, and military leaders shaping the future of national security and deep tech. From breakthrough science to strategic policy, we dive into the high-stakes decisions behind the world’s hardest technologies.

• Payload: www.payloadspace.com
• Ignition: www.ignition-news.com
• Tectonic: www.tectonicdefense.com